Treatment of Corn Starch Wastewater Using an UASB Reactor

UASB 반응조를 이용한 옥수수 전분폐수의 처리

The performance of Upflow Anaerobic Sludge Blanket(UASB) reactor for treatment of corn starch wastewater was investigated using continuous and batch experiment. Results showed that the corn starch wastewater had different characteristics in terms of biodegradability and methane potential, depending on the manufacturing precess. COD removal efficiencies were maintained over 70% up to the loading rate of 3.2 kg $COD/m^3{\cdot}day$ and the maximum gas production rate was about 55 l/day, equivalent to 3.5 l/day per liter of reactor volume, at the loading rate of 8.4 kg $COD/m^3{\cdot}day$. In the anaerobic serum bottle test(SBT) carried out along with continuous operation, the sludge activity was found to increase from 0.03 to 0.53 g $COD-CH_4/g\;VSS{\cdot}day$ as granular sludges were developed in 130 days operation. SBT gave valuable informations on the characteristics of wastewaters to be treated as well as on the sludge activity. The overall morphological characteristics of granular sludges cultivated on corn starch wastewaters were similar to those cultivated on various organic industrial wastewaters such as distillery and sugar.

UASB 반응조를 이용한 옥수수 전분폐수의 처리도를 연속 및 회분식실험으로 조사하였다. 옥수수 전분폐수는 제조공정에 따라 생분해도와 메탄회수율이 달랐다. 유기부하 3.2 kg $COD/m^3{\cdot}day$까지 COD 제거율은 70% 이상으로 유지되었으며, 최대 가스발생량은 부하 8.4 kg $COD/m^3{\cdot}day$에서 약 55 l/day로서 반응조 단위 체적당 약 3.5 l/day의 가스가 발생하였다. 연속실험과 동시에 수행된 회분식(SBT) 실험에 의하면 슬러지의 활성도는 운전 130일이 경과하는 동안 0.03에서 0.53g $COD-CH_4/g\;VSS{\cdot}day$으로 증가하였으며, 슬러지도 입상화되었다. SBT 실험은 처리대상 폐수에 대한 정보 뿐만 아니라, 슬러지의 활성도에 대한 유익한 정보를 제공하였다. 옥수수 전분폐수를 처리하는 과정에서 형성된 입상슬러지의 형태학적 특성은 주정폐수이나 당을 처리한 입상슬러지와 유사하였다.