Enhanced Rhodamine B degradation by GAC/Mn–Sn particles electrodes

Abstract

Rhodamine B (RhB) wastewater could be degraded by a three-dimensional electrolytic reactor with surface-modified titanium anodes, and a variety of materials had been tried to prepare for particles electrodes to enhance its removal effects, among them, granular activated carbon (GAC) with large specific surface areas and stable chemical properties was selected as particles materials and coated by manganese oxidation (Mn) as the main active ingredient. The experimental results showed that 98.3% of RhB and 60.7% of chemical oxygen demand were removed respectively, and the RhB wastewater's biodegradability was improved either. On the superficial sites of GAC/Mn–Sn particles, hydroxyl radicals were generated, and some absorbed RhB molecular was initially decolored by hypochlorite removing the two ethyl groups on both sides of the molecular, then oxidized by hydroxyl, and continually decomposed by these strong oxidants into a variety of intermediates. HIGHLIGHTS The removal rate of Rhodamine B (RhB) was increased obviously by the three-dimensional electrode reactor, packed with surface-modified GAC/Mn–Sn particles electrodes.; Hydroxyl radicals were probably generated by the surficial active sites of GAC/Mn–Sn particles electrodes that metastable solid Mn–Sn oxides were catalytic and conductive to the electrochemical process.; The biodegradability of wastewater was increased.;

Keywords

• gac/mn–sn particles electrodes
• rhodamine b (rhb)
• three-dimensional electrode reactor (tder)