Study on methane generation from UASB treatment system applied for wastewater from Hoa Binh Sugarcane Company

Abstract

The sugarcane wastewater often contains a large amount of organic matters including nitrogenous and phosphorous compounds. This is a serious pollution source that causes the adverse effect on water recipient and aquatic species. In a number of sugarcane wastewater treatment technologies, the upflow anaerobic sludge blanket (UASB) has been widely studied and applied because of its advantages including the effective operation with high organic loading rate and the methane recovery potential. In this study, the wastewater flows of Hoa Binh Sugarcane Company (HOASUCO) have been analysed, and methane generation potential has been also investigated for wastewater treatment by UASB. The findings have shown that the integrated wastewater flow with the flow rate of 2000-2200 m3/day has been highly polluted by organic matters, suspended solids and had slight acidity (pH 6.22); the wastewater flows from the washing equipment and from the flue gas absorption system have been highly polluted with COD of 2200 and 2565 mg/l and flow rates of 910 and 220 m3/day respectively. The highest treatment efficacy (89.9 %) has been attained at the organic loading rate (OLR) of 4.8 g COD/l/day and the hydraulic retention time of 12 h. The generated biogas has had at the average of 0.36 l/g COD with OLR of 4.8 g COD/l/day and contained 60.7 % CH₄.