以上海市老段浦I、II和北夏3座水平潜流人工湿地黑臭河道处理系统为研究对象,进行了水平潜流湿地处理黑臭河道氨氮的转化及脱氮机理的研究。研究表明,3座人工湿地的pH值均呈弱碱性,且沿湿地水流方向变化较小。溶解氧值在0.09—0.35mg/L范围内波动,氨氮沿湿地的流向呈递减的趋势,亚硝态氮及硝态氮浓度较低。在老段浦人工湿地的同一土样中,亚硝化细菌的数量远大于硝化细菌的数量,北夏人工湿地中,湿地前端的亚硝化细菌与硝化细菌的数量近似相等,但在湿地末端亚硝化细菌数量要远小于硝化细菌的数量。原位曝气抑制反硝化反应试验研究表明,3座人工湿地都发生了"新"的脱氮途径-短程硝化-反硝化反应,其中两座老段浦人工湿地50%的氮以短程硝化-反硝化反应去除。北夏人工湿地中约20%的氮以短程硝化反硝化的途径去除。
To study the mechanism of horizontal subsurface constructed wetland, three full scale constructed wetland used to treat black-odor river were studied on pH, NH 4+-N , NO 2- -N, NO 3- -N and the number of ammonia oxidizing bacteria and nitrite oxidizing bacteria. Shaking conical flasks method was used to observe the transformation of NH +4-N under the aerobic condition. It was found that pH was alkalescence and changed slightly along with the length of con-structed wetland. Dissolved oxygen concentration ranged from 0.09 mg/L to 0.35 mg/L. The concentrations of ammonia nitrogen were characterized by a trend of decrease along with the length of all CWs. NO 3- -Nand NO -2 -Nwas always low along with the length of constructed wetlands. There were more ammonia oxidizing bacteria than nitrite oxidizing bacteria in LDP constructed wetland, whereas, the number of ammonia oxidizing bacteria was approximately equal to the number of nitrite oxidizing bacteria. In onsite artificial aeration system, it was found that partial nitrification and denitrification occurred in the CWS. Approximately 50% nitrogen was removed by partial nitrification and denitrifica-tion in two Lao duanpu constructed wetlands, and 20% in Beixia constructed wetland.