引黄水库水人工湿地预处理效能研究

Study on pretreatment effect of water supply in reservoirs of Yellow River by using constructed wetland

采用上下回流式人工湿地系统处理引黄水库水,同时考察了水力负荷、水力停留时间、温度以及植物的生长状况等对人工湿地系统处理效果的影响.结果表明,上下回流式人工湿地系统对引黄水库水有较好的处理效果,COD、TP、TN、NH4+—N、NO3-—N、NO2-—N的平均去除率分别为56.61%,51.35%,59.84%,56.39%,61.17%和69.14%.按照国家地表水环境质量标准(GB3838—2002),经过该湿地系统处理后,出水COD平均值达到Ⅰ类水质标准;出水TP平均值达到Ⅱ类水质标准;出水TN平均值达到Ⅳ类水质标准;出水NH4+—N平均值达到Ⅱ类水质标准.另外,研究表明,本系统在水力停留时间为3 d时,水力负荷为0.2 m/d处理效果最好,温度的变化与污染物的去除率呈正相关关系,植物生长旺盛程度直接影响着整个系统的处理效果.

The up and down flow subsurface constructed wetland is used to treat the water which from the reservoirs of the Yellow River, and the influence of hydraulic load, hydraulic retention time, temperature and the growth of plants on the constructed wetland＇ s treatment effect are investigated. The results show that the up and down flow subsurface constructed wetland performed well, the average removal rates of COD, TP, TN, NH4^＋ - N, NO3^- - N, NO2^- - N are 56.61% , 51.35% , 59.84% , 56.39% , 61.17% and 69.14% respectively. According to the China standard for surface water resources （GB3838--2002） , after the treatment of the wetland, Mean effluent COD can reach nearly Grade Ⅰ . Mean effluent TP can reach Grade Ⅱ. Mean effluent TN can reach GradeⅣ. Mean effluent NH4^＋ -N can nearly reach Grade Ⅱ. Otherwise, the research also show that when the hydraulic retention time is 3 d, and the hydraulie load is 0.2 m/d the wetland system has the best treatment effects. The change of the temperature is positively correlated with the removal rates of the pollutants. The growth degree of the plants affected the treatment effects of the whole system directly.