Mixed silica and alumina hosted carboxylate oxide for removal of chromium species from wastewater

Abstract

Increasing in the use of various chromium species over the past few decades has inevitably resulted in an increased flux of their metallic substances in aquatic life. Therefore, experimental work was developed to improve the physical and chemical characteristics of the prepared mesoporous SiO 2 -Al 2 O 3 mixed oxides via a sol-gel process. The effective key parameter on the properties of the materials was achieved by the addition of carboxylate functional group such as Alph-hydroxyl isobuteric acid (AHIBA) during the gelation process and prior the calcinations step. Better performance of these carboxylate resins are attributed to the complexing ability of the carboxylate groups toward polyvalent chromium species which is added to the normal sorption properties of the oxides. Urea has been used as a means of producing an aluminum precipitate that is easier to filter than that produced by rapid addition of base. Introduction of Al and Si salts together to form mixed oxide modified the way of their substitution in the hosting resin than when they were separately added. The data revealed that mesoporous materials with very narrow pore diameter distribution (micron-sized) and high surface area were obtained. The surface areas and pore size distributions were mainly depend on SiO 2 content. Systematic investigations were carried out on the set of the prepared mixed oxides with different porosity, cross-linking degree and exchange loading to find out the best sorbent for chromium removal. The final objective in all cases was aimed at determining feasible and economically reliable solution to the environmental problems related to the tannery industry.

Recent Advances in Silica-Based Materials for the Removal of Hexavalent Chromium: A Review

“…Here, the silica content provides high surface area, whereas the aluminum oxide forms the cross- linking with carboxylate groups of AHIBA so that better adsorption sites would be available for the chromium ions by the polymeric oxide (Table 4). 148 Recently, acrylamide was polymerized within the pore regions of the silica particles. The composite particle maintained the mechanical properties of polyacrylamide (PAA) to serve efficiently in the adsorption process.…”

Performance evaluation of zirconium silicate composite for removal of cadmium and zinc ions

“…The initial pH was attuned to the desired values to the following experimental using 0.01M HCl and/or 0.01 M NaOH solutions. The zirconia-silicate composite was synthesized via the sol-gel technique as exemplified in the previous work [20,24,25].…”