组合人工湿地对城镇污水处理厂尾水中有机物的去除特征研究

A pilot-scale study on removal characteristics of organic substances in municipal sewage plant effluent by a hybrid constructed wetland

采用物理分级和三维荧光光谱法,研究了组合人工湿地对城镇污水处理厂尾水中不同形态有机物的去除特征.结果表明,组合人工湿地对污水处理厂尾水具有较好的深度处理效果,出水水质基本可以达到国家地表水环境质量标准(GB38382-2002)Ⅲ或Ⅳ类水标准.组合人工湿地处理系统对尾水中CODCr和BOD5总体去除率分别达到35.2%和44.3%,对尾水中总有机碳(TOC)、溶解性有机碳(DOC)、颗粒有机碳(POC)的平均去除率分别为46.9%、45.9%、48.3%.组合人工湿地系统不同单元对尾水中有机物的去除贡献率存在差异,其中,潜流湿地单元对尾水中CODCr和BOD5及其不同组分有机碳的去除效率较高.试验期间,由于藻类滋生,表流湿地单元出水中有机物含量波动较大,去除效果明显降低,藻类被打捞后,出水水质明显改善.三维荧光光谱分析结果显示,各个处理单元取样点的水样三维荧光光谱均出现4个明显的荧光峰.人工湿地各单元出水溶解性有机质(DOM)中,类蛋白和类腐殖酸物质含量较高,类富里酸物质含量较低.人工湿地对类蛋白和类腐殖酸物质有较强的去除作用.

A hybrid constructed wetland（HCW） was applied at pilot scale for advanced treatment of municipal sewage plant effluent.The characteristics of different forms of organic matter in influent and effluent samples from the HCW were investigated with physical fractionation and three-dimensional fluorescence spectroscopy.The results indicate that the HCW can purify the municipal sewage plant effluent with excellent efficiency.The quality of effluent water can reach class-Ⅲ or Ⅳ criteria（GB3838-2002）.In this study,the HCW removed 35.2% CODCr and 44.3% BOD5,46.9% total organic carbon（TOC）,45.9% dissolved organic carbon（DOC）,and 48.3% particulate organic carbon（POC）.Compared to other treatment units in the HCW,subsurface flow constructed wetlands showed relatively higher removal efficiency for organic substances.However,due to the blooming of alga,the removal rates of organic substances decreased during the experiment.Of course,the quality of the effluent improved when the alga was cleaned.In addition,four different types of peaks were found in each treatment unit based on the three-dimensional fluorescence spectroscopy analysis.The majority of the organic compounds in the HCW effluent were high protein-like and humic acid-like substances;few were fulvic acid-like substances.In conclusion,the HCW has high removal efficiencies for protein-like substances and humic acid-like substances in effluent from a municipal sewage plant.