Study On Reactivation Of Aerobic Granular Sludge Stored In Different Ways And Application To Treatment Of Benzyl Chloride Wastewater

In order to explore the feasibility of treating industrial wastewater in continuous flow reactor,aerobic granular sludge?AGS?stored in different ways was successfully reactivated and then was inoculated into a continuous flow reactor to treat benzyl chloride wastewater.The results and conclusions are as follows:?1?Reactivation of AGS.The reactivation experiments were conducted in three SBRs?storage condition of sludge in R₁ reactor:20²5°C,open to air;R₂ reactor:20²5°C,sealed;R₃ reactor:4°C in refrigerator?.After 60-day-storage,AGS's color became darker and its settling property,microbial activity as well as capacity of removing pollutants worsened.Through 20-day-reactivation,granulation rates of the sludge in R₁and R₃ were beyond 98%,and sludge in R₁ and R₃ had better performance than that of R₂reactor.Because of the lack of oxygen during storage,internal filamentous bacteria grew and then led to the destruction of granular structure.Thus,in R_2,the sludge and water indexes were relatively poor.And morphologic changes,SEM images of R₂ reactor indicated that the reactivation effect of AGS stored under sealed condition at room temperature was dissatisfactory.?2?Acclimation of AGS in continuous flow reactor.AGS was used to treat benzyl chloride wastewater in a continuous flow reactor.AGS performed good capacity of decontamination and stability after the 50-day-acclimation.When proportion of the wastewater was 100%,removal rate of COD achieved 90%and removal rate of TIN was above 80%.The results of kinetic experiments showed the acclimated AGS had lower?_maxax and Y and slightly higher K_d.?3?Influence of HRT and effluent recycling upon the treatment efficiency of AGS.In order to improve the treatment efficiency,HRT?3,4,6,8 and 10 h?was changed.While the HRT was at 8 h,it was found that the settling property of AGS was relatively stable and removal rate of COD,TIN and TP were 97.0%,84.0%and 82.1%respectively.Then with HRT of 8 h,the study was conducted at different effluent recycling ratios?0.75:1,1:1 and 1.25:1 respectively?.The research result indicated that AGS's physiochemical properties and removal rate were better at the ratio of 1:1.?4?Steady operation.While the HRT was 8 h and reflux ratio was 1:1,the steady operation of AGS treating benzyl chloride wastewater was studied.During the period,AGS has changed its morphology and the MLSS kept increasing steadily with fine settling property,and the granulation rate of AGS was higher than 90%.In the later stage of the experiment,removal rate of COD and TIN both stayed above 90%.