Use of Thermally Modified Jarosite for the Removal of Hexavalent Chromium by Adsorption

Crystals

A. Martinez-Luevanos¹  Ma de Jesús Soria-Aguilar²  F. R. Carrillo-Pedroza²  Gregorio González³  N. G. Picazo-Rodríguez³  Gabriela Baltierra³  Isaías Almaguer Guzmán⁴ 

[1] Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, Saltillo 25280, Mexico;Facultad de Metalurgia, Universidad Autónoma de Coahuila, Monclova 25710, Mexico;Instituto Tecnológico Superior de Monclova, Tecnológico Nacional de México, Monclova 25701, Mexico;Peñoles, CIDT-SEPSA, Torreon 27220, Mexico;

关键词: jarosite;    adsorption;    hexavalent chromium;   

DOI  :  10.3390/cryst12010080

来源: DOAJ

【 摘 要 】

Jarosites are residues generated during the purification of zinc and are composed mainly of iron sulfates ((Na, K)Fe₃(SO₄)₂(OH)₆). Due to the large volume of jarosite generated during the process, these residues tend to be deposited in large land areas and are not used. In the present work, jarosite was used without heat treatment (JST) as an adsorbent of hexavalent chromium contained in a sample of wastewater from a chrome plating industry under the following conditions: C₀ = 200 mg/L of Cr, T = 25 °C, and pH = 3. It was only possible to remove 34% of Cr (VI). Subsequently, a thermal treatment of a jarosite sample (JTT) was carried out at 600 °C. The heat-treated sample was later used as an adsorbent in the same conditions as those for JST. The maximum chromium removal was 53%, and the adsorption capacity was 10.99 mg/g. The experimental data were fitted to the Langmuir model and to the pseudo-second-order kinetic model. It was determined that the adsorption process involved electrostatic attractions between the surface of the positively charged adsorbent and the chromium anions contained in industrial wastewater.

【 授权许可】

Unknown