Guanting Reservoir Biofilm Of Micro-polluted Water Pretreatment Process

Guanting Reservoir used to be one important potable water source for Beijing City. Its water quality became worse and worse as the result of point resource and no-point resource contaminations of upstream and neighborhood of the reservoir. Guanting Reservoir could not supply potable water for Beijing City since 1997. Recently, supply-require contradiction of Beijing water source becomes more strident. Beijing government proposes to resume the potable water source function of Guanting Reservoir.In this research, quality of water entering into Guanting Reservoir and water in Sanjiadian Reservoir are analyzed, and biofilm treatment process experiments on this two kinds of source water are executed under normal and low temperature to test the removal effect of COD,NH₄⁺-N, TN. The feasibility of biofilm pre-treatment process at upstream or downstream is discussed from the technical review so as to offer technical support for Guanting Reservoir water quality melioration.This research includes two parts: water in Guanting Reservoir and water in Sanjiadian Reservoir. The former is treated by biological contact A/O process and Biostyr process. The later is treated only by biological contact oxidation process (BCOP).1. Water entering into Guanting Reservoir is seriously polluted. Its quality is complicated, is mainly higher water standard GB V and fluctuates greatly. Its temperature is low in winter and last for long time. It is a typical representative of seriously polluted surface water source in North China.2. Biological contact A/O process has evident removal effect of COD_Cr, NH₄⁺-N, TN in water entering into Guanting Reservior. Under optimal condition, effluent COD_Cr is steadily around 25mg/L, effluent NH₄⁺-N is lower than 0.5mg/L, and the average of TN removal rate is 16.0%(the maximum is 38.1%). The results show that Biological contact A/O process could successfully resume the quality of water entering into Guanting Reservior from the technical view.3. The results of influence factors experiment show that the raw water quality has important influence on the treatment, such as influent COD_cr loading, influent NH₄⁺-N loading and influent C/N.4. According to the character that the raw water quality fluctuates greatly and has important influence on the treatment, "influent loading" is proposed to be important control parameter in Biological contact A/O process design and operation. The proposed parameters is influent COD_Cr loading that is lower than 0.6kg COD_Cr/m³.d and influent NH₄⁺-N loading that is lower than 0.08kg NH₄⁺-N/m³.d.5. Biological contact A/O process can operate under low temperature and maintain good NH₄⁺-N removal effect. Low temperature experiment results show that under the...