Uranium removal from aqueous solutions onto biochar and irradiated sewage sludge

Abstract Sorption of uranium in aqueous solutions was studied using sewage sludge in raw form and after irradiation, as well as after thermal modification for production of biochar. Different parameters were tested during the sorption procedure such as pH, concentration, competitive ions and temperature. All the investigated materials exhibited significant sorption performance. The structural changes of the sorbents due to irradiation or/and thermal treatment were examined through XRD, FTIR and SEM/EDS before and after sorption. The sorption process followed the quasi-secondary kinetic model and Langmuir isotherm, and the thermodynamic parameters indicated chemisorption and an exothermic process. The results showed that these materials are promising candidates for environmental applications.