给排水专业英语课文翻译
给水排水专业英语翻译
《给水排水专业英语》Lesson 1specif ic yield[spə'sifik][ji:ld] 单位产水量mass curve累积曲线capita l investment投资recurring natura l event['nætʃərəl] 重现历史事件subter ranea n [sʌbtə'reiniən] 地下的ground water地下水surfac e water地表水tap [tæp]开关、龙头；在…上开空（导出液体）swampl and ['swɔmplænd] n. 沼泽地；沼泽地带capill ary [kə'piləri] n. 毛细管adj. 毛状的,毛细管的hygro- [词头] 湿（气），液体hygros copic [,haigrəu'skɔpik] adj. 易湿的，吸湿的hygros copic moistu re 吸湿水stratu m ['streitəm] n. [地质学]地层，[生物学]（组织的）层aquife r ['ækwəfə] ['ækwifə] n.含水层，地下蓄水层satura tion[,sætʃə'reiʃən] n.饱和(状态)，浸润，浸透，饱和度hydros tatic[,haidrəu'stætik] adj. 静水力学的,流体静力学的hydros tatic pressu re 静水压力watertable 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]Phreat ic surfac e [fri(:)'ætik]地下水（静止）水位，浅层地下水面Superf icial [sju:pə'fiʃəl] adj. 表面的,表观的，浅薄的Porosi ty [pɔ:'rɔsiti] n. 多孔性,有孔性,孔隙率Unconf ined ['ʌnkən'faind] adj. 无约束的，无限制的Permea bilit y [,pə:miə'biliti] n. 弥漫, 渗透, 渗透性Permea meter [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 depres sion[kəun] 下降漏斗, [水文学]下降锥体drawdo wn ['drɔ:daun] n. 水位下降(降落,消耗,减少)integrate ['intigr eit] 【数学】作积分运算；求积分observ ation well [,əbzə:'veiʃən] 观测井，观测孔extrac tion [ik'strækʃən] n. 抽出，取出，提取（法），萃取（法）deriva tion [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deplet e [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)unconf ined aquife r 潜水含水层，非承压含水层，无压含水层confin ed aquife r 自流含水层，承压含水层homoge neous [,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Aquacl ude 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sophis ticat ed [sə'fistik eitid] adj. 复杂的，需要专门技术的；诡辩的,久经世故的equili brium [,i:kwi'libriəm] n. 平衡,均衡WaterSupply（给水工程）A supply of wateris critic al to the surviv al 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》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。
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
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(全)
《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。
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。
给排水环工专业英语(华南理工大学)课文翻译下
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。
给水排水专业英语翻译上学期
第一单元水中的主要污染物Water briefiy水因含有过量的气态，液态和固态成分而被认为受到污染。
可能污染水的物质是列举不完的这里简要的讨论一些主要的污染物。
有机污染物Organic origin有机污染物是由来自农村及城市的生活污水和以动物和植物为原料的工业废水而产生的。
Although wastes虽然生活污水是可降解有机污染物最广泛的来源，但是工业也可以产生大约与其等量的此种污染物。
The waters最大的工业有机废物的制造者是食品和纸浆造纸工业，这些工业有众多生产厂家，其中许多厂家都将大量的有机废物排入水体。
One people一个甜菜加工厂在它主要的生产期内所产生的有机废物相当于一个拥有五十万人口的城市所排放的生活污水量。
The problem有机废物被细菌分解消耗水中的氧，进而产生严重的问题。
Since environment因为鱼类和水生物依靠溶解氧，而好氧有机物却破坏了这种水生环境。
When result当这种废物消耗过量的氧时，就会造成严重的腐化性污染状态。
活性物质Living disease活性物质能污染水的包括细菌，病毒和可以引起疾病的其它微生物。
These slaughter这些有机物可能通过生活污水或某些种类的工业废水进入水体，尤其是那些马制革或动物屠宰有关的工业而进入水体中。
Since environment虽然在世界上大多数发达国家引起伤寒和霍乱的细菌得到了有效的控制，但是在很多不发达国家仍然存在危险。
When result可能引起肠道或其它传染病的难以消灭的病毒会造成持续的水污染问题。
植物营养素Plant water刺激植物生长的植物营养素也是水的一种主要污染物。
The present在植物营养素当中两种最基本水污染元素是氮和磷，并且也存在其他的微量元素。
These nitrates这些元素在自然水中存在很少，绝大部分是由生活污水，某种工业污废水，土地施肥后的排水和含硝酸盐量高的地下层提供的。
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。
给排水环工 专业英语(华南理工大学)课文翻译 上
给排水环工专业英语(华南理工大学)课文翻译下Unit 1环境工程本书的内容：本书的目的是使工科和理科学生对环境问题的跨学科的研究有所了解：环境问题的起因，环境问题受关注的原因，如何控制环境问题。
本书包括如下内容：﹡对环境和环境系统而言环境问题含义的描述﹡关于造成环境破坏的基本原因的信息﹡要了解环境问题性质并且量化环境问题所必需的基本科学知识﹡环境控制技术在在水、大气和固废污染问题方面运用的现状﹡我们目前对人类活动与自然之间的许多复杂的相互关系的理解和控制的科学知识的严重不足﹡采用现有技术可以用来消除或减轻有许多环境问题，当实际上并没有，这是因为社会缺乏意愿去处理环境问题，或因为在许多情况下缺少处理环境问题所需的资源一些重要的定义当新词在这本书中第一次出现时，它的定义以正楷大写字母开头的形式给出（正如这里给出的）或以粗体字体给出。
﹡环境：是指我们周围的物理和生物生境，我们可以看到，听到，触到，闻到和感到这些事物。
﹡系统：根据韦氏字典，系统为相关和相联的一组或一系列事情形成一个单元或有机体，例如：太阳系，灌溉系统，供应系统和世界或宇宙。
﹡污染：可以定义为空气、水或土壤的物理化学或生物特性发生恶化以至于对人类或生物有机体的健康、生存或活性造成了危害。
当改善环境质量的目的是用来改善人体健康时，环境这个词的含义就拓宽到包括各种社会、经济和文化方面，但这样的拓宽对许多实际情况不可行的，对为一学期时间设计的课程而言是不现实的。
从而我们对环境问题调查时把环境的定义做了限制。
各系统间的相互作用与水、大气或土地系统来说有一些不同的相关环境问题。
而许多问题只是适用于其中的一个系统，正因为此这也说明了上述分类的合理性。
如此的分类还有利于更容易对一个系统内相关问题的理解。
并且从行政管理方面看也是合理的，因为政府机构经常把环境问题分为空气污染、供水、污水处理和固体废物处置几个方面来处理。
但有许多重要的环境问题并不局限于大气、水或土地系统中的某个单一系统，而是包含各系统之间的相互作用。
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 of4.0m 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 of23m/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。
给排水专业英语翻译
Particle-ParticleInteractionsParticle-particle interactions are extremely important in bringing about aggregation by means of Brownian motion .the theory that has been developed to describe particle-particle interactions is based on the consideration of interaction between two charged flat plates and between two charged spheres.As neither of these developments is directly applicable to the particles found in wastewater ,as described above,the analysis for two charged flat plates will be used for illustrative purposes.The two principal face involved are the forces of repulsion,due to the electrical properties of the charged piates,and the van der Waals forces of attraction.It should be noted that the van der Waals forces of attraction do not come into play until the two plates are brought together in close proximity to each other.The net total energy shown by the solid lines on Figure 3 is the difference between the forces of repulsion and attraction.The two conditions,with respect to the forces of repulsion ,are illustrated onFigure 3.as shown for conditions 1, the forces ofattraction will predominate at short and long distances.The net energy curve for condition 1containsa repulsive maximum that must be overcome if theparticles,represented as the two plates,are to be heldtogether by the van der Waals force of attraction.Incondition 2,there is no energy barrier toovercome .Clearly ,if colloidal particles are to beremoved by microflocculation,the repulsive force mustbe reduced.although floc particles can form at alongdistances as shown by the energy curve for condition1, the net force holding these particles together isweak and the floc particles that are formed can beruptured easily. Particle Destabilization with Potential-Determining Ions and ElectrolytesTo bring about particle aggregation through microflocculation,steps must be taken to reduceparticle charge or to overcome the effect of thischarge.the effect of the charge can be overcome by(1)the addition of potential-determining ions,which will be taken up by or will react with the colloid surface to lessen the surfaceto lessen chargeand(2)the addition f electrolytes,which have theeffect of reducing thethickness of the diffuse electric layer and, thereby,reduce the zeta potentialUse of Potential-Determining Ions.The addition of Potential-Determining ions to promotecoagulaion can be illustrated by theaddition of strong acids or bases to reduethe charge of metal oxides or hydroxides to near zero so that coagulation can occur.The effect of addingpotential-determining ions in a solution containing charged particles is illustrated on figure4.The magnitude of the effect will depend on the conc entration of potential-determining ionsadded.The f ollowing ratios,known as the Shultz-Hardy rule,can be used to assess theeffectiveness of potential-determining or counterions:1:1/2^6:1/3^6or100;1.6:0.13(3)It is interesting to note that depending on the concentration and nature of the counterions added,it is possible to reverse the charge of the double layer a nd develop a new stable particle.The effect of adding counterions to a solution containing charged particles is illustrated on Figure 5.The upper curve on Figure 5 represents the surface charge of the particle as a function of the concentration of counterions added .The lines designated kT represent the thermal kinetic energy of the particle .The lower diagram is a plot of the turbidity that would result if the particles that have been destabilized and have undergone microflocculation were removed by settling .As shown ,when the surface charge (either positive or negative)is greater than the thermal kinetic energy of the particles ,the particles will not flocculate and original turbidity is observed.Additional detail on the use of counterions may be found in Shaw(1966).The use of potential determining ions is not feasible in either water or wastewater treatment because of the massive concentration of ions that must be added to bring about sufficient compression of the electrical double layer to effect perikinetic flocculatin.Use of Electrolytes .Electrolytes can also be added to coagulate colloidal suspensions .Increased concentration of a given electrolyte will cause a decrease in zeta potential and a corresponding decreasein repulsive forces as illustrated in condition 2 on Figure 3 and on Figure 4.The concentration of an electrolyte that is needed to destabilize a colloidal suspension is known as the critical coagulation concentration(ccc).Increasing the concentration of an indifferent electrolyte will not result in the restabitization of the colloidal particles .As with the addition of potential-determining ions ,the use of electrolytes is also not feasible in wastewater treatment .As discussed subsequently ,a change in the particle charge will occur when chemicals are added to adjust the pH of the wastewater to optimize the performance of hydrolyzed metal ions used as coagulants.Particle Destabilization and Aggregation with Polyelectrolytes Polyelectrolytes may be divided into two categories :natural and synthetic .Important naturalpolyelectrolytes include polymers of biological origin and those derived for starch products such as cellulose derivatives and alginates .Synthetic polyelectrolytes consist of simple monomers that are polymerized into high-molecular-weight substances .Depending on whether their charge ,when placed in water ,is negative .positive ,or neutral ,these polyelectrolytes are classified as anionic ,cationic , and nonionic ,respectively .The action of polyelectrolytes may be divided into the following three general categories.Charge Neutralization .In the first category ,polyelectrolytes act as coagulants that neutralize or lower the charge of the wastewater particles .Because wastewater particle s normally are charged negatively ,cationic polyelectrolytes are used for this purpose . In this application ,the cationic polyelectrolytes are considered to be primary coagulants .To effect charge neutralization ,the polyelectrolyte must be adsorbed to the particle .Because of the large number of particles found in wastewater ,the mixing intensity must besufficient to bring about the adsorption of the polymer onto the colloidal particles .With inadequate mixing ,the polymer will eventually fold back on itself and its effectiveness in reducing the surface charge will be diminished .Further , if the number of colloidal particles is limited ,it will be difficult to remove them with low polyelectrolyte dosages .Polymer Bridge Formation . The second mode of action of polyelectrolytes is interparticle bridging (see Figure 6) .In this case ,polymers that are anionic (usually anionic to a slight extent when placed in water) become attached at a number of adsorption sites to the surface to the surface of the particles found in the wastewater .A bridge is formed when two or more particles become adsorbed along the length of the polymer .。
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℃。
给水排水工程及环境工程专业英语翻译
Unit5 A篇 Distribution systems（44）配水系统通常为住宅，商业，工业和消防系统设计，以达到满足对水需求相结合的目的。
在任何时候都应该达到令人满意的压力。
管道系统，抽水站，存储设施，消防栓，内部连接设备和其他附属设备是系统的主要组成部分。
配电系统通常可归类为网格系统，分支系统，或网格系统和分支系统的组合系统。
系统的结构主要取决于街道模式，地形，程度和当地区域的发展、位置的处理和存储工程。
图1示出了几种基本系统的性质。
网格系统的通常是优选的分支系统，因为它可以从至少两个方向上任何一点提供电力。
分支系统不能进行这种类型的流通，因为它有许多端子或死角。
一个网格或组合系统还可以将循环的馈线，从几个方向分发流量。
在一些会发生急剧变化的地形（丘陵或山区）的地方，它是用来划分成两个或多个服务区域或区域的常见分布系统。
在在海拔较高的低洼地区能保持合理的压力是一个难题。
通常的做法是各个系统互连，正常操作过程中互连后关闭阀门。
分配系统的特性可以通过用于给水量的压力来判定。
压力应该足够大用来满足消费者和消防的需求。
同时还不能过量，因为压力水头是重要的考虑因素。
此外，随着压力的增长，泄水量也增长，钱会被用于运输和处理产品而浪费。
因为在给水系统中的投资很大，经济设计的优化很重要。
给水系统中的水量是通过当地水的需求量再加上消防需求量。
管子的尺寸应该要避免高流速。
为了达到校方的需求，最小要选择直径为6的管子。
为了实现配水系统的水力设计，必须提供当地水的消耗率的预期，这些设计流量的方式，地理分布，和系统所需压力梯度。
应该再次强调，设计师应该调查的最高日用水率加防火和每小时的最大速率，以确定哪些管的设计。
消费的空间分布可以通过研究的人口密度，以及商业和工业用途的模型来确定或者预测改区域的估计。
学生们请注意，该区域的最大时用水量可能在住宅最大时的区域内，但不与商业或工业的最高值重合，反之亦然。
分配系统的分析通常是通过简化第一骨架的系统.这个可能涉及更换不同直径与当量管或更换与系统的当量管.当量管的管道系统的指定流速的水头损失与它所替换系统的水头损失是相同的。
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。
给排水专业英语Unit 6翻译
Unit 6供水系统水源的特性通常决定了取水构筑物的规划、设计和操作，以及净水、输水和配水构筑物。
被用于供给社区和工业用水的两种主要水源被称为地表水和地下水。
溪流、湖泊和河流属于地表水。
从水井中抽取的水源为地下水源。
表2-1描绘了一个用于服务一个小型社区的水资源系统的延伸。
每种情况下的水源决定了取水构筑物的和水处理构筑物的种类。
城市中的管网被称作配水系统。
这些管道本身通常被称作输水干管。
干管中的水压通常被保持在200-860kPa的范围内。
在低需水时段（通常是夜间）由水处理厂所输出的过量的水被储存在蓄水池中。
蓄水池通常会被提升（如随处可见的水塔）或者位于地表。
这些蓄水是用以应对白天的高需水时段的。
蓄水不仅能够补偿用水需求的变化，还使得小型水厂的建设成为了可能。
同时，蓄水还可以作为火灾突发时的应急用水。
人口和用水模式是控制大量用水需求的主要因素，同时他还决定着水源类型和水资源系统的整个组成部分。
选择一个合适的给水水源的首要步骤之一是确定它必须满足的供水量。
需水量的要素包括平均日用水量和最大用水量。
基于下述两个原因，必须对平均日用水量进行估算：（1）以确定地表水处于低流量或地下水水位降至最低高度的紧急时段，水源满足连续用水需求的能力；（2）以评估在上述紧急时段满足供水需求所需存储的水量。
在确定水泵型号和管道尺寸、压力损失以及在时段最高需水量时能够补给充足水量的蓄水需求量之前，必须先估算出最大用水量。
给水系统中的用水量受很多因素的影响。
例如，仅仅是有压力的水可充分供应这个事实，就常常刺激水过量适用于灌溉草坪、花园，清洗汽车、运行空调设备以及其他家庭和工业活动。
影响用水量的主要因素如下：1.工业活动2.水表3.管理系统4.生活水平5.天气以下因素同样在较小程度上影响着用水量：排水系统的发展程度、系统压力、水价和是否可以使用私人水井。
工业所带来的影响是使得人均用水量得到了增长。
小型乡镇以及城郊社区的人均用水量通常会低于工业化社区。
给排水专业英语蓝梅课文翻译第七单元
给排水专业英语蓝梅课文翻译第七单元
摘要：
一、引言
二、给排水专业英语的重要性
三、第七单元课文概述
四、第七单元课文翻译
1.蓝梅课文原文
2.蓝梅课文翻译
五、总结
正文：
一、引言
作为给排水专业的一名技术人员，掌握专业英语是非常重要的，它可以帮助我们更好地理解和交流专业技术知识。
本篇文章将为您提供给排水专业英语蓝梅课文翻译第七单元的内容。
二、给排水专业英语的重要性
给排水专业英语涉及到给水、排水、污水处理等方面的专业术语。
掌握这些专业英语词汇，有助于提高技术人员在实际工作中的沟通效率，同时也有利于技术人员查阅相关领域的专业资料。
三、第七单元课文概述
第七单元课文主要讲述了给排水系统中的井、井盖、井室等设施的英文表达方式，以及相关设备的安装、维护等方面的专业英语词汇。
四、第七单元课文翻译
1.蓝梅课文原文
（省略）
2.蓝梅课文翻译
（省略）
五、总结
通过本文的介绍，相信大家对给排水专业英语蓝梅课文翻译第七单元有了更深入的了解。
掌握这些专业英语知识，有助于提高我们在给排水领域的专业素养和实际工作中的沟通效率。
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。
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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.
Aeromonas
Aeromonas 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。
他们并没有因此特别从饮水与健康问题有关。
不过重要的是要意识到它们的存在,因为他们有时会与疾病有关,人们可能已经生病与其他条件或减少他们的免疫系统,无法应付(杜福尔1990)。
他们通常被称为环境细菌,但是我也遇到偶然的条款或异养在这种情况下(虽然异养严格意味
着他们得到的能源和细胞碳氧化的有机物质,也就是说,在植物或饲养比photosvnchesis animals-rather)。
实验室开展plare商榷的地方,通常这些细菌培养。
将会有许多不同类型的环境bacturia但imporiant下面列出的饮用水安全。
气单胞菌属
气单胞菌属在新鲜和常见盐水域。
有几个物种,每一个支持一个特定的环境。
气单胞菌属bydropbila发现主要在干净的河水,气单胞菌属sobria死水,气单胞菌属caviae在海洋水。
因为它们很常见,人们试图在河流的污染指标使用它们。
他们已知的导致腹泻和感染在软组织受损皮肤接触受污染的河流或湖泊的水。
气单胞菌属caviae是最常见的腹泻。
腹泻感染通常是温和的,虽然偶尔更严重的症状,包括出血性腹泻、慢性结肠炎(结肠炎症)。
气单胞菌属中发现了治疗氯化水,有时,有re-growth分布管道。
氯只有似乎暂时影响他们,这可能意味着,这会阻止它们繁殖但不杀死他们。
如果离开了(大概,这样他们就可以拿回自己的呼吸和休息有点氯后攻击)。