Electrocatalytic degradation of wastewater: Anode preparation and performance study

Abstract

Wastewater treatment is becoming ever more critical due lo diminishing water resources, increasing waste-water disposal costs, and stricter discharge regulations that have lowered permissible contaminant levels in waste streams Textile wastewater includes a large variety of dyes and chemicals additions those make the environmental challenge for textile industry not only as liquid waste but also in its chemical composition. Main pollution in textile wastewater came from dyeing and finishing processes Major pollutants in textile wastewaters are high suspended solids, chemical oxygen demand, heat, colors, acidity, and other soluble substances. The presence of even small amount of dye in water (example 10-20 mg/L) is highly visible and affects the water transparency and the gas solubility of water bodies. In addition, only 47%, of 87% of dyestuff are biodegradable It has been documented that residual color is usually due to insoluble dyes which have low biodegradability as reactive blue 21, direct blue 80 and vat violet with COD/BOD ratio 59.0, I7.7.and 10.8, respectively. Conventional oxidation treatment have found difficult) to oxidize dyestuffs and complex structure of organic compounds at low concentration or if they are especially refractor) to the oxidants. To ease the slated problems advanced oxidation processes (-AOPS) have been developed to generate hydroxyl free radicals and other oxidizing agents by different techniques. The electrochemical method for the oxidation of organic pollutants for waste water treatment has attracted a great deal of attention recently, mainly due to the development of new effective anode material Dimensionally Stable Anode (DSA) consists of a mixture of oxides, usually prepared by the thermal decomposition of suitable precursors One of the maim targets of the electrochemical industry is to achieve an applied potential difference. V, as close as possible to the thermodynamic value. This project work deals with electro-catalytic treatment of real textile effluent (COD-1400 mg/I) and synthetic dye effluent of reactive red RB. ii Here is an attempt for oxidation of real effluent synthetic and dye effluent of reactive red KB with mainly two laboratory (by thermal deposition method) made electrode (anode) Ti/Ir (0.3) Ti (0.2) Pb (0.5) O2 and Ti/Ru(0.14) Ir(0.2) Sn (0.66) O2. With Ti/Ir(0.3) Ti (0.2) Pb(0.5) O2 Anode complete COD Reduction achieved in 10min at constant voltage condition with best operative parameters are investigated (3V, 600 RPB, 1.4gm NaCI, and pH-6-14), for synthetic dye effluent complete dye reduction achieved in 9 min at constant voltage condition with best operative parameters are investigated (4V, 800RPM, 1.5gm NaCI, pH-1). For Real Textile wastewater is reaction rate constant k=0.00004553 (min)-1(ppm)-1 and for synthetic dye effluent k=0.0000506 (min)-1(ppm)-1. With Ti/Ru (0.14) Ir (0.2) Sn (0.66) O2. Anode complete COD reduction achieved in 9 min at constant voltage condition with best operative parameters are investigated (3V, 925 RPM, 1.5gm NaCI, and pH-6-14), for synthetic dye effluent complete dye reduction with best operative parameters are investigated (3.8V, 900RPM, 1.5gm NaCI, pH-1) for Real Textile Wastewater is reaction rate constant k=0.0000302 (mim-1(ppm)-1, and for synthetic dye effluent k=0.0000569 (min)-1(ppm)-1.