沉积物微生物燃料电池对湿地水体中Cu(Ⅱ)去除与脱附效果的研究  

The effect of sediment microbial fuel cells on the removal and desorption of Cu(Ⅱ) in wetland water

作　　者：许亚清 李颖 李峰泉 崔静 鲍齐彦 蔡一侨 李艳丽 邓欢 XU Yaqing;LI Ying;LI Fengquan;CUI Jing;BAO Qiyan;CAI Yiqiao;LI Yanli;DENG Huan(School of Environment,Nanjing Normal University,Nanjing 210023;Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control,Nanjing 210023;College of Engineering,Nanjing Normal University Zhongbei College,Zhenjiang 212300)

机构地区：[1]南京师范大学环境学院,南京210023 [2]江苏省物质循环与污染控制重点实验室,南京210023 [3]南京师范大学中北学院工学院,镇江212300

出　　处：《环境科学学报》2024年第7期36-48,共13页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金面上项目(No.42177033)。

摘　　要：为了揭示沉积物微生物燃料电池(Sediment Microbial Fuel Cells,SMFCs)对水体重金属的去除和脱附效果及其机制,采集了海滨湿地沉积物(Coastal wetland sediments,CWS)和湖泊湿地沉积物(Lake wetland sediments,LWS)并构建SMFCs,其中,阳极室装入CWS或LWS并连接50Ω或1000Ω外阻,采用沉积物中的土著微生物产电.实验包括CWS-50Ω、CWS-1000Ω、LWS-50Ω和LWS-1000Ω共4个处理,并设置开路SMFCs作为对照.产电启动成功后,向阴极室充入Cu(Ⅱ)浓度为100 mg·L^(-1)的CuCl2溶液,开始Cu(Ⅱ)去除试验.结果显示,48 h后,CWS-50Ω、CWS-1000Ω、LWS-50Ω和LWS-1000Ω处理对Cu(Ⅱ)的去除率分别达到93.56%、95.51%、96.33%和97.75%,而断路对照的Cu(Ⅱ)去除率为5.67%.Cu(Ⅱ)去除试验结束后,将阴极室Cu(Ⅱ)溶液更换为去离子水,开始脱附试验.脱附120 min后,上述处理的Cu(Ⅱ)脱附率分别为1.15%、2.65%、2.43%和3.05%,而对照的Cu(Ⅱ)脱附率达到96.36%.脱附试验结束后取出阴极碳毡,通过XPS检测发现上述处理的阴极表面均存在Cu(Ⅱ)和Cu(0),其中,Cu(0)的比例分别达到9.38%、16.95%、21.59%和25.93%.本研究还对沉积物原始样本及所有处理阳极表面细菌的16S rRNA基因进行了测序和基因定量.结果显示,SMFCs显著增加了产电细菌相关属的优势度和细菌数量,其中,Desulfovibrio、Clostridium和Geoalkalibacter为CWS-50Ω和CWS-1000Ω阳极表面的优势产电菌属,Clostridium、Brevundimonas和Bacillus为LWS-50Ω和LWS-1000Ω阳极表面的优势产电菌属.本研究创新点在于揭示了SMFCs不仅可以高效去除水体Cu(Ⅱ)污染,还能有效避免Cu(Ⅱ)从碳毡电极上脱附,从而保证水体修复效果的长效性.本研究还阐明了Cu(Ⅱ)在阴极表面的吸附和还原是SMFCs去除Cu(Ⅱ)的机制,据此认为提升SMFCs阴极效率以增加阴极表面Cu(0)/Cu(Ⅱ)的比例有望进一步提高SMFC对水体重金属的去除效果.The objectives of this study are(1) to reveal the effectiveness of sediment microbial fuel cells(SMFCs) for heavy metal removal and desorption from the water and(2) to elucidate relevant mechanisms.Coastal wetland sediment(CWS) and lake wetland sediment(LWS) were collected to construct the SMFCs.Indigenous microorganisms in CWS or LWS sediments could generate electricity when the anode chambers were loaded with CWS or LWS and connected to 50 Ω or 1000 Ω external resistors.There were four treatments,CWS-50Ω,CWS-1000 Ω,LWS-50 Ω,and LWS-1000Ω,and open-circuit SMFCs were set as control.After the start-up of power production,the cathode chamber was filled with CuCl2 solution containing 100 mg·L^(-1) Cu(Ⅱ) to initiate the Cu(Ⅱ) removal test.The results demonstrated that after 48 hours,the Cu(Ⅱ) removal efficiencies were 93.56%,95.51%,96.33% and 97.75%,for CWS-50 Ω,CWS-1000 Ω,LWS-50 Ω,and LWS-1000 Ω treatments,respectively,whereas 5.67% for the control.Then,the Cu(Ⅱ) solution in the cathode chamber was replaced with deionized water to initiate the desorption experiment for 120 min,and the desorption rates of Cu(Ⅱ) were 1.15%,2.65%,2.43%,and 3.05%,respectively,whereas 96.36% for the control.Afterward,the carbon felts of the cathodes were taken out for XPS analysis.The results showed that both Cu(Ⅱ) and Cu(0) presented on the cathode surface,and the relative atomic content proportions of Cu(0) were 9.38%,16.95%,21.59%,and 25.93% for CWS-50 Ω,CWS-1000 Ω,LWS-50 Ω,and LWS-1000 Ω,respectively.This study also conducted sequencing and gene quantification of the 16S rRNA genes of bacteria on original sediment samples and the anode surfaces of all treatments.The results demonstrated that operating SMFCs significantly increased the dominance and quantity of exoelectrogenic bacteria associated genera.Desulfovibrio,Clostridium,and Geoalkalibacter were dominant on the anode CWS-50 Ω and CWS-1000 Ω,while Clostridium,Brevundimonas,and Bacillus were dominant on the anode LWS-50 Ω and LWS-1000 Ω.This study

关 键 词：水体修复 重金属污染 阴极效率 解吸附 产电细菌 

分 类 号：X52[环境科学与工程—环境工程]