Remediation of model wastewater polluted with methyl parathion by reverse micelle entrapped peroxidase

2011 ◽  
Vol 46 (4) ◽  
pp. 345-354
Author(s):  
Zoheb Karim ◽  
Qayyum Husain ◽  
Rohana Adnan ◽  
Naseem Akhtar
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Reverse Micelle ◽  
Oxidation Reaction ◽  
Methyl Parathion ◽  
Catalytic Performance ◽  
Redox Mediators ◽  
Ph Dependency ◽  
Effects Of Ph ◽  
Catalyzed Oxidation

The peroxidase/reverse micelle (RM) system effectively catalyzed the oxidation reaction in cyclohexane, while peroxidase from bitter gourd in aqueous buffer exhibited low catalytic activity. The oxidation of methyl parathion (MPT) has been optimized with effects of pH in the water pools, concentration of peroxidase and degree of surfactant hydration (Wo). The peroxidase/RM system showed a strong pH dependency. Its optimum catalytic activity was obtained when the peroxidase/RM was prepared in a buffer of pH 3.0. The effect of different redox mediators on the peroxidase-catalyzed oxidation of MPT was investigated. MPT was slowly oxidized by the peroxidase/RM system while the addition of phenol as a redox mediator strongly enhanced the catalytic performance of the peroxidase/RM system. Hydrogen peroxide strongly inhibited the activity of peroxidase; when the H2O2 was present at more than 0.80 mM, the MPT transformation was significantly reduced.

scholarly journals Properties and catalytic performance of sulphate-vanadia impregnated fumed silica as oxidative catalyst

2015 ◽  
Vol 11 (2) ◽  
Author(s):  
Nor Masdiana Zulkeple ◽  
Norhasyimah Mohd Kamal ◽  
Jamilah Mohd Ekhsan ◽  
Salasiah Che Me ◽  
Swee Ean Lim ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Charge Transfer ◽  
Surface Area ◽  
Sulphuric Acid ◽  
Fumed Silica ◽  
Catalytic Performance ◽  
Support Surface ◽  
High Catalytic Activity ◽  
Impregnation Method

A series of sulphate-vanadia impregnated fumed silica oxidative catalysts were synthesized via impregnation method. The samples were prepared by impregnation of 1 wt% of vanadium and 0.2 M of sulphuric acid onto fumed silica as support. Surface area of the silica supported samples were similar of 118 m2/g. UV-Vis DRS results showed existence of o supported V species and the charge transfer bands associated with O2- to V5+ in tetrahedral environments. Catalytic performance were evaluated via epoxidation of 1-octene to 1,2-epoxyoctane using hydrogen peroxide as an oxidant. It had been demonstrated that sulphate-vanadia impregnated fumed silica had high catalytic activity of 626 ± 0.2 mmol epoxide was produced after 24 h reaction. This may indicate that more oxidative sites were generated after the impregnation of V and sulphate onto the SiO2 matrixes.

scholarly journals Selective Allylic Oxidation of Terpenic Olefins Using Co-Ag Supported on SiO2 as a Novel, Efficient, and Recyclable Catalyst

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Abderrazak Aberkouks ◽  
Ayoub Abdelkader Mekkaoui ◽  
Mustapha Ait Ali ◽  
Larbi El Firdoussi ◽  
Soufiane El Houssame
Keyword(s):  
Hydrogen Peroxide ◽  
High Activity ◽  
Oxidation Reaction ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Allylic Oxidation ◽  
Catalyst Amount ◽  
Gel Method ◽  
Ft Ir ◽  
Butyl Peroxide

Co-Ag supported on the SiO2 catalyst was synthesized by the sol-gel method and characterized using XRD, FT-IR, TG-DTG, BET, CV, and SEM/EDX analysis. The catalytic performance of the resulting catalyst was examined by the oxidation of mono and sesquiterpenic olefins using hydrogen peroxide and tert-butyl peroxide as oxidant agents. Various parameters such as catalyst amount, temperature, and solvents have been studied. The Co-Ag supported on the SiO2 catalyst showed a high activity, selectivity, and recyclability for the selected oxidation reaction.

scholarly journals Determination of hydrogen peroxide by FIA based on the cobalt(II)-catalyzed oxidation reaction of stilbazo.

1988 ◽  
Vol 37 (5) ◽  
pp. 248-252
Author(s):  
Toshio DEGUCHI ◽  
Ryoichi TAKESHITA ◽  
Akira TANAKA ◽  
Isao SANEMASA
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidation Reaction ◽  
Catalyzed Oxidation

Selectively Catalyzed Oxidation of Benzyl Alcohol by FeIII–TAML/Hydrogen Peroxide

2015 ◽  
Vol 723 ◽  
pp. 601-604 ◽  
Author(s):  
Ran Li ◽  
Ge Wang ◽  
Yan Chun Liu ◽  
Xiao Bin Chen ◽  
Zhi Min Sun ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Benzyl Alcohol ◽  
Reaction Temperature ◽  
Oxidation Reaction ◽  
Macrocyclic Ligands ◽  
Temperature Reaction ◽  
Oxidation Of Benzyl Alcohol ◽  
Catalyzed Oxidation

Benzyl alcohol was selectively oxidized to benzaldehyde with iron (III) complexed to tetra amido macrocyclic ligands (FeIII–TAML) as catalyst and 30% H2O2 as oxidant. The effect of reaction temperature, reaction time, solvent, amount of catalyst and oxidant on the reaction of catalyzed oxidation of benzyl alcohol were explored. The conversion and selectivity of this oxidation reaction were calculated from calibrated GC yields of benzyl alcohol and benzaldehyde. When oxidation reaction was conducted under the conditions: solvent NMMO: ethanol = 1: 1, n (H2O2): n (benzyl alcohol) = 2, n (catalyst): n (benzyl alcohol) = 1%, temperature 80 ̊C and reaction time 60 minutes, the conversion was 91.23% and the selectivity was 90.12%.

scholarly journals The Direct Synthesis of Hydrogen Peroxide over AuPd Nanoparticles: An Investigation into Metal Loading

2021 ◽  
Author(s):  
Joseph Brehm ◽  
Richard J. Lewis ◽  
David J. Morgan ◽  
Thomas E. Davies ◽  
Graham J. Hutchings
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Oxidation State ◽  
Direct Synthesis ◽  
Catalytic Performance ◽  
Metal Loading ◽  
Subsequent Degradation ◽  
Small Nanoparticles

AbstractThe direct synthesis of H2O2 from molecular H2 and O2 over AuPd catalysts, supported on TiO2 and prepared via an excess chloride co-impregnation procedure is investigated. The role of Au:Pd ratio on the catalytic activity towards H2O2 formation and its subsequent degradation is evaluated under conditions that have previously been found to be optimal for the formation of H2O2. The combination of relatively small nanoparticles, of mixed Pd-oxidation state is shown to correlate with enhanced catalytic performance. Subsequently, a detailed study of catalytic activity towards H2O2 synthesis as a function of AuPd loading was conducted, with a direct correlation between catalytic activity and metal loading observed. Graphic Abstract

Te-template approach to fabricating ternary TeCuPt alloy nanowires with enhanced catalytic performance towards oxygen reduction reaction and methanol oxidation reaction

2015 ◽  
Vol 3 (11) ◽  
pp. 5850-5858 ◽  
Author(s):  
Haibo Li ◽  
Cancan Ren ◽  
Shuling Xu ◽  
Lei Wang ◽  
Qiaoli Yue ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Methanol Oxidation ◽  
Geometric Structure ◽  
Oxidation Reaction ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Methanol Oxidation Reaction ◽  
Alloy Nanowires

Alloying Pt with both Te and Cu could effectively improve ternary TeCuPt catalytic activity for electronic and geometric structure effects.

Catalytic performance of Keplerate polyoxomolybdates in green epoxidation of alkenes with hydrogen peroxide

RSC Advances ◽  
2015 ◽  
Vol 5 (86) ◽  
pp. 70424-70428 ◽  
Author(s):  
Fariba Jalilian ◽  
Bahram Yadollahi ◽  
Mostafa Riahi Farsani ◽  
Shahram Tangestaninejad ◽  
Hadi Amiri Rudbari ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Catalytic Performance ◽  
Epoxidation Of Alkenes

The catalytic activity of three Keplerate POM, Mo72M30 (V, Cr and Fe), in the green epoxidation of alkenes with 30% H2O2 in water are investigated. Mo72Cr30 was shown the highest catalytic activity and efficiently reused without any loss of activity.

Thermal Treatment Effect on Catalytic Activity of Au/TiO2 for CO Oxidation

2014 ◽  
Vol 548-549 ◽  
pp. 254-258
Author(s):  
Asif Mahmood ◽  
Shahid M. Ramay ◽  
Yousef Al-Zeghayer ◽  
Sajjad Haider ◽  
Muhammad Ali Shar ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Thermal Treatment ◽  
Co Oxidation ◽  
Oxidation Reaction ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Preferential Oxidation ◽  
Reaction Heat ◽  
Oxidation Performance ◽  
Positive Effect

A novel and well-organized study for the synthesis and enhanced catalytic activity of Au/TiO2catalysts has been developed. A momentous improvement in the catalytic activity of Au/TiO2in CO oxidation and preferential oxidation reaction by thermal treatment has been studied. Au/TiO2catalyst (Au (1 wt.%) supported on TiO2) was prepared by conventional deposition-precipitation method with NaOH followed by washing, drying and calcination in air at 400 °C for 4 h. Thermal treatment of Au/TiO2was performed at 450 °C under 0.05 mTorr. The activity of the catalysts has been examined in the reaction of CO oxidation and preferential oxidation (PROX) at 25-250 °C. The catalytic performance was found to be strongly affected by thermal treatment of the prepared catalyst prior to the reaction. Heat treatment after Au deposition has a positive effect on the CO oxidation performance. This is attributed to the introduction of a stronger interaction between the oxide and Au which improves the catalytic activity.

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