环境工程专业英语翻译范围

1.From the very early industrial period in the United States, which started about 1920, until several years after the Second World War, there was little concern for the proper methods of disposal of waste materials that were generated as by-products during manufacturing processes. Up until the 1960`s it was quite common to find fresh water rivers and streams fouled with waste chemicals from manufacturing, salt water from oil production wells and wastes acids from steel mill activities. Virtually every conceivable waste oil, solvent, or resin waste could be found in the rivers.

2. In order for an industry to implement waste minimization/ waste reduction, certain elements need to be in place. First there should be ownership or management commitment. This should be a written policy indicating support of waste minimization. Management must be recognized as desirous of this program before employees will adopt it with any enthusiasm. The commitment has to be real, to affect production decisions, and to be a part of job performance evaluations.

3. The overall objective of environmental analysis is to obtain information about both natural and pollutant species present in the environment so as to make a realistic assessment of their probable behavior. In the case of pollutants, this involves assessment of their actual or potential environmental impact, which may be manifest in several ways. Thus, a pollutant species may present a toxicological hazard to plants or animals. It may also cause contamination of resources so that they cannot be utilized for other purposes.

4. Solid: Total solids in wastewater are, by definition, the residues after the liquid portion has been evaporated and the remainder dried to a constant weight at 103oC. Differentiation between dissolved solids and undissolved, that is , suspended, solid are accomplished by evaporating, filtered and unfiltered wastewater samples. The difference in weight between the two dried samples indicates the suspended solids content. To further categorize the residues, they are held at 550oC f or 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.

5. Water flows more slowly in lakes than in rivers, and therefore the residence time of water is much longer in a lake. In the summer, the upper watersm called the epilimnion (the surface lake) are warmed by the sun. These warmer waters, being lighter than the colder ones lower lake waters (the hypolimnion) are cold and relatively airless. Between the two lies a transition layer, the thermocline, in which both temperature and oxygen content fall off they become as dense as the lower layers, the entire lake water circulates as a unit and become oxygenated. This enrichment is, in fact, enhanced by the greater solubility of oxygen in colder waters.

Furthermore, the reduced metabolic rates of all organisms at lower temperatures result in a lesser demand for

oxygen. Then, the waters below support the aquatic life through the winter.

6. For many years people were relatively unconterned about pollution of the oceans because the great mass of the sea can dilute a huge volume of foreign matter to the point where it has little effect. In recent years this attitude has changed for several reasons. For one, pollutants are often added in such relatively high concentration in local areas that environmental disruption does occur. In addition, the quantity of pollutants dumped into the ocean has grown so large that some scientists fear that global effects may be significant.

7. As mentioned earlier in the discussion of biological treatment, it is advantageous to change little particles into big ones that settle faster. So it is also with inorganic pollutants. Various inorganic colloidal particles are waterloving and therefore rather adhesive; in their stickiness the sweep together many other colloidal particles that would otherwise fail to settle out in a reasonable time. This process is called flocculation. Lime, alum, and some salts of iron are among these so called flocculating agents.

8. The augmentation of the atmosphere’s greenhouse effect from anthropogenically derived CO

has the potential for significantly warming

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global climate. By increasing the length of the growing season, the consequences of this warming may in the short term be beneficial. In the long term, however, continued global warming may have deleterious effects on global agriculture. According to a National Research Council report,

levels could climatic warming associated with increased atmospheric CO

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be expected to cause significant changes in agricultural zones。These changes could include: (1) an expansion of arid and semiarid regions; (2) poleward advance of arid and arable zones; and (3) summer temperatures too high for full productivity of important middle latitude crops such as corn and soybeans .

9. The net effect of these changes would be to reduce areas suitable for agriculture and disrupt existing agricultural patterns in many regions in the northern hemisphere. This could, of course, result in severe economic disruption and untold misery for billions of people. The most

induced global warming would be melting of the sever consequence of CO

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polar ice caps and the subsequent rise of ocean levels and inundation of coastal plains. Such a scenario would have disastrous consequences for many of the largest population centers on the planet. Based on current additions to the atmosphere, such extreme consequences and projected CO

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would not, however ,be expected for at least several centuries. Within

the next fifty years, changes in agricultural zones are more likely.

10.The principal means for control of particulate emissions from industrial sources are cyclones，electrostatic precipitators, fabric filters and scrubbers. In addition to these conventional devices, granular bed and panel bed filters have been applied to a limited extent and research is being conducted on devices or combinations of conventional devices, such as charged drop let scrubbers. Cyclonic collectors are round conically shaped vessels in which the gas stream enters tangentially and follows a spiral path to the outlet. The spiral motion produces the centrifugal forces that cause the particulate matter to move toward the periphery of the vessel and collect pm the walls and fall to the bottom of the vessel. The centrifugal force is the major force causing separation of the particulate in a cyclone separator.

11.Gas cleaning by electrostatic precipitation is particularly suited for gas streams which can be easily ionized and which contain either liquid or solid particulate matter. The method of removal consists of passing the particle-laden gas through an electrostatic field produced by a high voltage electrode and grounded collection surface. The gas is ionized by the high voltage discharge and the particulate matter is charge by the interaction of the gas ions. The particle migrate to the collecting surface which has an opposite polarity and neutralized. The operating principle of electrostatic precipitation thus requires three basic steps :(1)electrical charging of the suspended particulate matter;

(2)collection of the charged particulate matter on a grounded surface ;（3）removal of the particulate matter from the collecting surfaces by mechanical or flushing with liquids.

12. Wet collectors use water“sprays”to collect and remove particulate matter. Here are many variations of wet collectors but they may generally be classified as low of high energy scrubbers. Low energy scrubbers of 1 to 6 inches of pressure drop may consist of simple spray tower, packed tower or impingement plate tower. The lower energy scrubber finds frequent application in incinerators, fertilizer manufacturing, lime kilns. And iron foundries. The wet scrubbers can provide high collection efficiency but may involve treatment of liquid wastes with settling ponds. They also saturate the gas stream and produce a resultant steam plume. The principal mechanisms involved in wet scrubbing are: increasing the size of the particles by combination with liquid droplets thereby increasing their size so they may be collected more easily，and \or trapping them in liquid film and washing them away.

13. Biofiltration: An Innovative Air Pollution Control Technology for VOC Emissions. The 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. Not until recently, however, have biological technologies been seriously considered in the United States for the removal of pollutants from other environmental media. 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 U S.

14. The principal reasons why biofiltration is not presently well recognized in the U.S., 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. Specifically, regulatory programs in most U.S. states have not yet addressed, in a comprehensive manner, the control of air toxics, VOC and odors from smaller sources. Moreover, little financial support for investigating the applicability of biofiltration for these sources has been provided by government agencies. Finally, although several important papers on biofiltration have been published in English, most of the technical reports summarizing recent results, were published in German.

15. Only a few examples of pollution effects can be considered in the sections to follow. All 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. A more complete decription could fill several books. One of the most obvious local effects of particles in the atmosphere is a reduction in visibility. Only a few decades ago, soiling by soot and smoke was clearly apparent in almost every urban center. Reduction in visibility results in a social cost due to slowdown of air traffic and the need for instrument-guided landing systems.

16. In the air pollution episodes cited, the local presence of gases was objectionable because of odor, taste, or obvious corrosive or chemical effects. Today these gross sensory insults are rarely encountered. However, subtle health effects persist, such as eye or nose irritation or difficult breathing. In the extreme, health effects extend to the brain (CO) and stomach (several pollutants alone or in combination) 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.

17. Hazardous substances disposal practices in the United States have traveled full circle. Prior to 1978 there were few if any regulations regarding of these materials. Improper disposal of these chemicals resulted in health problem for many citizens, contaminated water supplies, and destruction of wildlife. With the enactment of the Resource Conversation and Recovery Act of 1978. Manufacturing facilities now have an obligation to account for all waste materials that generated by the facility. Implementation of RCRA has been slow.

18. The relationship between polluted water and disease was firmly established with the cholera epidemic of 1854 in London, English Protection of public health, the original purpose of pollution control, continues to be primary objective in many areas. However, preservation of water resource, protection of fishing areas, and maintenance of recreational waters are additional concerns today. Water pollution problem intensified following World War II when dramatic increase in urban density and industrialization occurred. Concern over water pollution reached a peak in the mid-seventies.

19. The detrimental impacts of air pollution are limited to those involving human health. Plants and animals are also susceptible. For example, fluorine is emitted from aluminum, glass, phosphate, fertilizer, and some clay-baking operations in significant quantities. Frequently, the plant damage is observed on the fruit or on the flowers, either of which significantly lowers the value of the crop. Fluorine affects plants at concentrations several orders of magnitude below that at which human health is affected.

20. In Europe, biofiltration has been successfully to control odors, and both organic and inorganic air pollutants that are toxic to human .The development of biofiltration in West Germany，most of which took place in the late 1970s and the 1980s, was brought about by a combination of increasingly stringent regulatory requirements and financial support from federal and state governments. 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. It is estimated that the total number of biofilter and soil bed installation in the US and Canada is currently less than 50 and they are predominantly used for odor control.

21. Some particles are particularly damaging because they adsorb gases which cause more intense irritation locally. Gases also penetrate into the deepest lung pockets. Both particles and gases entering the body