Preparation and Adsorption Performance on Congo Red of Sodium Alginate-Lanthanum Hydrogel Spheres

Abstract

Sodium alginate-lanthanum (SA/Lan) hydrogel spheres were prepared by ion cross-linking method to remove Congo Red (CR) in an aqueous solution. The adsorption performance was assessed through batch experiments. The experiment revealed that the highest adsorption capacity of SA/Lan for CR was achieved when the mass concentration of La³⁺ was 1%, the dosage was 2 g·L⁻¹, the initial concentration of CR was 30 mg·L⁻¹, the adsorption time was 60 min, and the reaction temperature was 25°C. The adsorption capacity of 10.81 mg·g⁻¹ was the corresponding figure. The adsorption process was consistent with the Langmuir and pseudosecond-order models.