Decolourization and COD removal from textile waste water by chemical, adsorption and biological treatment methods

Abstract

The water pollution is in increasing trend over the past few decades. With the countries moving towards the industrialization for their economic growth, there is a critical threat to bio-nature of the water. The industries generally consume a huge amount of water, and dispose them in the contaminated form which is often toxic. Among the industries, more water is procured for the textile industries especially in the dyeing units. Most of the dyes in the textile industries are reactive in nature and provide several adverse effects. Several methods were employed to remove the contaminated substances to purify the textile based waste water. In the present paper, the effluent water samples from the dyeing unit from Kanchipuram was obtained and analyzed for its initial parameter values following the standard methods. From those obtained values, the chemical oxygen demand (COD) is about 1170 mg/L and the color value was at 1093 Pt-CO. Subsequently, the waste water is chemically treated with the combined Sodium Hypochlorite-lime-ferrous solution. Similarly, the zeolite and prepared coconut charcoal is employed as an adsorbent to treat the wastewater. All the treated samples were tested to analyze the effect of each treatment. The outcomes obtained from the analysis were compared with the initial values to measure the efficiencies of each technique. Almost all the treatment procedure employed in the study yield efficiency about 90% in COD and color removal. From the comparison over the techniques, it is evident that the inorganic adsorbent removes the color and Chemical Oxygen Demand effectively about 94% and 95% respectively.