Removal of Methylene Blue and Congo Red Dyes by Pretreated Fungus Biomass – Equilibrium and Kinetic Studies

Abstract

Adsorption potential of macrofungi spent mushroom waste (SMW) (Agaricus bisporus) to remove methylene blue (MB) and congo red (CR) dyes from aqueous solution was investigated using native and Pre-treated biomass using autoclave at optimum conditions. Batch experiments for the spent mushroom were carried out. Spent mushroom waste was observed to have uptake capacity of 239.818 mg/g and 76.412 mg/g for MB and CR, respectively. Optimum pH for biosorption uptake onto the fungal biomass was observed to be pH 8 for MB and pH 5 for CR. The optimum contact time was found to be 4 h for MB and 3:30 h for CR. Optimum average particle size was obtained to be 0.089 mm. Three equilibrium isotherm models have been used for representing the experimental statistics. The Langmuir model gave the best results for each dye. Three kinetic models were used for the MB and CR using the spent mushroom biomass, good matching was found between pseudo second order kinetic model and experimental data (R2 > 0.999). Fourier-Transform Infrared (FTIR) test showed that the functional groups (carboxyl, alcohols, and alkanes) at the surface of fungi biomass play the principal role in biosorption of dyes. Scanning Electron Microscopy (SEM) and Scanning Electron Microscopy with energy Dispersive of X-ray (SEM-EDX) revealed surface texture and porosity indicating better surface area for the dye reaction. The usage of autoclaved biomass is a whole lot safer as it does now not pose any danger to the environment.