Effects Of BES Combined With CER On Acid Production By Anaerobic Fermentation Of Waste Activated Sludge

During anaerobic fermentation of excess sludge,the yield of VFA is low due to the low degree of hydrolysis and poor cracking efficiency.To solve this problem,in this study,cation exchange resin(CER)was added to the excess sludge to promote the hydrolysis of the sludge,and then sodium 2-bromoethanesulfonate(BES)was added to inhibit the activity of methanogens.By studying the cracking effect of CER pretreatment on excess sludge,the effect of CER on the acid production performance of anaerobic fermentation,the effect of CER and BES combined treatment on the acid production performance of anaerobic fermentation,and the efficiency of CER recycling,the research on the efficiency of CER recovery and utilization was conducted.The accumulation of VFA by anaerobic fermentation provides a new theoretical reference.(1)The excess sludge was pretreated by adding different doses of CER.The results showed that adding CER in excess sludge could promote the release of SCOD,and with the increasing of CER,the amount of SCOD increased gradually.When the CER content is 3.5 g/g TSS,the SCOD content in this group is 50 times of that in the blank control group within 24 hours,and 30 times of that in the blank control group within 48 hours.And the release process of SCOD is staged,the first stage comes from EPS,and the second stage comes from inside cells.(2)Adding CER in the anaerobic fermentation process of excess sludge showed that CER could promote the output of VFA in anaerobic fermentation of excess sludge,and the output of VFA with CER content of 2.0 g/g TSS was 43.68% higher than that of the blank control group.(3)BES combined with CER can increase the yield of VFA,but the composition of VFA has little change.Compared with the blank control group,the VFA yield of the experimental group added with BES increased by 59.91% on average.The addition of BES can slightly improve the activities of protease and CODH enzyme,and at the same time,it has a strong inhibitory effect on coenzyme F420.BES can also lead to the transformation of humic substances and further cracking of sludge.The results of microbial community identification showed that the relative abundance of Methanobacterium decreased greatly with the dosage of BES.When the BES concentration was 20 mmol/L,the relative abundance of Methanobacterium was the lowest,which resulted in the accumulation of VFA.(4)The research of recycling CER shows that the VFA of the recycled CER is 2.85%lower than that of the original CER.The acid production efficiency of recycled CER is weaker than that of original CER.