外加碳源对生物炭基潜流人工湿地净化污水处理厂尾水效能的影响  

Effect of external carbon addition on pollutants removal from the tail water of a sewage treatment plant by biochar-based subsurface flow constructed wetland

作　　者：刘勇超 陈启斌[1] 王朝旭[1] 王加勇 孙兆森 张业国 魏阳 LIU Yongchao;CHEN Qibin;WANG Chaoxu;WANG Jiayong;SUN Zhaosen;ZHANG Yeguo;WEI Yang(College of Environmental Science and Engineering,Taiyuan University of Technology;Stecol Corporation North International Engineering Co.,Ltd.)

机构地区：[1]太原理工大学环境科学与工程学院 [2]中电建市政建设集团北方国际工程有限公司

出　　处：《环境工程技术学报》2023年第4期1295-1303,共9页Journal of Environmental Engineering Technology

基　　金：山西省自然科学基金项目(201901D111066);校企合作项目。

摘　　要：生物炭作为一种多功能生态环保材料,近年来被广泛应用于人工湿地污水处理中,其可为异养反硝化提供碳源,从而提高人工湿地的脱氮能力。通过室内构建石英砂/杏仁壳生物炭基质(体积比7∶3)人工湿地,同时以石英砂基质人工湿地为对照,运行后期通过外加碳源设计不同碳氮比(C/N),且分别采用连续流和间歇流的运行方式,探究外加碳源对生物炭基水平潜流人工湿地深度净化实际污水处理厂尾水效果的影响。结果表明:外加碳源前,人工湿地的化学需氧量(COD)去除率为负,总氮(TN)和硝氮(NO_(3)^(−)-N)去除率在41 d内持续降低;而外加碳源后,石英砂单元和石英砂/生物炭单元的COD去除率分别增至37.88%~90.44%和73.60%~97.90%,TN和NO_(3)^(−)-N去除率也明显提高。在外加碳源使进水C/N为8且间歇流运行时,石英砂/生物炭单元的TN和NO_(3)^(−)-N去除率最高,分别达65.61%和74.20%。生物炭添加提高了湿地微生物生物量,同时创造了有利于反硝化作用发生的氧化还原环境,使石英砂/生物炭单元的COD、TN和NO_(3)^(−)-N去除率分别提高了5.66%~130.35%、9.34%~54.03%和8.71%~63.04%。外加碳源与生物炭添加可作为一种有效手段强化实际污水处理厂尾水人工湿地系统的脱氮效能。As a kind of multifunctional eco-friendly material,biochar has been widely used in sewage treatment by constructed wetlands in recent years,which can provide carbon source for heterotrophic denitrification and enhance nitrogen removal capacity of constructed wetland.To explore the effect of external carbon addition on deep purification of the tail water of a sewage treatment plant by biochar-based horizontal subsurface flow constructed wetland,two parallel indoor experimental units were set with quartz sand/almond shell biochar(volume ratio 7∶3)and quartz sand(the control)as the constructed wetland matrix,respectively.Moreover,in the later phase of operation,different C/N ratios were designed by external carbon addition and the operation modes of continuous flow and intermittent flow were adopted,respectively.Results showed that before external carbon addition,chemical oxygen demand(COD)removal rate of constructed wetland was negative,and total nitrogen(TN)and nitrate nitrogen(NO_(3)^(−)-N)removal rates continued to decrease during 41 days.However,COD removal rates of quartz sand and quartz sand/almond shell biochar units increased to 37.88%-90.44%and 73.60%-97.90%,respectively,and TN and NO_(3)^(−)-N removal rates also significantly increased after external carbon addition.The maximum removal rates of TN and NO_(3)^(−)-N in quartz sand/biochar unit were 65.61%and 74.20%,respectively,as the influent C/N ratio was increased to 8 by external carbon addition and the intermittent flow mode was running.Biochar addition increased the microbial biomass of the constructed wetland,and created the appropriate redox environment facilitating denitrification.Therefore,the removal rates of COD,TN,and NO_(3)^(−)-N of the wetland unit set with quartz sand/almond shell biochar increased by 5.66%-130.35%,9.34%-54.03%,and 8.71%-63.04%,respectively,compared with the control.The external carbon addition and biochar application could be an effective measure to strengthen the denitrogenation efficiency of constructed wetland

关 键 词：外加碳源 生物炭 潜流人工湿地 污水处理厂尾水 硝态氮 

分 类 号：X703[环境科学与工程—环境工程]