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IntroductionImmobilizationorseparationofcontaminantscontainedinpollutedwaterisanobjectiveofincreasingimportanceinavarietyofenvironmentalsettings.Theextentofpesticidecontaminationofthewaterenvironmenthasrecentlyraisedmuchconcernbecauseofthepotentialhealthh… 相似文献
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Andrea Baglieri Daniela Borzí Cristina Abbate Michéle Négre Mara Gennari 《Journal of environmental science and health. Part. B》2013,48(3):220-225
The ability of a sodium montmorillonite (CLONa) and two commercial available organoclays having interlayer organic cations possessing different functional groups (CLO20A and CLO30B) was investigated for adsorbing two pesticides namely fenexamid (FEX) and pyrimethanyl (PMT). The two organoclays displayed a higher affinity with the pesticides than the unmodified clay, but the improvement in adsorption capacity varied according to the characteristics of the pesticide and the interlayer organic cation. FEX was adsorbed to a greater extent than PMT by both organoclays, which may be due to the higher hydrophobicity of FEX thereby indicating considerable hydrophobic interaction between the adsorbent/adsorbate systems. Our findings may find application in the removal of water-soluble pesticides from aquifers. 相似文献
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J.P. Aguer M.C. Hermosin M.J. Calderon J. Cornejo 《Journal of environmental science and health. Part. B》2013,48(3):279-296
Abstract The adsorption isotherms of fenuron (l, l‐dimethyl‐3‐phenylurea) on three smectites (SWy and SAz montmorillonites and SH hectorite) differing in their layer charge (SH<SWy<SAz) and saturated with several inorganic and organic cations were determined. The isotherms and sorption parameters from Freundlich equation indicate low adsorptivity on inorganic clays, but medium sorption in organoclays (OCls). Fenuron adsorption on homoionic smectites increases with decreasing layer charge and hydratation power of the inorganic exchangeable cation (except Fe3+), indicating that fenuron adsorbs as neutral molecule on uncharged siloxane surface by hydrophobic bonding, with some contribution of polar bond (fenuron C=O group and water associated to exchangeable cation). In the case of Fe3+‐saturated smectite fenuron protonation, provided by the interlayer acidic environment, promotes further sorption of fenuron as cationic form. The sorption on organoclays is enhanced via hydrophobic interaction with organocations, which is favoured for high layer charge and basal spacing and organocation saturation close to CEC. Quaternary alkylamonium is more efficient in high layer charge smectite, whereas primary alkylammonium is more efficient in medium charge smectite. The low values of the maximum sorption obtained with homoionic inorganic and organic smectites (100 and 5000 μmol/Kg) represent one fenuron molecule for each 2000–200 exchange sites and indicate that fenuron sorption is mainly associated to the outer exchange sites. This low adsorptivity of fenuron, as consequence of its high water affinity (high water solubility) would suggest high mobility of fenuron in natural soil and water systems. 相似文献
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