Removal of heavy metals from wastewater using low-cost biochar prepared from jackfruit seed waste

The present study focuses on using jackfruit seed waste (JSW) for bioremediation of heavy toxic metals from water. The fruit is abundantly grown in India and Far East countries and produces myriad tons of seeds. A simple procedure is developed in the laboratory by thermally activating JSW by orthophosphoric acid at 500 °C. Surface morphology, porosity, and structural analyses of the resultant biochar were conducted. The activated biochar was applied for batch adsorption of several heavy metal ions: Fe(III), Cd(II), Cu(II), Pb(II), and Mn(VII) at pH 7. The average heavy metal uptake by activated JSW biochar is 76.4 mg g⁻¹, 79.4 mg g⁻¹, 97.9 mg g⁻¹, 79.9 mg g⁻¹, and 79.8 mg g⁻¹ for Fe(III), Pb(II), Cu(II), Cd(II), and Mn(VII), respectively. The experimental conditions were optimized to remove heavy metals at neutral pH. The adsorption process was exothermic, and Langmuir and pseudo-second-order kinetic study models were best fitted. The observation was in close agreement with the experimental data. Thermal and structural characterization of biochar at post-adsorption analyses was conducted. The study has distinguished features of simplicity, cost-effectiveness, and viability compared to many of the literature-reported biomass waste.