Biosorption of methylene blue dye using a novel chitosan pectinase blend

Biosorption is a key phenomenon that has been used to remove the aquatic pollutants like dyes and heavy metals present in industrial effluents. The current study aims at the development of a chitosan-pectinase blend (CPB) to separate the methylene blue (MB) dye from its synthetic solution. Pectinase, an enzyme isolated from a consortium of Bacillus species, is imbibed in the blend. The electron micrographs revealed the rough surface of the adsorbent, and its amorphous nature was evident from broader peaks in diffraction patterns. The FTIR analyses indicated the perfect blend formation through the presence and shifts in the characteristic peaks. Maximum adsorption was exhibited at pH 7.0, 30 °C, 30 min of contact time and an adsorbent dosage of 2.5 g/L. On comparison, the pseudo-second-order model was found to be the suitable fit with the highest R² value closer to 1. Different isotherm models were experimentally fitted and the maximum adsorption capacity was obtained at 16.81 mg/g and the Temkin isotherm suits the best. The polymer blend showed an agreeable extent of desorption of MB dye which was evident from the desorption studies and, thereby, the biosorbent could be reused for removing the dye to the maximum extent.