Adsorption of Heavy Metals in the Presence of a Magnetic Field on Adsorbents with Different Magnetic Properties

Abstract

The application of static magnetic fields during adsorption as an unconventional method for the removal of heavy metals such as Cd2+ and Zn2+ was studied in this work. Two different materials were employed as adsorbents: activated carbon from bituminous coal and bone char. The magnetic characterization of these materials reveals that the activated carbon from bituminous coal is a ferromagnetic material, while the bone char is a paramagnetic material. Both adsorbents were used as received; i.e., no additional modification was employed to alter or improve their magnetic properties. Adsorption studies included adsorption isotherms at 30 °C, at pH 5, and equilibrium times of 72 h. The adsorption results obtained depended on the magnetic nature of both the adsorbent and the adsorbate. It was determined that because of its ferromagnetism (hence, its chemical composition), the activated carbon performed better when an external magnetic field was present during the adsorption process. An increase of 63% and 15% in its adsorption capacity was measured for Cd2+ and Zn2+, respectively.

Removal of Heavy Metals Using Adsorption Processes Subject to an External Magnetic Field

“…Like the source, the configuration of the magnetic field is significant in the design of an adsorption system assisted by magnetic fields, since the influence, gradient of intensity and direction will determine the type of effect in some of the adsorption phases. The configuration of the magnetic field will influence in various ways ranging from orienting, hydrating and redirecting the adsorbate, to magnetize, activate and prevent the degeneration of the adsorbent [111][112][113][114][115].…”

Magnetic Field Usage Supported Filtration Through Different Filter Materials

“…It was found that due to its ferromagnetism, activated carbon was working better under the influence of external magnetic field. There was an increase in the adsorption capacity by 63% for Cd 2+ and 15% for Zn 2+ [36]. The difference in the removal efficiency of metals in our own research and Gonzalez studies [36] is due to the time of water magnetization.…”

“…There was an increase in the adsorption capacity by 63% for Cd 2+ and 15% for Zn 2+ [36]. The difference in the removal efficiency of metals in our own research and Gonzalez studies [36] is due to the time of water magnetization. Gonzalez applied a magnetic field throughout the whole experiment duration, while the authors of this work only applied a magnetic field for a period of 10 min when water was in the raw water reservoir.…”

“…Research on the removal of metals using filter material and magnetic field was also conducted by the research group Gonzalez [36]. They used model Cu and Zn solutions.…”

“…In the case of activated carbon, the manganese removal efficiency was again lower in the samples of magnetized water than in the control samples without the influence of MF. Research on the removal of metals using filter material and magnetic field was also conducted by the research group Gonzalez [36]. They used model Cu and Zn solutions.…”