STUDIES ON BIOSORPTION OF PHENOLIC COMPOUNDS FROM AQUEOUS SYSTEM USING AGRICULTURAL WASTES

Abstract

The present work is studied using agricultural waste sugarcane bagasse (SCB) for biosorption of phenol and phenolic compounds from water and industrial effluent as well the synthetic solutions of phenols used to develop the biosorption technique. The biosorption efficiency of agricultural solid waste bagasse to adsorb phenolic compounds phenol, ortho-chlorophenol (o-CPh), para-chlorophenol (p-CPh), and ortho, para-dichlorophenol (o,p-DCPh) from the solution system and industrial effluents under batch equilibrium conditions was investigated. The elemental ions of the biosorbent bagasse are identified by Fourier transform infrared (FTIR) spectroscopy. The biosorption technique has been carried out using batch experiment by the experimental parameters of biosorbent dose (0.5-5 g), contact time (upto 5 hrs), initial concentration of sorbates (0.5 to 10.0 mg/L), particle size of biosorbent, pH of system solutions (3 to 12) and operational temperature (30 to 50 ⁰C). The biosorption of phenolic compounds is raised with raising the pH from 3.0 to optimal value and then dramatically downize with raising the pH from that optimal value to avobe. The highest biosorption is achieved at pH 6.5 for phenol, ortho-chlorophenol and para-chlorophenol and at pH 6.0 for ortho, para-dichlorophenol. Biosorption equilibrium is established within 90 minutes for phenol and o-CPh and 120 minutes for p-CPh, and o,p-DCPh. The biosorption experimental data were employed to analyze in the isotherm and kinetic equations. The data found from experiments were fitted well into the pseudo first order kinetic equation, with the correlated coefficient (R 2 ) greater than 0.99 in all cases respectively. The maximum monolayer biosorption capacity of sugarcane bagasse for the selected phenolic compounds phenol, oCPh, p-CPh and o, p-DCPh has found to be 0.357, 0.361, 0.282 and 0.363 mg/g respectively,

as calculated by the Langmuir isotherm equation at 30⁰C. The biosorbed compounds could be

recovered by desorption with the help of 1M alkaline solution (NaOH) in all cases. After regenerations bagasse can be used as fuel purposes. The studies showed that the agricultural waste bagasse has the promise for use as an effective adsorbent material for biosorption of phenolic compounds from water and industrial effluents.