Live and lyophilized fungi-algae pellets as novel biosorbents for gold recovery : critical parameters, isotherm, kinetics and regeneration studies

Abstract

This study aimed to evaluate the potential of live and lyophilized fungi-algae pellets as biosorbents for gold recovery and their regeneration ability. The optimum conditions determined by Taguchi method were 1 g/L co-pellets, 9–10 mm size at 250 rpm of agitation speed and pH 3.5 and 2.0 for live and lyophilized co-pellets, respectively. The porous characteristics of fungi-algae pellets played an important role on gold adsorption. Lyophilized co-pellets achieved adsorption capacity of 112.36 mg/g which were comparable with some synthesized granular adsorbents and performed better than the live co-pellets due to more cell-wall polysaccharides involved in gold interaction. 97.77% of gold was selectively absorbed by the lyophilized co-pellets from multi-metal wastewater in column reactor. This study may provide new insights into the application of fungi-algae pelletized reactor in bioremediation of contaminated wastewater by precious metals and their recovery and the in-situ regeneration of biosorbents.