摘要
接种城市污水厂二沉池污泥,以乙酸钠为碳源,通过合理控制NO_(3)^(-)-N浓度和COD/NO_(3)^(-)-N启动短程反硝化(PD),并考察了长期投加不同Cd^(2+)浓度的PD性能、胞外聚合物EPS和微生物群落变化。经过84 d的驯化成功启动PD,出水NO_(2)^(-)-N浓度和亚硝酸盐积累率(NAR)均处于较高水平,其最高值分别为33.94 mg/L和81.24%,系统平均NAR为71.99%。Cd^(2+)胁迫试验表明,与空白对照组S1相比,S2(2.5 mg/L)、S3(5 mg/L)和S4(10 mg/L)均呈现不同程度的短程反硝化性能恶化趋势,到第36天S2、S3和S4平均NAR分别下降了12.48%、14.59%和19.00%,但在高浓度Cd^(2+)(5、10 mg/L)条件下,系统仍具有较高的NAR。重金属对微生物活性的毒性抑制导致S2的EPS含量高于S3和S4的EPS含量,EPS含量显著增加说明微生物通过分泌大量EPS来吸附Cd^(2+)。微生物高通量测序表明,变形菌门、拟杆菌门和绿弯菌门居PD系统主导地位,反应器NO2^(-)-N积累菌属Thauera的丰度表现为S2(2.13%)>S3(0.28%)>S1(0.2%)>S4(0.1%),表明10 mg/L的Cd^(2+)不利于Thauera菌属生长,Cd^(2+)浓度低于5 mg/L时Thauera菌属有生长的趋势。
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 NO_(3)^(-)-N concentration and COD/NO_(3)^(-)-N,and the performance of partial denitrification with different concentrations of Cd^(2+),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 Cd^(2+)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 Cd^(2+)(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 Cd^(2+).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 Cd^(2+)was not conducive to the growth of Thaurea,and when the concentration of Cd^(2+)was lower than 5 mg/L,Thaurea tended to grow.
作者
李鸿
张立秋
张绍青
李淑更
薛嘉俊
刘晓玲
姚海楠
陈思宇
LI Hong;ZHANG Li-qiu;ZHANG Shao-qing;LI Shu-geng;XUE Jia-jun;LIU Xiao-ling;YAO Hai-nan;CHEN Si-yu(School of Civil Engineering,Guangzhou University,Guangzhou 510006,China;Key Laboratory for Water Quality and Conservation of the Pearl River Delta,Guangzhou 510006,China;School of Environmental Science and Engineering,Guangzhou University,Guangzhou 510006,China)
出处
《中国给水排水》
CAS
CSCD
北大核心
2021年第5期10-16,25,共8页
China Water & Wastewater
基金
国家自然科学基金:资助项目(51478127,51708140)
广州市科技计划项目(201510010051)。
