Pilot-scale electrochemical advanced oxidation (EAOP) system for the treatment of Ni-EDTA-containing wastewater

作者：Wu Lei, Shikha Garg, Ying Dai, Siru Lv, Yuan Wang, T. David Waite · 发表于：Journal of Hazardous Materials · 年份：2024 · DOI：10.1016/j.jhazmat.2024.134840 · 被引用次数：33 · 研究领域：Advanced oxidation water treatment、Environmental remediation with nanomaterials、Electrochemical Analysis and Applications

Electrochemical advanced oxidation processes (EAOP) have shown great potential for the abatement of complexed heavy metals, such as metal-EDTA complexes, in recent studies. While removal of metal-EDTA complexes has been extensively examined in bench-scale reactors, much less attention has been given to the efficacy of this process at larger scale. In this study, we utilize a 72 L pilot-scale continuous flow system comprised of six serpentine flow channels and 90 pairs of flow-through electrodes for the degradation of Ni-EDTA complexes and removal of Ni from solution. The influence of a range of key operating parameters including flow rate, current density and initial Ni-EDTA concentration on rate and extent of Ni-EDTA degradation and Ni removal were examined. Our results showed that at a feed flow rate of 36 L h1, current density of 5 mA cm2 and initial Ni-EDTA concentration of 1 mM, the pilot-scale system achieved 74% total Ni removal, 78% total EDTA removal and 40% TOC removal with energy consumption of 13.6 kWh m-3 order1 and energy efficiency of 7.9 g kWh-1 for total Ni removal. A mechanistically-based kinetic model, which was developed in our previous bench-scale study, provides a satisfactory description of the experimental results obtained in the pilot-scale unit. Long term operation of the pilot-scale unit resulted in corrosion of PbO2 anode along with inorganic scaling as well as organic fouling on the PbO2 surface resulting in an obvious decline in Ni-EDTA degradati...