Disinfection Efficiency of the Waste Stabilization Ponds Coupled with Aquatic Plant Ponds

산화지와 수생식물 처리지를 결합한 통합 처리 시스템의 살균효율에 관한 연구

In this paper, changes of the coliform bacteria were investigated when aquatic plant pond was used for separating algal particles from waste stabilization ponds(WSPs). Three different types of integrated natural systems were operated. It was found that there were no significant interferences for the disinfection efficiency of two integrated systems (WSPs coupled with water hyacinth ponds) used for treating domestic sewage and upgrading the secondary effluent as well. However, when constructed wetland (CW) was combined with the shallow algal ponds and used for the secondary effluent, it seriously interfered with the disinfection efficiency due to the regrowth and/or after-growth of the coliform bacteria, which can readily metabolize the amino acids and sugars leached from plants. In order to find out the primary disinfection parameters, several sets of the batch test were run. It was found that sunlight is the most predominant factor for the coliform decay. During the night, algal toxicity partly supports the decay but during the day, deteriorates it by attenuating the sunlight. The pH in the range of 4 to 10 did not affect the decay in the dark.