Gel-entrapped biomass of Lactarius salmonicolor for the effective treatment of aquatic Co2+ and Mn2+ pollution.

A fungal biomass, Lactarius salmonicolor (L. salmonicolor), was entrapped in a silica gel matrix to evaluate the removal of Co²⁺ and Mn²⁺ ions from an aqueous medium and a real effluent. The batch experiments were carried out to investigate the influences of biosorbent dosage, initial pH, contact time, and temperature. The results showed that no pH adjustment was necessary to obtain maximum removal of both Co²⁺ and Mn²⁺ ions by silica gel immobilized L. salmonicolor biomass (SILSB). Thirty and ten minutes were found to be necessary time to establish biosorption equilibrium for Co²⁺ and Mn²⁺ removal, respectively. The biosorption of both metal ions was best described by the pseudo-second-order kinetic model. The data of the isotherm modeling proved that the Co²⁺ and Mn²⁺ biosorption occurred by monolayer coverage of SILSB surface with the biosorption capacities of 117.70 and 137.05 mg g⁻¹, respectively. The highest biosorption yields of Co²⁺ and Mn²⁺ ions in the continuous system are found using 50 mg (2 g L⁻¹) of SILSB as the optimum amount. The biosorption capacity did not significantly change by increasing the flow rate from 0.5 to 4.0 mL min⁻¹. The real wastewater treatment also showed that SILSB had remarkable biosorption efficacy for Co²⁺ and Mn²⁺. Metal ion-biosorbent interactions were examined by FTIR, pH_ZPC, SEM, EDX, elemental, and BET analyses. As a consequence of its excellent biosorption performance for the removal of Co²⁺ and Mn²⁺ ions, SILSB might be used as an efficient biosorbent in wastewater treatment. [ABSTRACT FROM AUTHOR]