Wireless Electrocoagulation in Water Treatment Based on Bipolar Electrochemistry

• Published in: Electrochimica acta Vol. 229; pp. 96 - 101
• Main Authors: Qi, Zhenlian, You, Shijie, Ren, Nanqi
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2017; Elsevier BV
• Subjects: Anodic dissolution; Bipolar electrochemistry; Coagulants; Electric fields; Electrochemistry; Electrocoagulation; Electrodes; Graphite; Iron; Turbidity; Voltage drop; Water treatment; Wireless; Wireless; Iron; Electrocoagulation; Bipolar electrochemistry
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2017.01.151

[Display omitted] •Wireless electrocoagulation based on bipolar electrode (BPE) is proposed for water treatment.•The coagulant produced is more dependent on the geometrical configuration of BPE rather than electrochemical parameters.•The wireless operation can solve the problems caused by electrode connection. The present study reports the wireless electrocoagulation (WEC) based on bipolar electrochemistry where the iron sheets were used as sacrificial bipolar electrodes (BPEs) and two graphite plates served as driving electrodes. Driven by the interfacial potential difference induced by electric field in solution, the iron dissolution started at the anodic pole, achieving the generation of iron coagulant and thus turbidity removal. The total iron concentration produced was found to be more dependent on the geometrical configuration of BPE rather than electrochemical parameters. That is, placing the BPE with the length in parallel to electric field could generate iron concentration of 84.6% higher than that when placed vertically. Besides, increasing the number of BPE from one to three led to the increase in coagulant production by 2.1 times. Moreover, to maximize the voltage drop and minimize the material used, the BPE was designed into different geometrical shapes. The “H-shaped” BPE could achieve almost the same iron concentration as the unmodified BPE even the relative cathode/anode surface area was as low as 0.36. This accounted for efficient coagulant production by saving as great as 40% of the electrode material and cost. The wireless operation can not only solve the problems caused by electrode connection, but also allow arbitrary number of sacrificial BPEs working simultaneously in a very simple setup. In addition, the WEC performance can be easily controlled by the geometrical configuration of BPE. All these factors will be expected to make the electrocoagulation process much easier, more economical and more reliable in water treatment.