The electrochemical advanced oxidation processes coupling of oxidants for organic pollutants degradation: A mini-review

The electrochemical advanced oxidation processes(EAOPs) have been extensively applied in the treatment of organic pollutants degradation.Herein,the mini review provides the coupling systems about EAOPs and different oxidants(e.g.,persulfate(PS),peroxymonosulfate(PMS),and ozone(O3)),including EAOPs-PS systems,EAOPs-PMS systems,EAOPs-peroxone systems,and photoelectro-oxidants systems,for the organic compounds degradation.The coupling system of EAOPs with oxidants is an effective way to improve the generated free radicals(e.g.,HO^·and SO4^·-) concentration and to accelerate pollutant degradation.In this review,we make a summary of the homogeneous and heterogeneous EAOPs-oxidant processes.The reaction mechanisms of EAOPs combined with different oxidants are elucidated in detail,as well as the synergistic effect for improving the degradation and mineralization efficiency.

Synchronous mineralization of three aqueous non-steroidal anti-inflammatory drugs in electrochemical advanced oxidation process

Electrochemical degradation performances of three non-steroidal anti-inflammatory drugs(NSAIDs),acetaminophen(ACT),aspirin(ASP)and ibuprofen(IBP),were investigated and compared in their alone and mixture conditions using Ti/SnO_(2)-Sb/La-PbO_(2).The pseudo-first-order degradation kinetics(k)order was k_(IBP-A)(0.110 min^(-1))>k_(ASP-A)(0.092 min^(-1))>k_(ACRT-A)(0.066 min^(-1))in their alone condition,while that was k_(ACT-M)(0.088 min^(-1))>k_(ASP-M)(0.063 min^(-1))>k_(IBP-M)(0.057 min^(-1)) in their mixture condition.The·OH apparent production rate constant of 5.23 mmol L^(-1)min^(-1)m^(-2) and an electrical energy per order(E_(EO)) value of 6.55 Wh/L could ensure the synchronous degradation of the NSAIDs mixture.The mineralization efficiency of NSAIDs mixture was 86.9%at 240 min with a mineralization current efficiency of 1.67%.Acetic acid and oxalic acid were the main products in the mineralization process for the both conditions.In the mixture condition,there were higher k values at lower initial concentrations and higher current density,while the presence of carbonate and humic acid inhibited their degradation.The results indicated electrochemical advanced oxidation process can effectively and synchronously mineralize NSAIDs mixture in wastewater.

Influence of MnO_(x)deposition on TiO_(2)nanotube arrays for electrooxidation

TiO_(2)has demonstrated outstanding performance in electrochemical advanced oxidation processes(EAOPs)due to its structural stability and high oxygen overpotential.However,there is still much room for improving its electrochemical activity.Herein,narrow bandgap manganese oxide(MnO_(x))was composited with TiO_(2)nanotube arrays(TiO_(2)NTAs)that in-situ oxidized on porous Ti sponge,forming the MnO_(x)-TiO_(2)NTAs anode.XANES and XPS analysis further proved that the composition of MnO_(x)is Mn2O3.Electrochemical characterizations revealed that increasing the composited concentration of MnO_(x)can improve the conductivity and reduce oxygen evolution potential so as to improve the electrochemical activity of the composited MnO_(x)-TiO_(2)NTAs anode.Meanwhile,the optimal degradation rate of benzoic acid(BA)was achieved using MnO_(x)-TiO_(2)NTAs with a MnO_(x)concentration of 0.1 mmol L^(-1),and the role of MnO_(x)was proposed based on DFT calculation.Additionally,the required electrical energy(EE/O)to destroy BA was optimized by varying the composited concentration of MnO_(x)and the degradation voltage.These quantitative results are of great significance for the design and application of high-performance materials for EAOPs.