Preparation of Biocomposite Adsorbent Spheres from Bioglass Reinforced Biopolymer Alginate and Adsorption of Crystal Violet.

Crystal violet is a cationic dye widely used in biomedical research, industrial dyeing, microbiology, and the textile industry. To remove this toxic dye, which has harmful environmental effects, environmentally friendly composite bioadsorbent spheres were prepared using alginate, a brown seaweed-derived biopolymer, and bioglass. Crystal violet adsorption was performed using a biocomposite adsorbent prepared by adding 14% bioglass to an alginate matrix. The effects of adsorbent amount, dye concentration, contact time, and pH on the adsorption process were investigated. In this study, a maximum removal efficiency of 65.68% was achieved using 40 mg of adsorbent in 20 mL of a 5 mg/L crystal violet solution after 120 min at a stirring speed of 200 rpm. The Langmuir model estimated a theoretical maximum adsorption capacity (qmax) of 5.57 mg/g based on the three investigated initial concentrations (5, 10, and 15 mg/L). The data were analyzed using Response Surface Methodology. ANOVA indicated that contact time had the greatest effect on removal efficiency. Isotherm and kinetic studies revealed that the Langmuir and Dubinin-Radushkevich isotherm models adequately described the adsorption process, and that the second-order kinetic model provided the best fit. These findings suggest that the adsorption is consistent with monolayer adsorption on a relatively homogeneous surface, and that binding may occur via low-energy physical interactions within micropores. The developed bioadsorbents demonstrated promising performance for crystal violet removal.