土木工程专业英语http:/www.swust.net.cnLesson 5 Environmental Engineering 环境工程New words and phrases: perturbation ecosystem subdiscipline depletion anaerobic scum grease coagulation sedimentation emanate colloidal filtration pesticide herbicide fertilizer centrifuge aquiferimpoundment ozone carcinogenic eutrophic algae runoff refuse disposal 垃圾处理by-product 副产品, 出乎意料的结果deal with 安排, 处理, 涉及土木工程专业英语http:/www.swust.net.cnEnvironmental engineering is a branch of engineering that is concerned with pollution by the structures, machines, systems, and processes that are involved in human activities.环境工程是和结构、机械、系统，以及涉及到人类活动的过程 所产生的污染有关的一个工程学的分支。The development of civilization has caused perturbation of much of the Earths ecosystem, resulting in pollution of the air, land and water. 文明的发展已经引起许多地球生态系统的紊乱，造成空气、陆 地和水的污染 。 It is the task of the environmental engineer not only to design systems to assuage this pollution but also to educate people in protecting their surroundings from additional pollution. 环境工程师的任务不仅是设计出一些系统来减轻这个污染，而 且还要教育人们保护他们周围的环境免遭额外的污染。The practice of environmental engineering is divided into various subdisciplines.环境工程专业又被分为了不同的分支学科。 Environmental engineering 环境工程土木工程专业英语http:/www.swust.net.cnIn many cases, rivers, lakes, and oceans have become polluted from discharges of liquid wastes from residential, commercial, and industrial sources. 在许多情况下，河流、湖泊和海洋已经被由住宅、商业、 和工业源点排放的废液所污染 。 Many of these bodies of water have been reclaimed because of a movement in the 1970s to construct new wastewater treatment facilities and to improve old ones. 许多这些水体已经被回收了是因为20世纪70年代的一场修 建新的废水处理设施和改进旧的设施的运动。 Both physical-chemical and biological processes are used to remove from the liquid wastewater stream. 可以采用物理化学方法和生物学方法从废液中除去污染物 。 Water treatment and disposal 水处理土木工程专业英语http:/www.swust.net.cnIt is this organic matter that causes a depletion of oxygen in rivers and lakes, with consequent anaerobic conditions leading to fish kills and noxious odors. 正是这种有机物会使江河湖泊中的氧气耗尽，形成导致鱼 类死亡的厌氧环境并产生有害气体。 The physical-chemical and biological processes remove an abundance of the organic matter along with floatable scum and grease from the waste stream.物理化学方法和生物学方法消除了大量的有机物质连同来 自废水中的漂浮的浮渣和油脂。 Chemical disinfection inactivates bacteria, viruses, and protozoa in the waste stream. 化学消毒可使废水中的细菌、病毒和原生动物钝化。The physical and chemical processes used for removing solids from the waste stream include screening, sand and grit separation, chemical coagulation, and plain sedimentation. 用来除去废水的固体化学物的物理和化学方法包括过筛、 砂和粗砂分离、化学凝结和简单沉淀。 Water treatment and disposal 水处理土木工程专业英语http:/www.swust.net.cnBiological processes include activated sludge, contact towers, and biological discs.生物学方法包括活性污泥、接触塔和生物圆盘。 The application of these treatment processes to residential, commercial, and industrial wastewaters has reduced the pollutional load on many rivers, lakes, and harbors. 这些处理方法应用到住宅、商业和工业废水上，已经降低了 许多河流、湖泊和海港的污染程度 。 There do remain, however, cases of large metropolitan areas that have not complete their clean-up campaigns, and in many other regions discharges of untreated mixtures of sanitary wastes and stormwaters occur during heavy rains. 然而，仍然有部分大城市没有完成它们的卫生大扫除活动 ，在许多其他地区，暴雨期间未经处理的生活污水和雨水的混 合液随意排放。 Water treatment and disposal 水处理土木工程专业英语http:/www.swust.net.cnThese discharges emanate from large conduits that carry both sanitary and storm wastes.这些排放物来自于输送生活污水和雨水的管道。 The impurities that run off the land during a storm mix with the sanitary wastes in the pipes, and the quantity of wastewater overtaxes the carrying capacity of the conduits；a portion of this mixture flows into the nearest body of water before it can reach the wastewater treatment facility.在暴雨期间，陆地上的杂质和管道中的生活污水混和在一 起，废水的数量超过了管道的输送能力，混合物的一部分在到 达废水处理设施前就流进了附近的水体。It is usually too expensive to construct a whole new set of separate sanitary conduits; 通常，由于成本太高而不能修建一整套新的单独生活污水 管道；Water treatment and disposal 水处理土木工程专业英语http:/www.swust.net.cnhowever, some cities, like Chicago, have begun to solve the problem by constructing a system of deep underground tunnels that store the large quantities of discharges during the storm, following which the wastewaters can be bled into the treatment facilities at reasonable rates.然而，有些城市，像芝加哥，已经开始修建一个深埋的地 下隧道系统来解决这个问题，该系统可以存储暴雨期间的大量 排出物，这样废水就能以一个合理的速度流进处理设备。 Where wastewater must be discharged into lakes and dry streams, a higher level of treatment must be employed, including removal of nutrients and colloidal matter. 在那些废水必须被排入湖泊和干河的地方，必须采用更高 水平的处理措施，包括营养物和胶质物的去除 。Physical-chemical and biological treatment processes are employed as for wastewater treatment. 物理化学和生物处理方法被用来处理废水。 Water treatment and disposal 水处理土木工程专业英语http:/www.swust.net.cnIn addition, chemicals are introduced for precipitation of nutrients, followed by coagulation and filtration for removing solids remaining after biological treatment; and in some cases granular activated carbon or membrane filtration is