Performance of a subsurface-flow constructed wetland in Southern China

Abstract： The operational performance of a full-scale subsurface-flow constructed wetland, which treated the mixed industrial and domestic wastewater with BOD5/COD mean ratio of 0.33 at Shatian, Shenzhen City was studied. The constructed wetland system consists of screens, sump, pumping station, and primary settling basin, facultative pond, first stage wetland and secondary stage wetland. The designed treatment capacity is 5000 m3/d, and the actual influent flow is in the range of <2000 to >10000 m3/d. Under normal operational conditions, the final effluent quality well met the National Integrated Wastewater Discharge Standard(GB 8978-1996), with the following parameters(mean values): COD 33.90 mg/L, BOD5 7.65 mg/L, TSS 7.92 mg/L, TN 9.11 mg/L and TP 0.56 mg/L. Seven species of plants were selected to grow in the wetland: Reed, Sweetcane flower Silvergrass, Great Bulrush, Powdery Thalia and Canna of three colours. The growing season is a whole year-round. The seasonal discrepancy could be observed and the plants growing in the wetland are vulnerable to lower temperature in winter.The recycling of the effluent in the first stage of the wetland system is an effective measure to improve the performance of the wetland system. The insufficient DO value in the wetland system not only had significant effect on pollutants removal in the wetland, but also was unfavourable to plant growth. The recycling of effluent to the inlet of wetland system and artificial pond to increase DO value of influent to the wetland is key to operate the subsurface constructed wetland steadily and effectively. 作 者： SHI Lei    WANG Bao-zhen    CAO Xiang-dong    Wang Jin    LEI Zhi-hong    WANG Zhi-ren    LIU Zheng-ying    LU Bing-nan   作者單位： SHI Lei,WANG Bao-zhen,Wang Jin,LU Bing-nan(Faculty of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150006, China.)

CAO Xiang-dong,WANG Zhi-ren(Longgang District Environmental Protection Agency of Shenzhen City, Longgang District, Shenzhen 518000, China)

LEI Zhi-hong(Shenzhen Institute of Environment Science, Shenzhen 518000, China)

LIU Zheng-ying(Longtian Shatian Sewage Manage Co., Ltd., Shenzhen 518000 China) 

期 刊： 環(huán)境科學學報(英文版)  ISTICSCI   Journal： JOURNAL OF ENVIRONMENTAL SCIENCES  年，卷(期)： 2004, 16(3)  分類號： X703  Keywords： subsurface-flow constructed wetland    operational performance    marsh plants    pre-treatment    facultative pond