농경지역의 대규모 축산단지에서 배출되는 축산계 부하의 점오염과 비점오염 분류와 정량화

Abstract

Livestock manure discharged from agricultural areas has different treatment and fertilization processes depending on the type of livestock. Swine manure is generally treated in livestock wastewater treatment plants and then sprayed as liquid fertilizer or discharged into rivers, whereas cattle manure is composted in livestock excreta resource facilities such as biogas plants, and a large amount is applied to the land. However, the source unit of the livestock manure load applied in Korea''s total maximum daily load (TMDL) is not divided into point pollution type and non-point pollution type. The species and pollution load of livestock manure generated in Yongji Watershed where swine are the main livestock, and Dukcheon Watershed where cattle are mainly raised were investigated through a series of measurements and calculations. The result of this study showed the pollution load of livestock manure was clearly classified into PS type and NPS type, and in particular, the NPS pollution load was relatively large. As for the results measured in two watersheds of different livestock breeds, swine and cattle, BOD and TP showed high EMC concentrations in cattle breeding areas, whereas TN showed significantly higher values in swine breeding zones. This finding led us to conclude that there are differences in the water quality management criteria to be focused on depending on the type of livestock. In addition, the load of NPS was fluctuated sensitively to the rainfall intensity, and it implied that the rainfall intensity should be considered as one of the influencing factors when a pollution load of livestock manure is applied to the TMDL.