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ace water or underground water without any treatment.. According to the china government, in 1985, the hole country discharged the industrial waste water 25.65 billion tons, and 4/5 of the water was directly discharged without any treated. (Ling Mingrui, 2008). Industrial wastewater can cause two kinds of pollution: chemical pollution and thermal pollution. Clearly, the Industrial wastewater contains high concentrations of oil, grease, heavy metals, volatile organic compounds, acids, alkalis, dyes or other nonconventional pollutants. In Madras, the waste from currieries, textile mills and other industrials department is poured into the waterways. The cyanide is also cited as a leading cause of the buffaloes’ death. (Somasundaram, Ravindran, Tellam, 1993)Thermal pollution also cannot be ignored. Thermal pollution may be defined as the rise or fall in the temperature of a natural body of water caused by human influence. It often caused by generating station, smelter and industrial manufacturers. High water temperature can decrease oxygen levels of river, lake. The low level of O2 will kill the organisms, such as fish, shellfish.

Urban sewage also leads to water pollution. The urbanization in less developed countries, especially in Latin America and the Caribbean, has increased greatly. However, the development of urban sewage systems there is far backward. It makes most wastewater be discharged into waterways without treatment. (Martinelli. eta, 2006)According to data offered by Somasundaram, Ravindran and Tellam(1993), 93% of the underground water of Madras in Indian is exceeded the limit—25% over the Ca limit, 11% the Mg limit, 14% the SO4 limit, 70% the NO3 limit. The major cause of exceeding of these chemical elements is urban sewage. The table 1.1 shows the concrete information.

In fact, personal care Personal Care Products and Household Cleaning Products can make bad effect on the environment. The articles of everyday use such as window clear stain remover, hair dye, cologne, antibacterial soap, hand lotion contains sulfonate, phosphoric acid ester, sulfamate, chlorhydric acid and other chemical compositions which can damage the nature. In addition, the egesta of humans or pets are the other kind of urban sewage. This pollutant source can leads to diseases spreading. The germ in the egesta easily spread through the waterways. When people use this dirty water, people have access to the illness. The egesta are rich in nutrient. The P, N in the waste can cause the similar result as Nutrient runoff.
Sa˜o Paulo is one of largest cities in Brazil and nearly 18 million people live in it. The urban population discharge plenty of household water into water body, but only one-tenth wastewater is disposed before it is poured. (Martinelli. eta, 2006)

代写留学生作业The problem of water pollution is a global issue, but the factors of water pollution in developing nations are more complex and serious. Because of the lagging sewage treatment system and lack of money, this problem cannot be solved by just one country or the third world countries. The developed world must work with the developing world to deal with it, and then the mistreatment to the water can begin to be reversed