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Kinetics of degradation of perchloroethylene under ultrasonic irradiation and photooxidation in aqueous solution

Kargar M., Nabizadeh R., Naddafi K., Nasseri S., Mesdaghinia A., Mahvi A. H., Alimohammadi M., Nazmara S.

Environment Protection Engineering

2013

Vol. 39, nr 4

29--38

Sonolysis and photodegradation of various compounds such as chlorinated aliphatic hydrocarbons are the recent advanced oxidation processes. Perchloroethylene PCE is one of these compounds mainly used as a solvent and degreaser. In this work, elimination of perchloroethylene in aqueous solution by ultrasonic irradiation and photooxidation by UVC were investigated. Head space gas chromatography with FID detector was used for analyses of PCE. Results showed that PCE could be effectively and rapidly degraded by ultrasonic irradiation, photooxidation by UVC and combination of these methods. The order of studied reactions for degradation PCE has been determined.

Potential of granulated modified nanozeolites Y for MTBE removal from aqueous solutions: Kinetic and isotherm studies

Ghadiri S. K., Nabizadeh R., Mahvi A. H., Nasseri S., Mesdaghinia A. R., Talebi S. S.

Polish Journal of Chemical Technology

2012

Vol. 14, nr 2

1-8

Adsorption of methyl tert-butyl ether (MTBE) from aqueous solutions by granulated modifi ed nanozeolites Y was investigated. Nanozeolite Y powders were converted into granulated zeolites and subsequently modifi ed with two cationic surfactants (20 mmol/dm3), to be used as adsorbent. Granulated nanozeolites were characterized by BET surface area analysis, elemental analysis and X-ray diffractometer. Hexadecyltrimethylammonium (HDTMA-Cl) modifi ed granulated zeolite had more effective performance than N-cetylpyridinium bromide (CPB) modifi ed granulated zeolite. The most conventional adsorption isotherms and kinetic models were applied to describe MTBE adsorption and reaction dynamic, respectively. The equilibrium sorption data fi tted the Langmuir 2 isotherm model and the kinetic study was followed the pseudo-second-order model. The maximum adsorption capacities for HDTMA-Cl modifi ed zeolite and CPB modifi ed granulated zeolite were 333.33 and 142.8 mg/g, respectively as calculated by the Langmuir model. This study demonstrated that the removal of mtbe by granulated modifi ed nanozeolites Y is a promising technique.

Photocatalytic reduction of hexavalent chromium in aqueous solutions with zinc oxide nanoparticles and hydrogen peroxide

Assadi A., Dehghani M. H., Rastkari N., Nasseri S., Mahvi A. H.

Environment Protection Engineering

2012

Vol. 38, nr 4

5--16

Photocatalytic reduction of Cr(VI) to Cr(III) in aqueous solutions under UV irradiation and ZnO semiconductor catalyst was investigated using potassium dichromate as a model compound. The effects of pH, catalyst dose (0.05-0.15 g/dm3), Cr(VI) initial concentration (0.1-15 mg/dm3) and hydrogen peroxide concentration on photocatalytic reduction of Cr(VI) were investigated. The reduction rate of chromium was more favorable in acidic solution. Hydrogen peroxide was added as a reduction reagent for enhancement of the photoreduction. The process of photoreduction of Cr(VI) approximately followed first-order kinetics. Drinking water samples and wastewater were collected and photocatalytically treated for reduction of Cr(VI).