Eco‐Friendly Biosorption of Uranium from Aqueous Solutions Using Sepiolite‐Cavex CA37 Composite Biosorbent.

Cavex CA37 is a dental material used for positive tooth impressions. After the mold is taken, it hardens through a fast‐chemical reaction with air, then becomes waste after usage. In this study, natural sepiolite and Cavex CA37 are mixed at certain ratios to obtain a composite SCX‐37 biosorbent that is used for the biosorption of UO22+${\rm{UO}}_2^{2 + }$ ions from a synthetic aqueous solution. Parameters affecting biosorption, such as solution pH, ambient temperature, contact time, and UO22+${\rm{UO}}_2^{2 + }$ ion concentration, are investigated. The biosorption of UO22+${\rm{UO}}_2^{2 + }$ ions on SCX‐37 reaches equilibrium in 120 min with 97.56% efficiency at 30 °C and pH 4. The isotherms (Langmuir, Freundlich, and D‐R) and thermodynamic values of the biosorption of UO22+${\rm{UO}}_2^{2 + }$ ions on the SCX‐37 biosorbent are calculated according to the obtained data. It is determined that there is a high correlation between experimental results and all three isotherm models. The adsorption capacity is found to be 41.39 mg g−1. The biosorption of UO22+${\rm{UO}}_2^{2 + }$ ions onto the SCX37 biosorbent is a chemisorption process with an adsorption energy of 40.50 kJ mol−1. [ABSTRACT FROM AUTHOR]