Application of the Optimized Pre-ozonation Treatment for Potential Resource Recovery from Industrial Textile Effluent

Abstract

ABSTRACT Treatment of the textile effluent becomes complex due to the high color, organic load, dissolved solids content, and toxicity of the textile effluents. An optimized pre-ozonation treatment has been proposed, aimed at the maximum color and organics removal leading to possible resource recovery at the field-scale. The standalone ozonation at optimum conditions of pH, salinity, and dye concentration resulted in the color removal and chemical oxygen demand (COD) removal of 96.13% and 67.40%, respectively, for synthetic textile effluent. The percentage removal of individual dyes from synthetic textile effluent was also analyzed. The standalone ozonation treatment of real textile effluent at optimum conditions resulted in 94.6% color removal and 67.4% COD removal. The pre-ozonation treatment followed by a sequential batch reactor proved effective in the removal of color (98.6%) and organic load (91.6%) of the real textile effluent. Pre-ozonation enhanced the biodegradability of the textile effluent, as observed by the 81.8% increase in biodegradability index and 126.2% increase in specific oxygen uptake rate. The proposed industrial textile effluent scheme, when applied to the industry producing 3500 kg fabric per day, presented a potential recovery of 157 m3 effluent and 375 kg salt per day, which can result in the net annual saving of about INR 3.7 million, including additional treatment cost. The proposed treatment scheme significantly contributes to sustainable textile production.