Zilong Li , Nuo Xu , Shihua Liu , Yawen Wang , Vishnu D. Rajput , Tatiana Minkina , Faying Fan , Wa Gao , Yufei Zhao
{"title":"Electrocatalysis coupled super-stable mineralization for the efficient treatment of phosphorus containing plating wastewater","authors":"Zilong Li , Nuo Xu , Shihua Liu , Yawen Wang , Vishnu D. Rajput , Tatiana Minkina , Faying Fan , Wa Gao , Yufei Zhao","doi":"10.1016/j.ces.2024.120910","DOIUrl":null,"url":null,"abstract":"<div><div>The automotive, electronics, and aerospace sectors use electroless nickel plating (ENP) technology for surface treatment. Hypophosphite, a widely used reducing agent in ENP, generates large volumes of hypophosphate (H<sub>2</sub>PO<sub>2</sub><sup>-</sup>) and nickel ions (Ni<sup>2+</sup>) in its wastewater which poses potential risks to human health. However, it is a highly challenging task to remove and recycle the H<sub>2</sub>PO<sub>2</sub><sup>-</sup> and Ni<sup>2+</sup> from such wastewater. In this study, a novel electrocatalysis coupled super-stable mineralization process was developed for the treatment of phosphorus-containing ENP wastewater. The electrocatalytic system, utilizing commercial lead dioxide and stainless steel as the anode and cathode, separately, achieved remarkable results in simultaneously removing H<sub>2</sub>PO<sub>2</sub><sup>-</sup> and recycling valuable Ni<sup>2+</sup> ions from ENP wastewater, with a 99.1 % oxidation efficiency for H<sub>2</sub>PO<sub>2</sub><sup>-</sup> to PO<sub>4</sub><sup>3-</sup> and a high recovery rate of 99.8 % for nickel. In order to meet industrial emission standards, layered double hydroxide (CaAl-LDH) and its calcined derivatives (CaAl-900) were employed as super-stable mineralizers for the further treatment of total phosphorus (TP) and residual Ni<sup>2+</sup> in the wastewater. The mechanism underlying the enhanced treatment of ENP wastewater was elucidated through free radical quenching experiments, revealed superoxide radicals (·O<sub>2</sub><sup>–</sup>) as the primary active species. It is noteworthy that the successful treatment of actual ENP wastewater was achieved, meeting standard discharge requirements. This study provides novel insights for achieving resource-efficient wastewater treatment and promoting environmentally friendly electroplating industries.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"302 ","pages":"Article 120910"},"PeriodicalIF":4.1000,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Engineering Science","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0009250924012107","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The automotive, electronics, and aerospace sectors use electroless nickel plating (ENP) technology for surface treatment. Hypophosphite, a widely used reducing agent in ENP, generates large volumes of hypophosphate (H2PO2-) and nickel ions (Ni2+) in its wastewater which poses potential risks to human health. However, it is a highly challenging task to remove and recycle the H2PO2- and Ni2+ from such wastewater. In this study, a novel electrocatalysis coupled super-stable mineralization process was developed for the treatment of phosphorus-containing ENP wastewater. The electrocatalytic system, utilizing commercial lead dioxide and stainless steel as the anode and cathode, separately, achieved remarkable results in simultaneously removing H2PO2- and recycling valuable Ni2+ ions from ENP wastewater, with a 99.1 % oxidation efficiency for H2PO2- to PO43- and a high recovery rate of 99.8 % for nickel. In order to meet industrial emission standards, layered double hydroxide (CaAl-LDH) and its calcined derivatives (CaAl-900) were employed as super-stable mineralizers for the further treatment of total phosphorus (TP) and residual Ni2+ in the wastewater. The mechanism underlying the enhanced treatment of ENP wastewater was elucidated through free radical quenching experiments, revealed superoxide radicals (·O2–) as the primary active species. It is noteworthy that the successful treatment of actual ENP wastewater was achieved, meeting standard discharge requirements. This study provides novel insights for achieving resource-efficient wastewater treatment and promoting environmentally friendly electroplating industries.
期刊介绍:
Chemical engineering enables the transformation of natural resources and energy into useful products for society. It draws on and applies natural sciences, mathematics and economics, and has developed fundamental engineering science that underpins the discipline.
Chemical Engineering Science (CES) has been publishing papers on the fundamentals of chemical engineering since 1951. CES is the platform where the most significant advances in the discipline have ever since been published. Chemical Engineering Science has accompanied and sustained chemical engineering through its development into the vibrant and broad scientific discipline it is today.