| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 599795 | Colloids and Surfaces B: Biointerfaces | 2013 | 10 Pages |
•Rice husk has the potential to treat U(VI) in wastewater.•pH of the medium strongly affected the removal of U(VI).•Langmuir model provided the best correlation to the experimental data.•Thermodynamics showed that removal of U was spontaneous at low temperature.•H2SO4 and EDTA proved most successful as eluting agents.
In this research, biosorption efficiency of different agro-wastes was evaluated with rice husk showing maximum biosorption capacity among the selected biosorbents. Optimization of native, SDS-treated and immobilized rice husk adsorption parameters including pH, biosorbent amount, contact time, initial U(VI) concentration and temperature for maximum U(VI) removal was investigated. Maximum biosorption capacity for native (29.56 mg g−1) and immobilized biomass (17.59 mg g−1) was observed at pH 4 while SDS-treated biomass showed maximum removal (28.08 mg g−1) at pH 5. The Langmuir sorption isotherm model correlated best with the U(IV) biosorption equilibrium data for the 10–100 mg L−1 concentration range. The kinetics of the reaction followed pseudo-second order kinetic model. Thermodynamic parameters like free energy (ΔG0) and enthalpy (ΔH°) confirmed the spontaneous and exothermic nature of the process. Experiments to determine the regeneration capacity of the selected biosorbents and the effect of competing metal ions on biosorption capacity were also conducted. The biomass was characterized using scanning electron microscopy, surface area analysis, Fourier transformed infra-red spectroscopy and thermal gravimetric analysis. The study proved that rice husk has potential to treat uranium in wastewater.
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