Single-step and two-step syntheses of magnetic carbons from coffee residue: elimination of sulfamethazine by adsorption

• Published in: International journal of environmental science and technology (Tehran) 2023, Vol.20 (1), p.755-768
• Main Authors: khenniche, l., Saidou Souleymane, M., Chemache, Z., Benissad-Aissani, F., Amrane, A.
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Chemical Sciences; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Engineering; Environmental Science and Engineering; Environmental Sciences; Material chemistry; Original Paper; Soil Science & Conservation; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 1735-1472; 1735-2630
• DOI: 10.1007/s13762-022-04116-9

The magnetization process of activated carbons prepared from coffee residue was performed according to two protocols: The first one involved a chemical impregnation with a mixture of two salts: FeSO 4 ·7H 2 O and FeCl 3, followed by a treatment with NaOH (2 M). The second procedure required an impregnation with both salts mentioned above, taken alone or in mixture, followed by a pyrolysis at 600 °C during an hour. A commercial activated carbon treated in the same way was used as reference. Physicochemical analysis of all materials revealed that activated carbon treated with iron sulfate (FeSO 4 ·7H 2 O) alone contains magnetite; activated carbon prepared with iron chloride (FeCl 3 ) alone contains magnetite, while activated carbon prepared with a combination of both salts contains magnetite and maghemite. Adsorption tests for the sulfamethazine removal from the aqueous phase were carried out at pH = 6 and pH = 4. Magnetized carbon prepared with an impregnation ratio of 75% iron sulfate followed by pyrolysis gave the most effective performance with an elimination efficiency of 64.12% of sulfamethazine.