Attached Treatment using Combined Septic Tank and Soil Filter of Treated Livestock and Farm House Wastewater

축산폐수 처리수 및 농가 생활잡배수의 합병정화조와 Soil Filter 에 의한 연계처리

This study was conducted in order to investigate removal rate of organic matter, nitrogen and phosphorus to reduce environmental polluation with treatment to attach combined septic tank to 3 stage soil filter after mixing anaerobic treated water of livestock wastewater and low concentrated wastewater generated in farm house. Because anaerobic filter bed was packed in combined septic tank and a microorganism was accumulated in combined septic tank with increasing hydraulic retention time(HRT), if HRT $4{\sim}12day$, CODcr was removed $63.4{\sim}84.0%$. Also, $NH_4\;^+-N$ and $PO_4\;^{3-}-P$ were removed $3.9{\sim}5.4%$ and $18.3{\sim}29.0%$, respectively. In being re-treated by 3 stage soil filter, although hydraulic loading rate was gradually increased, CODcr, $NH_4\;^+-N$ and $PO_4\;^{3-}-P$ were removed above 90% due to filtration, adsorption, ion exchange, and action of soil microorganism. Generally, the attached treatment of combined septic tank and 3 stage soil filter did suitably treat livestock wastewater to water standard of discharge applied from '96 year, in view of decreasing pollution loading amount and recycling of agricultural water.

본 연구에서는 축산농가에서 환경오염의 저감방안을 강구하기 위하여 축산폐수의 혐기성 처리수와 생활잡배수를 혼합하여 합병정화조와 3단 soil filter를 연계하여 처리한 결과, 다음과 같은 결론을 얻었다. 합병정화조에서 처리함에 있어서 합병정화조내 충전된 여상과 체류시간의 증가로 인한 미생물의 축적에 의하여 NRT $4{\sim}12$일에서 CODcr 제거효율은 $63.4{\sim}84.0%$이며 NH4+-N와 PO43--P는 각각 $3.9{\sim}5.4%$와 $18.3{\sim}29.0%$로써 HRT가 증가함에 따라 높은 효율을 나타내었다. 3단 soil filter에 의하여 재처리함에 있어서 표면적 부하율의 점진적인 증가에도 불구하고 여과, 흡착, 이온교환 및 토양 미생물의 작용으로 인하여 표면적 부하율이 증가함에 따라 CODcr, NH4+-N 및 PO43--P의 제거효율은 90% 이상을 나타내었다. 이상의 결과를 미루어볼 때, 오염부하량 감소 및 농업용수로의 재이용 측면에서 축산폐수의 합병정화조와 Soil filter에 의한 연계처리를 할 경우에 '96년부터 적용된 축산폐수의 방류수 수질기준에 적합한 것으로 나타났다.