Microwave Chemistry Synergistic Hydrolysis Acidification/Aerobic Composting To Degrade Organic Pollutants In Sludge

Persistent organic pollutants have a biological amplification effect and have"three causes"（carcinogenic,teratogenic,and genetic mutation）effects.The direct application of sludge with a high content of organic pollutants will have a serious impact on the safety and effectiveness of the sludge for agricultural use,it needs to be degraded when used in agriculture.This thesis takes municipal sludge as the research object.Through hydrolytic acidification,microwave chemical hydrolysis acidification and aerobic composting of sludge,the degradation and removal of sludge polycyclic aromatic hydrocarbons,benzo（a）pyrene and mineral oil in different treatment processes are studied.Circumstances,the results are as follows:（1）The optimal conditions for hydrolysis and acidification were determined based on the soluble organic matter SCOD and p H changes.Under the optimal conditions,the effects of different reflux ratio and reaction time on the removal rate of polycyclic aromatic hydrocarbons,benzo（a）pyrene and mineral oil were studied.The results showed that when the inoculation rate was 20%,the reaction temperature was 45℃,the reaction time was 48h,and the water content was 97%,the sludge hydrolysis and acidification effect was better,the p H was 3.54,and the SCOD was 31400mg/L.Under the condition of 200%reflux ratio,hydrolysis acidification can remove 34.43%of mineral oil,28.67%of polycyclic aromatic hydrocarbons,and 18.23%of benzo（a）pyrene.When the residence time is 15h,the removal rate of mineral oil is 32.28%,the removal rate of polycyclic aromatic hydrocarbons is25.47%,and the removal rate of benzo（a）pyrene is 10.17%.（2）Based on the study of hydrolysis and acidification,the effects of microwave reaction conditions,sophorolipid and H₂O₂addition on the removal of polycyclic aromatic hydrocarbons,benzo（a）pyrene and mineral oil were explored.Microwave radiation can accelerate the fragmentation of sludge particles and dissolve intracellular substances;sophorolipids can improve interface contact activity and promote the desorption of organic pollutants;strong oxidant H₂O₂can oxidize organic pollutants;the combination of the three promotes the hydrolysis and acidification reaction,increases the contact range of oxidants and pollutants,so that the removal rate of mineral oil reaches 47.2%,the removal rate of polycyclic aromatic hydrocarbons reaches 37.05%,and the removal rate of polycyclic aromatic hydrocarbons reaches 37.05%.（a）The removal rate of pyrene reached 17.84%.（3）The aerobic composting experiment studied the effects of different pretreatments on the aerobic composting process and the degradation of organic pollutants,and analyzed the clinker nutrients.The results show that the hydrolytic acidification treatment can shorten the aerobic composting time by 2 days,and the concentrated sludge is 1 day earlier than the dewatered sludge composting.Hydrolytic acidification pretreatment can increase the removal rate of mineral oil by 6.55%,polycyclic aromatic hydrocarbons by 18.42%,and benzo（a）pyrene by 5.9%;microwave chemical hydrolysis and acidification pretreatment can increase the removal rate of mineral oil by 13.16%,polycyclic aromatic hydrocarbons Increased by 24.07%,benzo（a）pyrene increased by 14.74%.Both hydrolytic acidification pretreatment and microwave chemical hydrolysis acidification pretreatment can promote aerobic compost maturity and degradation of organic pollutants,and microwave chemical hydrolysis acidification has a stronger promoting effect.The organic pollutant content of the sludge after aerobic composting meets the"Agricultural Sludge Pollutant Control Standard"（GB 4284-2018）.The loss of total nitrogen and phosphorus is too large,and the organic matter content of the sludge is in line with"Agricultural Mud Quality of Sludge Disposal of Urban Wastewater Treatment Plant"（CJ/T 309-2009）.39 pictures,13tables,80 references.