Study On Targeted Microwave Treatment Of Municipal Dewatered Sludge

Municipal dewatered sludge refers to the solid residue produced by dewatering wet sludge by drainage or filtration.In recent years,the production of municipal sludge has increased sharply.In 2020,the annual output of municipal sludge in China has exceeded 60 million tons.The increasingly severe situation of sludge treatment has seriously hindered the progress of environmental protection and treatment in China.At present,the current situation of municipal dewatered sludge treatment in China mainly has some problems,such as imperfect process,low treatment efficiency and difficult degradation of complex components.Therefore,it is imperative to improve and innovate the municipal dewatered sludge treatment process.In this paper,a new targeted microwave treatment method for organic matter of municipal dewatered sludge is proposed.Compared with the traditional conventional heating treatment of municipal dewatered sludge,microwave treatment has the advantages of high efficiency,energy saving,uniform heating,disinfection and sterilization,and is easier to reduce,stabilize and clean the sludge.Targeted materials can make the sludge temperature rise faster,react with the organic matter in the sludge,make the sludge treatment more thorough and consume less resources.In this paper,the microwave treatment effect of photocatalysts including nano titanium dioxide,nano zinc oxide,nano zirconia aqueous solution and nano titanium dioxide aqueous solution on municipal dewatered sludge was studied;The effects of nano magnetic iron oxide,nano magnetic Fe3O4 microspheres and nano Mg O ethanol dispersion on microwave treatment were investigated;From hydrogen peroxide,sodium hypochlorite solution,manganese dioxide,potassium permanganate and other oxidants,the best oxidant is the compound solvent of sodium hypochlorite solution and manganese dioxide;The best extractant was selected from ethanol,dimethyl carbonate and tributyl phosphate;From the point of view of promoting sludge targeted microwave and solidification residue treatment,the best curing agent was selected as liquid water glass;The effects of the dosage of sodium bicarbonate,anhydrous sodium sulfate,trisodium citrate and sodium hydroxide on the reduction of sludge organic matter in microwave sludge treatment were studied;The cost and application market of targeted microwave treatment process for municipal dewatered sludge are analyzed.Finally,the most suitable process method for targeted microwave treatment of municipal dewatered sludge was developed.When the amount of municipal dewatered sludge was 10 g,the microwave power was 700 W and the microwave time was 2min,the amount of nano titanium dioxide was 0.1%,the amount of manganese dioxide was 2%,the amount of liquid water glass was 2% and the amount of anhydrous sodium sulfate was 5%.After this treatment,the organic matter content of municipal dewatered sludge was reduced by 41.44%,and a light building filling material with a density of 0.8592g/m L was obtained.