可持續(xù)發(fā)展經(jīng)濟ppt介紹之循環(huán)經(jīng)濟講解environment-文庫吧資料
2025-01-28 12:26本頁面
【正文】 es. ? In the ., an estimated million people a year bee ill from infectious agents. 3 ? Scientists monitor water quality by using bacterial counts, chemical analysis, and indicator anisms. ? One method of measuring water quality involves measuring the number of colonies of fecal coliform bacteria present in a water sample. ? Drinking water should not contain any colonies/100 milliliters, ? Chemical analysis includes checking inanic and anic chemicals present, sediment content, and turbidity of water. ? Indicator species are living anisms that are monitored to determine levels of pollution. 4 Sources of Water Pollution Point sources Nonpoint sources Water quality 5 Point and Nonpoint Sources NONPOINT SOURCES Urban streets Suburban development Wastewater treatment plant Rural homes Cropland Factory Animal feedlot POINT SOURCES 6 Sources of water pollution The leading sources of water pollution are agriculture, industries, and mining. 1. Agricultural activities are the leading cause of water pollution from erosion, overgrazing, fertilizers and pesticides, and excess salt from irrigated soils. 2. Industrial facilities are another large source of water pollution, and mining is a third source. 7 ? One of every five people in the world lacks access to safe drinking water. ? Niyfive percent of people in developed countries and 74% o
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