Assessment of chitosan coated Aspergillusniger as biosorbent for dye removal and its impact on the heavy metal and physicochemical parameters of textile wastewater

Abstract

Efficiency of biosorbent from chitosan coated dead fungal biomass of Aspergillus niger for dye removal with its impact on metals and physicochemical parameters of textile industry wastewater were assessed. Dye and metal concentrations of wastewater were determined using UV and Atomic Absorption Spectrophotometers respectively, before and after column biosorption using simulation optimized parameters with biosorbent. Physicochemical parameters were determined using standard methods. Simulated and industrial wastewaters data were analysed statistically with one way ANOVA and T-test. Biosorption of dye was classified with Langmuir and Freundlich isotherms. Results showed that at dye concentration of 100 mg/L, 6.90 mg/g of indigo dye adsorbed per mass (qe); in 1.87 mg/L of wastewater, 0.07 mg/g of dye adsorbed per unit mass (qe). Isotherm model fitted well to Freundlich with constant 0.04 and 8.45 mg/g in textile and simulated wastewater respectively. Metals in wastewater ranged from 0.071 to 1.102 mg/L. Acidity, COD Zn, Pb, Fe, Ni, Mn, Cu, Cd, Cr, Co, Mg ions were reduced by 32.94, 39.02, 84.95, 34.57, 44.19, 42.19, 49.09, 25.13, 43.66 and 32.03% respectively after treatment while TDS, conductivity, alkalinity, turbidity, pH increased. Chitosan coated A. niger could be effective in removing dyes and heavy metals from textile wastewater.   Key words: Aspergillus niger, biosorbent, physico-chemical, heavy metals, textile wastewater.