HOME > Technotes > Magnetic Activated Carbons (MACs)

Magnetic Activated Carbons (MACs)

Adsorption of Contaminants by MACs and Magnetic Separation1)

MACs have high efficiency for adsorption from dilute solution and the magnetic character. MACs are prepared chemically or physically by dispersing magnetic particles on activated carbon (AC). MACs have high specific surface areas due to their microporous structure and a high adsorption ability for a variety of soluble organic compounds and heavy metal ions. By using the magnetic separation system, it is advantageous to separate the absorbents from water, because of the rapid separation. The ability of MACs is compared with that of AC as shown in Table 1.

Table 1.  Characteristics of Magnetic Activated Carbon (MAC)

Values in the parentheses are obtained by subtracting inorganic components from MAC.
  Adsorption of Iodine
(mg/g)
Specific Surface Area
(m2/g)
Hole Volume
(ml/g)
Hole Diameter
(nm)
AC 1070(1142) 968(1033) 0.567 2.34
MAC 730(1034) 773(1095) 0.490 2.53

Photograph 1 demonstrates that MAC particles can be easily pulled up by a magnet. MAC adsorbed with methylene blue (MB) can be easily recovered from suspension by a magnet (magnetic separation), as shown in Photograph 2. Similarly, MAC can rapidly adsorb pollutants such as bisphenol A (BPA) and be effectively removed by a magnet. Fig.1 shows the change of the absorption spectra of BPA by adding MAC particles.

1) A.Nakahira, S.Nishida, and K.Fukunishi, J.Ceramic Soc. Jpn., 114[1] 135-137(2006).

Powdered MAC

Photograph 1. Powdered MAC

Adsorption of MB on MAC and Magnetic Separation

Photograph 2. Adsorption of MB on MAC

Adsorption of MB on MAC and Absorption Spectra; C。

Fig. 1.Absorbance Change of BPA by Adding MAC. BPA initial concentration : 4.41 x 10-4 mol dm-3, MAC: (0) 0ppm, (1) 120ppm, (5) 440ppm.

Go to page top