water treatment technology--1

HOMESewage treatment technologies(wastewater treatment)The wide spectrum of available technologies for the design of sewage treatment plants.The design of sewage treatment plants (also called "wastewater treatment plants") includesseveral treatment units, typically:1.Pre-treatment: one or more units for the physical separation of gross solids (sand,litter) and flotables (FAT, oil and grease, etc.).2.Biological treatment: one or more types of biological reactors in series.3.Clarification, disinfection and post-treatment of treated wastewater (when required).4.Sludge treatment (some sewage treatment plants do not require sludge treatment).There exist numerous types of biological reactors for sewage treatment.They can be classified according to:Process biochemistry:∙Aerobic process (e.g., activated sludge, wastewater maturation ponds, trickling filters, high-rate stabilization ponds).∙Anaerobic process (e.g., anaerobic ponds, UASB-Upflow Anaerobic Sludge Blanket reactors).∙Facultative process (or mixed) (e.g., facultative ponds, some constructed wetlands, wastewater reservoirs).Process intensity:∙Intensive reactors (e.g., activated sludge, UASB anaerobic reactors, high-rate trickling filters).∙Super-Intensive reactors (e.g., membrane reactors, activated sludge combined with fixed biomass).∙Extensive reactors (e.g., waste stabilization ponds, wastewater reservoirs, SAT-Soil Aquifer Treatment, constructed wetlands, macrophyte ponds).∙Semi-intensive reactors (e.g., anaerobic ponds, low-energy aerated lagoons, low-rate trickling filters, high-rate stabilization ponds).Operational regime:∙Continuous flow reactors (e.g., continuous flow activated sludge, UASB type anaerobic reactors, trickling filters, stabilization ponds, constructed wetlands,macrophyte ponds).∙Sequential batch reactors - SBR (e.g., sequential batch activated sludge, sequential batch wastewater reservoirs).∙Pulse reactors (e.g., some types of vertical flow constructed wetlands, intermittent sand filters).∙Perfectly mixed and plug-flow reactors.Biomass characteristics:∙Suspended biomass reactors (e.g., activated sludge, UASB type anaerobic reactors, stabilization ponds, aerated lagoons).∙Fixed biomass reactors (or biofilm) (e.g., tickling filters, SAT, constructed wetlands, macrophyte ponds, rock filters, intermittent sand filters).∙Combined biomass reactors.Selecting the best technology for wastewater treatment in a specific project.No one of the above technologies is definitely better than the others.Each one has its advantages and disadvantages regarding construction costs, operational costs, energy use, size, operation simplicity, stability, reliability, etc.Each one suits better to different specific conditions.One of the most difficult tasks in the conceptual design of a sewage treatment plant is the selection of the most appropriate technology for the specific conditions of the project.The designer should obtain an optimal combination of:∙High public health and environment protection.∙Low construction and operational costs.A proper conceptual design is a key element for the technical success of the project: good quality effluents, simple and reliable operation, low costs, low environmental impact.The present trend in Israel and many other countries is to move from the design of sewage treatment plants as an isolated event, towards design within the framework of regional environmental planning.The geographic unit defining a region is generally the catchment basin (watershed in American English). Thus, catchment basin planning based on wide public health and environmental considerations is substituting the relatively simple sewage treatment plant design as an engineering practice.The conceptual design of sewage treatment plants within the catchment basin framework goes beyond the classical engineering profession, and requires the involvement of a multidisciplinary team of professionals.Copyright ?2002-2008 Juanicó - Environmental Consultants Ltd. All rights reserved.如何用物理法处理污水？处理处理法就是利用物理作用除去污水的漂浮物、悬浮物和油污等，同时从废水中回收有用物质的一种简单水处理法。

常用于水处理的物理方法有重力分离、过滤、蒸发结晶和物理调节等方法。

重力分离法指利用污水中泥沙、悬浮固体和油类等在重力作用下与水分离的特性，经过自然沉降，将污水中比重较大的悬浮物除去；离心分离法指在机械高速旋转的离心作用下，把不同质量的悬浮物或乳化油通过不同出口分别引流出来，进行回收；过滤法是用石英沙、筛网、尼龙布、隔栅等作过滤介质，对悬浮物进行截留；蒸发结晶法是加热使污水中的水气化，固体物得到浓缩结晶；磁力分离法是利用磁场力的作用，快速除去废水中难于分离的细小悬浮物和胶体，如油、重金属离子、藻类、细菌、病毒等污染物质。

How physics sewage treatment. Handling sewage treatment is the use of physical action to remove floating objects, such as suspended solids and oil. Meanwhile useful substances from water waste a simple treatment method. Gravity methods commonly used in the treatment of the physical separation, filtration, evaporation and crystallization method and physical conditioning. Gravity separation refers to the use of sewage sediment, suspended solids and other oil-water separation under the force of gravity and the characteristics After Settlement, a large proportion of sewage to remove suspended solids; centrifugal separation refers to the high-speed rotating machinery centrifugal effect, different quality of suspended solids or emulsified oil exports through different drainage, and for recycling; Quartz sand filtration is used. mesh, nylon sheets, which features such as filter media, suspended for withholding; evaporation and crystallization of the sewage water is heated gasification. be concentrated and crystallized solids; Magnetic separation is to use the strength of the magnetic field, Fast wastewater difficult to remove suspended solids and colloidal small separation, such as oil, heavy metal ions, algae, bacteria, viruses and other pollutants.。