Ibuprofen removal from aqueous medium by zeolite-supported nano-scale zero-valent iron/persulfate

Pharmaceuticals can enter the aquatic environment directly or indirectly through various activities because of their high consumption. Their presence in the environment may pose a threat to human and ecological health. Therefore, these pollutants must be removed from wastewater before they are given to the receiving environment. In recent years, studies on sulphate radical based advanced oxidation processes have gained importance for the removal of pollutants such as pharmaceutical. In this study, the removal of ibuprofen from aqueous solution by zeolite supported nano-scale zero-valent iron (Z-nZVI)/persulfate was investigated. Therefore, Z-nZVI was synthesized by the borohydride-based chemical reduction method in laboratory using zeolite as a support material. The combination of Z-nZVI and persulfate was very more effective for the removal of ibuprofen in comparison to nZVI alone and persulfate alone. The most effective zeolit:nZVI mass ratio was determined as 1:1 for the removal of ibuprofen in Z-nZVI/persulfate system. In the study, the effect of factors such as zeolite:nZVI mass ratio, initial solution pH, Z-nZVI amount, persülfate concentration, initial ibuprofen concentration, chloride and bicarbonate anions and humic acide on ibuprofen removal efficiency by Z-nZVI/persulfate were evaluated through a series of batch experiments. The most effective zeolite: nZVI mass ratio for ibuprofen removal in the Z-nZVI/persulfate system was 1:1. Ibuprofen removal efficiency was found to be high at the original pH of the solution. With the increase in Z-nZVI up to 0.2 g/L, the removal efficiency increased, but decreased at dosages above 0.2 g/L. The removal efficiency increased with increasing persulfate concentration. With the increase in ibuprofen concentration, the removal efficiency decreased. In this experimental work, complete removal of ibuprofen were realized by the use of Z-nZVI/persulfate system. The dominant radical for the removal of ibuprofen by Z-nZVI/persulfate was sulfate radical. Key words: İbuprofen Removal, Advanced Oxidation, Persulfate, Sulfate Radical, Zeolite, Z-nZVI