Pages 327–331
Abstract
Research summary supplied by the authors
This paper presents the design and performance evaluation of a modular effluent treatment system (ETS) tailored for medium-scale tannery wastewater. Tannery effluent is highly polluted, containing organics (BOD, COD), suspended solids, sulfides and chromium at very high concentrations (often thousands of mg/L)[1][2]. The proposed modular plant integrates sequential stages: screening and equalization, primary coagulation–flocculation with chemical dosing, dissolved air flotation (DAF), followed by biological oxidation and optional tertiary membrane filtration. In pilot trials, the coagulation/DAF unit removed >90% of total suspended solids (TSS) and >98% of Cr(III), and reduced COD and BOD by about 65– 70%[3]. The downstream activated-sludge bioreactor further degraded the residual organics (achieving overall COD/BOD removals on the order of 85– 95%[4]), yielding an effluent that met typical discharge standards. The modular skid-mounted design allows incremental capacity expansion and more efficient resource use[5][6]. Key advantages include high pollutant removal, flexibility for small/ medium tanneries, and relatively simple operation. These results indicate the modular ETS is a technically and economically viable solution for improving tannery wastewater management in medium-scale operations.