摘要
以异养硝化-好氧反硝化菌为主体,构建了微氧-缺氧双区式微生物电解池MEC(R1),并以缺氧单区MEC(R2)作为对照组,采用连续进水方式,研究其对低C/N比轻度污染废水的脱氮处理效果及微生物强化机制。结果表明,在进水COD 70~80 mg/L、TN质量浓度35~40 mg/L、电流3m A、溶解氧(DO)质量浓度0. 5~1. 0 mg/L的条件下,连续运行约1个月后,R1出水COD、TN质量浓度即可达到一级A排放标准;当C/N比为2~5时,R1出水TN质量浓度为(4. 90±1. 08)^(14. 50±0. 133) mg/L,COD为(8. 20±2. 36)^(12. 53±5. 03) mg/L,均达到了一级A标准,硝化-好氧反硝化及弱电强化作用是脱氮和COD去除的主要途径。高通量测序分析结果表明,R1中细菌多样性虽与R2相当,但细菌丰富度明显大于R2;而且,R1中的贫营养硝化反硝化菌属Zoogloea丰度明显大于R2,且含有自养型反硝化菌属Moheibacterm、好氧反硝化菌属Ferruginibacter和Denitratisoma及可为反硝化提供聚β-羟丁酸的Plasticicumulans菌属。研究表明双区式MEC可有效处理低COD、低TN、低C/N比的废水,且具有启动快的特点,具有良好的应用潜力。
The given paper intends to pursue and assess the feasibility for treating the lower C/N slightly polluted sewage by means of a novel dual-stage microbial electrolysis cell (MEC) (R1). The reactor R1 consists of the micro-oxygen stage (R11)and the anoxic stage (R12),which have been inoculated via the heterotrophic nitrification-aerobic denitrifying (HN-AD) bacteria and the activated sludge from the secondary clarifier,respectively. For the treating purpose,we have set up the anoxic single MEC (R2) with the activated sludge inoculation as the control object. During the entire startup period,it is necessary to keep the operation condition of the 2 reactors with the influent COD of70-80 mg/L and the influent TN of 35-40 mg/L at the current of 3 mA,with the dissolved oxygen being 0. 5-1. 0 mg/L,and the hydraulic retention time being as long as for 12 h. The results of our testing experiment indicate that the effluent COD and TN of R1 can be expected to meet the emission standard of level A through a continuous operation for about one month,though R2 may not be successful. However,once the startup goes successful with the increase of C/N ratio from 2 to 5,it would be possible for the effluent TN concentrations of R1 to decrease from (14. 50 ± 0. 133) mg/L to (4. 90 ± 1. 08) mg/L,whereas the effluent fluctuation of the COD concentrations can be made stable to be kept between (8. 20 ± 2. 36) mg/L and (12. 53 ± 5. 03)mg/L. Thus,the treating efficiency for R1 turns to be higher due to existence of HN-AD bacteria and the light current. Furthermore,we have also analyzed the bacteria abundance situation,the actual state of the bacteria and the diversity of the structure of the bacteria communities from the point of view of high-throughput sequence. The results of the above said investigation and analysis may show that the diversity indices of the bacterial community in the 2 reactors may not be different enough,for the species richness index of R1 turns out to be higher than that in R2.Moreover,the relative abundance of Zoogloea,one of the oligotrophic simultaneous nitrification and de-nitrification bacteria,turns out to be higher with R1 than with R2. In addition,in R1,we have detected that more powerful autotrophic denitrifying bacteria of Moheibacter,aerobic denitrification bacteria of Ferruginibacter, Denitratisoma, and bacteria Plasticicumulans can be found and determined with the capacity to provide poly beta hydroxybutyric acid for aerobic identification. Thus,it can be concluded that the dual-stage microbial electrolysis cell enjoys greater potential capacity for treating the micro-polluted sewage at lower C/N ratio.
作者
赵芝清
严新杰
李新宇
陶海波
陈晓慧
许宁
ZHAO Zhi-qing;YAN Xin-jie;LI Xin-yu;TAO Hai-bo;CHEN Xiao-hui;XU Ning(Department of Environmental Engineering,Quzhou University,Quzhou 324000,Zhejiang,China;College of Environment&Resource Sciences,Zhejiang University,Hangzhou 310058,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2020年第3期1074-1082,共9页
Journal of Safety and Environment
基金
国家自然科学基金项目(21607092)
衢州学院博士科研启动项目(BSJX201601)
省级大学生科技创新活动计划暨新苗人才计划项目(2018R435002)
国家级大学生科技创新活动计划项目(201811488020)。
关键词
环境工程学
低C/N比
轻度污染废水
双区式MEC
微氧
群落结构
environmental engineering
low C/N ratio
micropolluted wastewater
dual electrodes microbial electrolysis cell
low-oxygen
community structure
