STUDY OF ENVIRONMENTAL PARAMETERS OF WASTE WATER GENERATED AFTER DYEING WITH REACTIVE DYES

Abstract

Now-a-days, environmental consciousness is very imperative for all industries to maintain sustainability of lives and likewise other industries the major attention is also given to the arena of textile wet processing. In textile coloration industries, greater amount of cellulosic materials are now being colored with reactive dyes, contributing up to 36% of the overall dyestuff consumption. Cellulosic fibers of a specific shade (color) are produced by the chemical reaction of fibers with a mixture of reactive dyestuffs, salt, soda and auxiliary chemicals. Though this dye gives a superior quality in cellulosic fiber dyeing, but after dyeing a colossal amount of concentrated effluent liquor is generated due to immense hydrolysis of dyes. So, this textile effluent is considered as a major threat for the overall environment while discharged it in water bodies without further treatment. This research work is confined to the analysis of different parameters (DO, BOD, COD and pH) of waste water, generated from reactive dyeing of cotton at various conditions. The study shows the assessment of effluent variables after dyeing of 100 % cotton fabric with three synthesized reactive dyes namely, homo bi-functional (VS) Reactive Black-5, hetero bi-functional (MCT/VS) Reactive Red-195 and mono functional (VS) Reactive Blue-19 under four concentrations 0.5%, 2.5%, 4.5% and 6.5% respectively. So, the effluent water contained mainly vinyl sulphone and mono chloro triazine functionality which comes from the hydrolyzed and unfixed dyes. Acidity or alkalinity of waste water was indicated by pH meter where comparatively lower values of pH are found for the after-treated solution than the solution of reactive dyes after the dyeing. In this analysis DO, BOD and COD values of solution after dyeing are found to be greater than that of solutions after dyeing-fixing. At the end of the study it is found that, homo bi-functional (VS) Reactive Black-5 provide maximum and vinyl sulphone (VS) Reactive Blue-19 give the minimum DO, BOD and COD values for all corresponding dye concentrations. Besides, waste water with 6.5 % and 0.5% dye concentration shows the greatest and least DO, BOD and COD values for each and every individual reactive dyestuff. So, it can be said that, waste water having least DO value has more BOD and COD values which must have more adverse effect on environment and vice-versa. Thus, this research work gives a comprehensive guideline for the industry people to understand effluent nature at different conditions and maintain sustainable environment by the selection of appropriates dye