Lead removal from synthetic wastewater by biosorbents prepared from seeds of Artocarpus Heterophyllus and Syzygium Cumini

The present investigation deals with removal of lead (Pb⁺²) ions from waste water using biosorbent prepared from seeds of Artocarpus heterophyllus (SBAh) and Syzygium cumini (SBSc). Biosorbents surface has been characterized through FT-IR spectroscopy to probe the presence of functional groups. Response surface methodology enabled optimized conditions (Pb⁺² concentration 2 μg/mL, pH 5.8 and bioadsorbent dose 60 mg) resulted in Pb⁺² removal ~96% for SBAh and ~93% for SBSc at agitation speed 300 rpm. The adsorption capacity has been found to be 4.93 mg/g for SBAh and 3.95 mg/g for SBSc after 70 min. At optimal experimental conditions, kinetics of biosorption was explained well by inter-particle diffusion model for SBAh (R² = 0.99) whereas Elovich model best fitted for SBSc (R² = 0.98). Further, both the biosorbents followed Temkin adsorption isotherm model.