Study On Emergency Treatment Of Source Water By Sudden Polluted Accident

During recent years accidental pollutions often occur in water sources in our country, causing great economic loss and society unstableness, even serious destruction of ecological environment. So they have become the potential threat to our economy and people's living standard. Accidental pollutions have the characteristics of uncertainty, drainage basin, processing difficulty, long-term influence and emergency main body dubiousness. Moreover, the pollutants concentration is usually several times to dozens of times of drinking water standards and current water treatment process can not deal with this kind of pollutions. Therefore, it is essential to establish an early-warning and emergency treatment system of water source pollutions.Heihe River is the main drinking water source of Xi'an. It can provide 70% of the city total water supply. As its range is very large the management becomes very difficult. And in recent years water quality becomes worse and worse, resulting water quality deterioration events easy to occur. So the safety and reliability of city water supply can not be ensured.In this paper Heihe River is taken as the research background and several potential pollutants are selected as the research subjects. By simulating the pollution situations of Heihe River the emergency treatment methods of removing particular pollutants are investigated to help water sources management and water works operation.(1) The possible pollution sources and pollutants are determined after on-site investigation of Heihe River.(2) Petroleum can not be effectively removed by conventional water treatment process and to some extent it can be disposed of by powered activated carbon. But the total oil in water can not be treated to meet the requirements of drinking water standards. The process of PAC+ClO₂ can effectively remove petroleum pollutants. Under this process the petroleum concentration with 10 times of limit value can be treated below the limit value. When the dosages of PAC and ClO₂ are 30mg/L and 8mg/L, the removal rate can get to 98%.(3) Ammonium can be treated with natural zeolite. But the selective adsorption of modified mordenite is significantly improved. When the dosage of natural zeolite and PAFC are 3g/L and 25mg/L, the source water where ammonium exceeds the limit value by 5 times can be treated to meet the drinking water standards.(4) The treatment measures for accidental pollutions and periodic pollutants are proposed. And they are on the basis of the experimental data of heavy metals and high load pollutants and the operation characteristics of Heihe River.