Solubility data of recalcitrant contaminants in cosolvents is essential to determine their potential applications in enhanced soil remediation.The solubilities of phenanthrene,anthracene,fluoranthene and benzo[a]pyren...Solubility data of recalcitrant contaminants in cosolvents is essential to determine their potential applications in enhanced soil remediation.The solubilities of phenanthrene,anthracene,fluoranthene and benzo[a]pyrene in ethyl lactate/water and ethanol/water mixtures were measured using equilibrium techniques.The cosolvency powers derived from solubility data were then applied to the model developed from the solvophobic approach to predict the capability of ethyl lactate and ethanol in enhancing the desorption of contaminants from soils.Both ethyl lactate and ethanol cosolvents were shown to be able to enhance the solubilisation of the tested four polycyclic aromatic hydrocarbons by 〉 4 orders of magnitude above the levels obtained with water alone.However,ethyl lactate demonstrated a greater capacity to enhance PAH solubility than ethanol.The cosolvency powers of ethyl lactate/water system obtained from the end-to-end slope （σ） and the end-to-half slope （σ 0.5） of the solubilisation curve were 1.0-1.5 and 2.0-2.9 higher than ethanol/water system respectively.In line with this,ethyl lactate/water was demonstrated to enhance the desorption of contaminants from soil by 20%-37% and 18%-61% higher compared to ethanol/water system in low organic content and high organic content soils respectively,with a 2：1 （V/W） ratio of solution：soil and with cosolvent fraction as low as 0.4.With the exception of benzo[a]pyrene,the experimental desorption results agreed fairly with the predicted values,under an applied solution：soil ratio that was enough to hold the capacity of released contaminants.展开更多
Liquid phase hydrogenolysis of ethyl lactate to 1,2-propanediol was performed over silica supporting cobalt catalysts prepared by two different methods： precipitation-gel （PG） technique and deposition-precipitation...Liquid phase hydrogenolysis of ethyl lactate to 1,2-propanediol was performed over silica supporting cobalt catalysts prepared by two different methods： precipitation-gel （PG） technique and deposition-precipitation （DP） procedure. The cobalt species （Co3O4/cobalt phyllosilicate） present in the corresponding calcined PG and DP catalysts were different as a consequence of the preparation methods, and Co--OH---Co olation and Si--O--Co oxolation molecular mechanisms were employed to elucidate the chemical phenomena during the different preparation procedures. In addition, the texture （BET）, reduction behavior （TPR and in-situ XRD）, surface dispersion and state of cobalt species （XPS）, and catalytic performance differ greatly between the samples. Because of small particle size, high dispersion of cobalt species and facile reducibility, the Co/SiO2 catalyst prepared by precipitation-gel method presented a much higher activity than the catalyst prepared by deposition-precipitation method. Metallic cobalt is assumed to be the catalytically active site for the hydrogenolysis reaction according to the catalytic results of both cobalt samples reduced at different temperatures and the structure changes after reaction.展开更多
基金supported by the Research Innovation Services of the University of Nottingham,UK under the Grant No. NRF4318The Faculty of Engineering at the University of Nottingham Malaysia Campus is also acknowledged for its support towards this project
文摘Solubility data of recalcitrant contaminants in cosolvents is essential to determine their potential applications in enhanced soil remediation.The solubilities of phenanthrene,anthracene,fluoranthene and benzo[a]pyrene in ethyl lactate/water and ethanol/water mixtures were measured using equilibrium techniques.The cosolvency powers derived from solubility data were then applied to the model developed from the solvophobic approach to predict the capability of ethyl lactate and ethanol in enhancing the desorption of contaminants from soils.Both ethyl lactate and ethanol cosolvents were shown to be able to enhance the solubilisation of the tested four polycyclic aromatic hydrocarbons by 〉 4 orders of magnitude above the levels obtained with water alone.However,ethyl lactate demonstrated a greater capacity to enhance PAH solubility than ethanol.The cosolvency powers of ethyl lactate/water system obtained from the end-to-end slope （σ） and the end-to-half slope （σ 0.5） of the solubilisation curve were 1.0-1.5 and 2.0-2.9 higher than ethanol/water system respectively.In line with this,ethyl lactate/water was demonstrated to enhance the desorption of contaminants from soil by 20%-37% and 18%-61% higher compared to ethanol/water system in low organic content and high organic content soils respectively,with a 2：1 （V/W） ratio of solution：soil and with cosolvent fraction as low as 0.4.With the exception of benzo[a]pyrene,the experimental desorption results agreed fairly with the predicted values,under an applied solution：soil ratio that was enough to hold the capacity of released contaminants.
文摘Liquid phase hydrogenolysis of ethyl lactate to 1,2-propanediol was performed over silica supporting cobalt catalysts prepared by two different methods： precipitation-gel （PG） technique and deposition-precipitation （DP） procedure. The cobalt species （Co3O4/cobalt phyllosilicate） present in the corresponding calcined PG and DP catalysts were different as a consequence of the preparation methods, and Co--OH---Co olation and Si--O--Co oxolation molecular mechanisms were employed to elucidate the chemical phenomena during the different preparation procedures. In addition, the texture （BET）, reduction behavior （TPR and in-situ XRD）, surface dispersion and state of cobalt species （XPS）, and catalytic performance differ greatly between the samples. Because of small particle size, high dispersion of cobalt species and facile reducibility, the Co/SiO2 catalyst prepared by precipitation-gel method presented a much higher activity than the catalyst prepared by deposition-precipitation method. Metallic cobalt is assumed to be the catalytically active site for the hydrogenolysis reaction according to the catalytic results of both cobalt samples reduced at different temperatures and the structure changes after reaction.
