| Title | REDUCTIVE/OXIDATIVE TREATMENT WITH SUPERIOR PERFORMANCE RELATIVE TO OXIDATIVE TREATMENT DURING THE DEGRADATION OF 4-CHLOROPHENOL |
| Abstract | This study obtained information on the effectiveness of the photo-assisted Fenton oxidation of 4-chlorophenol (4-CP) combined with
zero-valent pretreatment. The kinetic rate parameters of the process as well as the operating conditions were determined. Homogeneous
photo-assisted Fenton enhanced processes lead to 33% mineralization of 4-chlorophenol (1.25 mM) in solutions containing Fe-ions (2-
10 mg/l) and H2O2 (10 mM) within 2 h under visible light irradiation. When this solution was pretreated with zero-valent Fe (14 g/70 ml) in
Ar atmosphere, the mineralization attained levels of >80% after the second stage photo-assisted Fenton process. Intermediates that could
be effectively degraded by photo-Fenton reactions were not attained in the absence of zero-valent Fe pretreatment. The pretreatment by
zero-valent Fe under light lead to about 70% of the stoichiometric amount of chloride contained in 4-CP. Partial recovery of chloride ions
indicated the formation of chloro-intermediates. These intermediates were experimentally detected by high-pressure liquid chromatograph
(HPLC)-MS and the most important intermediates were identified. Fenton photo-assisted processes were effective employing
very low concentrations of Fe2+(2-5 mg/l) after the pretreatment stage that do not need to be separated after the 4-CP degradation
process. This is important for the practical application of the novel combined heterogeneous-homogeneous process. Evidence for the stable
catalytic performance of the coupled process to degrade 4-CP is presented. The effect on the 4-CP degradation of Fe-ion, H2O2, 4-CP
concentration and gas atmosphere was systematically investigated. The activation energy (Ea) of 2.66 kJ/mol was found for the abatement of
4-CP. |
| Source | Applied catalysis. B, Environmental (Print) 59, pp. 249–257 |
| Journal | Applied catalysis. B, Environmental (Print) |
| Editor | Elsevier, Amsterdam ;, Paesi Bassi |
| Year | 2005 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.apcatb.2005.02.014 |
| Authors | RAJA P., BOZZI A., JARDIM W.F., MASCOLO G., RENGANATHAN R., KIWI J. |
| Text | 42187 2005 10.1016/j.apcatb.2005.02.014 REDUCTIVE/OXIDATIVE TREATMENT WITH SUPERIOR PERFORMANCE RELATIVE TO OXIDATIVE TREATMENT DURING THE DEGRADATION OF 4 CHLOROPHENOL RAJA P., BOZZI A., JARDIM W.F., MASCOLO G., RENGANATHAN R., KIWI J. a Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology, Lausanne 1015, Switzerland b Institute of Chemistry, UNICAMP, State University of Campinas, Campinas, Sau Paulo, Brazil cWater Research Institute, CNR IRSA, Via F de Blasio 5, Bari 70123, Italy d Department of Chemistry, Bharathidasan University, Tiruchirappalli, Tamilnadu, India This study obtained information on the effectiveness of the photo assisted Fenton oxidation of 4 chlorophenol 4 CP combined with zero valent pretreatment. The kinetic rate parameters of the process as well as the operating conditions were determined. Homogeneous photo assisted Fenton enhanced processes lead to 33% mineralization of 4 chlorophenol 1.25 mM in solutions containing Fe ions 2 10 mg/l and H2O2 10 mM within 2 h under visible light irradiation. When this solution was pretreated with zero valent Fe 14 g/70 ml in Ar atmosphere, the mineralization attained levels of >80% after the second stage photo assisted Fenton process. Intermediates that could be effectively degraded by photo Fenton reactions were not attained in the absence of zero valent Fe pretreatment. The pretreatment by zero valent Fe under light lead to about 70% of the stoichiometric amount of chloride contained in 4 CP. Partial recovery of chloride ions indicated the formation of chloro intermediates. These intermediates were experimentally detected by high pressure liquid chromatograph HPLC MS and the most important intermediates were identified. Fenton photo assisted processes were effective employing very low concentrations of Fe2 2 5 mg/l after the pretreatment stage that do not need to be separated after the 4 CP degradation process. This is important for the practical application of the novel combined heterogeneous homogeneous process. Evidence for the stable catalytic performance of the coupled process to degrade 4 CP is presented. The effect on the 4 CP degradation of Fe ion, H2O2, 4 CP concentration and gas atmosphere was systematically investigated. The activation energy Ea of 2.66 kJ/mol was found for the abatement of 4 CP. 59 Reductive/oxidative treatment with superior performance relative to oxidative treatment during the degradation of 4 chlorophenol 2005_Appl_Cat_B_Env_con_Kiwi_.pdf Articolo in rivista Elsevier 0926 3373 Applied catalysis. B, Environmental Print Applied catalysis. B, Environmental Print Appl. catal., B Environ. Print Applied catalysis. Print giuseppe.mascolo MASCOLO GIUSEPPE TA.P07.002.002 Sviluppo di nuovi processi di controllo dell inquinamento idrico. |
