{"title":"Magnetic separation and recovery of powder particles from water using Fe3O4@CTS-BDAT","authors":"Peng Cheng, Chuang Liu, Sicong Du, Chongxuan Xu, Xu Han, Ting Zhu, Wenyan Liang","doi":"10.1016/j.seppur.2025.132528","DOIUrl":null,"url":null,"abstract":"A novel magnetic separation method has been developed to efficiently separate and recover powder particles used in water or wastewater treatment processes. The magnetic composites were prepared through the grafting of 2,4-bis(dimethylamino)-6-chloro-(1,3,5)-triazine (BDAT), chitosan (CTS), and SiO<sub>2</sub> onto the Fe<sub>3</sub>O<sub>4</sub> surface, obtaining Fe<sub>3</sub>O<sub>4</sub>@BDAT, Fe<sub>3</sub>O<sub>4</sub>@CTS, Fe<sub>3</sub>O<sub>4</sub>@CTS-BDAT, Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>@BDAT, and Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>@CTS-BDAT. g-C<sub>3</sub>N<sub>4</sub>, Ni/Fe-PAC, and La/Al-BTC were chosen as the target particles. Results showed that Fe<sub>3</sub>O<sub>4</sub>@CTS-BDAT exhibited the best separation performance, achieving efficiencies of 98.3 %, 97.2 %, and 99.1 % for the three target particles, respectively. These high efficiencies were maintained over a broad pH range (3.0–11.0) and initial target particle concentrations (50–5000 mg/L). The target particles could be detached from the magnetic aggregates using an electromagnetic field, with efficiencies exceeding 75.3 %. Characterization using SEM, XPS, and FTIR revealed that Fe<sub>3</sub>O<sub>4</sub>@CTS-BDAT possessed a microsphere cluster structure, with a saturation magnetization of 64.02 emu/g, a point of zero charge (pH<sub>PZC</sub>) of 7.7, and a d<sub>50</sub> value of 3.56 μm. Microscopic image analysis displayed that fluid kinetic energy and magnetic dipole force facilitated the formation of magnetic aggregates during the stirring stage. The size of these aggregates increased from 2 to 10 to 15–30 μm during stirring and further expanded to 18–37 μm during the separation stage. Particle image velocimetry (PIV) analysis indicated that the magnetic aggregates migrated towards the magnet via eddy currents, with maximum velocity from 0.532 to 1.412 m/s. DLVO and MDLVO models revealed that the magnetic interaction energy of Fe<sub>3</sub>O<sub>4</sub>@CTS-BDAT was sufficient to surpass electrostatic repulsion, thereby enabling efficient capture and separation of target particles.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"33 1","pages":""},"PeriodicalIF":8.1000,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Separation and Purification Technology","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1016/j.seppur.2025.132528","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
A novel magnetic separation method has been developed to efficiently separate and recover powder particles used in water or wastewater treatment processes. The magnetic composites were prepared through the grafting of 2,4-bis(dimethylamino)-6-chloro-(1,3,5)-triazine (BDAT), chitosan (CTS), and SiO2 onto the Fe3O4 surface, obtaining Fe3O4@BDAT, Fe3O4@CTS, Fe3O4@CTS-BDAT, Fe3O4@SiO2@BDAT, and Fe3O4@SiO2@CTS-BDAT. g-C3N4, Ni/Fe-PAC, and La/Al-BTC were chosen as the target particles. Results showed that Fe3O4@CTS-BDAT exhibited the best separation performance, achieving efficiencies of 98.3 %, 97.2 %, and 99.1 % for the three target particles, respectively. These high efficiencies were maintained over a broad pH range (3.0–11.0) and initial target particle concentrations (50–5000 mg/L). The target particles could be detached from the magnetic aggregates using an electromagnetic field, with efficiencies exceeding 75.3 %. Characterization using SEM, XPS, and FTIR revealed that Fe3O4@CTS-BDAT possessed a microsphere cluster structure, with a saturation magnetization of 64.02 emu/g, a point of zero charge (pHPZC) of 7.7, and a d50 value of 3.56 μm. Microscopic image analysis displayed that fluid kinetic energy and magnetic dipole force facilitated the formation of magnetic aggregates during the stirring stage. The size of these aggregates increased from 2 to 10 to 15–30 μm during stirring and further expanded to 18–37 μm during the separation stage. Particle image velocimetry (PIV) analysis indicated that the magnetic aggregates migrated towards the magnet via eddy currents, with maximum velocity from 0.532 to 1.412 m/s. DLVO and MDLVO models revealed that the magnetic interaction energy of Fe3O4@CTS-BDAT was sufficient to surpass electrostatic repulsion, thereby enabling efficient capture and separation of target particles.
期刊介绍:
Separation and Purification Technology is a premier journal committed to sharing innovative methods for separation and purification in chemical and environmental engineering, encompassing both homogeneous solutions and heterogeneous mixtures. Our scope includes the separation and/or purification of liquids, vapors, and gases, as well as carbon capture and separation techniques. However, it's important to note that methods solely intended for analytical purposes are not within the scope of the journal. Additionally, disciplines such as soil science, polymer science, and metallurgy fall outside the purview of Separation and Purification Technology. Join us in advancing the field of separation and purification methods for sustainable solutions in chemical and environmental engineering.