Treatment Performances of Capillary Infiltration System for Municipal Wastewater

The treatment performances of capillary infiltration system fed by municipal wastewater were investigated in this paper. The composite fillers were constructed in capillary infiltration system to reach the prospective treatment effects. Compared to the single filler, composite filler promoted the ventilating condition and improved the distribution situation. The higher treatment efficiencies of NH₄ ⁺-N, TN, COD and TP were achieved. It was found that the optimum hydraulic load and the ratio of feeding time and drying time (F/D) of the capillary infiltration system were 10 cm/d and 1:3 (F=45 min, D=135 min), respectively. When the hydraulic load was 10 cm/d, the removal efficiencies of NH₄ ⁺-N, TN, COD and TP were 97.9%, 29.1%, 68.4% and 89.7%, respectively. Moreover, the average removal efficiencies of NH₄ ⁺-N, TN, COD and TP were 96%, 22.3%, 68.4% and 89.7%, respectively, under the situation of 1:3 F/D. These results would provide a valuable reference to the design of practical capillary infiltration project.