间歇流模拟人工湿地去氮除磷效果及N_2O排放的小试研究  

Experimental Study on Nitrogen and Phosphorus Removal and N_2O Emission in Batch-flow Constructed Wetlands with Three Substrates

作　　者：张志勇[1] 冯明雷[1] 杨林章[1] 王建国[1] 

机构地区：[1]中国科学院南京土壤研究所,江苏南京210008

出　　处：《农业环境科学学报》2007年第6期2129-2138,共10页Journal of Agro-Environment Science

基　　金：科技部863课题"河网区面源污染控制成套技术"(2002AA601012)

摘　　要：为研究不同基质人工湿地对氮、磷的去除效果及净化过程中N2O的排放,在温室内选用炉渣、沸石和土壤为基质,以水芹(Oenanthe javanica)、黑麦草(Lolium mutliflorum)和香根草(Vetiveria Zizanioides)为植被构建了人工湿地处理生活污水。结果表明,在较低的氮、磷负荷和水力停留时间为6d条件下,炉渣、沸石和土壤基质湿地对TN、NH4+-N、NO-3-N和TP的去除主要集中于污水停留的前3d,之后各污染物浓度下降的幅度较平缓。3种基质人工湿地系统对TN、NH4+-N和TP均表现出很好的去除效果,各系统的TN、NH+4-N和TP的平均去除率均超过91.0%;3种基质人工湿地系统对NO-3-N的去除率相对较低,为58.0%～85.5%。植物种类不同,其吸收N、P的能力存在很大差异。3种基质湿地中黑麦草对N、P的吸收能力远高于水芹和香根草;黑麦草吸收的N、P总量占各湿地系统TN、TP输入量的38.3%～57.4%和87.6%～91.1%,已成为人工湿地系统去氮除磷的主要途径;水芹和香根草的氮、磷吸收总量仅分别占各系统TN、TP输入量的9.7%～18.3%,15.6%～34.5%和4.7%～8.1%,6.1%～13.4%。炉渣、沸石和土壤湿地系统N2O的平均排放通量分别为3.68～15.19!g·m-2·h-1,4.29～8.33!g·m-2·h-1和7.03～18.94!g·m-2·h-1;整个试验期,3种基质湿地系统的N2O排放总量为4.24～21.82mg·m-2,占各系统TN输入量的0.014%～0.100%,此途径排出的N对各湿地系统TN的去除贡献很小。In greenhouse, three different constructed wetlands were established with slag, zeolite and paddy soil, respectively, as substrate, and with Oenanthe javanica,Lolium mutliflorum and Vetiveria zizanioides, respectively, as vegetation. Removal efficiencies of nitrogen, phosphorus and N2O emission from domestic sewage in three constructed wetland systems were studied. The results showed that when nitrogen and phosphorus load was low and hydraulic retention time was 6 days, the total nitrogen （TN）, total phosphorus （TP）, ammonia-nitrogen （NH4^＋-N） and nitrate-nitrogen （NO3^--N） in three different constructed wetlands were mostly removed within 3 days during wastewater retention time, but the concentrations of TN, TP, NH4^＋-N and NO3^--N decreased slowly from 3 to 6 days. The slag, zeolite and paddy soil-bed wetlands all displayed high efficiency in removing TN, NH4^＋-N and TP, with an average removal rate of over 91.0 %, but low efficiency in removing NO3^--N with a rate ranging from 58.0% to 85.5%. Different plants had different ability to assimilate nitrogen and phosphorus. The amounts of nitrogen and phosphorus assimilated by Lolium mutliflorum were much higher than those by Oenanthe javanica and Vetiveria Zizanioides. The amounts of nitrogen and phosphorus assimilated by Lolium mutliflorum, Oenanthe javaniea and Vetiveria Zizanioides accounted for 38.3%- 57.4% and 87.6%-91.1%, 9.7%-18.3% and 15.6%-34.5%, 4.7%-8.1% and 6.1%-13.4% of TN and TP inputted amounts in three different constructed wetlands, respectively, which indicated that the assimilation of N and P by Lolium mutliflorum was the main mechanism of TN and TP removal in three different constructed wetlands. The N2O flux from slag, zeolite and paddy soil-bed wetlands were 3.68-15.19 μg·m^-2·h^-1, 4.29-8.33μg·m^-2·h^-1 and 7.03-18.94μg·m^-2·h^-1, respectively. Total amounts of N2O flux was 4.24-21.82 mg·m^-2 from the three different constructed wetlands during the whole experimental periods, which accounted for 0.014%-0.100%

关 键 词：人工湿地 基质 生活污水 去除率 N2O排放通量 

分 类 号：X703.1[环境科学与工程—环境工程]