Effect of salts and pH on the removal of perfluorooctanoic acid (PFOA) from aqueous solutions through precipitation and electroflocculation

Abstract

This study shows that salt type and pH affect the removal of perfluorooctanoic acid (PFOA) from water through flocculation and electro-enhanced flocculation. PFOA concentrations decreased by approximately 80% with 20 mM FeCl3 and initial pH = 3–10. Electro-enhanced flocculation at pH = 3 reduced PFOA concentrations in water by approximately 70% with CaCl2 and KCl, and by 50% with NaCl. At alkaline pH, PFOA removal was approximately 20% with CaCl2 and KCl. PFOA removal was negligible without salts or with AlCl3, and with NaCl at alkaline pH. Differences in PFOA removal are likely due to the settling behaviour of the cation-PFOA complexes formed.

A Review on Removal and Destruction of Per- and Polyfluoroalkyl Substances (PFAS) by Novel Membranes

“…In some cases, the membrane’s pore size can be manipulated by controlling the solution’s pH, which affects PFAS removal [ 105 ]. The electrostatic repulsion force inside the membrane pores may be reduced when the pH is lowered, which leads to membrane pore size shrinkage and results in enhanced rejection rate [ 106 ].…”

Efficient removal of dyes in textile effluents using aluminum-based coagulant

“…Breaking down of the bonds between microfibers which assist to degradation and decolorizing the dyes have been the utmost stage of eradicating the color and toxicity of the dye. Lots of chemical methods have been introduced such as, electro-flocculation (Pensini et al, 2019), ozonation (Li et al, 2019), oxidation (Chávez et al, 2019), electrochemical destruction (Chaplin, 2019), coagulation (Abiola, 2019), ultrafiltration (Jönsson and Wallberg, 2009;Pathiraja, 2014) for depolluting the water and save the ecosystem for living being. Effluents from industrial wastewater hold complex matrix of water and carries noxious properties which is hard to depict.…”