环境工程与科学专业英语

Unit 2The objective of this book is to introduce engineering and science students to the interdisciplinary study of environmental problems: their causes, why they are of concern, and how we can control them.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。Pollution can be defined as an undesirable change in the physical, chemical, or biological characteristics of the air, water, or land that can harmfully affect the health，survival，or activities of humans or other living organisms.污染可以被定义为有害影响健康，生存，活动的人或其它生物体的空气，水，或土地的物理，化学或生物特性的不应该有的变化。A current example is the acid rain problem stemming from the emission of sulfur dioxide and nitrogen oxide gases into the atmosphere from the stacks of generating stations, smelters, and automobile exhausts.目前的一个例子是酸雨问题，根源是许多发电站，冶炼，汽车排出的废气中进入大气的二氧化硫和氮氧化物气体。These gases are then transported by air currents over wide regions, Rainfall “washes them out”, creating acid rain which is harmful to aquatic life, forests, and agricultural crops.然后这些气体被气流运送到广阔的区域。雨水“将它们洗去”，产生了对水生生物，森林和农作物有害的酸雨。Both phenomena, urbanization and industrialization, were and are fundamental cause of water and air pollution which the cities of that time were unable to handle. 城市化和工业化的现象，在过去和现在都是引起水和空气污染的根本原因，这在当时的城市还不能够处理。This led to a dramatic decrease in the incidence of waterborne diseases. Note that all wastes discharge into environment, and thus pollute our water, air, and land system. 这导致水传染疾病的发生率大量地减少。注意，所有的废物排放到环境中都会污染我们的水、空气和土地系统。Unit 8Air pollution is normally defined as air that contains one or more chemicals in high enough concentrations to harm humans, other animals, vegetation or materials.空气污染通常是指那种包含一种或多种化学物质富集到高浓度并足以伤害人类、其他动物、植物或材料的空气。By themselves, measured concentrations tell us nothing about the danger caused by pollutants, because threshold levels, synergy, and biological magnification are also determining factors.通过测出的浓度自身并不能告知我们有关污染物所带来的危险的信息，因为临界浓度、协同作用还有生物放大效应都是决定因素。Unit 10The concept of using microorganisms for the removal of environmentally undesirable compounds by biodegradation has been well established in the area of wastewater treatment for several decades.这种利用微生物的生物降解作用去除环境中非期望的化合物的观念在数十年前已经非常好地建立在废水处理方面。Moreover, while bioremediation techniques are now being applied successfully for the treatment of soil and groundwater contaminated by synthetic organics, at present there is very little practical experience with biological systems for the control of air contaminants among environmental professionals in the US.而且，尽管生物治理技术在处理被人工合成化合物污染的土壤和地下水得到了成功的应用，现在，在美国环保专业人员中，生物学系统在控制大气污染物方面只有很少的实践经验。The principal reasons why biofiltration is not presently well recognized in the US, and has been applied in only a few cases, appear to be a lack of regulatory programs, little governmental support for research and development, and lack of descriptions written in the English language. 对于那些为什么生物过滤法如今在美国还不是很好地被认识和只应用于仅仅很少的一些情况的主要原因，可以认为是缺少控制的计划、来自政府对此技术研究和发展支持，更是缺少用英语写成的有关这些技术的文献。The major objective of the present paper is to provide a comprehensive review of important aspects of biofiltration in order to more widely disseminate about this innovative APC technology, and to encourage its implementation where appropriate in the US.现在这篇论文的主要目的是提供一个关于生物过滤的重要方面的全面综述来更广泛传播这种APC创新技术，并且鼓励它在美国适合的地方的实施。Their work included the successful installation of several soil filters at a wastewater treatment plant near Seattle and demonstrated that biodegradation rather than sorption accounted for the odor removal.他们的工作包括在西雅图附近的废水处理工厂中成功地安装几个固体过滤器并证明了生物降解对气味的去除作用比吸附作用更优越。While soil beds have been shown to control certain types of odors and VOC efficiently and at fairly low capital and operating cost, their use in the US has been limited by the low biodegradation capacity of soils and the correspondingly large space requirements for the beds. 虽然已经证实土壤床可用相当低的投资和操作费用来有效的控制某些类型的臭味和挥发性有机化合物，但是，土壤的低生物降解能力和相对大的占地要求限制了土壤床在美国的应用。Unit 11All of the examples identify local, observable, or measurable impacts, because it is very difficult to develop direct relationships between specific pollutants and effects for exposures over the longer term or at great distances.这部分例子被认为是局部的，可见的或可测量的影响，因为去建立特定污染物及其长期、大面积的暴露所造成的影响之间的直接关系是很困难的。Damage to vegetation due to chronic exposure to atmospheric pollutants may be one of the more apparent precursor symptoms leading to identification of chronic air pollution.长期暴露于大气污染物中的植被所遭受的破坏也许是用以识别空气长期污染的一种较明显的前兆。While the specific pollutant or groups of pollutants generating the observed effects frequently could not be identified, there was sufficient information to implicate certain pollutants as significant contributors.当这种特定的污染物或多种污染物产生的被频繁观测到的影响不能被确认时，就有足够的证据表明这些污染物是重要的促成因素。Fluorine also has an effect at even lower concentrations when it is taken up by shrubs, trees, or grass which is subsequently eaten by cattle or other animals.即使氟的浓度很低，被灌木，树木或草吸收，随后被牛或其他牲畜进食，也会对这些动物造成影响。The animals act as concentrators of the fluorine, resulting in poor animal health and associated lower animal value or survival capability.这些动物作为氟的集中者，会导致动物健康的变坏，以及动物自身价值和生存能力的降低。Sulfur and nitrogen oxides react in the atmosphere to form acidic compounds which attack metal surfaces, a problem which has been particularly acute for the communications, switchgear, and computer industries.硫和氮氧化物反应，在大气中形成酸性化合物攻击金属表面，这个问题特别严重的影响通信，开关，和计算机产业。Unit 12However, preservation of water resources, protection of fishing areas, and maintenance of recreational waters are additional concerns today. Water pollution problems intensified following World War II when dramatic increases in urban density and industrialization occurred. Concern over water pollution reached a peak in the mid-seventies.但是，保存水资源、保护渔业水域以及维护娱乐休闲用水现在引起额外的关注。二次世界大战，伴随着工业化和城市密度大幅度增加，加剧了水污染问题。在七十年代中期对水污染的关注达到了一个高峰。Pollution of our water resources can occur directly from sewer outfalls or industrial discharges (point sources)or indirectly from air pollution or agricultural or urban runoff(nonpoint sources).水资源的污染可能直接来自于下水道排水口或工业污水排放（点源）或者间接的来自空气污染或者农业以及城市径流（非点源）。Most of these microorganisms in wastewater are harmless and can be employed in biological processes to convert organic matter to stable end products. However, sewage may also contain pathogens from the excreta of people with infectious diseases that can be transmitted by contaminated water.这些废水中的微生物大部分是没有什么害处的，能应用在生物处理过程当中，把有机物质转化成稳定的终端产品。然而，污水也可能含有病原体，这些病原体来自具有传染病人群的粪便，最后通过被污染的水传播开来。To further categorize the residues, they are held at 550 for 15 minutes. The ash remaining is considered to represent inorganic solids and the loss of volatile matter to be a measure of the organic content.对悬浮固体（残渣）进一步分类，把它们放在550下灼烧15分钟。残留的灰分代表无机固体，挥发掉的物质的量可以表示有机物含量。VSS can be an indicator of the organic content of raw wastes and can also provide a measure of the active microbial population in biological processes.挥发性悬浮固体可以指示未处理废水中有机物浓度，也能测量生物过程中微生物种群的活性。In addition to these chemical constituents, the concentration of dissolved gases, especially oxygen, and the hydrogen ion concentration expressed as pH are other parameters of interest in wastewater.除了这些化学成分，溶解气体特别是氧气的浓度，以及氢离子的浓度也就是pH，是其他的衡量废水的指标。The sources of these biodegradable contaminants include excreta and urine from humans; food wastes from sinks; soil and dirt from bathing, washing, and laundering; plus various soaps, detergents, and other cleaning products.这类可生物降解的污染物主要来源于人类的粪便和尿液，水池中食品废物，沐浴以及洗衣服时产生的脏物，再加上各类香皂，洗涤剂，其他洗涤产品。TOC is determined by measuring the amount of CO2 produced when the organic carbon in the sample is oxidized by a strong oxidizer and comparing it with the amount in a standard of known TOC.总有机碳是这样测定的：把样品中的有机碳用强氧化剂氧化，测定产生的二氧化碳的量，并将它与已知TOC的标准样品进行比较和对照。Most of the other common methods are based on the amount of oxygen required to convert the oxidizable material to stable end products.其它常见方法是基于把可氧化物质转化成稳定的终端产品所需要的氧气的量。The COD, or chemical oxygen demand, of the wastewater the measured amount of oxygen needed to chemically oxidize the organics present; the BOD, or biochemical oxygen demand, is the measured amount of oxygen required by acclimated microorganisms to biologically degrade the organic matter in the wastewater.COD即化学需氧量，废水中有机物的化学氧化反应所需要的氧量。BOD，生化需氧量，指驯化的微生物分解水中有机物所需要的氧量。BOD is the most important parameter in water pollution control. It is used as a measure of organic pollution, as a basis for estimating the oxygen needed for biological processes, and as an indicator of process performance.BOD在水污染控制中是最重要的参数。可以用来衡量有机污染，可以作为估计生物过程所需氧量的基础，以及过程性能的一个指标。The oxygen consumed, or biochemical oxygen demand (BOD), is proportional to the organic matter converted, and therefore BOD is a relative measure of the biologically degradable organic matter present in the system.消耗的氧气或者叫生化需氧量，和要转化的有机物质是成正比例的，因此，BOD可以间接的测量系统中可生物降解的物质。Unit 14One possibility is somehow to make these small particles join together to become larger ones, which can then be treated as suspended matter.一种可能的方法是让这些小的颗粒结合在一起变成一个大的整体，这样可以像处理悬浮物质那样除去。The combined piping is cheaper and is adequate in dry weather, but during a storm the total volume is apt to exceed the capacity of the treatment plant, so some is allowed to overflow and pass directly into the receiving stream or river.雨污合流的管道比较便宜，而且在干旱的天气时也足够使用，但是当下暴雨的时候，水的总体积容易超过污水处理厂的处理能力，这样就容许一部分污水溢流，直接排到受纳的小溪和河流中。The next stage is a series of settling chambers designed to remove first the heavy grit, such as sand that rainwater brings in from road surfaces, and then, more slowly, any other suspended solids, including organic nutrients that can settle out in an hour or so.接下来是一组沉淀池，首先可以去除大的沙砾，比如路面上被雨水冲刷下来的路面的沙子。然后，更慢的是其他的悬浮固体包括有机营养物在一个小时左右沉淀下来。The next series of steps is designed to reduce greatly the dissolved or finely suspended organic matter by some form of accelerated biological action. What is needed for such decomposition is oxygen and organisms and an environment in which both have ready access to the nutrients. One device for accomplishing this objective is the trickling filter.接下来的一系列步骤是通过某种形式加速的生物活动大大减少溶解的或者细小悬浮有机物。这样的分解需要氧气和有机物，以及一个容易获取营养物质的环境。能够达到这一目的的一个装置是滴滤池。In this device, long pipes rotate slowly over a bed of stones, distributing the polluted water in continuous sprays. As the water trickles over and around the stones, it offers its nutrients in presence of air to an abundance of rather unappetizing forms of life.在这个装置中，长管在石床上缓慢的旋转，并持续的喷洒使污水散布。当水沿石缝滴落时，就给滤床上那些大量的让人相当倒胃口的微生物们提供了氧气和营养物质。The treated waters then flow to a sedimentation tank, where the bacteria-laden solids settle out and are returned to the aerator. Some of the sludge must be removed to maintain steady-state conditions.经过处理的水流至沉淀池，在这里充满细菌的固体沉淀下来，并回流到曝气池。一些污泥必须被去除，以维持稳态状况。Although considerable purification is accomplished by the time wastewaters have passed through the primary and secondary stages, these treatments are still inadequate to deal with some complex aspects of water pollution.虽然很多污水经过一级和二级处理之后被认为已经完成了净化，但是对于一些复杂的水污染，这样处理还远远不够。Various inorganic colloidal particles are waterloving (hydrophilic) and therefore rather adhesive; In their stickiness they sweep together many other colloidal particles that would otherwise fail to settle out in a reasonable time.各种无机胶体粒子都是亲水的，所以具有一定的黏附性；由于具有粘性，这些粒子和许多其他胶体粒子聚集在一起，这样就可以让本不能沉淀的它们在一定时间内沉淀下来。Adsorption is the process by which molecules of a gas or liquid adhere to the surface of a solid. The process is selective-different kinds of molecules adhere differently to any given solid. To purify water, a solid that has a large surface area and binds preferentially to organic pollutants is needed. The material of choice is activated carbon, which is particularly effective in removing chemicals that produce offensive tastes and odors. These include the biologically resistant chlorinated hydrocarbons.吸附过程就是指气体或者液体分子黏附在固体表面。这个过程是选择不同种类的分子黏附到任何特定的固体上。为了净化水质，需要表面积大，能优先粘合有机污染物的固体。首选的材料是活性碳，它能特别有效地去除产生令人不爽的口味和气味的化学物质，包括抵抗生物降解的氯化烃。Potassium permanganate (KMnO4) and ozone (O3) have been used to oxidize waterborne wastes that resist oxidation by air in the presence of microorganisms. Ozone has the important advantage that its only byproduct is oxygen.高锰酸钾和臭氧经常用来氧化水中的某些废物，这些废物不能被微生物利用空气氧化。臭氧具有最重要的优点是，它唯一的副产物就是氧气。 However, if excess pressure is applied on the concentrated side, the process can be reversed, and the pure water is squeezed through the membrane and thus freed of its dissolved ionic or other soluble pollutants.然而，如果给浓溶液一方施加额外的压力，那么这个过程可以反转过来，浓溶液中的溶剂（纯水）被挤压通过薄膜，这样可以去除溶解性离子和其他可溶性污染物。Unit 15The key to this advance was the recognition that contamination of public water supplies by human wastes was the main source of infection, and that it could be eliminated by more effective water treatment and better waste disposal.这项进展的关键是认识到了被人类产生的废物污染的公共供水是最主要的感染源，通过更有效地水处理和更好的废物处理可以消除水传染病。Common precautions to prevent groundwater and surface water pollution include prohibiting the discharge of sanitary and storm sewers close to the water reservoir, installing fences to prevent pollution from recreational uses of water, and restrictions on the application of fertilizers and pesticides in areas that drain to the reservoir.防止地下水和地表水受到污染，常见的预防措施包括禁止公厕和雨污水接近水库，安装围栏阻止受到生活娱乐用水的污染，限制在向水库排水的地区施用肥料和杀虫剂。Screening, coagulation/flocculation, sedimentation, filtration, and disinfection are the main unit operations involved in the treatment of surface water. Water treatment operations fulfill one or more of three key tasks: removal of particulate substances such as sand and clay, organic matter, bacteria, and algae; removal of dissolved substances such as those causing color and hardness; and removal or destruction of pathogenic bacteria and viruses.格栅、混凝/絮凝、沉淀、过滤和消毒是处理地表水主要的操作单元。水处理操作通常需要执行一个或一个以上的三个主要的任务：颗粒物质的去除，诸如砂、黏土、有机质、细菌和藻类；溶解物质的去除，诸如具有一定色度和硬度的物质；致病细菌和病毒的去除和破坏。Occasionally, raw water with low turbidity can be treated by plain sedimentation (no chemicals) to remove larger particles and then filtration to remove the few particles that failed to settle out.有时，低浊度的原水可以通过普通沉淀法（不加化学试剂）进行处理，这样可以去除大的颗粒，然后过滤除去少数没有沉淀下来的颗粒。To remedy this, a chemical is added to coagulate/flocculate the small particles, called colloids, into large ones, which can then be settled out in sedimentation tanks or removed directly in filters.为了弥补这种不足，需要添加化学制剂让这些小颗粒也就是胶体，混凝或者絮凝成大的颗粒，这样就能在沉淀池中沉淀下来，或者直接过滤去除。Coagulation/flocculation is a chemical-physical procedure whereby particles too small for practical removal by plain sedimentation are destabilized and clustered together for faster settling.混凝/絮凝法是一种化学物理过程，那些太小的用普通沉淀法不能除去的颗粒，在这个过程中失去稳定性能，聚集在一起，从而能较快的沉淀。Coagulation is a chemical process used to destabilize colloidal particles. The exact mechanism is not well understood, but the general idea is to add a chemical which has positively charged colloids to water containing negatively charged colloids.混凝是使胶体粒子失去稳定性能的化学过程。具体的机制不是很好理解，但总的思路就是将带有正电的胶体加到含有负电胶体的水中.Rapid mixing for a few seconds is required to disperse the coagulant. Gentle mixing, called flocculation, of the suspension is then undertaken to promote particle contact. This is achieved by mechanical mixing through the use of slowly rotating paddles inside the coagulation/flocculation tank, or by hydraulic mixing which occurs when flow is directed over and around baffles in the tank.快速搅拌几秒使混凝剂分散开。悬浮液轻柔的混合，称为絮凝，这是为了促进颗粒的接触。这主要是通过混凝/絮凝池中的搅拌浆慢速的机械混合完成的，或者引导水流越过和环绕池中挡板，依靠水力混合。These appear as fluffy growths of irregular shape that are able to entrap small non-coagulated particles when settling downward.这些看起来松散的、形状不规则的增长物，在向下沉降的过程中能捕集极小的没有凝结的颗粒。The floc suspension is gently transferred from the coagulation/flocculation tanks to settling tanks, or directly to filters where the flocs are removed.絮状悬浮物轻轻的从混凝/絮凝池中转移到沉淀池，或者直接到过滤器除掉。Chlorination is the most common method of disinfecting public water supplies. Sufficient quantities of chlorine from chlorine gas or hypochlorites are added to treated water to kill pathogenic bacteria.氯化法在公共给水消毒中是最常用的一种方法。在水处理中，加入的氯气和次氯酸盐可以提供足量的氯，杀死致病菌。Ozonation, which has been used extensively in France, is now gaining acceptance in North America, especially as an alternative to prechlorination where natural organics are present. Although effective, ozone does not leave a lasting residual for long-term disinfection.臭氧消毒在法国已被广泛的使用，现在正逐渐的被北美接受，特别是在天然有机物存在的情况下，臭氧消毒可以作为预氯化的一种替代品。尽管效果好，但对于长期消毒而言，臭氧不残留消毒物，因而不能持续的发挥消毒作用。Its advantages over chlorine are that it leaves no tastes or odors, and unlike chlorine, it apparently does not react with natural organics to form compounds hazardous to humans.对比氯化物，它的优势是不留下任何气味和味觉，和氯化物不同的是，它显然不和天然有机物反应，不会形成对人体有毒的化合物。Aeration is used to remove excessive amounts of iron and manganese from groundwater. These substances cause taste and color problems, interfere with laundering, stain plumbing fixtures, and promote the growth of iron bacteria in water mains. By bubbling air through water, or by creating contact between air and water by spraying, dissolved iron or manganese (Fe2+,Mn2+) is oxidized to a less soluble form (Fe3+,Mn4+), which precipitates out and can be removed in a settling tank or filter.曝气可以用来去除地下水中过量的铁和锰。这些物质引起味觉和颜色问题，从而干扰洗衣，将水管设施染色，以及会促进给水干管中铁细菌的生长。通过向水中鼓气或者通过喷淋创造空气和水的接触，这样能将溶解性铁或锰氧化成不易溶解的形式，沉淀下来，可以在沉淀池或过滤器中去除。Then the carbonized material is activated by heating it in the presence of air, C02, or steam to burn off any tars it has and to increase its pore size. Adsorption of gases, liquids, and solids by activated carbon is influenced by the temperature and pH of the water as well as the complexity of the organics being removed.然后，碳化的物质在空气、二氧化碳或水蒸气存在的状况下加热活化，蒸发掉它的焦油，增大它的孔径。活性炭吸附气体、液体和固体主要受到水的温度、pH值以及要去除的有机物复杂性的影响。In reverse osmosis (RO), fresh water is forced through a semipermeable membrane in the direction opposite to that occurring in natural osmosis. Because the membrane removes dissolved salts, the main application for RO has been in desalination.在反渗透中，淡水被迫通过一个半透膜，和自然发生的渗透方向相反