Effect of magnetic field on nano-magnetite composite exhibits in ion-adsorption
| Autor: | H. S. Chua, Kien Woh Kow, Swee Pin Yeap, Yong Kuen Ho, Fabian Fosheng Lo, Rozita Yusoff, Firnaaz Ahamed, Peck Loo Kiew, Fabian Wai Lee Kung, Chung-Hung Chan |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Environmental Engineering
Nanocomposite Materials science 010504 meteorology & atmospheric sciences Magnetic domain Silica gel Composite number 010501 environmental sciences 01 natural sciences Pollution chemistry.chemical_compound Adsorption chemistry Chemical engineering Agglomerate Nano Environmental Chemistry Waste Management and Disposal 0105 earth and related environmental sciences Magnetite |
| Zdroj: | The Science of the total environment. 780 |
| ISSN: | 1879-1026 |
| Popis: | 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 the NMSG to a magnetic 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect