Applications of Pore-Expanded Mesoporous Silica. 1. Removal of Heavy Metal Cations and Organic Pollutants from Wastewater

Abstract

Postsynthesis pore expansion of as-synthesized MCM-41 silica using N,N-dimethyldecylamine affords material A, with open pore structure and readily accessible amine groups. The selective removal of the occluded amine gives rise to B, a highly porous, hydrophobic material with large surface area and pore volume. Materials A and B were found to be fast, sensitive, high-capacity recyclable adsorbents for metallic cations and organic pollutants, respectively.

Study of Stable Nitrogen Forms in Natural Surface Waters in the Presence of Mineral Substrates

“…The obtained results (see all fi gures) show increasing or decreasing the blocking phenomena (stimulating oxidation of nitrogen reduced forms in river waters) in polluted samples in the presence of suspended particles of calcium carbonate, keramzite and granite substrates. The stimulate effect of nitrogen oxidation has been explained by authors [25,28,29] through the adsorption of cationic surfactants on the surfaces of granite and expanded clay. Additionally, the phenomenon of adsorption of ammonium ions onto the surface of calcium carbonate itself or in combination with other low cost adsorbents from polluted waters was revealed in a series of published works [30][31][32].…”

Engineering and optimization of nano- and mesoporous silica fibers using sol–gel and electrospinning techniques for sorption of heavy metal ions

“…In the past decade, many investigations have been conducted on mesoporous SiO 2 as sorbent for removal of hazardous metal ions, such as Pb 2+ , Cd 2+ , and Hg 2+ , from wastewater [1][2][3][4][5][6][7][8][9]. To be effective heavy metal ion sorbents, the material should have high sorption capacity and be easily separated [10].…”

Poly(sodium acrylate) hydrogels as potential pH-sensitive sorbents for the removal of model organic and inorganic pollutants from water

“…In these representations, the quantity Q e expresses the mmoles of the adsorbed ion per gram of the adsorbent and it is calculated by the equation (Bekiari and Lianos, 2006;Sayari et al, 2005):…”

“…Thus, besides the classical activated carbon filters, different types of other materials have been proposed and developed, like organically modified synthetic porous silica (Bekiari and Lianos, 2006;Chu et al, 2008;Sayari et al, 2005), dendritic polymers (Arkas et al, 2003;Arkas et al, 2005) and hydrogels (Bekiari et al, 2008;Kofinas and Koussis, 2003). Hydrogels are three-dimensional chemically crosslinked polymer networks, able to swell in water, increasing substantially their original volume while keeping their integrity.…”