Chlorinated volatile organic compounds (VOCs), such as dichloromethane (DCM) and 1,2-dichloroethane (DCE) constitute an important environmental class of pollutants due to their high toxicity, inertness and widespread application in industry. These compounds can entry in the environment from effluent discharge of industries that use or produce DCE, air emissions and leachates from waste disposal sites. Despite DCE being the most abundant chlorinated groundwater pollutant on Earth, an efficient reductive in situ detoxification technology for this compound is not known. For instance, zero-valent iron (ZVI), which directly degrades several contaminants appears to be ineffective on irreducible compounds such as DCE, chlorobenzenes, as well as hydrocarbons. Recently, high-silica zeolites were shown to be effective in removing these types of compounds from water. In this study we focused on hydrophobic zeolites (ZSM-5, Y and Mordenite (MOR)), since they are the most promising zeolites support for VOC combustion, and many studies in literature deals with the adsorption properties of these zeolites from gas phase mixture. However, it has also been found that in gas phase water play an important role in regulating the interaction between organic compounds and zeolite. To date, studies and applications on organic pollutant adsorption on microporous zeolitic materials from aqueous media have been relatively scarce. In this work DCE adsorption from aqueous solutions onto hydrophobic zeolites was studied by using different combined techniques (gas chromatographic and thermogravimetric) to investigate the mechanisms of adsorption.
Adsorption of 1,2-Dichloroethane onto hydrophobic zeolites
NASSI, Marianna;MARTUCCI, Annalisa;ALBERTI, Alberto;PASTI, Luisa
2011
Abstract
Chlorinated volatile organic compounds (VOCs), such as dichloromethane (DCM) and 1,2-dichloroethane (DCE) constitute an important environmental class of pollutants due to their high toxicity, inertness and widespread application in industry. These compounds can entry in the environment from effluent discharge of industries that use or produce DCE, air emissions and leachates from waste disposal sites. Despite DCE being the most abundant chlorinated groundwater pollutant on Earth, an efficient reductive in situ detoxification technology for this compound is not known. For instance, zero-valent iron (ZVI), which directly degrades several contaminants appears to be ineffective on irreducible compounds such as DCE, chlorobenzenes, as well as hydrocarbons. Recently, high-silica zeolites were shown to be effective in removing these types of compounds from water. In this study we focused on hydrophobic zeolites (ZSM-5, Y and Mordenite (MOR)), since they are the most promising zeolites support for VOC combustion, and many studies in literature deals with the adsorption properties of these zeolites from gas phase mixture. However, it has also been found that in gas phase water play an important role in regulating the interaction between organic compounds and zeolite. To date, studies and applications on organic pollutant adsorption on microporous zeolitic materials from aqueous media have been relatively scarce. In this work DCE adsorption from aqueous solutions onto hydrophobic zeolites was studied by using different combined techniques (gas chromatographic and thermogravimetric) to investigate the mechanisms of adsorption.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
