1、Unit 10 Wastewater CharacteristicsHang XuHenan University of Science and TechnologyWastewater parameters provide a yardstick by which to assess the physical,chemical,and biological characteristics of wastewater.废水水质参数提供了衡量废水的物理、化学和生物特废水水质参数提供了衡量废水的物理、化学和生物特性的标准。性的标准。Meeting these parameters before d
2、ischarge ensures the wastewater released into surface waters presents no chance of harm or disruption to the environment or to humans within a wide range of water uses.在废水排放之前满足这些参数可以确保排放到地表水在废水排放之前满足这些参数可以确保排放到地表水中的废水在出现大范围用水时不会对环境或人类造成中的废水在出现大范围用水时不会对环境或人类造成危害。危害。1 Physical Wastewater Characterist
3、ics 废水的物理性质废水的物理性质1.l Solids in Water(1)废水中的固体颗粒Solids removal is of great concern in wastewater treatment.Suspended materials provide adsorption sites for biological and chemical agents,and give microorganisms protection against chlorine disinfectants.固体颗粒的和化学试剂提供吸附点位，保护微生物免受氯消毒剂作用影响去除在废水处理中是非常关键的。
4、悬浮固体为生物。Solids can be either suspended or dissolved in water,and are classified by their size and state,by their chemical characteristics,and by their size distribution.固体可以悬浮或溶解在水中，并且可以通过它们的尺寸、状态、化学特性以及它们的尺寸分布来进行分类。These solids consist of inorganic or organic particles,or of immiscible liquids such
5、 as oils and greases.这些固体由无机或有机颗粒组成，或不混溶液如油和油脂组成。Human water uses contribute other suspended materials.人类用水导致其他悬浮物质的产生。Large quantities of suspended solids(mostly organic in nature)are found in domestic wastewater.生活废水中存在大量悬浮固体（主要是有机物）。生活废水中存在大量悬浮固体（主要是有机物）。Industrial water use can add a wide variet
6、y of either organic or inorganic suspended impurities.工业用水中添加了各种各样的有机或无机悬浮杂质。工业用水中添加了各种各样的有机或无机悬浮杂质。The level of suspended solids(SS)is an important water quality parameter for wastewater treatment.悬浮固体（悬浮固体（SS）的水平是衡量废水处理的重要水质参数。）的水平是衡量废水处理的重要水质参数。It is used to measure the quality of the wastewater
7、influent,and to measure the quality of effluent.它可以用来衡量污水进水及出水的水质。Most treated wastewater discharges must meet a maximum suspended solids standard of 30 mg/L.大多数处理过的废水排放必须满足小于30 mg/L的最大悬浮固体标准。1.2 Turbidity(2)浊度浊度Clarity of water is usually measured against a turbidity index.水的澄清度通常用浊度来衡量。Insoluble p
8、articulates scatter and absorb light rays,impeding the passage of light through water.不溶性颗粒可以散射和吸收光线，阻碍了光通过水。Industrial and household wastewaters often contain many different turbidity producing materials(detergents,soaps,and emulsifying agents).工业和家庭废水通常含有许多能够产生浊度的物质（洗涤剂，肥皂和乳化剂）；这些是常见的的废水成分。In wast
9、ewater treatment,whenever ultraviolet radiation(UV)is used in for disinfection,turbidity measurements are essential.在废水处理中，每当使用紫外线辐射（UV）进行消毒时，浊度测量是必不可少的。1.3 Color(3)色度色度Color is not a common concern for wastewater treatment.颜色在废水处理中不是一个时常关注的参数。Ideally,wastewater early in the waste flow is a light br
10、ownish gray color.理论上，早期的废水流是浅棕灰色的。The flow becomes increasingly more septic as travel time through the collection systems increases,and as more anaerobic conditions develops.随着收集系统中废水行进时间的增加，并且随着更多的厌氧条件的发展，废水变得越来越不干净。As this occurs,normal color of wastewater changes from gray to dark gray and then
11、to black.当这种情况发生时，废水的颜色从灰色变为深灰色，然后变为黑色。1.4 Odor(4)气味Odor is an important problem in wastewater treatment.Most urban treatment plants physically cover odor source areas(treatment basins,clarifiers,aeration basins,and contact tanks).气味在废水处理中是一个重要的问题，大多数城市污水处理厂实际覆盖气味源区域（处理池、澄清池、曝气池和接触池）。However,these c
12、ontained spaces can cause problems with toxic concentrations of gas.So the units must be vented to wet chemical scrubbers to prevent toxic gas buildup.然而，这些封闭的空间中含有一些有毒的气体,因此这些单元必须在湿的化学洗涤器中进行，以防止有毒气体积聚。1.5 Temperature(5)温度Temperature can play an important role in how efficiently wastewater unit trea
13、tment processes perform.温度在废水单元处理过程的效率方面发挥重要作用。Biological wastewater treatment systems are generally more efficient at higher temperatures.生物废水处理系统通常在较高温度下更有效。Temperature affects how quickly and effectively chemicals dissolve and chemical reaction times as well.温度影响化学物质溶解的速度和效率以及反应时间。However,summer
14、heat increases chlorine demand,and promotes algae and microbial growth.然而，夏季温度的升高，也增加了氯的需求，同时促进了藻类和微生物生长。2 Chemical Wastewater Characteristics废水的化学性质2.1 Total Dissolved Solids(1)总溶解性固体Solids in water occur either in solution or in suspension.水中的固体以溶液或悬浮液形式存在。The solids in the water that would remain
15、 after filtration and evaporation as residue are called total dissolved solids(TDS).总溶解固体或TDS是经过滤和蒸发的残余物。Dissolved solids can be removed from water by filtration and evaporation,and also by electrodialysis,reverse osmosis,or ion exchange.可以通过过滤、蒸发、电渗析、反渗透或离子交换法从水中除去溶解的固体物质。A routine solids test used
16、 in wastewater treatment to determine the efficiency of the treatment process is the measurement of settleable solids.在废水处理中用于确定处理效率的常规方法是检测可沉淀固体。2.2 Metals(2)金属含量Metals in wastewater(heavy metals such as cadmium,copper,lead,zinc,mercury,and others)are of high concern because they are often toxic to
17、 humans,and can be extremely harmful if discharged to the environment.废水中的金属（重金属如镉、铜、铅、锌、汞等）是人们高度关注的问题，因为它们对人体有毒，如果排放到环境中会非常危险。Metals in sufficient concentrations will kill microorganisms in the activated sludge process.足够浓度的金属将会在活性污泥法中杀死微生物。Industrial wastes with high levels of toxic metals or orga
18、nic substances can contaminate sewage biosolids,thereby limiting biosolids disposal options and raising disposal costs.具有高水平有毒金属或有机物质的工业废物可能会污染污水中的污泥，从而限制生物固体的处置选择方式，并且会提高处理成本。2.3 Organics(3)有机物Organics often present in wastewater include proteins,lipids(oil and grease),carbohydrates,and detergents.
19、废水中的有机物主要包括蛋白质、脂质（油和油脂）、碳水化合物和洗涤剂。About 30%of this organic matter are not biodegradable.大约30%以上的有机物是不能生物降解的。The microbes that function in some biological treatment processes that rely on microbial decomposition consume dissolved oxygen(DO).在一些依赖于微生物分解的生物处理过程中发挥作用的微生物会消耗水中的溶解氧（DO）。This demand for oxy
20、gen is called the biochemical oxygen demand(BOD).对氧的需求称为生化需氧量（BOD）。BOD levels are measured by tests that determine how much DO aerobic decomposers use to decay organic materials in measured amounts of water held at 20C over a 5 day incubation period.BOD水平是通过测试测定好氧分解者在5天的潜伏期内，在68F(20C)下测定的水中使用多少来降解有机
21、物质来测定的。2.4 Inorganics(4)无机物Several inorganic constituents affect wastewater treatment.有几种无机的成分会影响废水处理。pH,chlorides,and nutrients including nitrogen and phosphorous,sulfur,toxic inorganic compounds,and heavy metals influence treatment processes.pH值、氯化物和营养物（包括氮和磷、硫、有毒无机化合物和重金属）会影响废水处理过程。The pH value i
22、ndicates the intensity of acidity or alkalinity in wastewater,and affects biological and chemical reactions.pH（氢离子浓度）表示废水中的酸碱度的强度，它会影响生物和化学反应。Chloride(a major inorganic constituent in wastewater)generally does not cause any harmful effects on public health.氯化物（废水中的主要无机成分）一般不会对公众健康造成任何有害影响。Chloride c
23、oncentration of wastewater is higher than raw water from sodium chloride,which commonly passes unchanged through the human digestive system.废水的氯化物浓度高于来自原水中的氯化钠（盐）的浓度，一般情况下通过人体消化系统后不发生变化。The nutrients of greatest concern in wastewater treatment are nitrogen and phosphorous.在废水处理中最受关注的营养物是氮和磷。Other nu
24、trients include carbon,sulfur,calcium,iron,potassium,manganese,cobalt,and all-boron essential to the growth and reproduction of plants and animals.其它营养素包括对植物和动物的生长和繁殖必需的碳、硫、钙、铁、钾、锰、钴和硼。3 Biological Wastewater Characteristic废水的生物性质3.1 Bacteria(1)细菌Bacteria are fundamental to several wastewater treatm
25、ent unit processes,especially those responsible for degradation of organic matter.细菌是多种废水处理单元过程的基础，特别是在有机物质降解工艺中。These include processes that occur in trickling filters,activated biosolids processes,and biosolids digestion.这些过程包括发生在滴滤池的活化生物固体过程和生物固体消化过程。These bacteria must be controlled,however.Exce
26、ssive growth of some species of ordinarily useful bacteria can reduce treatment efficiency.然而，这些细菌必须加以控制。一些有用的细菌（例然而，这些细菌必须加以控制。一些有用的细菌（例如，丝状体丝状菌（如，丝状体丝状菌（Sphaerotilus natans），丝状），丝状生物体）的过度生长可以降低处理效率。生物体）的过度生长可以降低处理效率。Bacterial presence in effluent must also be controlled.同时出水中的细菌浓度也需要控制。Words and E
27、xpressionyardstick ja:dstk n.衡量标准，准绳characteristics krktrstks n.特征，特点microorganism makr;gnzm n.微生物disinfectant dsnfektnt n.消毒剂immiscible liquid 相互不溶液体suspended solid 固体悬浮物turbidity t:bdti n.浊度emulsifying agent 乳化剂ultraviolet radiation 紫外线anaerobic condition 厌氧条件wet chemical scrubber 湿式化学洗涤器algae ldi
28、:n.藻类total dissolved solid 溶解性总固体activated sludge process 活性污泥过程lipid lpd n.类脂，脂质carbohydrate k:bhadret n.碳水化合物detergent dt:dnt n.洗涤剂，去垢剂，洗衣粉biodegradable badgredbl adj.可生物降解的dissolved oxygen 溶解氧biochemical oxygen demand 生化需氧量phosphorous fsfrs adj.含磷的sodium chloride 氯化钠digestive dadestv adj.消化的potas
29、sium ptsim n.钾manganese mni:z n.锰all-boron 全硼trickling filter 滴滤池biosolids digestion 污泥消化viruses varsz n.病毒eutrophication ju:trfken n.富营养化facultative pond 兼性塘protozoa prtz n.单细胞生物parasitic prstk n.寄生的3.2 Viruses(2)病毒Viruses are also a frequent concern in wastewater treatment.病毒在废水处理中也时常受到关注。Viruses
30、must have a host to live and reproduce.病毒必须有一个宿主来生存和繁殖。Because of their ability to remain dormant until an appropriate host ingests them,viruses that reenter the water supply from wastewater effluent can cause problems for downstream water use.它们能够保持休眠直到合适的宿主摄取它们，所以病毒进入废水会对下游用水产生影响。3.3 Algae(3)藻类Alg
31、ae are found in wastewater,as well as in fresh water,saltwater and polluted water.藻类存在于废水中，以及淡水，盐水和污水中。Since most algae need sunlight to live,they only grow near the water surface.They use oxygen and produce carbon dioxide at night.由于大多数藻类需要阳光才能生存，所以它们只在水面附近生长。它们在夜间里消耗氧气和产生二氧化碳。A large amount of alg
32、ae growth also increases the level of suspended solid concentration in the water,resulting in eutrophication.大量的藻类生长也会提升水中悬浮固体浓度的水平，造成富营养化。Algae play an important role in some kinds of wastewater treatment stabilization ponds.藻类在一些种类的废水处理稳定池中起重要作用。In aerobic and facultative ponds,algae(through photo
33、synthesis)often supply the oxygen needed for microbial breakdown of wastes,and,in turn,use the waste products the bacteria and other microbial life leave behind as a food source which is a natural,inexpensive,and simple way to remove wastes.在需氧和兼性池塘中，藻类（通过光合作用）经常提供废物的微生物分解所需的氧气，并且反过来使用细菌和其他微生物通过生命活动
34、分解的废物作为食物来源，这是一种天然的、廉价的和简单的废物处理方法。3.4 Protozoa(4)原生动物Protozoa are the simplest animal species,widely distributed and highly adaptable.原生动物是最简单的动物物种，分布广泛，适应性强。Mobile,single-celled,completely self-contained organisms,some protozoa are free-living,while a few others are parasitic.它们是移动的，单细胞的，完全自给的生物体，一些原生动物是自由生活的，而另一些是寄生的。Protozoan populations are an essential part of activated sludge treatment processes.原生动物种群是活性污泥处理过程的重要组成部分。
