潜流人工湿地处理污染河水冬季运行及升温强化处理研究

考察了冬季潜流人工湿地污染河水处理系统在不同水力负荷下对污染物去除的效果.结果表明,水温15℃左右时,水力负荷由30cm/d降低到15cm/d后,氨氮转化率由14%上升到39%,COD的平均去除率由20%上升到31%,水温的降低对氨氮去除效果有很大的影响.在湿地表面覆盖塑料地膜能有效地提高系统对污染物的去除效果,覆盖地膜后,氨氮平均去除率由29.4%上升到67.6%,COD的平均去除率由29.0%提高到46.6%,脲酶活性由0.025 mg/(g·d)上升到0.037 mg/(g·d),脱氢酶的活性由0.17μL/(d·g)上升到4.54μL/(d·g).微生物活性研究表明,覆盖地膜后系统温度的升高能提高系统中微生物的活性.植物污染物质释放试验表明,冬季地表植物腐烂会向水中释放大量的污染物质,影响系统的净化效果,因此秋季应对湿地植物及时进行收割.

Treatment Performance and Enhancement of Subsurface Constructed Wetland Treating Polluted River Water in Winter

Treatment performance of subsurface constructed wetland treating polluted river water in winter was studied. When hydraulic loading fell down from 30cm/d to 15cm/d, the average removal rates of ammonium nitrogen and COD rose up from 14% and 20% to 39% and 31% respectively. Water temperature had great influence on ammonium nitrogen removal. Membrane overlay on the wetland could improve pollutants removal efficiently. The average removal rates of ammonium nitrogen and COD could rise up from 29.4% and 29% to 67.6% and 46.6% respectively. Microorganism enzyme activity experiments show that increase of microorganism activity caused by membrane overlay contributed a lot to pollutants removal enhancement. Urease activity rose up from 0.025 mg/(g x d) to 0.037 mg/(g x d) with membrane overlay, and dehydrogenase activity rose up from 0.17 microL/(d x g) to 4.54 microL/(d x g) with membrane overlay. The pollutants releasing experiment of aquatic plants show that faded plants would release a lot of pollutants into water. Therefore, plants harvest was necessary in autumn.