Adsorption of low molecular weight halocarbons by montmorillonite

Autor:	Vincent L. Vilker, Thomas J Estes, Rajiv V. Shah
Rok vydání:	1988
Předmět:	inorganic chemicals Aqueous solution Trichloroethylene Chemistry Tetrachloroethylene Inorganic chemistry Sorption General Chemistry complex mixtures Surface coating chemistry.chemical_compound Adsorption Montmorillonite Desorption Environmental Chemistry
Zdroj:	Environmental Science & Technology. 22:377-381
ISSN:	1520-5851 0013-936X
DOI:	10.1021/es00169a003
Popis:	Montmorillonite clay from Clay Spur, WY, was found to adsorb several low molecular weight, hydrophobic halocarbons from aqueous solution at sub-parts-per-million levels. The halocarbons studied were trichloroethylene, tetrachloroethylene, hexachloroethane, and dibromochloropropane. When the montmorillonite was treated with sodium citrate-bicarbonate-dithionite (CBD), it adsorbed higher levels of halocarbons than the untreated clay. In addition, the CBD-treated clay exhibited a maximum in halocarbon adsorption around pH 4, while untreated clay showed little variation in adsorption over the pH range 2-10. Adsorption of trichloroethylene was inhibited by low concentrations of sodium chloride (0.01 M or greater) in solution. Aging the CBD-treated clay in water decreased its capacity to adsorb trichloroethylene. Desorption studies showed that the sorption of tetrachloroethylene to CBD-treated clay is an irreversible process when compared to sorption by fumed silica. The ability of montmorillonite to adsorb halocarbons and the instability of the clay in water are postulated to involve changes in the oxide surface coating on the clay.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::d2ac8925fdc57d6461e1365929f252c7 https://doi.org/10.1021/es00169a003 Zobrazit plný text záznamu