Multi component biosorption of U(VI), Cu(II), and Ni(ΙΙ) in the fixed bed column: dynamic mathematical modeling, GWO optimization, and biosorption experiments

In this study, the multi component biosorption by Cystoseria indica brown alga in a fixed bed column from a solution containing U(VI), Cu(II), and Ni(ΙΙ) was investigated at various flow rates (1.15, 2.3, and 4.6 mL/min) and bed heights (3.5, 5.25, and 7 cm). The results demonstrated that the biosorbent's affinity to metal ions follows the order of U(VI) > Cu(II) > Ni(ΙΙ). Furthermore, concentration overshoot was detected in all biosorption assays for Ni(II) ions. The best flow rate of 2.3 mL/min was selected, resulting in the maximum biosorption capacities of 133.2, 52.3, and 23.9 mg/g for U(VI), Cu(IΙ), and Ni(ΙΙ), respectively. The results also demonstrated that the biosorption capacity increases for U(VI) ion and decreases for Cu(IΙ) and Ni(Ι) ions as the bed height increases. The multi component biosorption process was modeled using the internal mass transfer model and the Gray Wolf Optimizer (GWO) algorithm. The modling results revealed that the mass transfer mechanism occurs through diffusion within the biosorbent's pores.