Investigation on ecological parameters and COD minimization of textile effluent generated after dyeing with mono and bi-functional reactive dyes

This research work designates for the assessment of effluent variables after dyeing of 100% cotton fabric with synthesized reactive dyes namely, Reactive Blue 19 (mono functional), Reactive Black 5 (homo bi-functional), and Reactive Red 195 and Reactive Yellow 145 (hetero bi-functional) dyes under four individual dye concentration 0.5%, 2.5%, 4.5% and 6.5%, respectively. Textile effluents were collected from two stages, after dyeing without and with additional fixing treatment mainly for the determination of DO, BOD, pH and minimization of COD values. Result exposed an overall COD reduction of about 95% for the effluent generated from both stages with all dye concentrations. Here most DO, BOD, pH values were obtained from textile effluents after dyeing stage whereas comparatively least values were revealed for the effluents collected after dyeing-fixing stage; and minimized COD values were found for both stages. In addition to this, the effluents containing mono functional Reactive Black 5 and hetero bi-functional Reactive Yellow 145 dyes shows the most and the least environmental parameters, respectively for all dye concentrations. (C) 2018 Elsevier B.V. All rights reserved.