Heterogeneous activation of persulfate by supporting ferric oxalate onto activated carbon fibers for organic contaminants removal

The development of highly efficient and environmentally friendly catalyst to activate persulfate (PS) is a promising technology for contaminants removal. Herein, a novel heterogeneous catalyst (FeOxa@ACFs) was designed by supporting ferric oxalate (FeOxa) onto activated carbon fibers (ACFs). FeOxa@ACFs could activate PS to achieve a removal of 96.8% for Reactive Red M-3BE (RR M-3BE) within 20 min and the apparent rate constant (k(obs)) was 3.6 times higher than that of FeOxa/PS system. Moreover, FeOxa@ACFs was capable of excellent recyclability and a broad pH adaptability (3.0-10.0). Radical capturing experiments indicated that sulfate, hydroxyl and superoxide radicals played a key role for contaminants removal. Interestingly, the k(obs) of RR M-3BE was unexpectedly 4 times enhancement after the introduction of p-benzoquinone, which is very different from the previously system with a negative influence. This study will open a promising avenue for building highly efficient and eco-friendly catalyst to remediate contaminated water.