The Effectiveness of Dairy Industry Wastewater Treatment Using Coconut Husk and Sugarcane Bagasse With Limestone as Filter Media

The dairy processing industry generates substantial quantities of high-strength wastewater containing elevated concentrations of biodegradable organic matter, fats, proteins, suspended solids, oil & grease, nitrogenous compounds, and phosphorus. Improper discharge of untreated dairy wastewater leads to severe environmental degradation including dissolved oxygen depletion, eutrophication, odor generation, groundwater contamination, and ecological imbalance. Conventional treatment technologies such as activated sludge processes, membrane bioreactors, sequencing batch reactors, and chemical coagulation systems are effective; however, they require high capital investment, continuous energy supply, skilled operation, and intensive maintenance, making them economically unfeasible for small and medium-scale dairy industries. Therefore, there is a growing need for sustainable, low-cost, decentralized, and environmentally friendly treatment technologies utilizing locally available materials. The present study investigates the effectiveness of coconut husk (CH), sugarcane bagasse (SB), and limestone (LS) as natural filter media for dairy industry wastewater treatment using a laboratory-scale vertical flow biofiltration system. The developed filtration unit consisted of layered media comprising gravel, limestone, sugarcane bagasse, and coconut husk arranged sequentially to achieve physical filtration, adsorption, microbial biodegradation, and chemical stabilization. Dairy wastewater samples were collected from Dinshaw’s Dairy Foods Ltd., Plot No. K-41/42, Five Star MIDC Industrial Area, Butibori, Nagpur – 441122, Maharashtra, India. The collected wastewater was analyzed for pH, turbidity, biochemical oxygen demand (BOD₅), chemical oxygen demand (COD), total suspended solids (TSS), oil & grease, total nitrogen (TN), and total phosphorus (TP) according to APHA Standard Methods. Experimental investigation demonstrated significant pollutant removal efficiencies with turbidity reduction of 88.2%, BOD₅ removal of 79.5%, COD reduction of 74.3%, TSS removal of 84.6%, oil & grease removal of 81.2%, TP reduction of 68.7%, and TN reduction of 62.4% under optimized hydraulic retention conditions. The developed natural filtration system demonstrated stable hydraulic performance, low operational cost, minimal energy requirement, and environmental sustainability, indicating strong potential for decentralized dairy wastewater treatment applications.