자연정화공법에 의한 인공습지에서 효과적인 축산폐수처리를 위한 최적 전처리방법 구명

Abstract

자연정화공법에 의한 축산폐수처리장에서 효과적으로 축산폐수를 처리하기 위해 인공습지 축산폐수처리 시스템에 전처리방법으로 수생식물여과조와 활성슬러지조를 적용하여 최적 전처리방법을 조사하였다. 또한, 최적 전처리방법을 실제 현장 축산폐수처리장에 연계하여 시공한 후 전처리방법의 효율성과 안전성을 검토하였다. 수생식물여과조와 인공습지를 연계한 소형 축산폐수처리장치에서 최종방류수 중 COD, SS, T-N 및 T-P의 처리효율은 각각 83, 89, 63 및 87%이었다. 활성슬러지조와 자연정화공법을 연계한 소형 축산폐수처리장치에서 최종방류수 중 COD, SS, T-N 및 T-P의 처리효율은 각각 96, 95, 86 및 92%이었다. 수생식물여과조 및 활성슬러지조는 인공습지 축산폐수처리장의 전처리공법으로서 질소와 인 처리효율을 향상시킬 수 있어 고농도의 축산폐수를 안정적으로 처리하기 위해 필요할 것으로 판단된다. 최적 전처리방법을 연계한 실제 현장 축산폐수처리장에서 COD, SS, T-N 및 T-P 의 처리효율은 모든 조건에서 각각 99.8, 99.9, 99.2 및 99.9%으로 높은 처리효율을 보였다. In order to obtain optimum pre-treatment methods and improve T-N and T-P removal efficiencies, removal rates of pollutants in small-scale livestock wastewater treatment apparatus with water plant filtration bed or activated sludge tank were investigated. Based on the results from the optimum pre-treatment in small-scale livestock wastewater treatment apparatus, removal efficiencies of pollutants in livestock wastewater treatment plant with water plant filtration and activated sludge beds. The removal rates of COD, SS, T-N, and T-P in effluent were 83, 89, 63 and 87% in small-scale livestock wastewater treatment apparatus with water plant filtration bed, respectively. The removal rates of COD, SS, T-N, and T-P in effluent were 96, 95, 86 and 92% in small-scale livestock wastewater treatment apparatus with activated sludge tank, respectively. For increasing the COD, SS, T-N, and T-P removals in small-scale livestock wastewater treatment apparatus, the water plant filtration and activated sludge beds are recommended. In livestock wastewater treatment plant with water plant filtration (<TEX>$1^{st}$</TEX> treatment) and activated sludge (<TEX>$2^{nd}$</TEX> treatment) beds, the concentrations of COD, SS, T-N, and T-P in effluent were 39, 15, 42 and <TEX>$1mg\;L^{-1}$</TEX>, respectively. It was shown that the concentrations of COD, SS, T-N, and T-P met acceptable effluent quality standard for livestock wastewater. Based on the above results, the removal rates of COD, SS, T-N, and T-P in effluent were over 99.8, 99.9, 99.2, and 99.9% in livestock wastewater treatment plant, respectively.