负荷对渗滤系统控制农业径流污染物的影响

为了考察负荷变化对渗滤系统拦截削减农业径流污染物性能的影响，在重庆市万州高峰镇鹿山河旁建立多级渗滤系统，开展了农业径流污染物净化效果的试验研究。结果显示，系统对污染物具有较好的去除效果，对化学需氧量(COD)、氨氮(NH4+-N)、总氮(TN)和总磷(TP)的平均去除率分别为35%、73%、37%和54%。污染物出水浓度随进水负荷的升高而升高，具有明显的线性关系。单位面积污染物去除负荷与进水负荷近似服从对数关系，低进水负荷时系统运行稳定，高进水负荷时系统污染物去除负荷波动较大。随着渗滤系统级数的增加，污染物出水负荷和去除负荷沿程上均体现出逐渐降低的趋势。渗滤系统沿程污染物负荷的变化兼具滨岸缓冲带、植被过滤带和生物接触氧化池的特点。

Impacts of the loading rate on the performance of a multi-stage filtration system removing pollutants in agricultural runoff

A multi-stage filtration system was built to indicate the impact of the loading rate on its performance in removing pollutants in agricultural runoff, which was located next to Lushan river in Gaofeng Town of Chongqing . The system was adaptive to variation of inflow quality and quantity. The average removal rates of chemical oxygen demand (COD), ammonia (NH4+-N), total nitrogen (TN) and total phosphorus (TP) were 35%, 73%, 37% and 54%, respectively. The effluent concentration increased with the increase of influent loading linearly. There was a significant logarithmic correlation between removal loading per unit area of the system and influent loading. The system was stable at low influent loading, but at high influent loading, the removal rate varied more. The removal loading and the effluent loading decreased steadily with the increase of the stages. Characteristics of clarification, vegetative filter strips and biological contact oxidation pond were combined in the filtration system.