Highly efficient simultaneous biosorption of Hg 2+ , Pb 2+ and Cu 2+ by Live yeast Yarrowia lipolytica 70562 following response surface methodology optimization: Kinetic and isotherm study

Abstract

Abstract In this research, biosorption of Hg2+, Pb2+ and Cu2+ from aqueous solution via Yarrowia lipolytica 70562 living mass was described. Correction and dependency of biosorption efficiency to effective variables like pH, initial Hg2+, Pb2+ and Cu2+ concentration, contact time and temperature was studied by central composite design under response surface methodology. Three responses were simultaneously studied by numerical optimization methodology. The optimum biosorption efficiency of Hg2+, Pb2+ and Cu2+ ions at 18, 22 and 25 mg L−1 onto Y. lipolytica 70562 was found to be 99.26%, 101.15% and 99.74% at pH of 6.4 and 25 °C after around 8 h under well mixing. Finally, optimum condition for acceptable and repeatable agreement among experimental and real data was explored. The artificial neural network (ANN) model was used for predicting simultaneous ‎biosorption of Hg2+, Pb2+ and Cu2+ ions based on experimental data. It was found that ‎using ANN model with 12 neurons at hidden layer for all three ions, the R2 of 0.989 and MSE of ‎‎0.993 for Hg2+ ion were obtained. The R2 of 0.981 and MSE of ‎‎1.155 for Pb2+ ion were obtained and also for Cu2+ ion the values of the R2 and MSE were found to ‎be 0.971 and 1.589, respectively. Langmuir isotherm model was best fitted with the equilibrium experimental. The experimental kinetic data was represented well by using pseudo-second-order model and intraparticle diffusion model.