Evaluation of Industrial Effluent Treatment Performance and Regulatory Compliance: Implications for Surface and Groundwater Quality in Agro and Leather-Based Industries

Abstract

The present study investigates the treatment efficiency and regulatory compliance of effluents generated by the sugar factory and distillery and leather-based industries, with implications for surface and groundwater quality. Significant variation in physicochemical characteristics and treatment performance was observed industries. In the sugar factory effluent, notable reductions were achieved with BOD decreasing from 1100 to 70 mg/L (93.6%), COD from 2100 to 320 mg/L (84.8%), and TDS from 5000 to 180 mg/L (96.4%), while TSS removal remained limited at 20%. The distillery effluent treated through a Continuous Processing Unit (CPU) exhibited high efficiency, with COD and TDS reduced from 2500 to 90 mg/L (96.4%) and pH adjusted from 3.3 to 7.5, indicating effective neutralization and pollutant removal. In contrast, leather industry effluent showed poor compliance with discharge standards, as outlet values of TDS (9450 mg/L), COD (2763 mg/L), hardness (1080 mg/L), and alkalinity (1365 mg/L) exceeded permissible limits, reflecting inadequate treatment performance. Heavy metal evaluation suggested elevated concentrations in the leather industry influent, particularly chromium (0.915 mg/L), lead (0.200 mg/L), cadmium (0.065 mg/L), arsenic (0.250 mg/L), and mercury (0.295 mg/L), with only partial reduction at outlet. Sugar factory effluent showed substantial decline in chromium (0.149 to 0.012 mg/L), copper (0.460 to 0.002 mg/L), and lead (0.066 to 0.005 mg/L), whereas distillery effluent exhibited an unexpected increase in chromium (0.046 to 0.283 mg/L). Overall, while progress has been made in improving wastewater management within the sugar and distillery sectors, the leather industry continues to exert considerable pressure on regional water resources.