Treatment of Grey Water by Subsurface Infiltration System with Different Hydraulic Loading

The treatment of grey water by subsurface infiltration system with 5 different hydraulic loadings was investigated under intermittent feeding.The results showed that the TN,NH+4-N and TP of the tested grey water and each effluent met the class Ⅰ-A criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002),but the effluent COD could only reach class Ⅲ criteria.The average removal efficiencies of turbidity,COD,NH+4-N and TP declined with the increase of hydraulic loading,while the removal efficiency of TN had no significant linear correlation with hydraulic loading.The average removal rates of turbidity,COD,TN,NH+4-N and TP were 47.09%,31.88%,22.54%,49.92% and 47.06% respectively while the hydraulic loading was 1 m3/(12 m2·4 h).The subsurface infiltration system exhibited potential for the treatment of grey water.