污水处理技术（Wastewater treatment technology）.docVIP

污水处理技术（Wastewater treatment technology） Sewage is the product of economic development and urban development. The early treatment of sewage is through A sewage collection system is collected and discharged to a nearby downstream water body so that it is diluted by water And natural purification. But with the increase of sewage discharge and the complexity of water quality, water bodies Limited self purification capacity has been overwhelmed. Pollutants leak into the water and enter the soil, Through the food chain endanger our health, resulting in enormous economic losses, constraints Economic development. Internationally, large-scale sewage treatment was conducted after World War ii, At the end of the 1970s, Britain, France, Germany and other countries spent huge sums of money to build 7000 to 8000 seats Sewage treatment plant, the United States invested hundreds of billions of dollars, the construction of more than 18000 processing plants. At the end of the 80s, the level of sewage treatment in these countries was further improved A batch of facilities with nitrogen and phosphorus removal efficiency. At present, these countries have entered the sewage In the advanced treatment stage, the water quality has been greatly improved. Sewage treatment worker in our country It starts with industrial waste water. In 1970s, a number of sewage disposal were constructed Facilities, in 1995, the countrys 643 cities have large and medium-sized sewage treatment plants 167. 2006 national urban environmental management and comprehensive renovation annual report shows that the National City The average rate of centralized treatment of domestic sewage was 42.55%, and the concentration of 200 municipal domestic sewage was concentrated The treatment rate was 0, accounting for 33.6l% of the total number of urban examinations in the city (595), and the national urban water The water quality compliance rate of the regional functional areas does not rise or fall (7.24% lower than that of t