Abstract:

In this research, we used an improved multilayer infiltration system to treat the slightly polluted reservoir water of the Shangzhuang Reservoir in the Haidian District of Beijing. Multi-transitional layers were adopted to increase the interface contact between the suspended organic matter and oxygen. In addition, an aeration device was used to increase oxygen supply so that the water hydraulic application loading can be greatly increased. The removal efficiencies of COD_Cr, TN, NH⁺₄-N, and TP were 48.57% to 94.87%, 18.49% to 70.21%, 20.51% to 87.50% and 56.92% to 80.65%,respectively. Furthermore, these effluent concentrations met the standard of classⅢ-Ⅳ for surface water. Biological nitrogen removal through nitrification and denitrification was the main removal mechanism of nitrogen. Phosphorus in waste water was mainly removed by fixation processed in the soil, such as adsorption and chemical precipitation.

Key words: multilayer infiltration system, nitrification, nitrogen and phosphorus removal, pilot