Biosorption of methylene blue dye by chemically modified aspergillus japonicus mg183814: Kinetics, thermodynamic and equilibrium studies

Abstract

The biosorption of methylene blue (MB) dye from aqueous solutions by raw Aspergillus japonicus (RAJ) and sulphuric acid-treated A. japonicus (SMAJ) was explored to recognize the dye evacuation productivity of adsorbent. Retaining in mind the end purpose to upgrade the adsorption capacity of A. japonicus and enhance the application execution, surface modification of A. japonicus was examined in this work. The characterization studies of newly prepared biosorbent material were performed by scanning electron microscope and Fourier-transform infrared spectroscopic analysis. The influencing parameters such as initial MB dye concentration, contact time, solution pH, temperature and biosorbent dosage were examined. The optimum conditions for the maximum removal of MB dye for an initial MB dye concentration of 25 mg/L were measured as follows: pH of 7.0, adsorbent dose of 0.6 g/L for RAJ and 0.3 g/L for SMAJ, contact time of 60 min for RAJ and 30 min for SMAJ, and temperature of 30°C. From the kinetic and equilibrium studies, the results demonstrated that biosorption process was portrayed by pseudo-second order and Freundlich isotherm model. The maximum adsorption capacity (qm) was calculated 45.78 mg/g using Langmuir equation. The results of the thermodynamic study showed that present biosorption process was exothermic and spontaneous in nature. The information from the above findings recommending that chemically modified microbial biosorbent could turn into a potential biosorbent for the removal of organic contaminants from wastewater.