Biocomposite application for the phosphate ions removal in aqueous medium

Mango stone biocomposite efficiency for the removal of phosphate ions (PO43−) from aqueous solution was investigated as a function of pH (2–8), biocomposite dose (0.05–0.40 g/100 mL solution), contact time (5–120 min), initial PO43− ions concentration (20–800 mg/L) and temperature (33–61 °C). Maximum PO43− ions removal was achieved at pH 2, biocomposite dose 0.3 g, contact time 90 min and initial PO43− ions concentration 200 mg/L. At optimized conditions, up to 95 mg/g PO43− adsorption was achieved. Biocomposite pre-treatment with surfactants (SDS, Tween-80, C-TAB, VIM and Surf excel) were also investigated and it was observed that surfactants pre-treatments decreased the adsorption capacity of the biocomposite. Thermodynamic study (ΔG0, ΔH0 and ΔS0) revealed that PO43− adsorption process onto biocomposite was spontaneous and endothermic in nature. Adsorption data fitted well to the Freundlich isotherm and pseudo-second-order kinetic model. Adsorbed PO43− was successfully desorbed using 1.0 M NaOH solution. Results revealed that biocomposite adsorbed PO43−, which could possibly be used for the adsorption of PO43− efficiently from wastewater. Keywords: Biocomposite, Phosphate ions, Modification, Modeling, Desorptio