【Water Pollution Situation】

Statistics show that the early seventies, the national total emissions of waste water at 3000-4000 tons; early eighties to more than 7,500 tons; and early nineties the country 35.56 billion tons of total waste water discharge, the wastewater A considerable part of the untreated directly into rivers and lakes。
From the national situation, the water pollution is the development from east to west, extending from the tributaries to the mainstream, spreading from urban to rural, from surface to underground infiltration spread to the region. Increasingly serious water pollution affect human drinking water。

【Status of Water】

Currently, the traditional water systems are facing many threats from:

1、Whether surface water or groundwater sources, affected by the overall deterioration of the environment, industrial wastewater, sewage discharge and other improper influence, has shown a deteriorating trend.

2、The technological transformation of the original water plant can not keep up the speed of water pollution. Traditional "Coagulation - Precipitation (or clarify) - Filter - chlorine disinfection, "the water treatment process, the water solubility and low molecular weight organic material is difficult to remove, and some of these substances to have "three to" feature (carcinogenic, mutagenic, teratogenic).
3、Most of the water industry are now using liquid chlorine, the disinfectant residual organic matter in water combined with, easy to form chloroform, with increased pollution, water plant disinfectant dosage was gradually increased. Left in the water of the "three to" other trace organic compounds, disinfection by chlorination, the increasing trend is more harmful, and a direct result of residual chlorine in tap water and feel and taste Difficult do People Meaning. 　　
4、As the city water supply pipe has a long history of secondary water pollution problems, in any large cities are prevalent。Buried in the ground water pipe network, Pipe wall is no doubt to varying degrees, scaling, rust, corrosion, and microbial adhesion to a variety of impurities in the pipe wall, especially in the hot summer months is more serious secondary pollution。In addition, the district's reservoirs, booster pump station, roof water tanks and the management of secondary pipe network, but also water quality and have different degrees。
5、The World Health Organization (WHO) statistics, the harmful substances in tap water up to over a hundred species, of which there are 11 strong carcinogens, such as alkyl halides, nitrite and so on。Chlorinated tap water can effectively kill bacteria, but the high temperature of 60 ℃ to form chloroform, and chloroform is a human suffering from the greatest source of various types of cancer。Water hardness resulted in the North far exceeded the incidence of gallstone disease is very high. Current urban polluted waters, in addition to heavy metals, but also contains a lot of pesticides, fertilizers, detergents and other harmful residues, even the water boiled, and the residue is still hanging on. In addition，because water in the transportation, compression, storage and other processes are vulnerable to secondary pollution。Therefore, the general should not be directly imported drinking water。