Ion Exchange to Capture Iron after Real Effluent Treatment by Fenton’s Process

The main drawback of Fenton′s process is the formation of ferric sludge. In this work, ion exchange (IE) appears as a complement to the Fenton process, allowing, on the one hand, to remove the iron excess present in the sludge, as well as reduce the COD of the real olive oil industry extraction wastewater (OOIEW) from the Fenton process. The Fenton process uses iron (II) sulfate as catalyst, therefore concentrations of iron up to 2 g L−1 could be present in the treated OOIEW. The iron and COD adsorption equilibrium behavior has been modelized by Langmuir, Freundlich and Temkin isotherms. Moreover, the resin efficiency was tested in a continuous fixed-bed column. It was concluded that the resin maintains iron adsorption capacity over at least three reuse cycles. Overall Fenton’s process followed by ion exchange seems to be a promising approach for the treatment of cumbersome industrial wastewaters.