Effect of ferrioxalate-exchanged resin on the removal of 2,4-D by a photocatalytic process

A new approach combining sorption and an advanced oxidation process has been developed for wastewater treatment. Fe3+ is incorporated into a cationic resin with or without the oxalate to afford two types of catalyst: ferrioxalate-exchanged resin (FOR) and ferric-exchange resin (FR), respectively. The removal of herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) by different resin-mediated processes including sole FOR, FOR/H2O2, UV/FOR, UV/R/H2O2, UV/FR/H2O2, UV/FOR/H2O2 was investigated and compared. The optimal result was obtained in the treatment of 2,4-D with FOR when the system was irradiated at 350 nm with 1 mM H2O2; 80% of the 2,4-D disappeared after an operation time of 60 min. In addition, two other organic pollutants, atrazine (ATZ) and 2-chloroaniline (2-ClA), were used as the starting materials to test the selectivity of the solid catalyst. The FOR was found to be a non-selective catalyst; pre-sorption on the surface of the resin was not an essential step for the photocatalysis. Sorption and radical oxidation were found to be the major reaction pathways for the removal of 2,4-D. The recycling of the FOR was easy and feasible.

A new approach combining sorption and an advanced oxidation process for wastewater treatment has successfully shown that ferrioxalate-exchanged resin (FOR) is capable of catalyzing and enhancing the removal as well as degradation of organic pollutants. The modified resin was found to be a non-selective catalyst; pre-sorption on the surface of the resin was not an essential step for the photocatalysis.Figure optionsDownload as PowerPoint slide