Biocomposite application for the phosphate ions removal in aqueous medium

Mango stone biocomposite efficiency for the removal of phosphate ions (PO4) 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 PO4 ions concentration (20–800 mg/L) and temperature (33–61 C). Maximum PO4 ions removal was achieved at pH 2, biocomposite dose 0.3 g, contact time 90 min and initial PO4 ions concentration 200 mg/L. At optimized conditions, up to 95 mg/g PO4 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 ( G0, H0 and S0) revealed that PO4 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 PO4 was successfully desorbed using 1.0 M NaOH solution. Results revealed that biocomposite adsorbed PO4, which could possibly be used for the adsorption of PO4 efficiently from wastewater. © 2017 Brazilian Metallurgical, Materials and Mining Association. Published by Elsevier Editora Ltda. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).