Electrochemical treatment of sugar industry wastewater: COD and color removal

• Effect of pH, current density and electrode gap on treatment of SIWW.
• Settling and filtration.
• Mechanism of electrochemical treatment.
• COD and color removal.
• Thermal analysis of sludge.

The removal of chemical oxygen demand (COD) and color of the Sugar industry wastewater (SIWW) was investigated using electrochemical (EC) process iron as electrode material. The process yielded maximum 84% COD and 86% color reduction at current density 178 A/m2, initial pH 6 and electrode gap 20 mm in 120 min of treatment. Effect of various parameters in range initial pH (2–10), current density (39–195 A/m2), electrode gap (10–25 mm) and treatment time (0–120 min) were evaluated on COD and color reduction of SIWW. Energy consumption, electrode loss, filtration and settling of sludge were found to pH dependent. Significant amount of COD and color reduction of wastewater by the process indicates that it may be better alternative to the convention biological treatment. Thermo gravimetric analysis of residue indicates its inorganic nature.

Sugar industry wastewater has organic nature and contains various organic and inorganic. When current is applied across electrode, cations of electrode metal generated, which further changed in metal hydroxides. These cations and metal hydroxides combine with organic pollutants of SIWW and make metal organic complexes, which settle down and soluble organics remain in treated effluent. COD reductions are due separation of organics from the effluent.Figure optionsDownload as PowerPoint slide