Integration of Improved Methods for the Treatment of Wastewater from a Soft Drink Industry

Beverage companies produce a large amount of wastewater in the cleaning step of returnable glass bottles. This study aimed to investigate combined processes (coagulation/flocculation, adsorption, and membrane separation) to treat the effluent from the washing machine of returnable soft drink bottles. Tests were conducted with aluminum sulfate, ferric chloride, and tannins (TANFLOC (R)) powder as coagulants/flocculants in different concentrations. After choosing the best coagulant, new tests were repeated by adding activated carbon. Based on the coagulant's best condition and activated carbon mass, the treated samples were subjected to a separation step with the ultrafiltration membrane (UF). The best treatment condition was the combined methods (TANFLOC + activated carbon + UF membrane), which showed a removal efficiency of 63.64, 54.92, and 64.98% for Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), and Biochemical Oxygen Demand (BOD), respectively. The BOD values are due to the presence of sugars in the effluent since its characteristics, such as high polarity and size less than 1 kDa, are unfavorable for the coagulation and UF processes, respectively. However, BOD removal efficiency was approximately 5% higher than the minimum required by legislation, which requires at least a 60% decrease in the raw effluent.