Synthetic vinasse treatment by combined UASB-ABR-AS system

Abstract

Vinasse, or ethanol industry wastewater, is a major source of environmental pollution owing to its high levels of organic matter, toxic substances, and hard biodegradable compounds. Treatment of vinasse can reduce environmental pollutants significantly, and if well treated, it can be used as a fertilizer. This research aimed to evaluate the performance of a combined laboratory-scale system consisting of an upflow anaerobic sludge blanket (UASB) reactor and an anaerobic baffled reactor (ABR) followed by an activated sludge (AS) reactor in treating synthetic vinasse. The research was conducted for 208 days. The combined UASB-ABR-AS system was fed by synthetic vinasse under organic loading rate (OLR) between 2.5 and 13.5 kgCOD/m3.day. The COD removal efficiency rates of UASB, ABR, and AS units were obtained at 84%, 77.1%, and 90.7%, respectively. The overall COD removal efficiency rates of the combined UASB-ABR-AS system and methane production were 99.6% and nearly 72% (613.71 L/kgCOD), respectively. These results indicated that using the combined UASB-ABR-AS system is suitable for synthetic vinasse treatment and improves the effluent quality according to environmental standards.