Retention of chromium by modified Al-Bentonite

Abstract

Retention of chromium (III) from a tanning wastewater by modified Al-bentonites was studied. One bentonite from San Juan province, Argentina, was used. Al-bentonite was prepared by contact of bentonite with hydrolyzed OH-Al solutions (0.10 M in Al) for 24 hours. The modified Al-bentonites were obtained by: a) treatment with 0.5 M sodium chloride; b) with 0.5 M sodium chloride adjusted at pH 8; and c) treatment with an hexametaphosphate solution after sodium addition. Then, the samples were dried at 100 °C and heated at 500 °C. The chromium (III) retention by samples was carried out in batch system putting in contact the material with a 2000 ppm Cr tannery waste at different times. The retained chromium was characterized by analyzing the supernatant using UV-visible spectroscopy. The different chromium retention was correlated with structural characteristics of the solids.

Enhancement of the bentonite sorption properties

“…Clays containing montmorillonite are referred to as bentonite, which belongs in the 2:1 clay family, composed of two tetrahedrally coordinated sheets of silicon surrounding an octahedrally coordinated sheet of aluminium ions. An evaluation of the montmorillonite sorption properties for the removal of heavy metals Ni and Cu was made in [2].…”

ADSORPTION STUDY OF RHODAMIN B DYE ON IRAQI BENTONITE AND MODIFIED BENTONITE BY NANOCOMPOUNDS TIO₂, ZNO, AL₂O₃ AND SODIUM DODECYL SULFATE

“…Adsorption is an important method commonly used for cleaning of wastewater for treatment and separation of colorant in industrial processes. Bentonite (Espantaleon et al, 2003;Özcan et al, 2004;Eren and Science Publications Afsin, 2008;Atia et al, 2006;Volzone and Garrido, 2002;Karahan et al, 2006) has been used directly or after modified for remove textile industry dyes from wastewater. Bentonite may be attributed to its high surface area, high chemical and mechanical stability and to a variety of surface and structural ability (Mockovciakova and Orolinova, 2009;Zhao et al, 1998) by surfactants to be efficient in the treatment of various pollutants (Ma et al, 2011).…”

Determination The Effect of ZnO on Iraqi Bentonite Surface Properties

“…Clays obtaining montmorillonite are referred to bentonite which belongs to the 2:1 clay family composed of two tetrahedrally coordinated sheet of silicon surrounding and an octahedrally coordinated sheet of aluminum ions. Clay can be modified to improve its sorption ability [2,3]; one of the methods is the use of magnetic modification in which, e.g., bentonite coated with iron can be obtained [4].…”