Land Application of Sewage Sludge Landfill Leachate

摘要

This investigation evaluated the feasibility of the 'living filter' concept as an alternative method of heavy metal leachate disposal to prevent contamination of groundwaters. Leachate collected from a simulated sewage sludge landfill was applied at rates of 0, 200, 400, and 600 Kg N/ha/yr to plots of rye grass (L. perenne) to evaluate the attenuation of contaminants. The concentrations of metals Cd, Cu, Fe, Ni, Pb, and Zn, as well as nitrogen content, were analyzed over a 5 month period in soil, soil-water lysimeter extracts, and grass samples before, during and after application of landfill leachate. Exchangeable nitrogen concentrations in soil were significantly higher at the 600 Kg, KgN/ha/yr rate while significantly greater concentrations were retained within the surface 30 cms. Soil-water extracts were significantly higher at the 400 and 600 Kg N/ha/yr rate and also highest in the surface layers.