Biosorption of Bromophenol Blue from Aqueous Solution Using Flamboyant (Delonix regia) Pod

Matured flamboyant pods (FBP) activated with ZnCl2 were used for batch adsorption of Bromophenol blue (BPB) dye under the effects of concentration (10-200 ppm), contact time (20-300 min), biosorbent dosage (20-120 mg) and particle size (300-850 µm). The data obtained were fitted to Langmuir and Freundlich isotherm models as well as pseudo-first-order (PFO), pseudo-second-order (PSO) and Elovich kinetic models. The highest adsorption capacity and removal efficiency of 7.5762 mg/g and 75.76%, respectively, were obtained under the effects of initial dye concentrations. The correlation coefficient (R2) for the Langmuir and Freundlich isotherms are in the range 0.9938-0.9979 and 0.9895-0.9953, respectively, while, R2, in the ranges 0.5931-0.815, 0.9962-1.000 and 0.8046-0.8828, were obtained for the PFO, PSO, and Elovich kinetic models, respectively. The order of fit of the kinetic models is PSO > Elovich > PFO. The study suggests flamboyant pod as promising biomass for the remediation of dye-bearing industrial effluents.