Details

Autor(en) / Beteiligte

• Hurwitz, Gil
• Pornwongthong, Peerapong
• Mahendra, Shaily
• Hoek, Eric M.V.

Titel

Degradation of phenol by synergistic chlorine-enhanced photo-assisted electrochemical oxidation

Ist Teil von

• Chemical engineering journal (Lausanne, Switzerland : 1996), 2014-03, Vol.240, p.235-243

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •Phenol was treated by a hybrid photo-assisted electrochemical oxidation process.•Hybrid photolytic and electrochemical process showed synergistic DOC removal.•Hybrid treatment is competitive with conventional advanced oxidation processes.•Hybrid treatment had the lowest energy demand tested, reduced DBP formation, and no residual toxicity. Hybridization of a UV-C photoreactor with an electrochemical cell led to the discovery of a distinctive synergistic mechanism for the degradation and mineralization of phenol when free chlorine-producing anodes were utilized in the presence of chloride. After 6h, photochemical (UV) treatment resulted in 29% phenol mineralization and electrochemical (EL) treatment resulted in 35% and 52% mineralization using boron-doped diamond (BDD) and ruthenium oxide on titanium (DSA-Cl2) anodes, respectively. However, the photo-assisted electrochemical (UVEL) process removed 88% and 96% of total organic carbon (TOC) after 6h with BDD and DSA-Cl2 anodes, respectively. The hybrid UVEL process generated highly reactive hydroxyl and chlorine radicals by the photolysis of in situ electrogenerated free chlorine. As a result, the UVEL treatment produced fewer chlorinated by-products compared to EL alone. UVEL with DSA-Cl2 had the highest TOC removal after 6h (96%), one of the highest mineralization rates (0.38h−1), and the lowest energy demand per order TOC removed (EEO=104kWhm−3order−1) without any residual toxicity after dechlorination. Generally, conventional advanced oxidation processes (UV/O3 and UV/H2O2) were most effective at mineralization up to 50%, but UVEL appeared more cost effective for mineralization beyond 75%.