"REMOVALOF VICTORIA BLUE B DYE BY BAGASSE FLY ASH"

Abstract

Dyes and dye intermediates consists of basic dyes, disperse dyes, reactive dyes, sulfur dyes, vat dyes, organic pigments, naphthols, and optical brighteners. Due to ever-growing demands in textiles, synthetic organic dyes are widely used for dyeing textile fibers such as cotton and polyester. It is expected to grow at a Compounded Annual Growth Rate (CAGR) of 4.7%, from 652,000 tonnes in 2004-05 to 90,000 tonnes in 2010-11. Indian companies consume around 6.6 % of the world production of dyes and intermediate dyes. India produces of dyes, 2 percent of which - 7,040 tonnes are directly discharged into the environment. The dyes are generally stable to light, oxidizing agents and heat. Their presence in wastewaters offers considerable resistance to their biodegradation and thus upsetting aquatic life. Moreover, the wasted dyes and color released in the effluent interfere with the transmission of light in the water bodies that receive the effluent. This in turn inhibits the photosynthesis activity of aquatic biota besides direct toxic effects on biota. The removal of color from dye bearing wastewater is of great environmental concern. More than half of the nearly 90 dyestuffs used in industries are non biodegradable. • Various treatment methods used for the removal of dyes from the waste water include adsorption, coagulation and sedimentation, chemical oxidation, photochemical, electrochemical technique, chlorination, ozonation, irradiation, ion exchange, reverse OSDIosis, membrane separation, biological treatment, etc. Adsorption is the best available techniques for the removal of dyes from the waste water which is economically feasible. Varieties of adsorbents are available which can be utilized for treatment of dye bearing wastewater. Usually activated carbon is used for adsorption. But due to its high cost there is need of low cost adsorbent. During recent years large numbers of low cost adsorbents have been investigated. In the present study Bagasse fly ash (BFA) is used for the removal of Victoria Blue B (VB) from the aqueous solution and adsorption studies have been carried out for evaluating their suitability as low cost adsorbents. The experimental studies for adsorption of VB using BFA were carried out in batch process. Maximum removal efficiency of VB synthetic waste water is optimized by varying the parameter like pH, adsorbent dose (m), contact time (t), temperature iii (T) and initial concentration (Co) of VB dye by BFA. The optimum, pH, m, t, T and Co were found 4.5 (Normal pH), 3g/1, 3hr, 313K and 100mg/1 respectively. Kinetic study shows that adsorption of VB on BFA follows the second order kinetics. Percent removal of VB dye increases with the increase in adsorbent amount of BFA. But the percent removal of VB decreases with increase in VB concentration for BFA. Langmuir isotherm is best-fitted the isotherm data for VB adsorption on BFA at almost all temperatures. However, the error analysis values and the non-linear correlation coefficients, R2, are comparable for Langmuir isotherm. Adsorption increases with increase in temperature for the BFA adsorbent, showing the endothermic nature of adsorption. iv