Erosion characteristics of ecological sludge evapotranspiration cover slopes for landfill closure

Abstract

The runoff and sediment processes under different conditions are investigated by the laboratory tests performed in ecological sludge evapotranspiration cover slopes of landfill closure. Erosion caused by rainfall is investigated in the bare slope and vegetation litter layer. Erosion easily occurs when the condition of the bare slope reaches 100 % coverage. The different matrices for sediment control are crucial for the specific condition. The ecological sludge evapotranspiration technology (EST) composite matrix has been prepared by modified sludge added with fiber and a piece of net. Under the condition of 30° slope and 80 mm/h rainfall intensity, modified sludge and clay have a similar basic runoff tendency. The modifier sludge naked slope reduces approximately 20 % the sediment value compared with that of clay naked slope. The EST composite matrix could provide the smallest sediment value in both non-vegetation and vegetation conditions. Vegetation in the modified sludge has a significantly faster growth than that for the cases of clay. The results show that EST composite matrix with grass used as the vegetation layer of the landfill cover system is very important and obviously feasible.