Optimization of Pb (II) biosorption by Harvested Microalgae (Chlorella vulgaris) using response Surface Analysis
Amin Keyvan Zeraatkar, Hossein Ahmadzadeh, Vahid Razaviarani, Ahmad Farhad Talebi
Published: September 01, 2021.
Abstract
Biosorption has been defined as affinity characteristics of certain biomolecules present in dead/live biomass to passively bind selected ions from aqueous solutions. In this study, the bioremoval of Pb (II) was studied using dead biomass of green microalgae species, Chlorella vulgaris. Important individual and combined factors affecting the sorption process, such as initial concentration of Pb (II) (100-500 mgL-1), pH (2.5-6.5), biomass concentration (0.1-0.5 gL-1) of C. vulgaris and contact time (20-120 min) were investigated to achieve the maximum removal of lead ions from aqueous solutions. The parameters were optimized by the experimental design concept using central composite design (CCD). The statistical parameters of the derived model were R2 = 87.91% and F value = 8.31. The response surface diagrams were plotted based on the defined model to show the effects of the variables on the Pb(II) bioremoval efficiency. A quadratic model was proposed by CCD which agreed well with the experimental data (R2 = 87.91%). Also, the model was able to predict optimal conditions of pH= 2.5, C0 = 100.0 mgL-1, Cbiomass = 0.4 gL-1 and t = 120.0 min for the target bioremoval of Pb (II) (100%).
Keywords: Biosorption; Microalgae; Lead; Optimization, Response Surface Analysis