| Bisphenol compounds(BPs)are a group of environmental organic pollutants,which have endocrine disrupting effects on organisms in the environment.However,current studies have only focused on the toxicology,analytical methods and the occurrence of in daily consumer products,and information on their environmental behavior is yet limited.In the present study,the detection level and frequency of 10 BPs in different sewage treatment plants located in Shenzhen was determined,the pollution characteristics and removal of the tested BPs in sewage treatment plants were analyzed.The fate of 10 BPs in influent,effluent and activated sludge was investigated using a simulated continuous flow activated sludge bioreactor in the laboratory.In addition,we also emphasized on the degradation of bisphenol S and kinetics of BPS-degrdading microorganisms.The purpose of this study is to help us better understand the environmental behavior and environmental risk assessment of BPs and provide a scientific thought and guidance for the removal of BPs in wastewater treatment.The main results in this thesis are as follows:1.A trace analysis method for bisphenols in sewage and sludge was established,and the distribution characteristics of 10 bisphenols in four representative sewage treatment plants(W1,W2,W3 and W4)in Shenzhen were revealed.The results showed that bisphenol compounds were mainly discharged into the environment through the effluent of the sewage treatment plant.The discharge fluxes of the sewage from the four sewage plants were 3599.79 g / d,2275.65 g / d,5523.82 g / d and359.55 g / d,respectively.Per capita emissions are 0.165-0.792 mg/ person / day.In the influent,BPA(614.46 ng/L and 522.97 ng/L)was the highest in W1 and W2,and BPB(329.73 ng/L)and BPZ(390.17 ng/L)in W3 and W4 were the highest.In the effluent,BPA(272.95 ng/L)was the highest in W1,BPZ(271.2 ng/L and 319.26 ng/L)was the highest in W2 and W3,and BPF(487.12 ng/L)was the highest in W4.In the sludge,BPAP(223.41 ng/g and 288.36 ng/g)had the highest detection in W1 and W2 wastewater treatment plants,BPZ(355.18 ng/g)has the highest detection capacity inW3 sewage treatment plant,and BPF(357.21 ng/g)has the highest detection capacity in W4 sewage treatment plant.Spearman grade correlation analysis showed that BPZ was positively correlated with HRT(HRT)and wastewater treatment capacity(WTC),and BPAF was negatively correlated with total organic carbon content(TOC).It is shown that the removal of BPZ and BPAF is related to HRT,WTC and TOC.2.The fate of 10 BPs in the influent,effluent and activated sludge was investigated using a simulated continuous flow activated sludge bioreactor in the laboratory.The extraction recoveries were in the range of 79.52-98.95%.Among them,Five bisphenolic compounds BPA,BPB,BPE,BPF and BPA(BPA class)show the trend of stable and then decrease in effluent and sludge.For example,the concentration of BPA in the effluent increased from 0 μg/L to 1366.6 μg/L in pH=9 reactor within 5days,then maintained at about 1300 μg/L,and decreased to 0 μg/L from the 10 th day,and the removal rate was 100%.The effluents of BPM,BPZ,BPAF,BPAP and TCBPA(TCBPA class)of bisphenolic compounds were increased first and then stabilized.For example,the concentration of TCBPA in the effluent tends to be stable after rising to 367.8 μg/L in the first 5 days,and the removal rate is about 40%.In addition,the effect of pH on the concentration of BPS was significant,which showed that the residue of BPS in neutral condition was higher than that in alkaline condition.For example,on the 13 th day,the amount of BPS detected in the effluent of pH=7 and pH=9 reactors was 1180.8 μg/L and 327.5 μg/L,respectively.3.The degradation kinetics and product composition of typical bisphenol compound BPS in sewage and sludge were studied.at the same time,the community structure,diversity and abundance of BPS degraded microorganisms were revealed,and the effect of organic matter on the above behavior was discussed.The results showed that bisphenol S was easy to be degraded in the process of activated sludge treatment,and the removal rate reached 100% in 7 days.The degradation product was determined to be 4-hydroxyl-(methyl)benzenesulfonic acid.Analysis based on 16 S rRNA gene deep sequencing expanded the knowledge of BPS degrading microbial community in bioreactors.The dominant phyla were Proteobacteria,Bacteroidetes,Acidobacteria and Chloroflexi.Seven major genera might be associated with BPSremoval,which were Pseudomonas,Azospira,Hydrogenophaga,Devosia,Delftia,Acidovorax and Rhodobacter.They were all affiliated to Proteobacteria.The addition of humic acid could facilitate the BPS removal and increase relative abundance of Pseudomonas,Hydrogenophaga and Acidovorax. |
