earticle

영어

Treatability test was performed to the low concentrated wastewater that was primarily treated by chemical coagulation and dissolved air flotation, using high efficient compact process to coffee wastewater. The results are as follows: The characteristics of the raw coffee wastewater was 852～1,550 mg/L for BOD5, 1,704～3,114 mg/L for CODCr, 680～1,320 mg/L for CODMn, and 373～933 mg/L for SS, and the characteristics of the low concentrated wastewater that was treated by chemical coagulation and dissolved air flotation was 460～680 mg/L for BOD5, 788～1,305 mg/L for CODCr, and 307～453 mg/L for CODMn, and 75～150 mg/L for SS. The removal efficiency for BOD and COD was about 50% and 80%, respectively. When the low concentrated wastewater was treated again by high efficient compact process (HECP) and operated in the condition that had CODCr volumetric load was below 8 kg/m3 ㆍd, and HRT was over 4 hours, and MLSS was 4,500 mg/L, the CODCr and CODMn for effluent was below 190 mg/L and 75 mg/L respectively, which meant the removal efficiency was over 80%. When the quantity of the wastewater or the pollution load is increased in the treatment plant using a conventional activated sludge process, the HECP method was found as the most efficient treatment method that is not restricted by the size of the plant.

한국어

커피 폐수(coffee wastewater)에 대한 HECP공법을 적용하여 화학적 응집침전과 가압부상에 의해 1차 처리한 폐수를 대상으로 Pilot 규모(pilot scale)의 처리성평가(treatability test)를 수행하였다. 실험 결과 얻은 결론은 다음과 같다. 커피폐수의 원폐수(raw coffee wastewater)는 BOD5 852～1,550 mg/L, CODCr 1,704～3,114 mg/L, CODMn 680～1,320 mg/L, SS 373～933 mg/L이고, 원 폐수를 화학응집후 가압부상에 의해 1차 처리한 처리수는 BOD5 460～680 mg/L, CODCr 788～1,305 mg/L, CODMn 307～453 mg/L, SS 75～150 mg/L로서 유기물(BOD와 COD) 제거율은 50%전 후, SS 제거율은 80% 정도로 나타났다. 화학응집에 의한 가압부상으로 1차 처리한 저농도의 폐수를 HECP공법으로 처리시 CODCr 용적부하율 = 8 kg/m3ㆍd이하, HRT = 4시간이상, MLSS = 4,500 mg/L에서 운전한 결과 유출수의 CODCr 및 CODMn이 각각 190 mg/L와 75 mg/L이하로 약 80% 이상이 제거되었다. 이와 같이 재래식 활성슬러지공법(conventional activated sludge process)의 기존 처리장에 장래 폐수발생량 또는 유입 오염부하량이 증가될 경우, 이를 안정적으로 처리하기 위하여 제한된 부지면적과 공장의 생산활동에 지장을 주지 않고, 기존 처리장을 개선할 수 있는 방법은 HECP공법이 효과적인 것으로 나타났다.