Development and characterization of bentonite-gum arabic composite as novel highly-efficient adsorbent to remove thorium ions from aqueous media

Elimination of radioactive ions from wastewater using powerful adsorbents is of great importance for reducing the environmental pollution. Within this context, Bentonite (BNT)-Gum Arabic (GA) composite was developed as a new adsorbent to excellently eliminate Th(IV) ions from aqueous media. The produced composite adsorbent was examined by FTIR and SEM/EDX techniques. The effects of main empirical parameters on the adsorption efficiency were optimized by factorial design analysis. The maximum elimination capacity of BNT-GA was determined as 885.4 mg g−1 at pH 4.5, in 30 min, and 24 °C. Thermodynamic studies showed that Th(IV) adsorption progressed exothermically and the spontaneity of the process was lessened with the increase in temperature. Kinetic findings exposed that the adsorption mechanism fits perfectly with the pseudo-second-order (PSO) model. A 96% part of the adsorbed Th(IV) ions was recovered from the composite adsorbent using 1.0 M HCl. The produced composite revealed remarkable adsorption/desorption efficiency even after 7 cycles. All results show that the prepared BNT-GA compound can be used for the effective exclusion of Th(IV) ions from wastewater due to its advantageous properties such as great elimination capacity, cost-effectiveness, and facile preparation.