DSA Anode Based Electrocatalytic Oxidation Removal Of PPCPs:Preparation,Performance And Mechanism

In recent years,with the increasing use of pharmaceuticals and personal care products(PPCPs),the emission of large amounts of PPCPs has posed a serious threat to the ecological environment.PPCPs have both hydrophobic and hydrophilic nature.Therefore,some of these can accumulate in plant and other organisms,be in water or in sediment and soil.Furthermore,PPCPs can have an adverse effect on health and even be carcinogenic in nature.Biological wastewater treatment and conventional drinking water treatment systems,including coagulation,sedimentation,and filtration,mainly removes BOD,COD,TN and TP,but it is almost impossible to remove PPCPs in water.In this perspective,advanced oxidation processes(AOPs)becomes an emerging,and prominent methods for the removal of PPCPs in the effluents.Dimensionally stable anode(DSA)cost-effective,long operating life,good electrochemical catalytic performance,high stability,and excellent physical and electrochemical performance.It is an ideal electrocatalytic anode material in electrochemical advanced oxidation process(EAOP).When using DSA to treat wastewater,it does not need to add oxidant.It has high flexibility,less land occupation,low economic cost,and is widely used in organic wastewater treatment.Although some traditional and new technologies can be used for removing PPCPs in water,the research on the degradation of PPCPs using electrocatalytic oxidation technology is relatively scarce.In addition,further studies are still required to inspect the reaction mechanisms of many remediation technologies.In view of this,we developed to prepare DSA electrodes used sol-gel method with titanium substrate coated with Sn O2,Sb and different ratios of Ru O2 and Ir O2 in this paper.The electrochemical properties of the electrodes were in-vestigated by the characterization of the oxygen evolution potential / chlorine evolution potential,active area,electrochemical impedance,and accelerated lifetime of anodes with different doping elements.The surface morphology and the structure of the above anode were characterized by scanning electron microscopy(SEM)and X-ray diffraction(XRD).The best anode material was selected as Ti / Sn O2-Sb-Ir O2-Ru O2 electrode.It has a higher oxygen evolution potential,a lower chlorine evolution potential,a larger active area with strong stability.Besides,this paper also has investigated the electrochemical oxidation of ibuprofen,atenolol,and carbamazepine in an undivided cell at different experimental parameters such as p H and current density on the anode of Ti / Sn O2-Sb-Ir O2-Ru O2.At p H 7.0,the removal efficiency of ibuprofen reached 92.7% at 20 m A cm-2 after 120 min;the removal efficiency of atenolol and carbamazepine reached 99.6% and 99.5% at 6 m A cm-2 after 60 min,respectively.Notably,we established a mathematical model to investigate the contribution of different reactive species(hydroxyl radicals(·OH)and reactive chlorine species(RCS))in the degradation process of three kinds of PPCPs pollutants in EAOP.The degradation of ibuprofen was mainly due to ibuprofen reaction with ·OH,taking the reaction for 60 min as an example,the total degradation rate of ibuprofen is 68.5%,the contribution rate of ·OH and RCS are 60.2% and 8.3%,respectively.The degradation of atenolol and carbamazepine is mainly due to the reaction of atenolol and carbamazepine with RCS,and the contribution rate of ·OH is negligible.Atenolol total degradation rate was 94.5%,·OH contribution rate was 17.1%,RCS contribution rate was 77.4%;carbamazepine total degradation rate was 98.8%,·OH contribution rate was 13.3%,RCS contribution rate was 85.5%.Besides,this study shows that the Ti/Sn O2-Sb-Ru O2-Ir O2 anode exhibits good electro catalytic activity together with chemical stability during the treatment of low-concentration of ibuprofen,atenolol,and carbamazepine in T actual reclaimed water.The experimental results show that the pollutants(such as atenolol and carbamazepine)which the main oxidation mechanism is RCS selective oxidation degraded in electrocatalytic oxidation is better and more stable.This study demonstrate the Ti/Sn O2-Sb-Ru O2-Ir O2 anode is an attractive alternative electrode in the EAOP system for the destruction of PPCPs effluent under environmentally relevant conditions.