Electrochemical Oxidation of Bromides on DSA/RuO₂Anode in the Semi-Industrial Batch Reactor for On-Site Water Disinfection

Abstract

The electrochemical oxidation of bromides for on-site water disinfection, on dimensionally stable DSA titanium coated RuO 2 anode is investigated by the polarization measurements and in the semi-industrial batch reactor under constant current conditions. During electrolysis of 0.4 M bromide with the current of 5 A, the concentration of bromine, Br 2 , tribromide ions, Br 3 -, hypobromous acid, HOBr, and hypobromite, BrO -, so-called equivalent bromine, Br eq , is determined using arsenometric titration at pH∼9 and pH∼3.5. At pH∼9, the concentration of 0.1 M is obtained, but solutions undergo to fast decomposition. In the acidified electrolyte, the stable bromine solution with the concentration of 0.15 M after 1.75 h of electrolysis is obtained, corresponding to 14 g dm −3 of "active bromine", a mixture of HOBr and OBr -. With typical dosing rate of active bromine for disinfection of ∼0.5 mg per liter of water, it is suggested that investigated batch semi-industrial reactor can be used for the treatment of ∼28.000 liters of water. Basic electrolysis parameters like, reactor voltage, temperature, pH, current efficiency, energy consumption is also determined. The reaction products are determined using thermodynamic equilibrium consideration and UV-vis spectroscopy measurements. The main loss reaction during electrolysis is considered, and appropriate analytical expressions are suggested.

Reactive Halogen Species-Mediated Electrocatalytic Oxidation of Arsenite(III)

“…Good correlations between Δ[As(V)] and Δ[RHSs] also indicate the potential use of As(III) oxidation reactions for quantifying RHSs. 42,54 ■ CONCLUSIONS This study demonstrated that electrochemically generated RHSs are effective in mediating As(III) oxidation at circumneutral pH. Electrochemical As(III) oxidation with high As V − FEs was readily achieved at relatively low potentials.…”

“…The former band was attributed to all possible bromine species, whereas the latter band was attributed solely to BrO − . 42,51 Notably, HBrO (pK a = 8.70) is typically observed at λ = 260 nm (ε = 100 L mol −1 cm −1 ), and its conjugate base BrO − displays an absorption band at λ = 330 nm with a relatively high absorption coefficient (ε = 332 L mol −1 cm −1 ). Both HBrO and BrO − exhibit weak absorption at λ = 232 nm (ε = 58 and 81 L mol −1 cm −1 , respectively).…”

NaBr-Assisted Photoelectrochemical and Photochemical Integrated Process for Isomerization of Maleate Esters to Fumarate Esters

“…39 Consequently, the strong absorbance peaks of Br 3 − (Br 2 + Br − , 0.39 μmol) as well as the weak absorption of HOBr (0.08 μmol) and Br 2 (0.27 μmol) were observed at around 266, 260, and 390 nm, respectively (Figures S4 and S5). 40,41 Figures S6 and S7 present the light harvesting efficiency (LHE) and the incident photon-tocurrent efficiency (IPCE) for the oxidation of Br − on the BiVO 4 /WO 3 /FTO photoelectrode, respectively. The IPCE values were 67% at 365 nm and 52% at 400 nm, which resembled the LHE spectrum of the BiVO 4 /WO 3 /FTO photoelectrode.…”

Dimensionally Stable Anode Based Sensor for Urea Determination via Linear Sweep Voltammetry

“…Metal oxide and mixed metal oxide electrodes are generating increasing interest due to their high stability and wide electrochemical window [ 7 , 8 , 9 ]. Metal oxide type sensors are excellent candidates for remote monitoring (online) and wireless applications, as they have a fast signal/response and long lifetime in different environmental conditions [ 7 , 9 , 10 ]. Mixed metal oxides have been mostly studied for electrochlorination and water treatment applications [ 6 , 7 , 11 , 12 ].…”

“…DSA ® -type electrodes have been widely studied in the literature [ 10 , 14 , 15 , 16 , 21 ]. To the best of our knowledge, there has not been any systematic investigation of the composition (Ti/RuO 2 -TiO 2 -SnO 2 (50:40:10 atom.…”