Basic Red 46 adsorption studies onto pyrolyzed by-product biomass

Abstract

In this study, the objective was to examine the utilization of the pyrolyzed by-products biomass as an adsorbent for extracting the dye Basic Red 46 (BR 46) from a solution. The pyrolyzed by-product containing Pleurotus mutilus biomass was characterized by thermogravimetric analysis (TGA), FTIR and µXRF. Different parameters effects such as, adsorbent dose, solution pH, contact time, temperature and initial dye concentration on the adsorption capacity of the pyrolyzed by-product biomass were examined. The solution was analyzed before and after the adsorption studies. With adsorbent dose of 1 g/L, contact time of 14 min, and solution pH of 7.5, the optimum yield of 88% was achieved. In order to fit the equilibrium data, the Langmuir, Freundlich, Temkin, and Khan isotherm models were used, and in order to fit the kinetics data, the pseudo-first-order, pseudo-second-order, Elovich, and Ritchie models were employed. Statistical analysis such as R2, RMSE,χ2 and ARE was used to assess which model has the best fit with the experimental data. The results demonstrated that the experimental equilibrium data are well described by the Langmuir model, and the kinetic studies indicated that the adsorption of BR46 followed the Ritchie model. The greatest BR 46 adsorption capacity determined from experimental equilibrium data was around 135 mg/g at pH = 7.5, adsorbent dosage of 1 g/L. Moreover, thermodynamic analysis has demonstrated that the adsorption process was physical, exothermic, and spontaneous in nature. These results indicated that pyrolyzed by-product biomass might be used as a cheap material to extract textile colors out of aqueous effluents.