[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.
Zhang
Jian
J
School of Environmental Science and Engineering, Shandong University, Jinan 250100, China. zhangjian00@sdu.edu.cn
Shao
Wen-Sheng
WS
He
Miao
M
Hu
Hong-Ying
HY
Gao
Bao-Yu
BY
D000641:Ammonia / Q000032:analysis*; D002681:China; D005618:Fresh Water / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D009930:Organic Chemicals / Q000032:analysis; D045483:Rivers; D012621:Seasons; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D000641:Ammonia; D009584:Nitrogen