| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 44783 | Applied Catalysis B: Environmental | 2016 | 10 Pages |
•First study on the removal of humic acids from water by electrochemical AOPs.•The main advantage of BDD anode is the complete mineralization of humic acids.•Carbon sponge cathode is a less suitable material due to adsorption of humic acids.•Adsorbed humic acids are subject to removal by OH produced in electro-Fenton.•Modelling of TOC removal by taking into account sorption and oxidation processes.
The management of natural organic matter in drinking water treatment plants is an important matter of concern. It can generate toxic disinfection by-products as well as decrease the efficiency of membrane filtration and oxidation processes. This is the first study that investigates the use of anodic oxidation (AO) and electro-Fenton (EF) for the removal of humic acids (HAs) from aqueous solutions. Both sorption and catalytic oxidation of HAs are assessed and discussed. These electrochemical advanced oxidation processes are based on the in situ production of hydroxyl radicals, a highly oxidizing agent. The EF process involves the use of carbon-based porous materials (carbon sponge) as cathode, leading to the fast adsorption of hydrophobic HAs. It has been observed that adsorbed HAs can react with hydroxyl radical produced in the bulk from Fenton’s reaction. Then, the release in the solution of more hydrophilic by-products from the oxidation of HAs leads to a rebound effect of the organic matter concentration. Therefore, the AO process using non-carbonaceous cathode materials appears to be more suitable for HAs removal. Using boron-doped diamond anode and stainless steel cathode, the mineralization efficiency of a HAs solution (TOC0 = 16.2 mg L−1) reached more than 99% after 7 h of AO treatment with a current intensity of 1000 mA. By considering both sorption and oxidation processes, this study proposed a new modelling approach to monitor TOC evolution during AO and EF processes.
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