Effect of magnetic field on nano-magnetite composite exhibits in ion-adsorption
Document Type
Article
Publication Date
8-1-2021
Abstract
Nano-magnetites are widely researched for its potential as an excellent adsorbent in many applications. However, the efficiency of the nano-magnetites are hindered by their tendency to agglomerate. In this work, we dispersed and embedded the nano-magnetites in a porous silica gel matrix to form a nanocomposite to reduce the extent of agglomeration and to enhance the adsorption performance. Our experimental results showed that the removal efficiency of Cu2+ ion has improved by 46% (22.4 +/- 2.2%) on the nano-magnetite-silica-gel (NMSG) nanocomposite as compared to pure nano-magnetites (15.3 +/- 0.6%). The adsorption capacity is further enhanced by 39% (from 11.2 +/- 1.1 to 15.6 +/- 1.6 mg/g) by subjecting theNMSG to amagnetic field prior to adsorption. We infer that the magnetic field aligned the magnetic domains within the nano-magnetites, resulting in an increased Lorentz force during adsorption. Similar alignment of magnetic domains is near to impossible in pure nano-magnetites due to severe agglomeration. We further found that the adsorption capacity of the NMSG can be manipulated with an external magnetic field by varying the strength and the configurations of the field. Equipped with proper process design, our finding has great potentials in processes that involve ion-adsorptions, for example, NMSG can: (i) replace/reduce chemical dosing in controlling adsorption kinetics, (ii) replace/reduce complex chemicals required in ion-chromatography columns, and (iii) reduce wastage of nano-adsorbents by immobilizing it in a porous matrix. (C) 2021 Elsevier B.V. All rights reserved.
Keywords
Nano-magnetite, Nanocomposite, Ion-adsorption, Silica gel matrix, Magnetic alignment
Divisions
sch_che
Funders
UCSI University under PSIF grant (Pioneer Scientist Incentive Fund) [Proj-In-FETBE-018],Ministry of Education, Malaysia [FRGS/1/2016/TK02/UCSI/02/1]
Publication Title
Science of the Total Environment
Volume
780
Publisher
Elsevier
Publisher Location
RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS