Jianhua Liu, Peicong Zhang, Qiaolin Hu, Yi Huang, Junfeng Li, Haiying Du, Wentao Zhang, Xianfei Chen and Daming Yu
{"title":"Efficient adsorption and separation of Mn–Cu–Cd composite pollutants using MOF-based calcium alginate composite hydrogels","authors":"Jianhua Liu, Peicong Zhang, Qiaolin Hu, Yi Huang, Junfeng Li, Haiying Du, Wentao Zhang, Xianfei Chen and Daming Yu","doi":"10.1039/D4NJ00629A","DOIUrl":null,"url":null,"abstract":"<p >ZIF-8, a metal–organic framework that has significant benefits such as a substantial specific surface area, abundant active sites, and high porosity, has extensive application in environmental remediation. However, ZIF-8 is powdery and easily agglomerated, making it difficult to separate ZIF-8 from aqueous solutions and thus limiting its practical application in wastewater treatment. In this work, sodium alginate was chosen as a gel matrix, and CaCl<small><sub>2</sub></small> as a cross-linking agent to form a calcium cross-linked MOF gel material (ZIF-8/SA). The batch adsorption investigations demonstrated that the saturated adsorption capacities of ZIF-8/SA in single Mn<small><sup>2+</sup></small> pollution solution and Mn–Cu–Cd composite pollution solution are 179.86 mg g<small><sup>−1</sup></small> and 101.86 mg g<small><sup>−1</sup></small>, respectively. Specifically, the adsorption of Mn<small><sup>2+</sup></small> followed the Langmuir model and exhibited monomolecular layer adsorption. Furthermore, the adsorption of Cu<small><sup>2+</sup></small> and Cd<small><sup>2+</sup></small> followed the quasi-first-order kinetic model, which is primarily physical adsorption. The adsorption order of ZIF-8/SA for contaminants in the adsorption process is as follows: Cu<small><sup>2+</sup></small> > Cd<small><sup>2+</sup></small> > Mn<small><sup>2+</sup></small>. The SEM-EDS, FT-IR, and XPS studies revealed that the adsorption mechanism of ZIF-8/SA mostly involves ion exchange, coordination of carboxyl/hydroxyl/amino groups, and electrostatic attraction. To summarize, the experimental findings of this study demonstrate that the synthetic ZIF-8/SA hydrogel has promising applications for practical pollution treatment.</p>","PeriodicalId":95,"journal":{"name":"New Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"New Journal of Chemistry","FirstCategoryId":"92","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/nj/d4nj00629a","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
ZIF-8, a metal–organic framework that has significant benefits such as a substantial specific surface area, abundant active sites, and high porosity, has extensive application in environmental remediation. However, ZIF-8 is powdery and easily agglomerated, making it difficult to separate ZIF-8 from aqueous solutions and thus limiting its practical application in wastewater treatment. In this work, sodium alginate was chosen as a gel matrix, and CaCl2 as a cross-linking agent to form a calcium cross-linked MOF gel material (ZIF-8/SA). The batch adsorption investigations demonstrated that the saturated adsorption capacities of ZIF-8/SA in single Mn2+ pollution solution and Mn–Cu–Cd composite pollution solution are 179.86 mg g−1 and 101.86 mg g−1, respectively. Specifically, the adsorption of Mn2+ followed the Langmuir model and exhibited monomolecular layer adsorption. Furthermore, the adsorption of Cu2+ and Cd2+ followed the quasi-first-order kinetic model, which is primarily physical adsorption. The adsorption order of ZIF-8/SA for contaminants in the adsorption process is as follows: Cu2+ > Cd2+ > Mn2+. The SEM-EDS, FT-IR, and XPS studies revealed that the adsorption mechanism of ZIF-8/SA mostly involves ion exchange, coordination of carboxyl/hydroxyl/amino groups, and electrostatic attraction. To summarize, the experimental findings of this study demonstrate that the synthetic ZIF-8/SA hydrogel has promising applications for practical pollution treatment.