Removal and recovery of lead (Pb²⁺) from industrial effluent using indigenous and tailor-made Aureobasidium sp. RBSS-303

The objective of this study was to assess the removal and recovery of Pb-II from industrial wastewater using a locally isolated strain of Aureobasidium sp. RBSS-303. The initial Pb²⁺ concentration of 600 mg/L resulted in maximum uptake capacity (Q_max 235.1 ± 0.3 mg/g). The biosorbent revival was attained by contacting with HCl (0.01 M), with 75.3% recovery of Pb²⁺. The Freundlich isotherm best explains the Pb²⁺ sorption performances. Maximum adsorption distribution coefficient of 1,309.6 mg metal/mL was observed at initial Pb²⁺ concentration value of 100 mg/L. Evaluation of nine kinetic models showed the removal rate of Pb²⁺ was reliant on diffusion control pseudo-second-order and saturation-mixed-order kinetic models with a high correlation coefficient value (R = 0.99). Fourier transform infrared spectroscopy analysis showed the major contribution of –NH₂ and –CN ligands of Aureobasidium sp. RBSS-303 in the sorption phenomenon of Pb²⁺. The biosorption assays carried out with effluent of the paint industry showed 76.8% efficiency for Pb²⁺ removal by the candidate biosorbent, regardless of the complex composition of the industrial effluent.