Modeling Studies For Removal of Azo Dyes From Aqueous Solutions By Low Cost Biosorbents

Abstract

One of the elements of nature that made living beings more aesthetic in the world is color. From the ancient times in India, different types of sources of coloring matters were used by the people. Initially the chief source of coloring matter had been nature and vegetation. But as the time passes, synthetic dyes of wide range of colors were used. These dyes show good color fastness properties which results in its tremendous use in different industries. One of the alarming environmental problems is the effluent which comes out from these industries and contains dyes causing contamination of soil. Various methodologies have been developed for the removal of dyes. Due to ecological and economic significance use of plant materials have been proposed as a promising innovative technology to remove dyes. Based on the green chemistry principle biosorption technique attains great attention due to its cost effectiveness and environmental friendliness. The study focus on use of low cost biosorbents as one of the potential materials to remove azo dyes from aqueous solutions. The selections of biosorbents were based on extensive review of literature. Guargum powder, watermelon shell powder and Aloe vera leaves powder were prepared and characterized through SEM, FTIR and GC-MS techniques. Batch adsorption experiments were carried out by changing different experimental conditions. Modeling studies were done through Langmuir adsorption isotherms and Freundlich adsorption isotherms for removal of methyl red and methyl orange from aqueous solutions. The study also delineates the maximum adsorption capacity of respective biosorbents. Isothermal kinetic study was done through pseudo first order and pseudo second order models. Correlation coefficient values were determined to correlate moderate fit of adsorption isotherm. The findings of ongoing study is an attempt to explore the potential of guargum powder, watermelon shell powder and Aloe vera leaves powder as a novel biosorbents in the removal of methyl red and methyl orange from