LI Hong,ZHANG Li-qiu,ZHANG Shao-qing,et al.Effects of Cd2+ Stress on Partial Denitrification and Change of Microbial Community[J].China Water & Wastewater,2021,37(5 5):10-16.
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Effects of Cd2+ Stress on Partial Denitrification and Change of Microbial Community

China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU] volume: 第37卷 Number: 5 5 Page: 10-16 Column: Date of publication: 2021-03-01
Author(s):
LI Hong1; 2; ZHANG Li-qiu1; 2; ZHANG Shao-qing1; LI Shu-geng2; 3; XUE Jia-jun1; 2; LIU Xiao-ling2; 3; YAO Hai-nan1; 2; CHEN Si-yu2; 3
(1. School of Civil Engineering, Guangzhou University, Guangzhou 510006, China; 2. Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Guangzhou 510006, China; 3. School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China)
Keywords:
partial denitrification; sodium acetate; cadmium stress; extracellular polymeric substances; microbial community
Abstract:
Using the sludge from the secondary settling tank of the municipal wastewater treatment plant as the inoculation sludge and sodium acetate as the carbon source,partial denitrification (PD) was started through reasonable control of NO3--N concentration and COD/NO3--N,and the performance of partial denitrification with different concentrations of Cd2+,the extracellular polymeric substances（EPS） and microbial community changes were investigated.The results showed that after 84 days of domestication, partial denitrification could be successfully started,and the NO2--N concentration of the effluent and nitrite accumulation rate (NAR) were at a relatively high level, with the highest values of 33.94 mg/L and 81.24%,the average NAR was 71.99%.The Cd2+ stress test showed that compared with the blank control group S1, S2 (2.5 mg/L),S3 (5 mg/L) and S4(10 mg/L) all showed different degrees of deterioration of partial denitrification performance. By the 36th day,the average NAR of S2,S3 and S4 decreased by 12.48%,14.59% and 19.00% respectively. Under the condition of high concentration Cd2+(5 mg/L and 10 mg/L), the system still had a higher NAR. The toxicity inhibition of heavy metals on microbial activity resulted in the EPS content of S2 being higher than that of S3 and S4. The significant increase in EPS content indicated that the microorganisms secreted a large amount of EPS to adsorb Cd2+. High-throughput sequencing showed that Proteobacteria, Bacteroidetes and Chloroflexi were dominant in partial denitrification system, and the abundance of Thauera was S2(2.13%)＞S3(0.28%)＞S1(0.2%)＞S4(0.1%), indicating that 10 mg/L of Cd2+ was not conducive to the growth of Thaurea, and when the concentration of Cd2+ was lower than 5 mg/L,Thaurea tended to grow.
Last Update: 2021-03-01