Performance of Grass Filter Strip in Copper and Zinc Removal in Surface and Subsurface Runoff

Abstract

Abstract. Three filter strips were conducted on self-designed soil bins. Taking a filter strip with no vegetation as contrast, the effectiveness of vegetation and soil conditions on heavy metals (including copper and zinc) removal efficiencies were investigated by simulated runoff experiment. The results showed that the adsorbed state is the main existing form of heavy metal. For surface runoff, most of total copper and total zinc are trapped in first 4m and it is ineffective to increase the distance beyond 4m for removal. Vegetation has no significant effect on total copper and total zinc removal, while the soil with higher content of organic matter is contributing to total Zn interception. For subsurface runoff, the removal efficiencies of total copper and total zinc can reach to above 95.38% and both vegetation and soil conditions have no significant effects. Vegetation is contributing to copper ion and zinc ion removal significantly. Soil condition is only a significant factor to zinc ion, with higher content of organic matter as a contributing factor.