Experimental Research On Pretreatment Technology For Micro-polluted Water Of Reservoir

The quality of raw water from the Sunvim Water Plant in Gaomi was micro-polluted raw water. Recently, intermittent water transfer and delivering water by open trench led to deterioration and instability of the water quality, some serious problems were appeared such as algae explosion, increasing organic content and odor. However current treatment facility of the Water Plant cannot fulfilled requirement of effluent quality.This issue’s research object was the raw water of the Sunvim Water Plant.The activated sludge pretreatment process and chemical oxidation pretreatment technology’s removal efficiencies of odor organics were discussed. We summarized the removal performance of pollutants, and we also optimizated the dosage of activated sludge, activated carbon and oxidant. At the same time, we carried out technical and economic estimates and determine the best treatment process.Sludge from sedimentation tank was bio-activated and used to enhance the coagulation through orthogonal test by the adsorption of activated carbon and the biodegradation of activated sludge. The results of combining activated sludge with PAC and PAM, indicated that the removal rate of CODMn, ammonia nitrogen, UV254, algae, taste and odor could reach 37.25%,17.79%,18.18%,40.98% and 75%, respectively, when adding 170 mg/L activated sludge,15 mg/L PAC and 0.08 mg/L PAM. For the test of combining activated carbon with activated sludge, PAC and PAM, when adding 5 mg/L activated carbon,170 mg/L activated sludge,12.5 mg/L PAC and 0.06 mg/L PAM, the removal rate of CODMn, ammonia nitrogen, UV254, algae, taste and odor could reach 43.14%,11.04%,21.21%,45.93% and 75%, the removal rate of CODMn, ammonia nitrogen and UV254 was higher 6% than the process of combining activated sludge with PAC and PAM. According to the comparison experiments, the combination of activated carbon with activated sludge, PAC and PAM qualified better enhanced coagulation effect than the combination of activated sludge with PAC and PAM.The process of chlorine dioxide, potassium permanganate, potassium monopersulfate, UV/potassium monopersulfate and potassium monopersulfate/ UV were used in this research, taste and odor of water was removed by strong oxidants. Compared with the effect of several pretreatment processes, the results showed that the treatment effect of chlorine dioxide was poor, and the cost was the lowest. The treatment effect of potassium permanganate was general, and it had little effect on chroma removal, the cost was the lower. Potassium monopersulfate, UV/potassium monopersulfate and potassium monopersulfate/UV process has better treatment effect, their optimized dosage were 1.0 mg/L,0.75 mg/L and 1.0 mg/L. The cost of UV/potassium monopersulfate process was the lower, and the removal rate of ammonia nitrogen, chroma, CODMn, and UV254, taste and odor intensity grade was 1. According to the comparison experiments, UV/potassium monopersulfate process was superior to other chemical oxidation pretreatment technology.