Efficacious biosorption of crystal violet pollutant dye from aqueous solutions via Padina pavonica derived alginate

Dyes are toxic, mutagenic, and hazardous to aquatic organisms. Calcium alginate beads derived from Padina pavonica were utilized for crystal violet (CV) bioremoval from water. They were examined using FTIR and SEM before and after CV biosorption, results demonstrated that the characteristics of alginate beads changed after CV biosorption. The bioremoval process of CV varies by environmental parameters including pH, incubation duration, alginate dosage, and initial CV concentration. These environmental factors influence on the CV biosorption process were investigated as one factor at a time. At pH 6, 70 mg/25 mL alginate dosage, and 2 mg L^{- 1} CV concentration after 5 h of incubation, the highest CV bioremoval efficiency was achieved. A correlation existed between the pseudo-second-order kinetic model and the kinetic assessments of the current results, which indicated chemisorption of CV on alginate beads. Moreover, the isotherms calculations revealed that the results were fit with Freundlich model, in which values of Freundlich constant (K_F), correlation coefficient (R²) and n were 1.582, 0.988 and 2.378, respectively, indicating that CV particles are arranged as multilayers on alginate beads surface. Calcium alginate beads derived from Padina pavonica are promising in dye biosorption from aqueous solutions with no hazardous influence on the environment.