洋湖生态新城水环境生态再生工艺及净水效果

Water Environment Ecological Regeneration Process and Its Purification Efficiency in Yanghu Ecological New Town in Changsha

建立了以湿地技术为核心工艺的城市水环境生态再生工艺系统，生活污水经组合工艺“MSBR＋人工湿地＋自然湿地”净化并再生利用。MSBR排放的尾水经三级复合型人工湿地净化后，水质可由一级B标准提升到一级A标准，人工湿地出水COD、SS、TN和TP日均值分别约为15．9、6、11．5和0．43mg／L，相应的去除率约为40．0％、57．1％、22．3％和32．8％。自然湿地中的溶解氧为5．8—7．2mg／L，水体水质最终稳定在地表水Ⅲ类标准（GB3838-2002），COD、TN和rrP日均值分别约为15、0．50和0．10mg,／L，对TN、TP的去除率分别约为95．7％、76．7％。组合工艺“MSBR＋人工湿地＋自然湿地”对COD、TN和TP的总去除率分别达到88．6％、97．4％和93．7％。

An urban water environment ecological regeneration process system was established, and wetland ecological regeneration technology was employed as core process. The collected sewage was purified and reclaimed by a combined process system consisting of modified sequencing batch reactor （ MSBR）, constructed wetland （CW） and natural wetland （NW）. The effluent from MSBR could be up- graded from the first class B criteria to the first class A criteria by a three-stage hybrid CW system. The average daily concentrations of COD, SS, TN and TP in the effluent from the CW were about 15.9 mg/ L, 6 mg/L, 11.5 mg/L and 0.43 mg/L respectively, and the corresponding removal rates were 40.0%, 57. 1% , 22.3% and 32.8% respectively. The dissolved oxygen in NW was about 5.8 to 7.2 mg/L, and the final effluent quality met the classⅢ criteria specified in the Environmental Quality Standards for Surface Water （GB 3838 -2002）. The average daily concentrations of COD, TN and TP were 15 mg/L, 0.50 mg/L and 0.10 mg/L respectively, and the removal rates of TN and TP were 95.7% and 76.7% respectively. The total removal rates of COD, TN and TP in the developed urban water environment ecological regeneration process system were 88.6%, 97.4% and 93.7% respectively.