【目录】 UNIT ONEText History of Water SupplyReading Material A Major Water Pollutants （Ⅰ）Reading Material B Major Water Pollutants （Ⅱ）UNIT TWOText WaterReading Material A Importance of WaterReading Material B The Nature of WaterUNIT THREEText Water ProblemsReading Material A The Hydrologic CycleReading Material B The Hydrologic Cycle and Water QualityUNIT FOURText The Purification of WaterReading Material A Softening of WaterReading Material B Softening of WaterUNIT FIVEText Basic Factors in Water AnalysisReading Material A Water TestingReading Material B The General Physical-chemical Principle of WaterUNIT SIXText Water-supply EngineeringReading Material A Drainage， Sewerage and SewageReading Material B Water SupplyUNIT SEVENText Plumbing——Background and StatusReading Material A Basic Principles of PlumbingReading Material B Sources of WaterUNIT EIGHTText Microbes as Chemical MachinesReading Material A BacteriaReading Material B Water Pollution and Its Effect on EnvironmentUNIT NINEText Groundwater Formation and Its MovementReadin Material A Sources of Water for Domestic UseReading Material B Multi-purpose Hydraulic ProjectsUNIT TENText Open Channel FlowReading Material A DamReading Material B Rock-fill Dams and SpillwayUNIT ELEVENText Environmental/Sanitary EngineeringReading Material A Sanitary EngineeringReading Material B Municipal EngineeringUNIT TWELVEText EcosystemReading Material A Problems Due to Plankton-algaeReading Material B The Death of MicroorganismsUNIT THIRTEENText Factors Responsible for the Burgeoning Air Pollution ProblemReading Material A The "Killer Smog"Reading Material B Economic Loss from Air PollutionUNIT FOURTEENText Solid Waste DisposalReading Material A Where Do Pollution Come from？Reading Material B Industry SludgesUNIT FIFTEENText Combating Water PollutionReading Material A OzoneReading Material B Acid RainUNIT SIXTEENText Paving the Way to Excellence in Water Supply SystemReading Material A Control of Data QualityReading Material B The Monitoring Approach of the Levels-of-service FrameworkAppendix Ⅰ VocabularyAppendix Ⅱ Translation for ReferenceAppendix Ⅲ Key to Exercises
【文摘】 Soils are normally much better able to resist acidification than lakes， rivers and streams，and so can take much more acid without noticeable ecological drawbacks. Their vulnerabilitydiffers depending on their type， the kind of bedrock they cover， and the use to which manputs them. The most vulnerable lands are those that have bedrocks poor in lime， covered withshallow layers of soil containing low concentrations of protective substances. Large parts ofScandinavia are like this. As well as the health of important ecosystem， human health may also be put at risk bypollution. ~ High concentrations of sulphur dioxide， nitrogen， oxides and dust have long beenknown to be harmful. This issue is only marginally related to the.problem of acid rain， sincesuch concentrations are usually only found close to the sources of pollution， and sulphur oxidelevels in many European and North American cities have been decreasing recently. Other， indirect， health hazards are suspected. These would be caused by the metals likelead， copper， zinc， cadmium and mercury released from soils and sediments by increased acidi-fication. They can get into groundwater， rivers ， lakes and streams used for drinking water，and be taken up in food chains leading ultimately to man. The releases of cadmium in particu-lar may give rise to a growing problem as acidity increases， as normal levels in human food arealready close to the acceptable daily intake. It seems that the risks arises as soon as the acidityof the water rises above normal. ……
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