Treatment of Brewery Effluent by UASB Process

A five‐month pilot study was conducted to examine the effectiveness of the upflow anaerobic sludge blanket (UASB) process for the treatment of effluent from a brewery in rural China. Results indicate that the process operated at 26° C could reduce over 89% of chemical oxygen demand (COD) and 92% of five‐day biochemical oxygen demand $\left({\mathrm{BOD}}_5\right)$ from the brewery effluent, with a hydraulic retention time (HRT) of 13.3 hr and a COD loading rate of 4.9 kg $\mathrm{COD}/m^3/\mathrm{day}\text{.}$ The brewery effluent in this study on average contained 2,692 ppm COD and 1,407 ppm ${\mathrm{BOD}}_5\text{.}$ The treated effluent on the other hand contained 295 ppm COD and 122 ppm ${\mathrm{BOD}}_5;$ both of which could be further reduced should the suspended solids be more effectively removed. Overall, this process was operated satisfactorily and smoothly, as reflected by the constant effluent pH and gas production rate, as well as the consistently high degrees of reduction of COD and ${\mathrm{BOD}}_5\text{.}$ Parameters such as sludge density, distribution of volatile suspended solids (VSS) and soluble COD in sludge bed, gas production rate, and nutrient levels are discussed.