Treatment Of Excess Activated Sludge By Combined Anaerobic Digestion And Hydrogen Peroxide Lysis

Existing tests show that hydrogen peroxide is a low cost green oxidant which can effectively improve the performance of sludge dewatering. According to anaerobic digestion is the most commonly used sludge stabilization technology, this paper examines the effect of the combined process of anaerobic digestion and hydrogen peroxide solution on the treatment of residual sludge.Comparison of hydrogen peroxide on excess sludge and anaerobic digestion sludge dewatering performance improvement effect. The results show that hydrogen peroxide can also effectively improve the dewatering performance of sludge anaerobic digestion, which demonstrated the feasibility of the combination process. Through the single factor experiment to explore the reaction factors on hydrogen peroxide conditioning of anaerobic digestion of sludge dewatering performance influence, and by orthogonal experiment that the influence factors in the selected range effect on sludge dewatering performance successively: initial p H value of the sludge, conditioning time, hydrogen peroxide dosage, temperature regulation. Optimum reaction conditions obtained by orthogonal test, the combined process of hydrogen peroxide sludge conditioning: the H2O2 amount 0.106 m L/g(AR hydrogen peroxide volume / dry sludge quality), initial p H of sludge value is 3, adjust time 60 min, adjust the temperature to room temperature. Under the optimum reaction conditions, the sludge specific resistance was reduced to 1.65×1012m/kg, and the water content of sludge cake decreased to 60.68% compared with the blank sample of anaerobic digested sludge without any treatment, which decreased by 87% and 19.4% respectively.The dehydration mechanism of the combined process was analyzed from two aspects of the sludge flocculation structure and the content and composition of EPS. The combined process can make the sludge become dense, compress the space in the body, release the free water which is not easy to remove in the gap, thereby reducing the difficulty of the sludge dewatering, and improving the dewatering performance of the sludge. Under the combined action of anaerobic digestion and hydrogen peroxide, the content of two kinds of EPS decreased, and the LB-EPS/TB-EPS of the sludge decreased, so that the sludge had better dewatering performance.To explore the possibility of Leachate Recirculation Treatment and analyze the effect of the treatment of leachate recirculation by the common anaerobic digestion of the solution and the residual sludge. And surplus sludge dewatering filtrate return to anaerobic digestion device jointly handle the gas production of anaerobic digestion with no apparent ill effects; reflux filtrate on anaerobic digestion treatment of sludge effect without adverse effects, can think soluble cell dewatering filtrate reflow process does not affect the anaerobic digestion. Under the combined action of anaerobic digestion and dilution, the COD and BOD5 were reduced to 220 and 64, respectively, 65.2% and 53.4%, respectively.