OPTIMIZATION OF ECO DERIVED ACTIVATED CARBONS NANOCOMPOSITES IN SEQUESTERING ANIONIC DYES AND METAL ION THERMODYNAMIC KINETIC STATISTICAL STUDIES

Abstract

The unrelenting industrial development has led to a subsequent increase in the amounts of wastewater generation. Industries viz., textile, leather, paper, food, printing, carpet, cosmetics use dyes to colour their products. Among the industries, textile industries generate large volumes of coloured wastewaters containing dyes/heavy metal ions and discharge into the natural water bodies. Untreated disposal of this coloured waters not only cause damage to aquatic life, but also to human beings through mutagenic/carcinogenic effect. Removal of dyes/metal ions from coloured effluents is one of the major environmental concerns in the present days. Among numerous techniques available for the reclamation of dyes and metal ions, adsorption has been reported convenient, due to its manageable properties. Two ecofriendly materials of plant and animal origins viz., Prosopis juliflora Bark, Goat Dung are identified as potential sorbents in the removal of Direct Brown 2, Reactive Red 152 and Cu(II) ions from aqueous and textile wastewater samples. These materials are subjected to modification, activation, synthesis of magnetic nano composites. The physio-chemical characteristics of the prepared activated carbons are studied using standard methods. Surface morphology and presence of functional groups of the carbons are explored by SEM, EDAX, BET, BJH and FT-IR analytical techniques. The optimal conditions viz., initial concentration, contact time, sorbent doses, pH, temperature environments for the maximum removal of dyes/metal ion are established through batch equilibration method. Desorption and regeneration experiments are performed for dyes/metal laden carbons to enumerate their reusability. The efficiency of nano modified sorbents for the removal of dyes is investigated. Varied isothermal and kinetic models are employed to verify the adsorption equilibrium and kinetic behavior of the sorption process. The thermodynamic constants of adsorption are evaluated. Performance of the six systems is substantiated by statistical tool verification (SPSS software). A comparative assessment on the sorption ability of activated carbons and their corresponding magnetic nanocomposites are made on the basis of experimental results. The sorption capacities of the identified materials are upscaled to textile wastewaters. Column experiments are carried out to quantify the carbons’ efficiencies for the aqueous/effluent dye solutions