Mineralization and deflourization of 2,2,3,3-tetrafluoro-1-propanol (TFP) by UV/persulfate oxidation and sequential adsorption

Abstract: This work demonstrates the combination of UV/persulfate and adsorption processes for treating 2,2,3,3-tetrafluoro-1-propanol (TFP) wastewater. Under the optimum conditions, 20mM persulfate , 254nm UV–C, and pH 3, 99.7% of TOC removal from an initial TFP solution of 1.39mM was achieved. The photolysis of persulfate by UV irradiation yielded the sulfate radical with high activity, which mineralized most of the TFP in 2h. The released fluoride ions were then removed by using a waste iron oxide, BT-4 adsorbent. 20gL−1 BT-4 adsorbed 95% of the fluoride that was produced by mineralization of 1.39mM TFP. The kinetics and isotherms of adsorption were examined to determine the fluoride removal efficiency of BT-4 which co-existed with the sulfate ions from the consumed sulfate radicals. Accordingly, the kinetics of adsorption was described by a pseudo-second-order rate model, while the adsorption isotherms were well fitted with the Langmuir model. BT-4 had a high adsorption capacity of 26.4mgg−1 (25°C) in removing the fluoride from TFP mineralization, suggesting that the co-existing sulfate ions never significantly affected the fluoride removal efficiency. [Copyright &y& Elsevier]