The Influence On Microwave Pretreatment Of Sludge Anaerobic Digestion And Dewatering Performance

Nowadays, people pay more and more attention to the environmental issue of sludge reduction. The reduction, stabilization and harmless research has important practical value. This paper use online mobile standing wave microwave reactors to pretreat activated sludge and combine with anaerobic digestion to achieve the purpose of reduction and recycling.This issue verifies microwave performance of anaerobic digestion and dewatering performance of sludge by pretreatment of different microwave irradiation. We pretreat activated sludge in different radiation conditions of:400W,60s,800W,30s;400W,300s,800W,150s and100W,2400s,1000W,240s Through three sets of experimental conditions on sludge,we evaluates sludge anaerobic digestion performance from the rate of organic matter degradation、SCOD、 the cumulative amount of bio-gas production and sludge retention time.Evaluates sludge dewatering performance through the vacuum pump filtration time and filtration sludge moisture content.According to the experiment we can draw the following conclusions:1. Microwave pretreated sludge effectively promotes the anaerobic digestion of sludge. With a gradual increase of the microwave power feed into the energy increases, the broken rate of sludge increases and the organic ingredients are fully degradable. The highest organic matter degradation rate reaches56.1%. This is conducive to sludge reduction and harmless, and significantly improved the cumulative amount of bio-gas production can be increased up to54.4%.2. Microwave pretreatment can significantly improve sludge dewatering performance. This is very beneficial for the subsequent treatment of the sludge.Sludge dewatering problems can be solved to some extent. But we should also notice that the dewatering process of sludge after the vacuum pump filtration:sludge moisture content just a little better than non-radiation rate, only1.7%to4.4%, this does not completely solve the difficult crux of dewatering, still needs to cooperate with other methods to further reduce the moisture content of sludge. 3. Microwave pretreatment can significantly shorten the anaerobic digestion time, reducing the sludge retention time (SRT).For sludge treatment and disposal this is significant. Shorten sludge retention time can not only reduce energy consumption, save water, electricity and heat consumption;but also increase the processing capability of the equipment, which can significantly reduce the construction costs, reduced investment.4. Efficiency and energy consumption of microwave radiation sludge theoretical calculations can be concluded that:microwave pretreated sludge can improve the effectiveness of sludge treatment. Simply consider the microwave energy consumption and income factors, microwave pretreatment combined with anaerobic digestion process sludge is more efficient compared with a separate anaerobic digestion process.This is worth further analysis and discussion.