Treatment of a real brewery wastewater with coagulation and flocculation: impact on organic substance and nutrients concentrations

Featured Application This work presents important data about the impact of the coagulation and flocculation process on the industrial-scale treatment of brewery wastewater, providing technical operators with essential information about the efficacy of various reagents under varied conditions.Abstract Brewery wastewater (BWW) often contains a high concentration of organic matter and nutrients, requiring pre-treatment before it can be effectively treated in conventional wastewater treatment plants. This study focuses on the use of coagulation-flocculation techniques to treat real industrial wastewater. Firstly, lab-scale tests have been carried out to determine the most effective coagulant and flocculant type and concentration. The levels of pollutants, including chemical oxygen demand (COD), biological oxygen demand in five days (BOD5), total nitrogen (Ntot), total phosphorus (Ptot), and orthophosphate (P-PO43-) have been measured to assess the efficiency of the procedure. Industrial scale tests were performed in optimal conditions in order to evaluate the effectiveness of the treatment on a larger scale and estimate the generation of chemical sludge. The most effective substances for coagulation and flocculation were polyaluminium chloride (PAC) and anion-active flocculant (AAF) ZETAG 4139 0.1%, respectively, at concentrations of 675 mgL-1 and 40 mgL-1. During industrial-scale tests, the process allowed the effective removal of TSS (86.8%), Ntot (51.8%), Ptot (95.5%), and P-PO43- (99.6%), while the limited removal of organic substances has been highlighted (BOD5: 34.3%; COD: 26.5%). The dry matter (DM) content of the separated sludge was found to be 4.5-5%, and a yield of 1.01 kgDM per kg of COD removed was obtained after flocculation treatment of the BWW. These findings can be beneficial for both the scientific community and technical operators, offering insights into the effectiveness of various coagulants and flocculants on industrial-scale wastewater treatment.