A Research On The Demonstration Project Test Of Ultrasonic-Anoxic/Aerobic Digestion For Sewage Sludge Disposal

With China’s sewage treatment industry has been developed rapidly, sewage treatment capacity and treatment rate is growing rapidly, which brought the sludge output increases rapidly. However, with the development of the sludge disposal in our country quite lagging behind, lack of effective secure sludge disposal method, and secondary pollution of sludge caused by early-juvenile, so sludge matter had got to come to the point that not allow to ignore.Sludge treatment and disposal security research and development of new technology is imminent.In this paper, according to the test results of the project in laboratory, laboratory test of the ultrasonic-anoxia/anaerobic and anoxia/anaerobic of sewage sludge digestion was contrasted. Based on this, a demonstration project device has been designed and completed. Through some sewage treatment plant in guangzhou demonstration project test, a dynamics model of ultrasonic-anoxia/anaerobic treatment technology had been established. By the law of Annual Cost, the cost of sewage sludge processing by demonstration project device had been estimated.First, according to the semicontinuous and laboratorial independent design pilot device, the sewage sludge digestion effect of ultrasonic-anoxia/anaerobic and anoxia/anaerobic had been compared. Research indicated that, with the digestion of the25days after stability, sewage sludge digestion of two kinds of technology got to stable state. Ultrasonic pretreatment sludge VSS removal rate reached51.98%, comparing with sludge VSS removal rate was only42.98%without the ultrasonic treatment. The variation trends of concentration of TCOD and supernatant SCOD、 TP and ammonia nitrogen are similar, but the concentration of supernatant nitrate nitrogen and nitrite nitrogen of sludge treated by ultrasonic aerobic/anoxic is higher. It indicated that the activity of nitrifying bacteria can be improved and nitration can be accelerated in sewage treated by ultrasonic.Secondly, with demonstration project test device in the sewage treatment plant field test, research shows after domestication20days or so, this process system achieved stable state. the average treated sludge quantity was0.25m3(as water ratio is99%).more than50%removal rate of VSS and above53%removal rate of TCOD in the discharged sludge, less than80mg/L SCOD in the liquid supernatant of the discharged sludge. According to the analysis of nitrogen forms change in the liquid supernatant of the discharged sludge, denitrification effect in sludge strengthened before stable system and weakened slightly after stable system.Finally, according to the theoretical basis of microbial dynamics model, growth rate model (Monod model) and microbial substrate using rate model, material balance analysis and experimental data analysis of ultrasonic-aerobic/anoxic treatment sludge,reactor dynamics model is:;Through the cost of demonstration project device and demonstration project operation of the economic cost analysis, that the cost of every tons of sludge (as water ratio is99%) is122.35yuan with ultrasonic-aerobic/anoxic process had been calculated by Annual Cost.The research of this paper provided test foundation for the spreadation and application of the ultrasonic-anoxia/anaerobic sewage sludge digestion technology.