Sorption behavior of selected fission products on spent alum sludge

The spent alum sludge was employed for the removal of specific fission products including ¹³⁷Cs, ⁸⁵Sr, ^152+154Eu, ⁹⁹Mo, and ⁹⁹Tc radionuclides from radioactive waste. The physicochemical features of spent alum sludge were investigated. The results illustrated that the uptake percentages were 94.2, 90.5, 87.6, 87.1, and 76.6%, correspondingly, for ⁹⁹Mo, ^152+154Eu, ⁹⁹Tc, ⁸⁵Sr, and ¹³⁷Cs. The kinetic studies illustrated that the adsorption process obeyed Langmuir kinetics which is a combination of first-order and second-order expressions. The findings demonstrated that the spent alum sludge can be applied successfully as a low-cost and effective adsorbent for the treatment of radioactive waste. (author)