Electrochemical Degradation of Phenol and 2-Chlorophenol Using Pt/Ti and Boron-Doped Diamond Electrodes

Abstract

To test the efficiency of the BDD electrode for complete mineralization of organic wastewater, phenol and 2-chlorophenol (2-CP) were treated electrochemically with both an active Pt/Ti electrode and a nonactive boron doped diamond (BDD) electrode, respectively, in neutral aqueous medium. Aqueous solutions of both phenol and 2-chlorophenol were treated electrochemically using an in-house fabricated flow through electrochemical cell (FTEC). The experimental variables included current input, treatment time, and the flow rate of the solutions. Depending on the magnitude of the applied current and reaction time, the compounds were either completely degraded or partially oxidized to other intermediates. Removal efficiencies reached as high as 93.2% and 94.8% both at the Pt/Ti electrode and BDD electrode, respectively, at an applied current of 200 mA for a 3.0 hr reaction and a flow rate of 4 mL/min. The BDD electrode was much more efficient for the complete mineralization of phenol and 2-chlorophenol than the Pt/Ti electrode.

Electrochemical Removal of Ammonium Nitrogen and COD of Domestic Wastewater using Platinum Coated Titanium as an Anode Electrode

“…In indirect anodic electro-oxidation, anodically generated chlorine and hypochlorite are used as the oxidizing agents for the decomposition of organics in the presence of chloride ions [38]. As the influent of our experimental domestic wastewater contained 43 mg/L of initial chloride ions and because the Pt/Ti anode used in our experiment was an 'active' electrode [39,40], we believe that the decomposition and the oxidation of organics (R) and removal of COD were due to indirect anodic oxidations and active chlorine-mediated reactions. An increase in voltage leads to an increase in current density and an increased current density increases charge loading, which in turn increases the pollutant removal efficiency [41].…”

Electrochemical Degradation of Triclosan at a Ti/SnO2‐Sb/Ce‐PbO2 Anode

“…It has been found that several chemical oxidants such as ferrate (K 2 FeO 4 ), permanganate (KMnO 4 ), and manganese oxides (MnO 2 ) also effectively degrade triclosan, but they lead to coloration and sludge formation in the treated water. Previous reports showed that triclosan can be degraded by electrochemical process using screen‐printed carbon electrode, mercury cathode, and boron‐doped diamond (BDD) electrode , while some other organic substances also undergo mineralization on the high oxygen over‐potential BDD anode . Despite the BDD electrode having an excellent stability with high oxygen evolution over‐potential (OEOP) towards organic oxidation, its high cost and normally the difficulties to find an appropriate substrate for deposition of the diamond layer limits the large‐scale application .…”

Emerging organic contaminants in wastewater: Understanding electrochemical reactors for triclosan and its by-products degradation

“…Moreover, comparative studies in electrodes combinations were described: Yoon et al (2012) reported a flow reactor for the electrochemical degradation of phenol and 2-chlorophenol using Pt/Ti and BDD electrodes, as well as Ambauen et al (2019) comprised a electrochemical oxidation batch reactor for salicylic acid degradation with BDD and Pt electrodes. In both studies similar removal rates in the different electrodes combinations were attained, showing that not only the electrodes type highly influence the compounds degradation efficiencies, but also the physicochemical characteristics of the contaminants to be degraded.…”

“…In both studies similar removal rates in the different electrodes combinations were attained, showing that not only the electrodes type highly influence the compounds degradation efficiencies, but also the physicochemical characteristics of the contaminants to be degraded. BDD and MMO have been mainly and equally used as anodes (Moreira et al, 2017), both showing similar performances in the degradation efficiency (Brillas and Martínez-Huitle, 2015;Skoumal et al, 2008;Yoon et al, 2012). BDD was reported as electrochemical inactivator of phenolic compounds (Sirés et al, 2007;Wang and Farrell, 2004), and Ti/MMO was used to degrade organic contaminants in wastewater (Yuan et al, 2013).…”