给排水环工专业英语(华南理工大学)课文翻译下

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给水排水专业英语翻译

《给水排水专业英语》Lesson 1specific yield [spə'sifik] [ji:ld] 单位产水量mass curve 累积曲线capital investment 投资recurring natural event ['nætʃərəl] 重现历史事件subterranean [sʌbtə'reiniən] 地下的groundwater 地下水surface water 地表水tap [tæp]开关、龙头；在…上开空（导出液体）swampland ['swɔmplænd] n. 沼泽地；沼泽地带capillary [kə'piləri] n. 毛细管adj. 毛状的,毛细管的hygro- [词头] 湿（气），液体hygroscopic [,haigrəu'skɔpik] adj. 易湿的，吸湿的hygroscopic moisture 吸湿水stratum ['streitəm] n. [地质学]地层，[生物学]（组织的）层aquifer ['ækwəfə] ['ækwifə] n.含水层，地下蓄水层saturation [,sætʃə'reiʃən] n.饱和(状态)，浸润，浸透，饱和度hydrostatic [,haidrəu'stætik] adj. 静水力学的, 流体静力学的hydrostatic pressure 静水压力water table 1. 地下水位，地下水面，潜水面2. 【建筑学】泻水台；承雨线脚；飞檐；马路边沟[亦作water-table]Phreatic surface [fri(:)'ætik]地下水（静止）水位，浅层地下水面Superficial [sju:pə'fiʃəl] adj. 表面的,表观的，浅薄的Porosity [pɔ:'rɔsiti] n. 多孔性,有孔性,孔隙率Unconfined ['ʌnkən'faind] adj. 无约束的，无限制的Permeability [,pə:miə'biliti] n. 弥漫, 渗透, 渗透性Permeameter [pə:mi'æmitə] n.渗透仪,渗透性试验仪)Clay [klei] n. 粘土，泥土gravel ['ɡrævəl]n.[总称]砾，沙砾，小石；砾石cone of depression [kəun] 下降漏斗, [水文学]下降锥体drawdown ['drɔ:daun] n. 水位下降(降落,消耗,减少)integrate ['intigreit] 【数学】作积分运算；求积分observation well [,əbzə:'veiʃən] 观测井，观测孔extraction [ik'strækʃən] n. 抽出，取出，提取（法），萃取（法）derivation [deri'veiʃən] n. 1. 导出，引(伸)出，来历，出处，得出，得到；诱导，推论，推理；溯源【数学】1) (定理的)求导，推导2) 微商，微分，导数【语言】词源，衍生deplete [di'pli:t] v. 耗尽, 使...衰竭refuse [ri'fju:z] n. 废物,垃圾vt. 拒绝，谢绝dump [dʌmp] n. 垃圾场，垃圾堆，堆存处vt. 倾卸，倾倒(垃圾)unconfined aquifer 潜水含水层，非承压含水层，无压含水层confined aquifer 自流含水层，承压含水层homogeneous [,hɔməu'dʒi:njəs] adj. 同类的,相似的，均匀的，均相的；同种类的，同性质的；相同特征的Aquaclude 不透水层，难渗透水的地层Offset ['ɔ:fset] n.偏移量抵销，弥补，分支，胶印，平版印刷，支管，乙字管Vt. 弥补,抵销,用平版印刷vi. 偏移，形成分支sophisticated [sə'fistikeitid] adj. 复杂的，需要专门技术的；诡辩的,久经世故的equilibrium [,i:kwi'libriəm] n. 平衡,均衡Water Supply（给水工程）A supply of water is critical to the survival of life, as we know it.（众所周知，水对生命的生存至关重要。

给水排水专业英语翻译

《给水排水专业英语》译文：（第一课）给水工程我们知道，水的供应对生命的生存至关重要。

人类需要喝水，动物需要喝水，植物也需要喝水。

社会的基本功能需要水：公共卫生设施的冲洗，工业生产过程耗水，电能生产过程的冷却用水。

在这里，我们从两方面讨论水的供给：）1、地下水供给2、地表水供给地下水是通过打井而得到的重要直接供水水源，也是一种重要的间接供水水源，因为地表溪流（或小河）会经常得到地下水的补给。

在靠近地表的通气层中，土壤孔隙内同时包含着空气和水。

这一地层，其厚度在沼泽地可能为零，在山区则可能厚达数百英尺，蕴涵三种类型的水分。

重力水，是在暴雨过后进入较大的土壤孔隙中的水。

毛细水是在毛细作用下进入较小的土壤孔隙中的水，它能够被植物吸收。

吸湿水是在不是最干燥的气候条件下由于分子间引力而被土壤稳定下来的水。

地表通气层的湿气是不能通过凿井方式作为供水水源的。

位于通气层以下的饱和层，土壤孔隙中充满着水，这就是我们通常所说的地下水。

包含大量地下水的地层称为含水层。

通气层和含水层之间的水面称为地下水位或浅层地下水面，地下水静压力与大气压力相等。

含水层可延伸相当深度）, but because the weight of overburden material generally closes pore spaces（但因为地层负荷过重会压缩（封闭、关闭）土壤孔隙，深度超过600m，即2000英寸，就基本找不到地下水了。

能够含水层中自由流出的水量称为单位产水量。

The flow of water out of a soil can be illustrated using Figure 1（土壤中水流如图1所示）. The flow rate must be proportional to the area through which flow occurs times the velocity（流量与流水面积成比例，流经该土壤面积的流量等于面积与速率成的乘积）, orQ=AvWhere（此式中）Q=flow rate , in m3/sec（流量，单位为m3/s）【cubic meter per second】A=area of porous material through which flow occurs, in m2（渗透性土壤的流水断面，单位为m2）v=superficial velocity, in m/sec（表观流速（表面流速），单位为m/s）表观流速当然不是水在土壤中流动的真实速度，因为土壤固体颗粒所占据的体积大大地降低了水流通过的空间。

环境工程专业英语翻译(中英对照)

Unit one Environmental Engineering环境工程What is this book about？这本书是关于什么的？The objective of this book is to introduce engineering and science students to the interdisciplinary study of environment problems；their cause，why they are of concern，and how we can control them. The book includes:这本书的目的是使理工科的学生了解跨学科间的研究环境问题;它们的起因，为什么它们受到关注，以及我们怎样控制它们。

这本书包括：●Description of what is meant by environment and environmental systems描述环境和环境系统意味着什么●Information on the basic causes of environmental disturbances关于引起环境干扰基础原因的基本信息●Basic scientific knowledge necessary to understand the nature of environmental problems and to be able toquantify them理解环境问题本质，并能够定量计算它们所必要的基本科学知识●Current state of the technology of environmental control in its application to water，air and pollution problems目前适用于水，空气和环境污染问题的环境控制技术的现状●Considerable gaps in our current scientific knowledge of understanding and controlling many of the complexinteractions between human activities and nature我们目前的科学知识在理解和控制人类活动和自然之间复杂的相互作用的科学知识上存在相当大的缺陷●Many environmental problems which could be eliminated or reduced by the application of current technology，butwhich are not dealt with because of society’s lack of will to do so，or in many instance because of a lack of resources to do so.许多环境问题可以应用现有技术消除或减少，但没有得到处理是因为社会缺乏这样做的意愿，或者像许多例子那样因为缺乏资源。

大学专业英语给排水专业课文翻译

第7章水处理工艺选择流域管理应该被视为给水系统运行的一部分，这对于保护原水水质非常重要。在取水构筑物之后，是水的处理工艺。目前在市政水处理的预处理工艺有：筛选，预沉淀或清淤，化学药剂添加和曝气。筛选应用在地表水的预处理之中。预沉淀常常用于从河水去除悬浮物质. 化学处理，在水厂内混凝之前，频繁用于提高预沉淀效果，处理难去除的物质，如味道和气味的化合物、色度，降低高的细菌浓度。用于预沉淀的传统化学药剂是聚合电解质和明矾。曝气习惯上是从地下水中除铁除锰的第一步，也是分离溶解性气体如硫化氢和二氧化碳的标准的方法。用于水厂的处理工艺依赖原水水源和所需的出厂水水质。选择用于处理的具体化学药剂基于运行所需反应的有效性和成本。例如，活性炭、氯、二氧化氯和高锰酸钾都可用于味道和气味的控制。虽然价格最低廉，但过量的氯化，会产生不期望出现的三卤甲烷。在地表水处理厂中经常提供用于投加两到三种除味的化学药剂的设备，所以操作者可以选择最有效和最经济的化学应用。没有用于各种水体的色度去除的固定方法。经过足够预处理明矾混凝，采用化学氧化药剂或者活性炭，可能提供满意的去除。另一方面，更昂贵的混凝剂有可能证明更加有效并降低整体化学药剂成本。也许在水处理工艺设计要考虑最重要的是提供灵活性。操作者应该有一些手段来改变某些化学药剂的应用点（投加点）。例如，加氯的投药管线常常提供满足前投加、中间投加、后投加氯的要求。应该提供多种药剂进料器和存储容器，使处理工艺能采用不同的化学药剂。原水水质的降解，或者药剂成本的改变，可能决定了在混凝中混凝剂和助凝剂使用药剂类型的改变。在地表水处理厂情况下，预留场地以背建额外的预处理设施建设空间是值得考虑的。河水流量可能由于水坝的建设、渠道的改进或者上游用水而改变。水质会因人为改变和流域的侵占而改变源于市政和工业废物和农业地表径流的污染物浓度可能增加。湖泊会变得更加富营养化。通过增加曝气装置容量、增加加氯量，使用沉淀池作为调节池，安装完毕后，水厂生产能力得到扩大，处理工艺转变成只去除铁锰。目前该水厂只能够运行曝气氧化去除铁锰与氯化消毒。由于水井供水稳定，全年的出厂水水质优良。图 2-3 的给水处理厂是一个始建于 1950 年代的传统的地表水处理厂。从那时起，湖水水源日益富营养化，已经提供额外的设备进行味道与气味的控制。在较差原水水质的关键时期，活性炭、二氧化氯和各种用于提高药品处理的辅助药剂目前是适宜的。在一年之中的大部分时间，最终出水是非常可口的，但是在春秋季节的湖泊倒层期间，味道和气味不能够被完全去除。对于水质剧烈变化的浑浊污染的河水而言，应该采用一个复杂而灵活的处理系统。一般的处理方案包括：用于沉砂的普通沉淀，混合与沉淀，必要的情况下采用混凝剂；分离处根据原水水质的变化，这个水厂的运行每天都会改变，每个季节都会改变。即使这样，一些难处理的无机或有机物质仍然能够通过复杂的处理系统。理以实现部分软化；在澄清池中的絮凝，双媒过滤，加氯获得余氯，pH 调节和结垢控制。一个河水处理厂应该具有足够的工艺高度，以防止任何污染紧急事件短流的可能性。第8章混凝显然，如果在水的混凝与软化过程中的化学反应将要发生的话，那么化学药剂必须与水进行混合。在这一章节我们将要开始关注必要的物理方法以完成混凝与软化的过程。下面将要提出的基本原理对于混合、絮凝以及过滤的操作都是适用的。或者，或者称为快速混合，是由此化学药剂快速均匀的分布到水中的过程。理想状态下，化学药剂会迅速分散到水中。在混凝和软化的过程中，在快速混合中发生的化学反应形成了沉淀。在混凝过程中形成氢氧化铝或氢氧化铁，而在软化过程中形成碳酸钙和氢氧化镁。在形成沉淀后，有必要使它们互相碰触，以使得它们能够聚集，然后形成更大的颗粒，叫做絮体。这个接触的过程叫做絮凝，它是通过缓慢、柔和的混合完成的。在给水处理与污水处理的过程中，混合的程

(完整版)(整理)环境工程专业英语翻译(中英对照)

建筑工程及给排水专业中英文对照翻译

建筑工程及给排水专业中英文对照翻译Laminar and Turbulent FlowObservation shows that two entirely different types of fluid flow exist. This was demon- strated by Osborne Reynolds in 1883 through an experiment in which water was discharged from a tank through a glass tube. The rate of flow could be controlled by a valve at the outlet, and a fine filament of dye injected at the entrance to the tube. At low velocities, it was found that the dye filament remained intact throughout the length of the tube, showing that the particles of water moved in parallel lines. This type of flow is known as laminar, viscous or streamline, the particles of fluid moving in an orderly manner and retaining the same relative positions in successive cross- sections.As the velocity in the tube was increased by opening the outlet valve, a point was eventually reached at which the dye filament at first began to oscillate and then broke up so that the colour was diffused over the whole cross-section, showing that the particles of fluid no longer moved in an orderly manner but occupied different relative position in successive cross-sections. This type of flow is known as turbulent and is characterized by continuous small fluctuations in the magnitude and direction of the velocity of the fluid particles, which are accompanied by corresponding small fluctuations of pressure.When the motion of a fluid particle in a stream is disturbed, its inertiawill tend to carry it on in the new direction, but the viscous forces due to the surrounding fluid will tend to make it conform to the motion of the rest of the stream. In viscous flow, the viscous shear stresses are sufficient to eliminate the effects of anydeviation, but in turbulent flow they are inadequate. The criterion which determines whether flow will be viscous of turbulent is therefore the ratio of the inertial force to the viscous force acting on the particle. The ratioμρvl const force Viscous force Inertial ?= Thus, the criter ion which determines whether flow is viscous or turbulent is the quantity ρvl /μ, known as the Reynolds number. It is a ratio of forces and, therefore, a pure number and may also be written as ul /v where is the kinematic viscosity (v=μ/ρ).Experiments carried out with a number of different fluids in straight pipes of different diameters have established that if the Reynolds number is calculated by making 1 equal to the pipe diameter and using the mean velocity v , then, below a critical value of ρvd /μ = 2000, flow will normally be laminar (viscous), any tendency to turbulence being damped out by viscous friction. This value of the Reynolds number applies only to flow in pipes, but critical values of the Reynolds number can be established for other types of flow, choosing a suitable characteristic length such as the chord of an aerofoil in place of the pipe diameter. For a given fluid flowing in a pipe of a given diameter, there will be a critical velocity of flow corresponding to the critical value of the Reynolds number, below which flow will be viscous.In pipes, at values of the Reynolds number > 2000, flow will not necessarily be turbulent. Laminar flow has been maintained up to Re = 50,000, but conditions are unstable and any disturbance will cause reversion to normal turbulent flow. In straight pipes of constant diameter, flow can be assumed to be turbulent if the Reynolds number exceeds 4000.Pipe NetworksAn extension of compound pipes in parallel is a case frequently encountered in municipal distribution system, in which the pipes are interconnected so that the flow to a given outlet may come by several different paths. Indeed, it is frequently impossible to tell by inspection which way the flow travels. Nevertheless, the flow in any networks, however complicated, must satisfy the basic relations of continuity and energy as follows:1. The flow into any junction must equal the flow out of it.2. The flow in each pipe must satisfy the pipe-friction laws for flow in a single pipe.3. The algebraic sum of the head losses around any closed circuit must be zero.Pipe networks are generally too complicated to solve analytically, as was possible in the simpler cases of parallel pipes.A practical procedure is the method of successive approximations, introduced by Cross. It consists of the following elements, in order:1. By careful inspection assume the most reasonable distribution of flows that satisfies condition 1.2. Write condition 2 for each pipe in the formh L = KQ n(7.5) where K is a constant for each pipe. For example, the standard pipe-friction equation would yield K= 1/C2and n= 2 for constant f. Minor losses within any circuit may be included, but minor losses at the junction points are neglected.3. To investigate condition 3, compute the algebraic sum of the head losses around each elementary circuit. ∑h L= ∑KQ n. Consider losses from clockwise flows as positive, counterclockwise negative. Only by good luck will these add tozero on the first trial.4. Adjust the flow in each circuit by a correction, ΔQ , to balance the head in that circuit and give ∑KQ n = 0. The heart of this method lies in the determination of ΔQ . For any pipe we may writeQ = Q 0 ＋ΔQwhere Q is the correct discharge and Q 0 is the assumed discharge. Then, for a circuit100/Q h n h Q Kn Q K Q L L n n ∑∑∑∑?-=-=- (7.6) It must be emphasized again that the numerator of Eq. (7.6) is to be summed algebraically, with due account of sign, while the denominator is summed arithmetically. The negative sign in Eq.(7.6) indicates that when there is an excess of head loss around a loop in the clockwise direction, the ΔQ must be subtracted from clockwise Q 0’s and added to counterclockwise ones. The reverse is true if there is a deficiency of head loss around a loop in the clockwise direction.5. After each circuit is given a first correction, the losses will still not balance because of the interaction of one circuit upon another (pipes which are common to two circuits receive two independent corrections, one for each circuit). The procedure is repeated, arriving at a second correction, and so on, until the corrections become negligible.Either form of Eq. (7.6) may be used to find ΔQ . As values of K appear in both numerator and denominator of the first form, values proportional to the actual K may be used to find the distribution. Thesecond form will be found most convenient for use with pipe-friction diagrams for water pipes.An attractive feature of the approximation method is thaterrors in computation have the same effect as errors in judgment and will eventually be corrected by the process.The pipe-networks problem lends itself well to solution by use of a digital computer. Programming takes time and care, but once set up, there is great flexibility and many man-hours of labor can be saved.The Future of Plastic Pipe at Higher PressuresParticipants in an AGA meeting panel on plastic pipe discussed the possibility of using polyethylene gas pipe at higher pressures. Topics included the design equation, including work being done by ISO on an updated version, and the evaluation of rapid crack propagation in a PE pipe resin. This is of critical importance because as pipe is used at higher pressure and in larger diameters, the possibility of RCP increases.Se veral years ago, AGA’s Plastic Pipe Design Equation Task Group reviewed the design equation to determine if higher operating pressurescould be used in plastic piping systems. Members felt the performance of our pipe resins was not truly reflected by the design equation. It was generally accepted that the long-term properties of modern resins far surpassed those of older resins. Major considerations were new equations being developed and selection of an appropriate design factor.Improved pipe performanceMany utilities monitored the performance of plastic pipe resins. Here are some of the long-term tests used and the kinds of performance change they have shown for typical gas pipe resins.Elevated temperature burst testThey used tests like the Elevated Temperature Burst T est, inwhich the long-term performance of the pipe is checked by measuring the time required for formation of brittle cracks in the pipe wall under high temperatures and pressures (often 80 degrees C and around 4 to 5-MPa hoop stress). At Consumers Gas we expected early resins to last at least 170 hrs. at 80 degrees C and a hoop stress of 3 MPa. Extrapolation showed that resins passing these limits should have a life expectancy of more than 50 yrs. Quality control testing on shipments of pipe made fromthese resins sometimes resulted in product rejection for failure to meet this criterion.At the same temperature, today’s resins last thousands of hours at hoop stresses of 4.6 MPa. Tests performed on pipe made from new resins have been terminated with no failure at times exceeding 5,700 hrs. These results were performed on samples that were squeezed off before testing. Such stresses were never applied in early testing. When extrapolated to operating conditions, this difference in test performance is equivalent to an increase in lifetime of hundreds (and in some cases even thousands) of years.Environmental stress crack resistance testSome companies also used the Environmental Stress Crack Resistance test which measured brittle crack formation in pipes but which used stress cracking agents to shorten test times.This test has also shown dramatic improvement in resistance brittle failure. For example, at my company a test time of more than 20 hrs. at 50 degrees C was required on our early resins. Today’s resins last well above 1,000 hrs. with no failure.Notch testsNotch tests, which are quickly run, measure brittle crack formation in notched pipe or molded coupon samples. This isimportant for the newer resins since some other tests to failure can take very long times. Notch test results show that while early resins lasted for test times ranging between 1,000 to 10,000 min., current resins usually last for longer than 200,000 min.All of our tests demonstrated the same thing. Newer resins are much more resistant to the growth of brittle crack than their predecessors. Since brittle failure is considered to be the ultimate failure mechanism in polyethylene pipes, we know that new materials will last much longer than the old. This is especially reassuring to the gas industry since many of these older resins have performed very well in the field for the past 25 yrs. with minimal detectable change in properties.While the tests showed greatly improved performance, the equation used to establish the pressure rating of the pipe is still identical to the original except for a change in 1978 to a single design factor for all class locations.To many it seemed that the methods used to pressure rate our pipe were now unduly conservative and that a new design equation was needed. At this time we became aware of a new equation being balloted atISO. The methodology being used seemed to be a more technically correct method of analyzing the data and offered a number of advantages.Thermal Expansion of Piping and Its CompensationA very relevant consideration requiring careful attention is the fact that with temperature of a length of pipe raised or lowered, there is a corresponding increase or decrease in its length and cross-sectional area because of the inherent coefficient of thermal expansion for the particular pipe material. The coefficient of expansion for carbon steel is 0.012 mm/m?Cand for copper 0.0168mm/m?C. Respective module of elasticity a re for steel E = 207×1.06kN/m2 and for copper E = 103×106 kN/m2. As an example, assuming a base temperature for water conducting piping at 0?C, a steel pipe of any diameter if heated to 120?C would experience a linear extension of 1.4 mm and a similarly if heated to copper pipe would extend by 2.016 mm for each meter of their respective lengths. The unit axial force in the steel pipe however would be 39% greater than for copper. The change in pipe diameter is of no practical consequence to linear extension but the axial forces created by expansion or contractionare con- siderable and capable of fracturing any fitments which may tend to impose a restraint;the magnitude of such forces is related to pipe size. As an example,in straight pipes of same length but different diameters, rigidly held at both ends and with temperature raised by say 100?C, total magnitude of linear forces against fixed points would be near enough proportionate to the respective diameters.It is therefore essential that design of any piping layout makes adequate com- pensatory provision for such thermal influence by relieving the system of linear stresses which would be directly related to length of pipework between fixed points and the range of operational temperatures.Compensation for forces due to thermal expansion. The ideal pipework as far as expansion is concerned, is one where maximum free movement with the minimum of restraint is possible. Hence the simplest and most economical way to ensure com- pensation and relief of forces is to take advantage of changes in direction, or where this is not part of the layout and long straight runs are involved it may be feasible to introducedeliberate dog-leg offset changes in direction at suitable intervals.As an alternative,at calculated intervals in a straight pipe run specially designed expansion loops or “U” bends should be inserted. Depending upon design and space availability, expansion bends within a straight pipe run can feature the so called double offset “U” band or thehorseshoe typ e or “lyre” loop.The last named are seldom used for large heating networks; they can be supplied in manufacturers’ standard units but require elaborate constructional works for underground installation.Anchored thermal movement in underground piping would normally be absorbed by three basic types of expansion bends and these include the “U”bend, the “L”bend and the “Z”bend.In cases of 90 changes indirection the “L” and “Z”bends are used.Principles involved in the design of provision for expansion between anchor points are virtually the same for all three types of compensator. The offset “U” bend is usually made up from four 90° elbows and straight pipes; it permits good thermal displacement and imposes smaller anchor loads than the other type of loop. This shape of expansion bend is the standardised pattern for prefabricated pipe-in-pipe systems.All thermal compensators are installed to accommodate an equal amount of expansion or contraction; therefore to obtain full advantage of the length of thermal movement it is necessary to extend the unit during installation thus opening up the loop by an extent roughly equal the half the overall calculated thermal movement.This is done by “cold-pull” or other mechanical means. The total amount of extension between two fixed pointshas to be calculated on basis of ambient temperature prevailing and operational design temperatures so that distribution of stresses and reactions at lower and higher temperatures are controlledwithin permissible limits. Pre-stressing does not affect the fatigue life of piping therefore it does not feature in calculation of pipework stresses .There are numerous specialist publication dealing with design and stressing calculations for piping and especially for proprietary piping and expansion units; comprehensive experience back design data as well as charts and graphs may be obtained in manufacturers’publications, offering solutions for every kind of pipe stressing problem.As an alternative to above mentioned methods of compensation for thermal expansion and useable in places where space is restricted, is the more expensive bellows or telescopic type mechanical compensator. There are many proprietary types and models on the market and the following types of compensators are generally used.The bellows type expansion unit in form of an axial compensator provides for expansion movement in a pipe along its axis; motion in this bellows is due to tension or compression only.There are also articulated bellows units restrained which combine angular and lateral movement; they consist of double compensator units restrained by straps pinned over the center of each bellowsor double tied thus being restrained over its length.Such compensators are suitable for accommodating very pipeline expansion and also for combinations of angular and lateral movements.层流与紊流有两种完全不同的流体流动形式存在，这一点在1883年就由Osborne Reynolds 用试验演示证明。

给水排水专业英语翻译Unit 6

Unit 6Water Supply System水源的性质一般决定了规划、设计和运行的收集、净化、传输和分配工作。

两个主要来源用于供应社区和工业需求被称为地表水和地下水。

溪流、湖泊和河流水源的表面。

地下水资源是那些从井泵。

无花果。

2 -1描述了一个扩展的水资源系统为一个小的社区。

源在每种情况下确定集合的类型作品和治疗类型的作品。

在城市的管道网络称为分销系统。

管道本身通常被称为水电源。

水在电源一般保持在200和860帕之间的压力(kPa)。

多余的水处理厂产生的时期,低需求(通常在夜间小时)举行。

可能较高的蓄水库(无处不在的水塔),或者可能是在地面上。

存储的水是用来满足白天的高需求。

存储可以弥补需求变化和允许一个较小的处理厂建成。

存储也是用来提供应急备份以防火灾。

人口和水的消费模式是主要因素,执政所需的水的数量,因此源和整个组成的水资源系统。

第一个步骤选择一个合适的供水来源是确定需求,将放在它。

水需求的基本要素包括日均耗水量和峰值速率的需求。

每日平均的水消费必须估计有两个原因:(1)确定水源的能力以满足持续要求在关键时期当表面流低或地下水的表都处于最低海拔;(2)为目的的估计量的储存水,将满足要求在这些关键的时期。

高峰需求的利率必须估计为了确定管道和管大小、压力损失和存储需求需要充足的水供应的高峰时期水需求。

有很多因素会影响水的利用对于一个给定的系统。

例如,事实是,水压力下的是其使用,通常可用刺激过度,灌溉草坪和花园,洗汽车,对于操作空调设备,和用于执行许多其他活动在家里和在行业。

以下因素影响了水消费的重要途径: 1。

工业活动;2。

测量;3。

系统管理;4。

的生活标准;5。

气候。

下列因素也影响着水消费程度较轻:污水处理程度,系统压力、水价格和可用性的私人水井。

行业的影响是提高人均水需求。

小乡村和郊区社区将使用更少的水人均工业化社区。

行业可能是最大的单一因素影响人均用水量。

第二个最重要的因素是消费者个人用水是否有水米。

蓝梅主编给排水科学与工程专业英语部分课文翻译中文版

第四单元给水系统一般来说，供水系统可划分为四个主要组成部分:（1）水源和取水工程（2）水处理和存储（3）输水干管和配水管网。

常见的未处理的水或者说是原水的来源是像河流、湖泊、泉水、人造水库之类的地表水源以及像岩洞和水井之类的地下水源。

修建取水构筑物和泵站是为了从这些水源中取水。

原水通过输水干管输送到自来水厂进行处理并且处理后的出水储存到清水池。

处理的程度取决于原水的水质和出水水质要求。

有时候，地下水的水质是如此的好以至于在供给给用户之前只需消毒即可。

由于自来水厂一般是根据平均日需求流量设计的，所以，清水池为水需求日变化量提供了一个缓冲区。

水通过输水干管长距离输送。

如果输水干管中的水流是通过泵所产生的压力水头维持的，那么我们称这个干管为增压管。

另外，如果输水干管中的水流是靠由于高差产生的可获得的重力势能维持的，那么我们称这个干管为重力管。

在输水干管中没有中间取水。

与输水干管类似，在配水管网中水流的维持要么靠泵增压，要么靠重力势能。

一般来说，在平坦地区，大的配水管网中的水压是靠泵提供的，然而，在不平坦的地区，配水管网中的压力水头是靠重力势能维持的。

一个配水管网通过引入管连接配水给用户。

这样的配水管网可能有不同的形状，并且这些形状取决于这个地区的布局。

一般地，配水管网有环状或枝状的管道结构，但是，根据当地城市道路和街区总体布局计划，有时候环状和枝状结构合用。

城市配水管网大多上是环状形式，然而，乡村地区的管网是枝状形式。

由于供水服务可靠性要求高，环状管网优于枝状管网。

配水管网的成本取决于对管网的几何形状合适的选择。

城市计划采用的街道布局的选择对提供一个最小成本的供水系统来说是重要的。

环状管网最常见的两个供水结构是方格状、环状和辐射状；然而，我们不可能找到一个最佳的几何形状而使得成本最低。

一般地，城镇供水系统是单入口环状管系统。

如上所说，环状系统有一些通过系统相互连接的管道使得通过这些连接接的管道，可以供水到同一个需水点。

给排水专业英语课文翻译

There are several species of bacteria that are widely found in the aquatic environment but so not normally cause illness in the immuno-competent. They are not therefore particularly associated with health problems from drinking-water. It is important to be aware of them nevertheless, as they have occasionally been associated with disease where people may already be ill with other conditions or their immune system is reduced and unable to cope (Dufour 1990).They are usually known as environmental bacteria, but I have also come across the terms adventitious or heterotrophic in this context (although heterotrophic strictly means they get their source of energy and cellular carbon from the oxidation of organic material, that is, by feeding on plants or animals-rather than photosvnchesis). Where laboratories carry out plare counts, it is often these bacteria that are cultured. There will be many different types of environmental bacturia but the imporiant ones for drinking-water safety are listed here.AeromonasAeromonas are commonly found in both fresh and salt waters. There are several species, each one favouring a particular environmental niche. Aeromonas bydropbila is found mainly in clean river water, Aeromonas sobria in stagnant water and Aeromonas caviae in marine water. They are so common that people have tried to use them in rivers as indicators of pollution. They are known to cause diarrhoea and infection in soft tissue where damaged skin comes into contact with contaminated river or lake water.Aeromonas caviae is the one most commonly associated with diarrhoea. Diarrhoeal infection is usually mild, although more severe symptoms have occasionally been known, including bloody diarrhoea and chronic colitis (inflammation of the colon).Aeromonas have been found in treated chlorinated water and sometimes, there is re-growth in the distribution pipes. Chlorine only appears to have a temporary effect on them and this may mean that it stops them from reproducing but does not kill them. If left (presumably so they can get their breath back and have a bit of a rest after the chlorine attack) they can continue as normal.有一些种类的细菌在水生环境中被发现,但通常不引起疾病immuno-competent。

给排水环工专业英语(华南理工大学)课文翻译下讲解

Unit 12水的净化水分子是没有记忆的,所以去讨论你所喝的水是被污染了并净化了多少次是可笑的(市没有意义的 , 好像水分子逐渐厌烦了(逐渐被耗尽了。

最重要的是你喝的水纯度如何。

对水的净化方法已发展到了很详细并且尖端的技术。

然而通常采用的净化水的方法对水污染的性质的通常的理解应该是容易理解的,并在某些情况下是显而易见的。

水中的杂质可分为悬浮的,胶体态的或溶解态的。

由于悬浮的颗粒大足以被沉淀或被过滤掉。

胶体态的或溶解态的杂质较难以去除掉。

去除他们的一个可能的方法是以某种方法把这些微小的颗粒物结合成比较大的颗粒然后采用去除悬浮物的方法来处理。

另一种可能的方法是把他们转变为气态然后是他们从水中散发到大气中,无论采用哪一种方法,有一点必须记住的是提升水或用泵将水输送通过滤床都需要能量。

根据这些原则,来考虑用于净化城市污水的步骤。

第一步是废水的收集系统。

从家庭、医院、学校排放的水中的污染物包含食物残渣、人类排泄物、纸张、肥皂、洗涤剂、污垢、织物和其他混杂的残骸,当然还有微生物。

这些混合物被称为厕所污水或生活污水。

这里 Sanitary 这个形容词比较不恰当,因为它几乎没有描述污水的情况,他只笼统地指人产生的污染物被污水管所排走。

这些污水,有时与污水管网中从商业建筑来的污染物、工业污染物及雨水污染物合流。

有些体系把污水与雨水分流而有些是合流。

合流制的管道便宜,并在旱季时是合理的,但在暴雨期时的总流量容易超过处理厂的容量,结果应允许有些水溢流而直接进入受体河流中。

初级处理当污水进入处理厂时,首先通过一系列的格栅以去除其中大的物体如老鼠或葡萄柚,然后通过一个磨碎装置以便把剩余的物体的大小减小至足够小以至在后续的工艺中可以有效的处理。

下一步是一系列的沉淀室来去除重的粗沙例如雨水冲刷路面带入的沙粒,然后其他悬浮的固体(包括有机营养物缓慢的沉淀而得到去除,这个过程需耗时大约一小时。

从开始到这个过程的整个工艺称为处级处理,这一级处理的费用相对低,但是没有完成多少任务。

给水排水工程专业英语文献翻译译文第一篇

一种利用蜜糖废水产生PHA的侧流工艺的建立方法摘要试验建立了一种利用蜜糖废水生产聚羟基烷酸脂（PHA）的三阶段过程。

该过程包括（1）糖蜜废水酸酵解，（2）PHA富集菌的筛选，（3）利用富集完毕的污泥和酵解之后的糖蜜废水批次累积PHA。

在发酵阶段，试验评估了PH（5~7）对有机酸型体分布以及产率的影响。

PH较高时乙酸和丙酸为主要产物，然而较低的PH值有利于丙酸和戊酸的产生。

试验评估了利用乙酸盐和发酵糖蜜废水为基质筛选的两类菌群的PHA积累能力。

考察了有机酸型体分布对利用醋酸盐筛选菌群产生的多聚体的组成以及产率的影响。

PHA富集产率在0.37到0.50CmmolHA/Cmmol VFA之间变化。

试验观察到了被利用有机酸的类型和多聚物成分的一种直接关系。

在糖蜜废水中，低氨氮浓度（0.1Nmmol/l）促进了PHA 的储存（0.59 Cmmol HA/Cmmol VFA）。

此外，试验建立了一种控制反应器运行利用发酵糖蜜废水筛选PHA富集菌群的方法。

利用高有机负荷以及低氨氮浓度选择了一种具有稳定储存PHA能力的菌群，富集产率达到0.59Cmmol HA/Cmmol VFA)，这一能力与醋酸盐筛选菌相似。

前言聚羟基烷酸脂被认为是优良的可生物降解塑料的候选者。

这类含有多种单体组分具有热塑性的多聚物是被细菌作为能量和碳储存物质的。

它们的结构特性与聚丙烯的结构性质一致，同时又具有诸多优势：可生物降解、可生物相容、能进一步由可再生碳源产生从而使可持续生产过程成为可能。

然而，PHAs与石化工业衍生的塑料制品在成本上相当大的差异成了这类高聚物部分替代后者的阻碍。

目前，商业可行的PHAs是由纯菌（野生的和基因重组的菌种）和纯底物（通常很昂贵）工业化生产而来。

PHAs的价格主要取决于底物成本，约占总成本的40%（Choi和Lee，1997）。

最近十年来，一系列低成本的碳源基质（例如淀粉、木薯粉水解物、乳清和蜜糖）在纯菌生产PHA过程中得到检验。

给排水专业毕业设计翻译中英文对照(20页)

Oxidize ditch craft in dirty water handle of application and development Summary: This text expatiated primarily the Carrousel oxidizes the construction, craft mechanism of the ditch and circulate the problem exsited in the process with the homologous the method of solution.Finally, introduce the Carrousel oxidize the latest research progress of the ditch and pointed out the future and main research direction.Key phrase: The Carrousel oxidizes ditch divideds by the phosphor takes off the nitrogen construction mechanism Application and Development of Carrousel Oxidation Ditch Process on Wastewater TreatmentAbstract: The structure and the techniques of carrousel oxidation ditch process on nitrogen and phosphor removal are introduced in this paper. The problems inrunning and their corresponding resolvent are also pointed. At last, The authorshowed the up to date research improvement and the mainly future research dire-ction.Key words: Carrousel; oxidation ditch; nitrogen and phosphor removal; structure;techniques1. ForewordOxidize the ditch( oxidation ditch) again a continuous circulation spirit pond( Continuous loop reactor), is a live and dirty mire method a kind of to transform.Oxidizing the dirty water in ditch handles the craft be researched to manufacture by the hygiene engineering graduate school of Holland in the 50's of 20 centuries success.Since in 1954 at Dutch throw in the usage for the very first time.Because its a water fluid matter good, circulate the stability and manage convenience etc. technique characteristics, already at domestic andinternational and extensive application in live the dirty water to is dirty to manage aqueously with the industry[1].Current application than oxidize extensively the ditch type include:The ( Pasveer) oxidizes the ditch, the ( Carrousel) oxidizes the ditch, ( Orbal) oxidizes the ditch, the type of T oxidizes the ditch( three ditch types oxidize the ditch), the type of DE oxidizes the ditch to turn to oxidize the ditch with the integral whole.These oxidize the ditch because of the difference of esse in construction with circulating, therefore each characteristics[2].This text will introduce construction, mechanism, existent problem and its latest developments that Carrousel oxidize ditches primarily.2. The Carrousel oxidizes the construction of the ditchThe Carrousel oxidize the ditch to be researched to manufacture by Dutch DHV company development in 1967.Oxidize the last the company of DHV in foundation of the ditch in the original Carrousel to permited specially the company EIMCO to invent again with its patent in the United States Carrousel 2000 system( see the figure ), realizes the living creature of the higher request takes off the nitrogen with divided by the function of .There has been in the world up to now more than 850 Carrousels oxidize the ditch with the Carrousel 2000 system are circulating[3].From diagram therefore, the Carrousel oxidizes the ditch the usage the spirit of that definite direction control with shake up the device, face to mix with the liquid deliver the level speed, from but make drive the liquid of admixture that shake up is in oxidize ditch shut match outlet circulate flow.Therefore oxidize the ditch have the special hydraulics flows the , current complete mix with the characteristics of the type reactor, have the characteristics that push the flow type reactor again, the ditch inside exsits obviously of deliquescence oxygen density steps degree.Oxidizing the ditch crosssection is rectangle or trapezoids, the flat surface shape is many for oval, the ditch internal water is deep general for 2.5 ～4.5 ｍ, the breadth is deep compare for 2:1, also have the deep water amount to 7 ms of, ditch inside average speed in water current is 0.3 ms/ s.Oxidize ditch spirit admixture equipments contain surface spirit machine, the spirit of turn to brush or turn the dish and shoot to flow the spirit machine, pipe type spirit machine with promote take care of type spirit machine etc., match with in recent years usage still contain underwater push machine[4~6].3. The Carrousel oxidizes the mechanism of the ditch3.1 The Carrousel oxidizes the ditch handles dirty and aqueous principleThe at the beginning common Carrousel oxidizes the dirty water in inside in craft of the ditch direct with dirty mire in reflux together enter oxidize the ditch system.The surface spirit machine makes fuse in the liquid of admixture the density of the oxygen DO increases about 2 the 3 mgs/ L.Under this kind of well the term of the oxygen , the microorganism gets the enough deliquescence oxygen comes and go to divided by the BOD;At the same time, the ammonia were too oxidized nitrate with second nitrate, this time, mix with the liquid be placed in the oxygen appearance.In the spirit machine downstream, after water current be become by the swift flow appearance of the spirit District of even flow the appearance, the water current maintains in the minimum current velocity, guaranteeing the live and dirty mire be placed in the floats the appearance.( average current velocity>0.3 ms/ s)Oxidize microbially the process consumed to fuse the oxygen in the water, until the value of DO declines for zero, mixing with the liquid report the anoxia appearance.Versa nitric that turn the function through anoxia area, mix with the liquid enter to have the oxygen area, completing once circulating.That system inside, theBOD declines the solution is a continuous process, the nitric turns the function to turn with the versa nitric the function take place in same pond.Because of structural restrict, this kind of oxidize the ditch although can then valid whereabouts BOD, divided by the phosphorus take off the nitrogenous ability limited[7].For the sake of the acquisition better divided by the phosphorus take off the nitrogenous result, Carrousel 2000 systems increased a oxygen District before common Carrousel oxidize ditch with the unique oxygen area.( call again that the versa nitric in front turns the area)The dirty mire in all refluxes enters the anaerobic District with 10-30% dirty water, can under the anoxia with 10-30% carbon source term complete remaining of dirty mire in reflux inside nitric acid nitrogen to versa nitric to turn, creates for the unique oxygen pond of hereafter unique oxygen term.At the same time, anaerobic District inside of concurrently the sex germs convert the dissolubility BOD VFA, the germ acquire the VFA its assimilation PHB, the energy source needed solves in the phosphoric water and cause phosphatic releasing.The anaerobic District a water enters the inner part installs the unique oxygen area that have the mixer, the so-called unique oxygen is a pond inside to mix with liquid since have no the numerator oxygen, also have no the compound oxygen( nitric acid root), the here unique oxygen environment is next,70-90% dirty water can provide the enough carbon source, can make the germ of released the phosphorus well.The unique oxygen area connects behind the common Carrousel oxidizes the ditch system, further completing to do away with the BOD and take off the nitrogen with divided by the phosphorus .Finally, mix with the liquid transfer the dirty mire inside in oxidize ditch enrich oxygen area eject, while enriching the oxygen environment germ surfeit, phosphorus from the water, ejecting the system with the dirty mire in surplus.Like this, in Carrousel 2000systems, than completed to do away with the BOD, COD with take off at the same time goodly the nitrogen divided by the phosphorus .Synthesizing and dirty water in the river City , long sand City decontamination center[s of the dirty the factory of water in the first in Kunming of adoption that crafts handles the movement result of the factory therefore:Through Carrousel 2000 system after handling, the BOD, COD, SS does away with the rate to all come to a 90% above, the TN does away with the rate comes to a 80%, the TP does away with the rate to also come to a 90%.3.2 The Carrousel oxidizes the ditch divideds by the phosphorus takes off the nitrogenous influence factor.Affecting the Carrousel oxidizes the ditch divideds by the phosphoric factor is dirty mire , nitrate density and quality densities primarily.The research expresses, being total and dirty mire as 11% that a hour biggest phosphorus 4% with deal is its fuck dirty mire deal within live and dirty mire, keep for the the germ physical endowment measures, but when dirty mire over 15 d hour dirty mire the inside is biggest to contain the obvious descent in deal in phosphorus , canning not reach the biggest divideding by the result of phosphorus on the contrary.Therefore, prolong persistently the dirty mire ( for example 20ds,25ds,30ds) is to have no necessary, proper choose to use within the scope of 8~15 d.At the same time, high nitrate density with low quality density disadvantage in divided by the process of phosphorus .Affecting the Carrousel oxidizes the ditch takes off the nitrogenous and main factor is DO, nitrate density and carbon source densities.The research expresses, oxidizing the ditch inside exsits deliquescence oxygen density steps degree namely the good oxygen area DO attains 3~3.5 mgs/ L, the anoxia area DO attains 0~0.5 mgs/ L is a prior condition to take place nitric turn reaction and versa nitricsturn the reaction.At the same time, ample carbon source and higher C/ the N ratio benefits to take off to complete nitrogenously[7].4. The Carrousel oxidizes problem and solution methods of the ditch esse.Though the Carrousel oxidizes the ditch has a water fluid matter good, the anti- pounds at the burthen ability strong, divided by the phosphorus take off the nitrogen efficiency. But, in physically of movement process, still exsits a series of problem.4.1 Dirty mire inflation problemWhen discard the aquatic carbohydrate more, the N, P contains the unbalance of deal, the pH value is low, oxidizing the dirty mire in inside in ditch carries high, fuse the oxygen density the shortage, line up the mire not etc. causes easily dirty mire in germ in form in silk inflation;Not the dirty mire in germ in form in silk inflation takes place primarily at the waste water water temperature is lower but the dirty mire carries higher hour.The microbial burthen is high, the germs absorbed the large quantity nourishment material, is low because of the temperature, metabolism the speed is slower, accumulating the rises large quantity is high to glue sexual and many sugar materials, making the surface of the live and dirty mire adhere to the water to increase consumedly, SVI the value is very high, becoming the dirty mire inflation.Cause that aim at the dirty mire inflation, can adopt the different counterplan:From the anoxia, water temperature high result in of, can enlargement tolerance or lower into the water measures to alleviate burthen, or the adequacy lowers the MLSS( control dirty mire reflux measure), making need the oxygen measures decrease;If the dirty mire carries high, can increase MLSS, to adjust the burthen, necessity the hour can stop into the water, stuffy a period of time;Can pass the hurl add the nitrogen fertilizer, phosphorus fatty, adjust the admixturenourishment in the liquid material equilibrium( BOD5:N:P=100:5:1);The value of pH over low, can throw to add the lime regulate;Bleach the powder with the liquid chlorin( press to fuck 0.3% of the dirty mire~0.6% the hurl adds), can repress the silk form germ breed, controling the dirty mire in combinative water inflation[11].4.2 Foam problemBecause entering to take the grease of large quantity in the water, handling system can't completely and availably its obviation, parts of greases enriches to gather in in the dirty mire, through turn to brush the oxygen agitation, creation large quantity foam;The mire is partial to long, the dirty mire is aging, and also easy creation foam.Spray to pour the water or divided by with the surface the of do away with the foam, in common use divided by the an organism oil, kerosene, the oil of silicon, throw deal as 0.5~1.5 mgs/ L.Pass to increase dirty mire in pond in spirit in density or adequacies let up the tolerance of , also can control the foam creation effectively.When contain the live material in surface in the waste water more, separate with the foam easily and in advance method or other methods do away with.Also can consider to increase to establish a set of divideding by the oil device moreover.But enhance most importantly the headwaters manage, reducing to contain the oil over the high waste water and other poisonous waste water of into[12].4.3 Float the problem on the dirty mireWhen contain in the waste water the oil measures big, whole system mire quality become light, can't like to control very much in operate process its at two sink the pond stop over time, resulting in the anoxia easily, producing the corrupt and dirty mire ascend to float;When spirit time over long, take place in pond the high degree nitric turn the function, making nitrate density high, at two sink theversa nitric in easy occurrence in pond turn the function, creation nitrogen spirit, make dirty mire ascend float;Moreover, contain the oil in the waste water?Take place the dirty mire ascend after floating should pause enter water, broke off or dirty mire in clearance, judge the clear reason, adjust the operation.The dirty mire sinks to decline the sex bad, can throw to add of oagulate or sloth materials, the improvement precipitates the sex;Such as enter the water carries big let up into the water measures or the enlargement reflux measures;Such as the dirty mire grain small lower the spirit machine turn soon;If discovers versa nitric turning, should let up the toerance , enlarge the reflux or row the mire measures;If discover the dirty mire is corrupt, should enlargement tolerance, the clearance accumulates the mire, and try the ameliorative pond internal water dint term[12].4.4 Current velocity is not all and the dirty mire sinks to accumulate the problemIn Carrousel oxidize ditch, for acquiring its special admixture with handles result, mix with liquid must with certain current velocity is in ditch circulate flow.Think generally, the lowest current velocity should should attain for an average current velocity for, doing not take place sinking accumulating 0.3~0.5 ms/ s.The spirit equipments that oxidize the ditch is general to turn to brush for the spirit of to turn the dish with the spirit of , turning to brush of immerse to have no depth for 250~300 mms, turn the dish immerse to have no depth for 480~530 mms.With oxidize the ditch water the deep(3.0~3.6 ms) comparing, turn to brush occupied the deep 1/10~ in water 1/12, turned the dish to also occupy the 1/6~ only 1/7, therefore result in to oxidize the ditch upper part current velocity bigger( roughly 0.8~1.2 ms, even larger), but the bottom current velocity is very small( especially at the water is deep 2/3 or 3/4 below, mix with theliquid has no current velocity almost), causing ditch bottom large quantity accumulate the mire( sometimes accumulate the mire thickness amount to a 1.0 ms), the valid capacity that reduced to oxidize the ditch consumedly, lowered to handle result, affected a water fluid matter.Adding the top, downstream leads to flow the plank is a valid method that ameliorative current velocity distribute, increases the oxygen ability with the most convenient measure.The upper stream leads to flow the plank installs at be apart from to turn the 4.0 places( upper stream) ：dish( turn to brush) axis, lead to flow plank high degree as the deep 1/5~ in water 1/6, combine the perpendicularity install in the surface;The downstream leads to flow the plank installs at be apart from to turn dish( turn to brush) axis 3.0 ms.Leading to flow knothole material can use metals or glass steels, but regard glass steel as good.Lead to flow the plank compares with other ameliorative measure, can't not only increase the motive consumes with revolves cost, but also can still than significantly exaltation 充oxygen ability with theories motive efficiency[13].Moreover, pass in the spirit on board swim to establish the underwater push machine can also turn to the spirit of the liquid of admixture that brush the bottom low speed area circulates to flow to rise positive push function, from but the solution oxidizes the problem that low and dirty mire in current velocity in bottom in ditch sink accumulates.Establish the underwater push machine useds for exclusively the push mixs with the liquid can make movement method that oxidize the ditch much more vivid, this for economy energy, lift the high-efficiency having the very important meaning[14].5. The Carrousel oxidizes the development of the ditchBecause the dirty water handles standard inside to divided by the phosphorus take off the nitrogenous request more and more strict,the development that Carrousel further oxidized the ditch to also get.Current, the research and application includes morely below two category type:Tiny bore spirit type Carrousel 2000 systems, Carrousel 3000 system.5.1 Tiny bore spirit type Carrousel 2000 systemTiny bore spirit type Carrousel 2000 tiny bore in adoption in system spirit( provide oxygen equipments as the drum breeze machine), the tiny bore spirit machine can produce the diameter of large quantity as a surface for or so and small spirit steeping, this consumedly increases spirit bubble accumulates, undering the certain circumstance in capacity in pond make the oxygen transfer the gross measures aggrandizement.( if deep increment in pond, its spread the quality efficiency will be higher)Produce the technique ability of the factory house according to the current drum breeze machine, the valid water of the pond is deep biggest amounting to a 8 ms, therefore can select by examinations according to the different craft request the fit water is deep.The tradition oxidizes the ditch pushes to flow is to make use of to turn to brush, turn a disc or pour the umbrella type form machine realizes of, its equipments utilization is low, the motive consumes big.Tiny bore spirit type Carrousel 2000 systems then adopted the underwater pushes the way that flow, rises to dive the propeller the leaf the motivation that round creation the direct function namely in the of water, at push to flow the function to can keep dirty mire from sinking to decline effectively again at the same time.As a result, the adoption dives the propeller since lower the motive consume, making mire water got again to mixs with adequately.Seeing from water power characteristic, tiny bore spirit type Carrousel 2000 systems are wreaths form the fold flows the pond type, concurrently pushing the flow type with complete mix with the typeflows .In regard to whole oxidize ditch, can think that oxidize the ditch is a complete mix with spirit pond, its density variety coefficient smallest even can neglect to do not account, enter the water will get the dilution quickly, therefore it have the very strong anti- pounds at the burthen ability.But have oxidize ditch inside of a certain very much the some pushing the characteristic of the flow type, in the nearby district in downstream in machine in spirit inDO density higher, but along with increase with spirit machine distance continuously then the density of DO lowers continuously.( appear the anoxia area)This kind of structure method makes friendly oxygen in area in anoxia area exsited to build the thing inside , making use of its water power characteristic well, coming to an efficiently the living creature takes off the nitrogenous purpose.Tiny bore spirit type Carrousel 2000 system though have the oxygen ability strong, divided by the phosphorus take off the nitrogen effective, cover the area little with can consume low etc. advantage, it also exsits at the same time the problem that tiny bore spirit equipments maintain.Current, the service life of the local and tiny bore spirit machine is 5 years in 4~, can amount to 10 years in 8~ goodly, but with import the tiny bore spirit machine compare to still have the certain margin.The spirit machine maintains unlike the form equipments is so convenient, it need to fuck the pond talent fixs, and also is to say once the tiny bore spirit machine appears the problem to need the adoption parallel two inconvenience for or third sets to solving problem, or adopting promoting device waiting to resolving, this too will giving production with managing bringing biggest[15 16].5.2 Carrousel 3000 systemCarrousel 3000 systems are in the Carrousel 2000 systems are ex- to plus a living creature the choice the area.That living creaturechoice area is a craft to make use of high organism carries to sieve germ grow, repress silk form germ increase, increase each pollutant do away with the rate, afterward principle together Carrousel 2000 system.Carrousel 3000 system of bigger increases to express at:An is to increased the pond deep, can amount to 7.5~8 ms, united at heart circle type, the pond wall uses totally, reducing to cover the area, lowering to build the price to increases to bear the low temperature ability at the same time;( can amount to 7 ℃ )Two is the liquid of admixture that spirit equipments that skillful design, the form machine descends to install to lead to flow , the anoxia of take out , adopt the underwater propeller solution current velocity problem;Three is to used the advanced spirit controller QUTE.( it adopt the much aer kind of changing the deal control mode)Four is to adopt the integral whole turn the design, starting from the center, including below wreath form consecution craft unit:Enter the well of water with the cent water machine that used for the live and dirty mire in reflux;Difference from four-part the choice pond that cent constitute with 厌oxygen pond.This outside is a Carrousel to have three spirit machine with a prepare versa nitric turn the pond 2000 system.( such as figure 2 show)Five is tube line that the design that the circular integral whole turn to make oxidize the ditch do not need additionally, can immediately realize dirty mire in reflux allotment in different craft unit[17].6. ConclusionThe Carrousel oxidizes the ditch because of having the good a phosphorus takes off the nitrogen ability, anti- pounds at the burthen ability with circulate to manage the convenience etc. the advantage, having got the extensive application.But because of technological development with social advance, that craft is necessarily willexaltation getting further.The author thinks:The Carrousel oxidizes the future research direction of the ditch will now of main below several aspects.1 Combination living creature method, research with develop the living creature model Carrousel oxidize the ditch.Like this can not only increases the microorganism gross of the unit reactor measures, from but increases the organism carries, but also living creature oneself the inside that have places the A/ the system of O enhances to take off the nitrogen result[18].2 Increases continuously the Carrousel oxidize the microbial activity in inside in ditch.For example throw to add the EM in oxidize ditch with single mind the germ grow, throws in that the salt of iron make the microorganism tame the live char in iron, devotion in living creature to become the formation to strengthen the germ gum regiment and increases to bear the toxicity pound at etc..3 Increasing the Carrousel oxidizes the ditch equipments function with supervise and control the technique.Function that increases form machine, underwater propeller, reduce to maintain the workload;Making use of DO, etc. of ORP many targets supervises and control the technique and changes the technique of is from now on the Carrousel oxidizes ditch science circulate necessarily from it road.4 Increasing the Carrousel oxidizes the ditch resistant to cold and bear toxicity can, reduce to cover the area to build the price with the engineering.Theoretical application, deep pond in water power term with the research of the craft function is to lowers the engineering builds the price and increases resistant to cold bear the toxicity can wait to provide the possible direction.氧化沟工艺在污水处理中的应用与发展摘要：本文主要阐述了Carrousel氧化沟的结构、工艺机理、运行过程中存在的问题和相应的解决方法。

给排水与环境工程专业英语

Part One Introduction Unit 1 Introduction of Water Supply
The human search for pure water supplies must have begun in prehistoric times. Much of that earliest activity is subject to speculation. Some individuals may have led water where they wanted it through trenches dug in the earth. Later a hollow log was perhaps used as the first water pipe.
Only by continual and costly attention to water quality control has it been possible to virtually eradicate waterborne diseases from developed countries. Such achievements must not, however, be allowed to mask the appalling situation regarding water supply and sanitation in much of the developing world. The growth of population in developing countries, due to the high birth rate, is such that unless strenuous efforts to increase water supply and sanitation facilities are made, the percentage of the world’s population with satisfactory facilities would actually decrease in the future. In developed countries, demands for water are now fairly static and basic waste quality-control measures are well established. However, many of the existing water-supply and sewage schemes are now relatively old so that their reconstruction will pose problems in the future. As knowledge of the effects of all forms of environmental pollution increases so new potential hazards appear, for example there is current concern about the possible carcinogenic hazards arising from the presence of minute concentrations of some organic compounds in water. Anthropogenic, or human-induced, pollutants have overloaded our envir commissioning of the first major public health engineering works of modern times. Thus by 1870 waterborne outbreaks had been largely brought under control in the UK and similar developments were taking place in Western Europe and the cities of the USA. The Industrial Revolution greatly increased the urban water demand and the late nineteenth century saw the construction of major water-supply schemes.

给水排水工程专业英语文献翻译原文第三篇

Journal of Membrane Science 376 (2011) 196–206Contents lists available at ScienceDirectJournal of MembraneSciencej o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /m e m s ciFouling and cleaning of RO membranes fouled by mixtures of organic foulants simulating wastewater efﬂuentWui Seng Ang 1,Alberto Tiraferri,Kai Loon Chen 2,Menachem Elimelech ∗Department of Chemical and Environmental Engineering,P.O.Box 208286,Yale University,New Haven,CT 06520-8286,USAa r t i c l e i n f o Article history:Received 6December 2010Received in revised form 7April 2011Accepted 9April 2011Available online 20 April 2011Keywords:Reverse osmosis FoulingWastewater efﬂuent CleaningOrganic foulantsWastewater treatment Efﬂuent organic matter Wastewater reclamation Membranesa b s t r a c tThe fouling and subsequent cleaning of RO membranes fouled by a mixture of organic foulants sim-ulating wastewater efﬂuent has been systematically investigated.The organic foulants investigated included alginate,bovine serum albumin (BSA),Suwannee River natural organic matter,and octanoic acid,representing,respectively,polysaccharides,proteins,humic substances,and fatty acids,which are ubiquitous in efﬂuent organic matter.After establishing the fouling behavior and mechanisms with a mixture of organic foulants in the presence and absence of calcium ions,our study focused on the clean-ing mechanisms of RO membranes fouled by the mixture of organic foulants.The chemical cleaning agents used included an alkaline solution (NaOH),a metal chelating agent (EDTA),an anionic surfactant (SDS),and a concentrated salt solution (NaCl).Speciﬁcally,we examined the impact of cleaning agent type,cleaning solution pH,cleaning time,and fouling layer composition on membrane cleaning efﬁ-ciency.Foulant–foulant adhesion forces measured under conditions simulating chemical cleaning of a membrane fouled by a mixture of the investigated organic foulants provided insights into the chemical cleaning mechanisms.It was shown that while alkaline solution (NaOH)alone is not effective in dis-rupting the complexes formed by the organic foulants with calcium,a higher solution pH can lead to effective cleaning if sufﬁcient hydrodynamic shear (provided by crossﬂow)prevails.Surfactant (SDS),a strong chelating agent (EDTA),and salt solution (NaCl)were effective in cleaning RO membranes fouled by a mixture of foulants,especially if applied at high pH and for longer cleaning times.The observed cleaning efﬁciencies with the various cleaning agents were consistent with the related measurements of foulant–foulant intermolecular forces.Furthermore,we have shown that an optimal cleaning agent con-centration can be derived from a plot presenting the percent reduction in the foulant–foulant adhesion force versus cleaning agent concentration.© 2011 Elsevier B.V. All rights reserved.1.IntroductionAs demand for potable water increases worldwide,the paradigm for selecting water sources to meet this demand is transitioning from conventional sources,such as reservoirs and lakes,to less con-ventional sources,such as treated secondary wastewater efﬂuent.In order to produce water of superior quality,the use of mem-branes in desalination and wastewater reclamation has become more widespread.Membrane fouling is a major impediment to the use of membrane technology for such applications,because fouling is inevitable.Despite research efforts to develop better anti-fouling membranes [1]and improved fouling-control strategies [2,3],membrane fouling still occurs over time.Thus,a long-term∗Corresponding author.Tel.:+12034322789;fax:+12034324387.E-mail address:menachem.elimelech@ (M.Elimelech).1Current address:Public Utility Board of Singapore,Singapore.2Current address:Department of Geography and Environmental Engineering,Johns Hopkins University,Baltimore,MD 21218,United States.solution would be to remove the foulant deposited on the mem-brane via chemical cleaning.To select the appropriate cleaning agents and adopt an effective chemical cleaning protocol for fouled membranes in wastewater reclamation,the implications of wastewater efﬂuent characteris-tics on membrane fouling have to be well-understood.Wastewater efﬂuent contains dissolved organic matter,commonly known as efﬂuent organic matter (EfOM),which comprises polysaccha-rides,proteins,aminosugars,nucleic acids,humic and fulvic acids,organic acids,and cell components [2–4].Organic fouling of the RO membranes by the EfOM can be extensive since EfOM is gener-ally small enough to pass through the pores of pretreatment (MF or UF)membranes [4].In particular,recent ﬁndings suggest that while biofouling can prevail on the tail-element of the membrane module,fouling of the lead-element exposed to reclaimed water is dominated by EfOM adsorption [5].In addition,higher potential of fouling was observed for the higher molecular weight hydropho-bic/aromatic fraction of the EfOM [6,7].The presence of Ca 2+in the feed source for the RO membranes has been reported to form complexes with the constituents of EfOM,such as polysaccharidesW.S.Ang et al./Journal of Membrane Science376 (2011) 196–206197[8]and natural organic matter[9],and to signiﬁcantly enhance membrane fouling.While our previous studies have addressed the fouling of RO membranes by individual organic foulant types,such as polysaccharides[10],proteins[11],and fatty acids[12],only recently have investigations reported on the effects of a combina-tion or mixture of foulants on the fouling of RO membranes[13,14].A variety of chemical cleaning agents are commonly used to clean RO membranes fouled by organic matter[15].Alkaline solutions remove organic foulants on membranes by hydroly-sis and solubilization of the fouling layer.Alkaline solutions also increase the solution pH,and,therefore,increase the negative charges and solubility of the organic foulant.Metal chelating agents remove divalent cations from the complexed organic molecules and weaken the structural integrity of the fouling layer matrix[16]. Surfactants solubilize macromolecules by forming micelles around them[17],thereby facilitating removal of the foulants from the membrane surface.In our earlier study on salt cleaning of organic matter-fouled RO membranes[18],we demonstrated that NaCl and other common inert salts can be used as an effective alternative for the cleaning of RO membranes fouled by gel-forming hydrophilic organic foulants.In the presence of a salt solution,the fouling layer swells and becomes more porous.As a result,this would facil-itate the diffusion of Na+into the fouling layer and breakup of Ca2+–alginate bonds by ion exchange.Understanding the fouling layer characteristics and the interaction of chemical agents with foulants is therefore critical for the effective cleaning of organic matter-fouled RO membranes.Atomic force microscopy(AFM)has been applied in mem-brane fouling/cleaning research to quantify intermolecular forces [10,19–21].Our research has shown that foulant–foulant inter-actions could be determined by performing force measurements using a carboxylate-modiﬁed latex colloid probe in an AFMﬂuid cell[10,20].The technique has been used to quantify the foul-ing behavior of a nanoﬁltration membrane fouled by humic acid and the cleaning efﬁciencies of EDTA and SDS[20],and has been extended to quantify RO membrane fouling by organic foulant in the form of alginate[10],BSA[11],and octanoic acid[12].In this study,the AFM has also been employed as an alternative tool to indicate the optimal concentration of cleaning agent for cleaning fouled membranes.The original protocol[11,12]for using the AFM has been modiﬁed to investigate the intermolecular adhesion force between different foulants.The objective of this study is to explore the mechanisms govern-ing the fouling of RO membranes by mixtures of organic foulants simulating wastewater efﬂuent,and the ensuing chemical cleaning of the fouled membranes by cleaning agents.To make this study rel-evant to wastewater reclamation,we systematically investigate the fouling of RO membranes by each individual organic foulant type (polysaccharides,proteins,humic acids,or fatty acids)and mix-tures containing several types of organic foulants in the absence and presence of calcium ions.Cleaning experiments are performed with the fouled membranes using NaOH,EDTA,SDS,and NaCl as model alkaline solution,metal chelating agent,surfactant,and salt cleaning solution,respectively.The intermolecular adhesion forces between the different foulants and estimated aggregate sizes in foulant mixtures were used to explain the fouling mechanism of RO membranes and the cleaning behavior of a cleaning agent on the fouled membranes.2.Materials and methodsanic foulants Louis,MO),Suwannee River natural organic matter(SRNOM) (International Humic Substances Society,St.Paul,MN),bovine serum albumin(BSA)(Sigma–Aldrich,St.Louis,MO),and octanoic acid(OA)(Sigma–Aldrich,St.Louis,MO),respectively.According to the manufacturer,the molecular weight of the sodium alginate ranges from12to80kDa.Other characteristics of SRNOM,includ-ing molecular weight and mass fraction of hydrophobic NOM,can be found elsewhere[22,23].According to the manufacturer,the molecular weight of the BSA is about66kDa.BSA is reported to have an isoelectric point at pH4.7[24].Octanoic acid(Sigma–Aldrich,St. Louis,MO)was selected to model fatty acids in EfOM because of its presence in food and solubility in water(saturation concentration of4.7mM at20◦C)[12].Sodium alginate,BSA,and SRNOM were received in powder form,and stock solutions(2g/L)were prepared by dissolving each of the foulants in deionized(DI)water.DI water was supplied from a Milli-Q ultrapure water puriﬁcation system(Millipore,Billerica, MA).Mixing of the stock solutions was performed for over24h to ensure complete dissolution of the foulants,followed byﬁl-tration with a0.45-␮mﬁlter(Durapore,Millipore,Billerica,MA). Theﬁltered stock solutions were stored in sterilized glass bottles at4◦C.Octanoic acid was received in solution(≥98%concentra-tion)and was stored at room temperature.To achieve the intended octanoic acid concentration during fouling,octanoic acid was dis-solved separately for at least8h prior to fouling so that,at the initiation of fouling,octanoic acid could be introduced as a solu-tion.A few hours before the initiation of fouling,the ionic strength of the stock solution was adjusted to the same concentration as that of the feed solution(10mM)and the stock solution pH was elevated,as needed,from ambient pH of3.9–9.0by adding small amounts of1M NaOH.2.2.Chemical cleaning agentsThe chemical cleaning agents used were:NaOH(pH11.0)as an alkaline solution,certiﬁed grade disodium ethylenediaminete-traacetate(Na2–EDTA)as a metal chelating agent,certiﬁed grade sodium dodecyl sulfate(SDS)as an anionic surfactant,and NaCl as a salt cleaning solution.The agents were purchased from Fisher Sci-entiﬁc(Pittsburgh,PA)and used with no further puriﬁcation.The stock chemical solutions were prepared fresh by dissolving each chemical in deionized(DI)water.The pH of the EDTA,SDS,and NaCl cleaning solutions was adjusted with1.0M NaOH as necessary.2.3.RO membraneThe relatively well-characterized thin-ﬁlm composite LFC-1 membrane(Hydranautics,Oceanside,CA)was used as a model RO membrane.The average hydraulic resistance was determined to be 9.16(±0.11)×1013m−1corresponding to a hydraulic permeabil-ity of10.9(±0.13)×10−11m s−1Pa−1.The observed salt rejection was98.7–99.3%,determined with a10mM(584mg/L)NaCl feed solution at an applied pressure of300psi(2068.5kPa)and a cross-ﬂow velocity of8.6cm/s.Membrane samples were received as dry large sheets,and were cut and stored in DI water at4◦C.The membrane has been reported to be negatively charged at solu-tion chemistries typical to wastewater efﬂuents,with an isoelectric point at about pH4.6[25].The membrane has been reported to be coated with a neutral polyalcohol layer rich in–COH functional groups,which renders the surface less charged than the surfaces of other polyamide RO membranes without a coating layer[25,26].2.4.Crossﬂow test unit198W.S.Ang et al./Journal of Membrane Science376 (2011) 196–206unit consists of a membrane cell,pump,feed reservoir,temper-ature control system,and data acquisition system.The membrane cell consisted of a rectangular plate-and-frame unit,which con-tained aﬂat membrane sheet placed in a rectangular channel with dimensions measuring7.7cm long,2.6cm wide,and0.3cm high. Both permeate and retentate were recirculated back to the feed reservoir.Permeateﬂux was registered continuously by a digital ﬂow meter(Optiﬂow1000,Humonics,CA),interfaced with a com-puter.Aﬂoating disc rotameter(King Instrument,Fresno,CA)was used to monitor the retentateﬂow rate.The crossﬂow velocity and operating pressure were adjusted using a bypass valve(Swagelok, Solon,OH)in conjunction with a back-pressure regulator(U.S.Para Plate,Auburn,CA).Temperature was controlled by a recirculating chiller/heater(Model633,Polysciences)with a stainless steel coil submerged in the feed water reservoir.2.5.Fouling and cleaning experimentsThe membrane wasﬁrst compacted with DI water until the permeateﬂux became constant,followed by the initial baseline performance for1h.The membrane was then stabilized and equi-librated with a foulant-free electrolyte solution for2h.Theﬂux at which the baseline run was performed was predetermined so that the initialﬂux would drop to a speciﬁedﬂux of2.3×10−5m s−1(or 83L m−2h−1)after adding the electrolyte solution.The chemistry of the foulant-free electrolyte solution and operating conditions adjusted in this stage were similar to those used for the ensuing fouling runs.As octanoic acid takes time to dissolve completely,the mixture of organic foulant solution has to be prepared8h before the fouling run.The feed foulant solution was prepared separately in another container.The chemistry of the feed foulant solution was adjusted to be identical to that of the foulant-free electrolyte solution so that the overall ionic strength and solution chemistry would not change when the feed foulant solution was added to initiate fouling. Fouling runs were carried out for17h.At the end of the fouling run, the solution in the feed reservoir was disposed off and chemical cleaning solution was added to the feed reservoir to clean the fouled membrane.At the end of the cleaning stage,the chemical cleaning solution in the reservoir was discarded,and both the reservoir and membrane cell were rinsed with DI water toﬂush out the residual chemical cleaning solution.Finally,the cleaned RO membrane was subjected to the second baseline performance with DI water to re-determine the pure waterﬂux.The crossﬂow velocity throughout the experiment,except dur-ing cleaning,was maintained at8.6cm/s.The operating conditions (i.e.,initialﬂux,crossﬂow velocity,and temperature)at this stage were identical to those applied during the initial baseline perfor-mance,so as to determine the cleaning efﬁciency by comparing the pure waterﬂuxes determined before fouling and after clean-ing.Throughout all the fouling/cleaning stages,the feed water in the reservoir,which was located on top of a magnetic stirrer,was mixed rigorously to ensure complete mixing of the feed water and cleaning solution.To conﬁrm the reproducibility of determined cleaning efﬁ-ciency,selected fouling/cleaning runs were duplicated.Results showed that fouling rate and cleaning efﬁciency obtained from the duplicate runs were within less than a5%difference.To investigate the change in the permeate quality during the fouling stage,permeate samples taken before and at the start and end of fouling were analyzed for salt(NaCl)rejection using an ICP-AES(ICP Optima3000,Perkin Elmer,Waltham,MA).Permeate and feed samplings obtained before the fouling run were collected at the end were collected during theﬁnal40min of the fouling run.2.6.AFM adhesion force measurementsAtomic force microscopy(AFM)was used to measure the inter-facial force between the foulant in the bulk solution and the foulant in the fouling layer on the membrane.The force measurements were performed with a colloid probe,modiﬁed from a commercial-ized SiN AFM probe(Veeco Metrology Group,Santa Barbara,CA).A carboxylate modiﬁed latex(CML)particle(Interfacial Dynam-ics Corp.,Portland,OR)was used as a surrogate for the organic foulants,because organic foulants(alginate and SRNOM)carry pre-dominantly carboxylic functional groups.To make a colloid probe, a CML particle with a diameter of4.0␮m was attached using Nor-land Optical adhesive(Norland Products,Inc.,Cranbury,NJ)to a tipless SiN cantilever.The colloid probe was cured under UV light for20min.The AFM adhesion force measurements were performed in a ﬂuid cell using a closed inlet/outlet loop.The solution chemistries of the test solutions injected into theﬂuid cell were identical to those used in the bench-scale fouling/cleaning experiments.Once all the air bubbles had beenﬂushed out of theﬂuid cell,the injection would stop and the outlet was closed.The membrane was equilibrated with the test solution for30–45min before force measurements were performed.The force measurements were conducted at three toﬁve different locations,and at least10measurements were taken at each location.Because the focus of this study was on the foulant–foulant interaction(adhesion),only the raw data obtained from the retracting force curves were processed and converted to obtain the force versus surface-to-surface separation curves.The force curves presented were the averages of all the representative force curves obtained at the different locations.The protocol for AFM analysis has been modiﬁed slightly to investigate the interaction between different foulant types. The AFM colloidal probe is soaked in organic foulant solution (2000mg/L alginate,BSA,or SRNOM,or>98%octanoic acid)for at least24h(at4◦C for alginate,BSA,and SRNOM solutions to prevent organic degradation,and at room temperature for octanoic acid). The membrane is fouled with200mg/L organic foulant(alginate, BSA,SRNOM,or octanoic acid)using the crossﬂow unit for about 17h.After transferring the colloidal probe to the AFMﬂuid cell and the membrane to the AFM disc puck,an electrolyte solution con-taining0.5mM CaCl2and8.5mM NaCl(adjusted to pH6.5±0.2) (identical solution chemistry as during fouling)is injected into the ﬂuid cell.The volume of electrolyte solution added is just enough toﬁll up theﬂuid cell so as to minimize the possibility ofﬂush-ing away the foulants on the membrane and probe surfaces.AFM force measurements are taken after20min of equilibration time.To investigate the effect of cleaning agent on the intermolecular adhe-sion force,the cleaning agent was added to the electrolyte solution at the same concentration as that used in the cleaning experiments.2.7.Light scatteringDynamic light scattering experiments were performed on foulant solution to determine the effective hydrodynamic diam-eters of the foulant aggregates in foulant mixtures using a multi-detector light scattering unit(ALV-5000,Langen,Germany). New glass vials(Supelco,Bellefonte,PA)for containing foulant solu-tions under various solution chemistries were cleaned prior to use by soaking overnight in a cleaning solution(Extran MA01,Merck KGaA,Darmstadt,Germany),rinsing with DI water,and drying inW.S.Ang et al./Journal of Membrane Science376 (2011) 196–206199Fig.1.Inﬂuence of individual foulant type on fouling of LFC-1membranes:(a)in the absence of Ca2+and(b)in the presence of0.5mM Ca2+.The total ionic strength of the feed solution wasﬁxed at10mM by adjusting with NaCl and the feed solution pH was adjusted to6.0±0.2,as necessary,by adding NaOH.Fouling conditions: foulant concentration of25mg/L,initial permeateﬂux of23␮m/s(or83L m−2h−1), crossﬂow velocity of8.6cm/s,and temperature of21.0±0.5◦C.of1M NaOH.The vial containing the foulant solution was vortexed (Mini Vortexer,Fisher Scientiﬁc)to homogenize the solution.The vial was then allowed to sit for30min before starting the light scattering experiment.All light scattering measurements were conducted by employ-ing the detector positioned at a scattering angle of90◦from the incident laser beam.The detector signal was fed into the correla-tor,which accumulated each autocorrelation function for15s.The intensity-weighted hydrodynamic radius of the colloidal aggre-gates was determined with second-order cumulant analysis(ALV software)[27].The reported size is the average of theﬁrst20mea-surements.3.Results and discussion3.1.Membrane fouling3.1.1.Fouling with individual foulantsFig.1presents the normalizedﬂux proﬁles for LFC-1mem-branes fouled by each individual foulant(alginate,BSA,SRNOM, or octanoic acid)in the absence(Fig.1a)and presence(Fig.1b)of Ca2+,respectively.In the absence of Ca2+,theﬂux decline proﬁles of membranes fouled by the various foulants are insigniﬁcant.The 2+Fig.2.Inﬂuence of a mixture of(a)2foulants or(b)more than2foulants on fouling of LFC-1membranes in the presence of0.5mM Ca2+.The total ionic strength of the feed solution wasﬁxed at10mM by adjusting with NaCl and the feed solution pH was adjusted to6.0±0.2,as necessary,by adding NaOH.Fouling conditions were identical to those in Fig.1.RO membranes by BSA,SRNOM,or octanoic acid is minimal.How-ever,we have observed that the presence of Ca2+can affect fouling behavior when the foulant concentrations are higher(300mg/L BSA;2mM or288mg/L octanoic acid)[11,12].3.1.2.Fouling with mixture of foulantsTo investigate the implications for wastewater reclamation, the effect of Ca2+on fouling of RO membranes by all possible combinations of two or more foulant types is investigated.The con-centration of each foulant type was maintained at25mg/L.Fig.2a shows the normalizedﬂux proﬁles of membranes fouled by a mix-ture of two foulants in the presence of Ca2+.The effect of Ca2+is most signiﬁcant for feed solutions containing alginate as one of the two foulant types.This mechanism will be further investigated with the aid of DLS and AFM paring theﬂux proﬁles of mem-branes fouled by alginate as a co-foulant,theﬂux-decline proﬁle of membrane fouled by alginate and octanoic acid is the least sig-niﬁcant due to the formation of octanoic acid–calcium complexes, which increase the hydrophilicity of the fouling layer[12].Fig.2b shows the normalizedﬂux proﬁles of membranes fouled by a mixture of three foulant types and all foulant types in the presence of Ca2+.In the presence of Ca2+,for membranes fouled by mixtures containing alginate,the effect of Ca2+onﬂux proﬁles is most signiﬁcant,especially for the membrane fouled by a mixture of alginate,BSA,and SRNOM(without octanoic acid).In compar-ing the latter with theﬂux proﬁle of the membrane fouled by all200W.S.Ang et al./Journal of Membrane Science376 (2011) 196–206Fig.3.Sodium ion(Na+)rejection of RO membranes measured before,and at the start and end of the fouling runs,at an adjusted feed solution pH of6.0.The membranes were fouled by combined foulant types,composed of25mg/L each of alginate,BSA,SRNOM,and octanoic acid.Permeate and feed samples obtained before the fouling run were collected30min before the onset of fouling.Samples taken at the start of the fouling run were initiated afterﬁrst discarding20mL of permeate(duration of8min).Permeate and feed samples taken at the end were collected during theﬁnal40min of the fouling run.Error bars indicate one standard deviation.Fouling conditions were identical to those in Fig.1.contained alginate and octanoic acid in the presence of Ca2+.The inhibitory effect of octanoic acid onﬂux-decline proﬁles can also be observed by comparing theﬂux proﬁle of combined foulant types of alginate,SRNOM,and octanoic acid in Fig.2b with the proﬁle of alginate and SRNOM in Fig.2a.3.1.3.Impact of fouling on salt rejectionFig.3presents Na+rejection of the RO membranes fouled by combined foulant types of alginate,BSA,SRNOM,and octanoic acid in the presence of Ca2+,at the start and end of the fouling runs.The trend of observed Na+rejection is similar both in the absence and presence of Ca2+.At the onset of fouling,the Na+rejection instan-taneously increases.This phenomenon is consistent with previous observations,which attributed the decrease in Na+permeability to the fouling layer acting as an additional selective barrier[12]. Toward the end of the fouling runs,the fouling layer becomes thicker and denser,resulting in even higher Na+rejection.It can be inferred that the presence of Ca2+resulted in a more compact fouling layer,which improves the ability of the fouling layer to fur-ther act as a selective barrier against the transport of Na+across the membrane.3.2.Fouling mechanisms3.2.1.Role of foulant–foulant interaction and foulant sizeRecent studies have demonstrated that the long-term organic fouling of RO membranes and the consequent behavior of water ﬂux are dominated by the feed water chemistry and strong foulant–foulant interactions[4,20,21,28].Quantifying these inter-actions provides a basis for the understanding of the fouling mechanisms and for the rational selection of a suitable cleaning strategy.As discussed in Section3.1.2,fouling behavior becomes signiﬁcant when alginate is one of the co-foulants.When alginate is absent from the feed solution,regardless of the other foulant types present,fouling is relatively insigniﬁcant.This behavior can be explained by evaluating the interaction forces among the differ-ent foulants.To investigate the effect of interactions of alginate with other foulant types,DLS analysis is performed on a solution contain-ing2foulant types(200mg/L alginate plus200mg/L of another foulant type)in the presence of Ca2+.Fig.4a shows that the alginate molecules in the solution have an effective hydrodynamic diame-ter of84nm,which is larger than the effective diameter of51nm of alginate molecules in a solution in which the foulant concentration is halved.The results imply that aggregation of alginate molecules is concentration dependent.The larger effective diameter of aggre-gates formed in400mg/L alginate solution as opposed to those formed in200mg/L alginate solution also implies a more exten-sive gel network at a higher concentration.The effective diameters of the foulant molecules in mixtures of alginate and BSA,alginate and SRNOM,and alginate and octanoic acid are,respectively,48, 63,and73nm.The effective diameter is an indirect indication of the foulant size due to aggregation between the foulants.Because of the varying interactions between alginate and another foulant type in the presence of Ca2+,the aggregate size differs for foulant aggregates of different foulant combinations.Fig.4b shows the intermolecular forces between foulant adsorbed on a colloidal probe and a membrane fouled by algi-nate as determined by AFM.For a membrane fouled by alginate and octanoic acid,the dominant foulant interactions are between alginate and alginate molecules(1.03mN/m)and between octanoic acid and octanoic acid molecules(0.90mN/m).For a membrane fouled by alginate and SRNOM,the dominant foulant interaction is between alginate and alginate molecules(1.03mN/m).For a membrane fouled by alginate and BSA,the dominant foulantinter-Fig.4.(a)Effective diameter of foulant aggregates in solutions of various foulant combinations that contain alginate as co-foulant.The foulant solution consists of200mg/L alginate plus200mg/L of another foulant type in an electrolyte solution of0.5mM CaCl2and8.5mM NaCl(same solution chemistry as that used in fouling experiments).TheW.S.Ang et al./Journal of Membrane Science376 (2011) 196–206201Fig.5.Proposed structure of fouling layer on membrane surface under different combinations of foulants.actions are between alginate and alginate molecules(1.03mN/m) and between alginate and BSA molecules(0.73–0.79mN/m).We observe that when alginate is present in the feed,regardless of the co-foulant,the interaction of alginate molecules among them-selves is most dominant,with the possibility of alginate molecules interacting with other molecules,especially BSA molecules.Comparing the effective diameters of the foulant aggregates in various2-foulant mixtures(Fig.4a)with the intermolecular adhe-sion force between different foulants(Fig.4b)reveals that there is an inverse correlation between the foulant aggregate size and the intermolecular adhesion force(foulant aggregate size generally decreases as intermolecular adhesion force increases).It is hypoth-esized that the interaction among the foulant types within the aggregates would affect the conformation,and hence,the size of the aggregates in the foulant solution.For example,the relatively stronger intermolecular adhesion force between alginate and BSA molecules in the feed solution in the presence of Ca2+results in a more‘compact’or‘tighter’conformation of the foulant aggregates as compared to the foulant aggregates formed from a solution of alginate and SRNOM.The deposition of the smaller and more‘com-pact’alginate–BSA aggregates results in a tighter fouling layer and a lowerﬁnalﬂux(Fig.5)[29].We note that the SA–SA aggregate does not follow the trend of a decrease in aggregate size with increasing adhesion force because alginate molecules tend to form extended gel networks in the presence of calcium ions[29],as opposed to the other combinations of foulants.3.2.2.Proposed structure of fouling layerThe fouling experiments reveal that membrane fouling in the presence of Ca2+is controlled by alginate.From the AFM force mea-surement analysis and the DLS experiments,the proposed structure of the fouling layer when severe fouling occurs under various solu-tion chemistries is schematically shown in Fig.5.The top drawing shows the likely conformation of the cross-linked alginate fouling layer when the feed contains alginate in the presence of Ca2+.In this case,the fouling layer has the typical structure resulting from the formation of an‘egg-box’shaped gel network on the mem-brane surface[29].The middle drawing shows the proposed fouling layer formed by a feed solution containing a mixture of alginate, BSA,SRNOM,and octanoic acid(each foulant has the same concen-tration).The DLS experiments show that the aggregates of foulant mixtures containing alginate as a co-foulant have smaller effective feed solution in which alginate is the sole foulant.When the algi-nate concentration is increased while maintaining the same total foulant concentration,the fouling layer becomes more porous due to the increase in the highly ordered alginate–calcium complexes on the membrane surface.The state of the fouling layer would affect the transfer of a cleaning agent to the fouling layer,and hence,the cleaning efﬁciency of the cleaning agent as delineated in the next sections.3.3.Cleaning of fouled membranes3.3.1.Type of cleaning agentFig.6presents the cleaning efﬁciencies of various cleaning agents on membranes fouled by combined foulant types compris-ing alginate,BSA,SRNOM,and octanoic acid in the presence of 0.5mM Ca2+.Cleaning was performed for15min without an oper-ating pressure(i.e.,no permeate)and at a crossﬂow velocityﬁve times higher than that during fouling.Cleaning the fouled mem-brane with DI water resulted in19%cleaning efﬁciency,which implies that the fouling layer on the membrane surface was largely irreversible.Conventional cleaning agents,such as NaOH(pH11),Fig.6.Cleaning efﬁciencies of various cleaning agents on membranes fouled by combined foulant types comprising alginate,BSA,SRNOM,and octanoic acid,with the concentration of each foulant type at25mg/L,in the presence of0.5mM Ca2+.Cleaning conditions:time,15min;temperature,21±0.5◦C;and no applied。

给排水专业汉英对照

AA/A/O法 anaerobic-anoxic-oxic process(厌氧-缺氧-好氧法)A/O法(厌氧-好氧法) anaerobic-oxic processA-A-O生物脱氮除磷工艺 A-A-O biological nitrogen and phosphorus removal processAB法 Adsorption Biodegradation process(吸附生物降解法)A-O除磷工艺 A-O phosphorus removal processA-O脱氮工艺 A-O nitrogen removal processBMTS型一体化氧化沟 BMTS intrachannel clarifier oxidation ditchBOD-污泥负荷 BOD-sludge loadK型叶轮曝气机 K type impeller aeratorLMPPhoredox nitrogen and phosphorus removal processr射线 gamma rayswater into groundwater aquifer氨氮 ammonia-nitrogen氨化反应 Nitragen氨基酸 amino acid铵盐 ammonium salt奥贝尔(Orbal)型氧化沟 Orbal oxidation ditch巴登福脱氮除磷工艺　Bardenpho nitrogen and phosphorus removal process白水(漂洗废水) white water(bleaching water)板框压滤 plate pressure filtration半渗透膜 semi-permeable membrane棒状杆菌属 corynebacterium薄膜式淋水材料 film packing 能使水流在填料表面形成连续薄水膜的淋水填料。

饱和常数(Ks) saturation constant饱和指数 saturation index,Langelier index 由理论推导公式得出一个指数，以定性地预测水中碳酸钙沉淀或暴雨公式 storm flow formula暴雨径流 storm runoff暴雨溢流井（截留井）storm overflow well, intercepting well 合流制排水系统中，用来截留、控制合流水量苯 benzene苯胺 aniline泵型叶轮暴气器 paddle impeller aerator泵站 pumping house 设置水泵机组、电气设备和管道、闸阀等的房屋。

给排水科学与工程专业英语Unit21-翻译

Cold water supplyUnder the Water Supply Regulations 1999: every dwelling is required to have a wholesome water supply system, and this should be provided in sufficient quantities for the needs of the user, and at a temperature below 20℃. The most important place to provide drinking water in dwellings is at the kitchen sink. However ,because there is a likelihood that all taps in dwelling will be used for drinking, they should all be connected in such a way that the water remains in potable condition. This means that all draw-off taps in dwellings should either be connected direct from the mains supply, or from a storage cistern that is protected. If no such location exists, drinking water should be provided near but not in toilet. However . drinking water fountains may be installed on toilet area, provided they are sited well away from WCs and urinals and comply with the requirements of BS 6465: Part 1 .冷水供应下供水1999年规定:每一个住宅都是需要有一个健康的供水系统,这应提供足够数量的用户的需要,在温度低于20℃。

给水排水专业英语翻译下学期

1 初级处理thematerial将原污水排入河道最要不得的方面就是漂浮物质。

itplants因此，格栅过去被用在居民区污水处理的第一道工序是很有道理的，甚至今天，格栅也被用在污水处理厂的第一道工序。

typicalapart典型的格栅是由一系列相隔2.5cm的钢条所组成的。

thetreatment 在现代污水处理厂当中，格栅的目的就是清除可能会毁坏设备或妨碍后序处理的物质。

inplants在一些旧的污水处理厂当中，格栅是人工清洗的，几乎所有的新处理厂当中都使用了机械清洗装置。

thebars当格栅被塞满到栅前水位上升时，清洗的耙子就会自动启动。

insmaller在很多处理厂当中，下一道处理工序是磨碎，圆形的研磨机被设计用来研磨通过格栅的物质，将它们研磨成0.3cm，甚至更小。

manyuse许多处理厂都在设计应用。

thesand第三道工序是清除粗砂和细砂，thismeters这道工序是非常重要的, 因为粗砂会磨损和损坏诸如水泵和流量计这样的设备，theout最普通的沉沙区，简单说就是流道当中宽敞的地方，在那里，流速慢下来，足以使重的沙砾沉淀下来。

Sandsolids细沙是大部分有机固体的2.5倍重，因此比轻的固体物质沉淀起来要快得多。

thematerial 沉沙区或沉砂池的目的就是去除粗砂和细砂而不能去除有机物质。

theproblems后者必须在处理厂当中作进一步处理，但是，细砂可以被作为填充物被倾倒而不产生适当的气味或其它问题。

followingpossible在大多数污水处理厂当中，紧随沉沙区域之后的是沉淀池，它使固体物质尽可能多的沉淀下来。

accordinglyminimum所以，持水时间要长，紊流要保持到最低限度。

thetank沉淀到底部的物质，通过管道被去除，而上清液从U型凹堰上溢流，水流通过有凹口的钢板，自始至终促使滤池从四周均匀排水。

settlingclarifiers沉淀池也被称为沉淀池、澄清池。

给水排水工程专业英语文献翻译译文第三篇

污水的有机污垢物污染的反渗透膜的污染和清洗摘要：被模拟的混合有机废水污水污染反渗透膜的结垢和随后的清洗已经有了系统的研究。

有机污染研究包括海藻，牛血清白蛋白（BSA），萨旺尼河天然有机物，与辛酸,分别代表多糖、蛋白质、腐殖酸和脂肪酸，在出水有机物中它们是无处不在的。

建立了存在或缺乏钙离子的混合有机污染物的结垢行为和机制后，我们的研究集中在被有机污染物质的混合物污染的渗透膜的清洗机制。

化学清洗剂代理包括碱（氢氧化钠），金属螯合剂（乙二胺四乙酸），阴离子表面活性剂（十二烷基硫酸钠），和浓缩盐溶液（氯化钠）。

具体来说，我们研究清洁剂型，清洁液，清洗时间，和结垢层组成对膜清洗效率的影响。

在有机污染物质的混合物污染的污染膜的的条件下模拟的化学清洗的调查时，粘附力值测量值提供了深入了解化学清洗机制。

结果表明，在单用碱性溶液（氢氧化钠）不能有效的破坏含钙有机污染形成的配合物，较高的pH值会导致有效的清洁，如果有足够的流体剪切力（由横向表面流提供）存在。

表面活性剂（十二烷基硫酸钠），一个强大的螯合剂（乙二胺四乙酸），和盐溶液（氯化钠）可以有效的清洗混合污染的反渗透膜，尤其是如果应用在高pH值和更长的清洗时间。

观察各种清洁剂的清洗效率均符合相关测量–分子间力值值。

此外，我们已经表明，最佳的清洁剂浓度可以从绘制的还原百分比–粘附力的值与清洗剂浓度的对比中推出。

1 景区简介全球范围对饮用水需求的增加，选择水源满足这一需求的方式从传统的来源，如水库、湖泊，转换到较常规来源，如污水二级污水处理。

为生产优质用水，使用膜进行海水淡化和废水回收已应用的更广泛。

膜污染是利用膜技术等应用的一个主要障碍，因为污染是不可避免的。

尽管努力研究开发更好的防污膜[和改进控制方法策略，膜污染仍随时间发生。

因此，长期解决办法是通过化学清洗清除沉积膜。

在废水中，回收为了选择适当的清洁剂和采用有效的化学清洗规程，必须了解废水排放特性的对膜污染的影响。

给排水专业英语中文2

从生长动力学方面比较苯酚丝代谢酶的突变体cutaneum R57的改良退化能力1 。

导言苯酚及其各种衍生物，以及许多其他芳香族化合物，被称为有害污染物。

它们可以在污水炼油厂，煤炭和化学工业中发现。

在污水处理中，除了物理和化学方法，用生物方法清除苯酚及其各种衍生物发挥着重要作用。

苯酚不容易降解，并且在足够高的浓度时对大部分种类的微生物是非常有害的。

即使那些物种有利用它作为底物促进发展的代谢能力，苯酚也能抑制他们的增长率。

水性酚醛废物已作为敏感的波动酚醛负荷在活性污泥的研究中研究多年。

各种苯酚降解微生物为了创新和改进工艺的生物的降解工艺已被广泛的研究。

一些原核微生物的研究已经开展了。

只有一些微生物如：假丝酵母属， Rodotorula ，并丝，可将酚类化合物作为唯一碳源和能源来源代谢。

目前人们在，有毒物质的微生物降解和有毒物质在废水处理设施抑制碳源方面给于了极大关注。

在合理浓度条件下的培养基上模型的生长观测中，苯酚一直是人们研究最为广泛的芳香分子。

可以在有毒化合物条件下保持特定生长率的微生物细胞，似乎受到培养基的双重控制。

在培养基上特定生长率μ呈上升趋势（莫纳德型的关系），但μ也往往由于加强抑制作用的S 的浓度增加而减少。

各种运动的关系被提出来试图描述μ的S 为底物和S 作为抑制剂中联合与依赖的关系。

有毒化合物的处理过程的影响是关于量化方面的抑制系数，Ki 。

霍尔丹方程，其中涉及特定生长率（ μ ）的浓度的苯酚，并考虑到最大的特定生长率（ μmax ）和衬底亲和力（Ks ）和抑制（Ki ）常数：2max s i =[phenol]/(K + [phenol] + [phenol]/K )μμ该方程经常被用来形容这种抑制作用。

属Trihosporon 代表组成的微生物类群有着一套独特的酶的能力，好氧生物能降解包括unsubstituted 苯酚的各种有机化合物。

第一步是在有氧情况下以邻苯二酚苯酚羟化酶代谢苯酚羟基。

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Unit 12水的净化水分子是没有记忆的，所以去讨论你所喝的水是被污染了并净化了多少次是可笑的（市没有意义的），好像水分子逐渐厌烦了（逐渐被耗尽了）。

最重要的是你喝的水纯度如何。

对水的净化方法已发展到了很详细并且尖端的技术。

然而通常采用的净化水的方法对水污染的性质的通常的理解应该是容易理解的，并在某些情况下是显而易见的。

水中的杂质可分为悬浮的，胶体态的或溶解态的。

由于悬浮的颗粒大足以被沉淀或被过滤掉。

胶体态的或溶解态的杂质较难以去除掉。

去除他们的一个可能的方法是以某种方法把这些微小的颗粒物结合成比较大的颗粒然后采用去除悬浮物的方法来处理。

另一种可能的方法是把他们转变为气态然后是他们从水中散发到大气中，无论采用哪一种方法，有一点必须记住的是提升水或用泵将水输送通过滤床都需要能量。

根据这些原则，来考虑用于净化城市污水的步骤。

第一步是废水的收集系统。

从家庭、医院、学校排放的水中的污染物包含食物残渣、人类排泄物、纸张、肥皂、洗涤剂、污垢、织物和其他混杂的残骸，当然还有微生物。

这些混合物被称为厕所污水或生活污水。

这里Sanitary 这个形容词比较不恰当，因为它几乎没有描述污水的情况，他只笼统地指人产生的污染物被污水管所排走）。

这些污水，有时与污水管网中从商业建筑来的污染物、工业污染物及雨水污染物合流。

有些体系把污水与雨水分流而有些是合流。

合流制的管道便宜，并在旱季时是合理的，但在暴雨期时的总流量容易超过处理厂的容量，结果应允许有些水溢流而直接进入受体河流中。

初级处理当污水进入处理厂时，首先通过一系列的格栅以去除其中大的物体如老鼠或葡萄柚，然后通过一个磨碎装置以便把剩余的物体的大小减小至足够小以至在后续的工艺中可以有效的处理。

下一步是一系列的沉淀室来去除重的粗沙例如雨水冲刷路面带入的沙粒，然后其他悬浮的固体（包括有机营养物）缓慢的沉淀而得到去除，这个过程需耗时大约一小时。

从开始到这个过程的整个工艺称为处级处理，这一级处理的费用相对低，但是没有完成多少任务。

二级处理接下来的一系列步骤是企图通过某些强化的生物作用来减少大部分溶解态或细小的悬浮有机物质。

分解有机物需要氧气和生物体及有利于提供营养的环境。

可达到上述目的的一个装置是滴滤池。

在此装置中，石头滤床上布有回转布水器，以便把污水（均匀的）连续的分布。

当污水以水滴流过石头滤料时，在有氧的情况下向大量的没有驯化过得生物体提供了营养。

另一种方法是活性污泥法。

在这里，污水在经过初级处理后被泵到一个曝气池中，然后与空气及含有细菌的污泥混合几个小时。

在活性污泥法中进行的生物反应与滴滤池中的相似。

污泥中的细菌代谢有机物；而作为二级消费者的原生动物以细菌为食。

经二级处理过的水流入沉淀池，在那里进行充满细菌的污泥沉淀下来然后回流到反应器中。

并且为了操持稳定必须去除掉一部分污泥。

与滴滤池相比活性污泥法所需的土地面积小，并且由于活性污泥法暴露于空气的面积小结果他发出的臭味也比滴滤池的少。

从生物处理过的出水仍然含有细菌，不宜于排放入地表水，更不用说排放入水源地。

既然微生物已经完成了任务，现在可以把他们杀死了。

所以最后的步骤是进行消毒，通常采用氯来处理。

在处理水最后排放前把氯气通入15分钟，这样可以杀死99%的有害的细菌。

三级处理或高级处理尽管污水经过初级处理和二级处理后已经在很大程度上得到了净化，但对有些复杂的水污染来说仍然不够。

第一在生活污水中的许多污染物没有被去除掉，并且一些硝酸盐和磷酸盐等无机离子仍然留在处理过的水中，正如我们知道的，这些污染物作为植物营养物，是造成富营养化的因素。

1.絮凝沉淀在讨论生物处理前提到过把细小的颗粒物转变为大的颗粒有利于他们的快速沉淀。

对无机污染物来说也是如此。

许多无机胶体颗粒是亲水性的，他们比较易于吸附于水分子；在他们吸附于水分子过程中又会席卷许多其他胶体颗粒从而不容易在合理（较短的）时间内沉淀下去。

2.吸附吸附是指气体分子或液体粘着于固体颗粒表面的现象。

这个过程对某一给定的固体来说对不同的分子的吸附是有选择性的。

在净化水时，选择有较大表面的并且易于吸附有机污染物的固体的必需的。

常用的吸附剂是活性炭，特别对那些产生难闻气味的化学物质有效，这些物质包括难以生物降解的氯代烃。

3.其他氧化剂高锰酸钾和臭氧已被用来氧化水中的不易被存在于水中的微生物在有氧的条件下氧化的污染物。

臭氧有着显著的优点因为它的产物只有氧气。

4.反向渗透渗透是指水可以通过膜而其他溶解性的离子却不可以通过。

在膜的正常过程中，该体系趋向于使膜的两侧的浓度达到平衡。

这意味着水会从纯水这一侧流向污水一侧（相对来说污染物多水浓度低），而这是我们不愿看到的结果，因为这样会增加污水的量。

如果在污水一侧施加超过正向动力的压力，水分子的流动方向会改变，污水中的水分子会挤过膜进入另一侧而使溶解态的离子及其他污染物得到分离。

专业英语Rapid advances in technology for the treatment of water and the partial treatment of wastewater took place in the developed countries over the next few decades.——接下来的几十年里，在发达国家对给水的处理和废水的部分处理方面的技术得到了快速发展。

This led to a dramatic decrease in the incidence of waterborne diseases.——这样就大大减少了水传染病的发生率。

Note that all wastes discharge into the environment, and thus pollute our water, air, and land systems.——我们应注意到排放到环境的所有废物会对我们的水、大气和土壤系统造成污染。

Reading Material: Studying the Environment（让我们来）思考一下在地球上人类的状况，我们称地球这个行星为我们的家。

在过去，大多数人的生活艰难并且寿命短。

而在20世纪初，由于医学、农业和工业技术的快速发展，好像给每个人一种希望——可以很快就能活得更长，有相当好的食物，有令人满意的工作和足够的住房。

但这个希望还没有实现。

在1982年，地球上有50亿人。

有四分之一的人有更长的寿命并过着奢侈的在一百年前认为是不可能的生活。

但与此同时，有四分子三的人没有足够或令人满意的水和住所，并且有三分之一以上的人营养不良并忍受着饥饿。

有史以来在1982年饿死的人最多。

大多数饿死的人住在极度贫穷的发展中国家。

但在20世纪末的今天，富有的国家也处于困境。

据大多数估计最有权威的估计，北美和西欧的平均生活水平最高的年份大约是在1967年。

即使是最富有的国家, 燃料、硬木和一些矿物也快耗尽了。

结果，一些如住房、食物燃料等必需品花费了越来越多的家庭预算，从而剩不下多少可以用于享受奢侈生活。

污染物质污染了城市、城镇甚至乡村环境。

无论我们多么的富有，污水或水中有毒的杀虫剂、充满烟雾的大气和街道或公园里的垃圾降低了每个人的生活水平。

日益增长的大量的人口对地球上的农业用地、矿物、水和燃料资源的消耗速度大于自然过程再生这些资源的速度。

这本身是很严重的问题。

但由于这些资源并不是均匀分布，所以在全球来说这个问题更严重。

生活在发达国家的那些四分之一的人利用了80％的（一年中）全人类消耗的资源。

而另外四分子三的人只消耗了20％的资源。

并且富人与穷人之间的差距越来越大。

今天，当即使在最偏远的非洲村庄也有晶体管收音机时，世界上的穷人知道他们是多么的贫困。

这种认识导致了政治上的不稳定。

多年前，一个国家的政治剧变与世界上其它国家没多大影响。

但时代发生了改变，因为现代技术基本上使所有拥有武器的国家可以破坏远远大于它们自己本土范围的领域。

结果，没有任何一个国家能忽略其它国家的问题。

Classifying Environmental Problems环境问题的分类环境问题往往是互相联系的。

有时对一个问题的解决却会造成另一个问题。

例如，当人生病并因病而死亡，很自然的我们想改善人体健康问题。

而当健康得到改善、幼儿死亡率降低后，结果可能导致人口爆炸。

——为了给日益增长的人口提供食物，经常把自然界动植物的生活环境变为农田，结果破坏了生态环境——而当动植物生活环境被破坏时，曾经生活在那里的野生植物、食肉动物和及其寄生物也会被消灭掉。

而由于缺少食肉动物及其寄生物，经常会使有害昆虫爆发成灾。

农夫使用杀虫剂来杀灭害虫保护农作物，但在这个过程中环境被污染。

而这个循环过程本身消耗了日益减少的化石燃料。

另外，当燃料在燃烧时产生了大气污染物。

（漏了一段）（a）Overpopulation人口过剩。

人口过剩可以定义为在给定的面积上的人超过了该土地可以维持的人数。

许多人争辩说发生在20世纪的人口爆炸，是目前我们面临的最重要的问题。

它之所以重要，首先是因为人口过剩是导致所有其它环境问题的根源：如果人少的话，将利用较少的石油，砍伐较少的树木并向河流倾倒更少的污水。

第二，人口过剩和饥饿及其附带问题通常在我们的重点考虑问题的表中比其它环境问题严重。

当一块土地可以用来种植作物避免我们的同类饿死时，很难说服人们认为该土地应该保留为公用场地来保护正在消失的森林或大草原.（b）Pollution污染。

污染指由于杂质的引进使环境的质量下降。

烟雾污染大气，污水污染水体，废旧汽车污染土地。

我们知道这些污染存在于环境中，它们能被看见，闻到或甚至感受到。

然而污染对人体健康或经济的影响，在相当程度上是不同的。

这里有两种截然不同的污染类型。

1. Concentration of Organic Wastes.有机污染物的累积所有活的生物都产生废物，也就是说废物是伴随着生物活动产生的。

当生物死亡后整个生物体变为废物。

.在现代文明以前，大多数有机废物在环境中没有积累起来，因为它们可以被其它生物分解掉，然后进入循环。

在现代，有机废物的自然分解并不总能有效的进行。

2.Introduction of Synthetic Chemicals into the Environment.向环境中引进的合成化合物：所有的东西都是由化学物质组成的——例如人、鹰、树、湖、塑料等。

尽管许多天然的化合物已经存在了几十亿年，直到最近人类才学会去制造新的化合物即合成化合物。

新的合成化合物的数量及种类以惊人的速度增长。

它们存在于颜料（涂料）、染料、食品添加剂、药剂、杀虫剂、肥料、耐火剂、建筑材料、衣物、清洁剂（洗液）、化妆品和塑料制品等等。

合成化合物以其性质多样性而闻名。

这些化合物中一些是药品每年可以救治几百万人的性命，另外一些是毒药。

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