Removal and recovery of uranium from aqueous solutions by Ca-alginate immobilized Trichoderma harzianum

The ability of Ca-alginate immobilized Trichoderma harzianum has been explored for removal and recovery of uranium from aqueous streams. Ca-alginate as polymeric support was selected after screening different matrices. Immobilization of Trichoderma harzianum to Ca-alginate improved the stability as well as uranium biosorption capacity of biosorbent at 28 ± 2 °C and 200 rpm. The suitability of packed bed column operations was illustrated by obtaining break through curves at different bed heights, flow rates and inlet uranium concentrations. The adsorption column containing 1.5 g dry weight of immobilized material has purified 8.5 L of bacterial leach liquor (58 mg/L U) before break through occurred and the biosorbent became saturated after 25 L of influent. Sorbed uranium was recovered in 200 ml of 0.1 N HCl resulting in 98.1–99.3% elution by 0.1 N HCl, which regenerated the biosorbent facilitating the sorption–desorption cycles for better economic feasibility without any significant alteration in sorption capacity/elution efficiency.