Sustainable wastewater management in the brewing industry: Utilizing cellulose acetate membranes derived from brewers’ spent grain for enhanced treatment efficiency

Abstract

Brewers’ spent grain (BSG), the primary by-product of the brewing industry, constitutes approximately 85.0% of the total by-products generated. BSG is known for its rich cellulose and non-cellulosic polysaccharide content, making it a valuable resource with significant potential for profitable recycling and reutilization. Given that the brewing sector is among the most substantial industrial consumers of water due to the water-intensive process of producing BSG, the effective management of wastewater in this industry is of paramount importance. This research focuses on investigating innovative wastewater management in the brewing sector. It employs the conversion of BSGs into a cellulose acetate membrane, thus enabling a physio-chemical treatment process utilizing the micro-filtration technique for wastewater treatment within the brewery industry. The results of this study demonstrate a substantial reduction in biochemical oxygen demand from the initial value of 16.65 mg/l (untreated) to 13.70 mg/l, 11.16 mg/l, 8.37 mg/l, 5.58 mg/l, and 3.14 mg/l after the first through fifth treatment cycles, respectively. Furthermore, the research indicates a high correlation with an R<sup>2 </sup>value of 0.999, affirming the viability and effectiveness of the treatment process. This is further substantiated by the results of chemical oxygen demand, total dissolved solids, total suspended solids, and hydrogen ion concentration analyses presented in this study. These findings not only validate the efficacy of utilizing BSG-derived cellulose acetate membranes but also emphasize the potential for revolutionizing wastewater treatment practices within the brewing industry. This research paves the way for sustainable, environmentally conscious strategies in industrial wastewater management, ensuring the optimal utilization of by-products while minimizing the environmental footprint of brewing operations.