河滩型复合人工湿地处理微污染河水的研究

Study on Treatment of Slight-polluted River Water by Composite Constructed Wetland in River Benchland

为分析污染负荷对河滩型复合人工湿地净化微污染河水的影响,设计了一级生态塘-潜流湿地-二级生态塘-生态沟渠的复合人工湿地工艺。结果显示,水力负荷是常规人工湿地3~8倍的情况下,进水COD、NH_(4)^(+)-N、TP浓度分别在38.5~91.2、1.82~4.49、0.41~0.90 mg/L之间,该工艺具有很好的耐冲击负荷能力。低、中污染负荷下处理后出水中3种污染物均达到Ⅲ类标准,高污染负荷下出水COD可达到Ⅳ类标准。尽管两个生态塘存在内源性有机污染物的释放,但潜流湿地和生态沟渠均能有效降解该有机污染物,最终出水浓度较低。

In order to analyze the effect of pollution load on the purification of slight-polluted river water, a composite constructed wetland technique used in river benchland was proposed, including first-level ecological pond-subsurface flow wetland-second-level ecological pond-ecological ditch. The results show that the technique has a good resistance ability to the impact of pollution load, when the hydraulic load was 3~8 times of that of conventional constructed wetland, the COD, NH_(4)^(+)-N and TP in influent were 38.5-91.2 mg/L, 1.82-4.49 mg/L, and 0.41-0.90 mg/L, respectively. After treatment, the concentrations of three pollutants in the effluent reached the class Ⅲ standard under low and medium pollution load, and the COD can reach the class Ⅳ standard under high pollution load. Although endogenous organic pollutants were released in the two ecological ponds, but the organic pollutants could be effectively degraded by both the subsurface flow wetland and ecological ditch, and the final effluent concentration was lower.