Mechanistic investigation of the mass transfer stages involved during the adsorption of aqueous lead onto Scopulariopsis brevicompactum fungal biomass

Abstract

The Scopulariopsis brevicompactum fungal biomass (SFB) was applied as an adsorbent for the uptake of aqueous lead species via the dynamic sorption process. The adsorption capacity dependence on the solution pH, contact time, initial adsorbate concentration and adsorbent concentration was investigated via batch mode. According to the experimental findings, the adsorption capacity was favoured by an increase in all the aforementioned process variables except adsorbent concentration. The optimum adsorption capacity was recorded at pH 6.0, 120 min, and 0.2 g/L adsorbent concentration. The process isotherm was explained by the D-R model, with predominated physisorption (E = 0.069 kJ/mol), while the pseudo-second-order model explained the process kinetics. The characterization results confirmed the presence of several metal-binding functional groups on SFB. Furthermore, by applying the mass transfer factor model, the dependence of the lead ions adsorptive mass transfer on the film diffusion regime was established. Thus, the adsorptive performance of the SFB was demonstrated in the study.