Microwave Synergy With Hydrogen Peroxide To Improve Sludge Dewatering Performance And Mechanism

The activated sludge process is the most widely used sewage treatment technology for urban sewage treatment.Following the improvement of the sewage collection and treatment capacity,the production of sludge volume is also increasing.The treatment of sludge,especially the improvement of sludge dewatering performance,has become a significant part of wastewater treatment plants.In this study,the object of study was the sewage sludge from concentration basin,and the dewatering performance of the sludge was improved by microwave combined with H2O2.It studied the four influencing factors such as H2O2 dosage,microwave power,microwave reaction time and sample p H,and inferred the possible mechanism.The main conclusions are as follows:(1)Microwave combined with hydrogen peroxide to treat sludge is better than single microwave conditioning or hydrogen peroxide conditioning.Combining with energy consumption and dewatering performance,the optimal conditions for improving the dewatering performance of microwave combined with hydrogen peroxide were as follows: p H=7,H2O2 dosage 0.15 m L/g,microwave time 4 min,microwave power 595 w.Under this condition,the sludge moisture content decreased to 64.43%,the sludge particle size could be used as the main response index of sludge dewatering performance.(2)A simple financing analysis was carried out on the microwave combined with hydrogen peroxide conditioning sludge.It cost per t dry sludge was 14282.7 yuan,and the sludge disposal cost in the later stage was 5905.9 yuan.The traditional mode operation cost is lower.However,the microwave combined with hydrogen peroxide method to adjust the sludge could effectively reduce the investment cost and operatingcost of the subsequent sludge disposal.(3)It studied the changes of organic components in the supernatant.It finds was while the microwave combined with hydrogen peroxide conditioning sludge released the polysaccharide-protein,the hydrophilic polar group was also detached;there was a correlation between the content of fluorescent substances and the dewatering performance of sludge.(4)Combined with the content of fluorescent substances,functional group distribution,and sludge morphology,It was speculated that the possible mechanism of microwave combined with hydrogen peroxide to adjust the dewatering performance of excess sludge is as follows: Hydrogen peroxide mainly changes the stability of the sludge flocs through its strong oxidizing property,releasing the interstitial water.On this basis,the microwave breaks the wall and releases the internal bound water.At the same time,the released proteins and polysaccharides aggregate the dispersed small particles into large particles,thereby improving the dewatering performance of the sludge.