Th(ІV), V(V), and Fe(ІІІ) biosorption from real wastewater of thorium chemical precipitation process by Ca-pretreated Cystoseria indica alga: breakthrough curves modeling in a fixed bed column and biosorption mechanism study

This research examined how Cystoseria indica brown macroalgae of the Phaophyta family can be pre-treated with calcium to sorb Th(IV), V(V), and Fe(III) from real wastewater resulting from the thorium chemical process using a fixed bed column whose bed height was 5.25 cm and its diameter was 1.5 cm. It was found that the competition between Th(IV) and V(V) ions is significant in Th(IV) biosorption from three-component feed solutions of Th(IV) - V(V) and Th(IV) - Fe(III). The biosorption capacity of Th(IV), V(V), and Fe(III) from real wastewater was also 104.60, 24.15, and 17.39 mg/g, respectively. It shows that the affinity of Th(ІV) ions to Ca-pretreated Cystoseria indica algae is higher than that of Fe(ІІІ) and V(V) ions. The biosorption breakthrough curves were modeled using Bohart-Adams, Thomas, Yoon-Nelson, Belter, adapted dose-response, Gompertz, and modified Gompertz models. The results showed that the modified Gompertz model better agreed with the experimental data. The Fourier transform infrared (FTIR) analysis and calcium concentration determination in real wastewater indicated that functional groups such as hydroxyl, amine, amide, methylene, carboxyl, and sulfate were most likely to participate in the ion exchange mechanism with Th(*V), V (V) and Fe(III) ions.