環(huán)境工程與科學專業(yè)英語.doc

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.這本書的目的是使理工科的學生了解跨學科間的研究環(huán)境問題：它們的起因，為什么它們受到關注，以及我們怎樣控制它們。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.污染可以被定義為有害影響健康，生存，活動的人或其它生物體的空氣，水，或土地的物理，化學或生物特性的不應該有的變化。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.目前的一個例子是酸雨問題，根源是許多發(fā)電站，冶煉，汽車排出的廢氣中進入大氣的二氧化硫和氮氧化物氣體。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.然后這些氣體被氣流運送到廣闊的區(qū)域。雨水“將它們洗去”，產(chǎn)生了對水生生物，森林和農(nóng)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. 城市化和工業(yè)化的現(xiàn)象，在過去和現(xiàn)在都是引起水和空氣污染的根本原因，這在當時的城市還不能夠處理。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. 這導致水傳染疾病的發(fā)生率大量地減少。注意，所有的廢物排放到環(huán)境中都會污染我們的水、空氣和土地系統(tǒng)。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.空氣污染通常是指那種包含一種或多種化學物質富集到高濃度并足以傷害人類、其他動物、植物或材料的空氣。By themselves, measured concentrations tell us nothing about the danger caused by pollutants, because threshold levels, synergy, and biological magnification are also determining factors.通過測出的濃度自身并不能告知我們有關污染物所帶來的危險的信息，因為臨界濃度、協(xié)同作用還有生物放大效應都是決定因素。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.這種利用微生物的生物降解作用去除環(huán)境中非期望的化合物的觀念在數(shù)十年前已經(jīng)非常好地建立在廢水處理方面。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，盡管生物治理技術在處理被人工合成化合物污染的土壤和地下水得到了成功的應用，現(xiàn)在，在美國環(huán)保專業(yè)人員中，生物學系統(tǒng)在控制大氣污染物方面只有很少的實踐經(jīng)驗。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. 對于那些為什么生物過濾法如今在美國還不是很好地被認識和只應用于僅僅很少的一些情況的主要原因，可以認為是缺少控制的計劃、來自政府對此技術研究和發(fā)展支持，更是缺少用英語寫成的有關這些技術的文獻。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.現(xiàn)在這篇論文的主要目的是提供一個關于生物過濾的重要方面的全面綜述來更廣泛傳播這種APC創(chuàng)新技術，并且鼓勵它在美國適合的地方的實施。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.他們的工作包括在西雅圖附近的廢水處理工廠中成功地安裝幾個固體過濾器并證明了生物降解對氣味的去除作用比吸附作用更優(yōu)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. 雖然已經(jīng)證實土壤床可用相當?shù)偷耐顿Y和操作費用來有效的控制某些類型的臭味和揮發(fā)性有機化合物，但是，土壤的低生物降解能力和相對大的占地要求限制了土壤床在美國的應用。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.這部分例子被認為是局部的，可見的或可測量的影響，因為去建立特定污染物及其長期、大面積的暴露所造成的影響之間的直接關系是很困難的。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.長期暴露于大氣污染物中的植被所遭受的破壞也許是用以識別空氣長期污染的一種較明顯的前兆。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.當這種特定的污染物或多種污染物產(chǎn)生的被頻繁觀測到的影響不能被確認時，就有足夠的證據(jù)表明這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.即使氟的濃度很低，被灌木，樹木或草吸收，隨后被?；蚱渌筮M食，也會對這些動物造成影響。The animals act as concentrators of the fluorine, resulting in poor animal health and associated lower animal value or survival capability.這些動物作為氟的集中者，會導致動物健康的變壞，以及動物自身價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.硫和氮氧化物反應，在大氣中形成酸性化合物攻擊金屬表面，這個問題特別嚴重的影響通信，開關，和計算機產(chǎn)業(yè)。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，保存水資源、保護漁業(yè)水域以及維護娛樂休閑用水現(xiàn)在引起額外的關注。二次世界大戰(zhàn)，伴隨著工業(yè)化和城市密度大幅度增加，加劇了水污染問題。在七十年代中期對水污染的關注達到了一個高峰。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).水資源的污染可能直接來自于下水道排水口或工業(yè)污水排放（點源）或者間接的來自空氣污染或者農(nóng)業(yè)以及城市徑流（非點源）。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.這些廢水中的微生物大部分是沒有什么害處的，能應用在生物處理過程當中，把有機物質轉化成穩(wěn)定的終端產(chǎn)品。然而，污水也可能含有病原體，這些病原體來自具有傳染病人群的糞便，最后通過被污染的水傳播開來。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.對懸浮固體（殘渣）進一步分類，把它們放在550下灼燒15分鐘。殘留的灰分代表無機固體，揮發(fā)掉的物質的量可以表示有機物含量。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.揮發(fā)性懸浮固體可以指示未處理廢水中有機物濃度，也能測量生物過程中微生物種群的活性。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.除了這些化學成分，溶解氣體特別是氧氣的濃度，以及氫離子的濃度也就是pH，是其他的衡量廢水的指標。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.這類可生物降解的污染物主要來源于人類的糞便和尿液，水池中食品廢物，沐浴以及洗衣服時產(chǎn)生的臟物，再加上各類香皂，洗滌劑，其他洗滌產(chǎn)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.總有機碳是這樣測定的：把樣品中的有機碳用強氧化劑氧化，測定產(chǎn)生的二氧化碳的量，并將它與已知TOC的標準樣品進行比較和對照。Most of the other common methods are based on the amount of oxygen required to convert the oxidizable material to stable end products.其它常見方法是基于把可氧化物質轉化成穩(wěn)定的終端產(chǎn)品所需要的氧氣的量。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即化學需氧量，廢水中有機物的化學氧化反應所需要的氧量。BOD，生化需氧量，指馴化的微生物分解水中有機物所需要的氧量。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參數(shù)。可以用來衡量有機污染，可以作為估計生物過程所需氧量的基礎，以及過程性能的一個指標。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.消耗的氧氣或者叫生化需氧量，和要轉化的有機物質是成正比例的，因此，BOD可以間接的測量系統(tǒng)中可生物降解的物質。Unit 14One possibility is somehow to make these small particles join together to become larger ones, which can then be treated as suspended matter.一種可能的方法是讓這些小的顆粒結合在一起變成一個大的整體，這樣可以像處理懸浮物質那樣除去。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.雨污合流的管道比較便宜，而且在干旱的天氣時也足夠使用，但是當下暴雨的時候，水的總體積容易超過污水處理廠的處理能力，這樣就容許一部分污水溢流，直接排到受納的小溪和河流中。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.接下來是一組沉淀池，首先可以去除大的沙礫，比如路面上被雨水沖刷下來的路面的沙子。然后，更慢的是其他的懸浮固體包括有機營養(yǎng)物在一個小時左右沉淀下來。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.接下來的一系列步驟是通過某種形式加速的生物活動大大減少溶解的或者細小懸浮有機物。這樣的分解需要氧氣和有機物，以及一個容易獲取營養(yǎng)物質的環(huán)境。能夠達到這一目的的一個裝置是滴濾池。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.在這個裝置中，長管在石床上緩慢的旋轉，并持續(xù)的噴灑使污水散布。當水沿石縫滴落時，就給濾床上那些大量的讓人相當?shù)刮缚诘奈⑸飩兲峁┝搜鯕夂蜖I養(yǎng)物質。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.經(jīng)過處理的水流至沉淀池，在這里充滿細菌的固體沉淀下來，并回流到曝氣池。一些污泥必須被去除，以維持穩(wěn)態(tài)狀況。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.雖然很多污水經(jīng)過一級和二級處理之后被認為已經(jīng)完成了凈化，但是對于一些復雜的水污染，這樣處理還遠遠不夠。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.各種無機膠體粒子都是親水的，所以具有一定的黏附性；由于具有粘性，這些粒子和許多其他膠體粒子聚集在一起，這樣就可以讓本不能沉淀的它們在一定時間內沉淀下來。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.吸附過程就是指氣體或者液體分子黏附在固體表面。這個過程是選擇不同種類的分子黏附到任何特定的固體上。為了凈化水質，需要表面積大，能優(yōu)先粘合有機污染物的固體。首選的材料是活性碳，它能特別有效地去除產(chǎn)生令人不爽的口味和氣味的化學物質，包括抵抗生物降解的氯化烴。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.高錳酸鉀和臭氧經(jīng)常用來氧化水中的某些廢物，這些廢物不能被微生物利用空氣氧化。臭氧具有最重要的優(yōu)點是，它唯一的副產(chǎn)物就是氧氣。 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，如果給濃溶液一方施加額外的壓力，那么這個過程可以反轉過來，濃溶液中的溶劑（純水）被擠壓通過薄膜，這樣可以去除溶解性離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.這項進展的關鍵是認識到了被人類產(chǎn)生的廢物污染的公共供水是最主要的感染源，通過更有效地水處理和更好的廢物處理可以消除水傳染病。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，常見的預防措施包括禁止公廁和雨污水接近水庫，安裝圍欄阻止受到生活娛樂用水的污染，限制在向水庫排水的地區(qū)施用肥料和殺蟲劑。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.格柵、混凝/絮凝、沉淀、過濾和消毒是處理地表水主要的操作單元。水處理操作通常需要執(zhí)行一個或一個以上的三個主要的任務：顆粒物質的去除，諸如砂、黏土、有機質、細菌和藻類；溶解物質的去除，諸如具有一定色度和硬度的物質；致病細菌和病毒的去除和破壞。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.有時，低濁度的原水可以通過普通沉淀法（不加化學試劑）進行處理，這樣可以去除大的顆粒，然后過濾除去少數(shù)沒有沉淀下來的顆粒。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.為了彌補這種不足，需要添加化學制劑讓這些小顆粒也就是膠體，混凝或者絮凝成大的顆粒，這樣就能在沉淀池中沉淀下來，或者直接過濾去除。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/絮凝法是一種化學物理過程，那些太小的用普通沉淀法不能除去的顆粒，在這個過程中失去穩(wěn)定性能，聚集在一起，從而能較快的沉淀。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.混凝是使膠體粒子失去穩(wěn)定性能的化學過程。具體的機制不是很好理解，但總的思路就是將帶有正電的膠體加到含有負電膠體的水中.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.快速攪拌幾秒使混凝劑分散開。懸浮液輕柔的混合，稱為絮凝，這是為了促進顆粒的接觸。這主要是通過混凝/絮凝池中的攪拌漿慢速的機械混合完成的，或者引導水流越過和環(huán)繞池中擋板，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.這些看起來松散的、形狀不規(guī)則的增長物，在向下沉降的過程中能捕集極小的沒有凝結的顆粒。The floc suspension is gently transferred from the coagulation/flocculation tanks to settling tanks, or directly to filters where the flocs are removed.絮狀懸浮物輕輕的從混凝/絮凝池中轉移到沉淀池，或者直接到過濾器除掉。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.氯化法在公共給水消毒中是最常用的一種方法。在水處理中，加入的氯氣和次氯酸鹽可以提供足量的氯，殺死致病菌。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.臭氧消毒在法國已被廣泛的使用，現(xiàn)在正逐漸的被北美接受，特別是在天然有機物存在的情況下，臭氧消毒可以作為預氯化的一種替代品。盡管效果好，但對于長期消毒而言，臭氧不殘留消毒物，因而不能持續(xù)的發(fā)揮消毒作用。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.對比氯化物，它的優(yōu)勢是不留下任何氣味和味覺，和氯化物不同的是，它顯然不和天然有機物反應，不會形成對人體有毒的化合物。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.曝氣可以用來去除地下水中過量的鐵和錳。這些物質引起味覺和顏色問題，從而干擾洗衣，將水管設施染色，以及會促進給水干管中鐵細菌的生長。通過向水中鼓氣或者通過噴淋創(chuàng)造空氣和水的接觸，這樣能將溶解性鐵或錳氧化成不易溶解的形式，沉淀下來，可以在沉淀池或過濾器中去除。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，碳化的物質在空氣、二氧化碳或水蒸氣存在的狀況下加熱活化，蒸發(fā)掉它的焦油，增大它的孔徑?；钚蕴课綒怏w、液體和固體主要受到水的溫度、pH值以及要去除的有機物復雜性的影響。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.在反滲透中，淡水被迫通過一個半透膜，和自然發(fā)生的滲透方向相反