Advanced oxidation of methyl tert-butyl ether (MTBE) by UV/TiO2 and H2O2-UV/TiO2 processes

2006 ◽  
Vol 6 (2) ◽  
pp. 77-85 ◽  
Author(s):  
C.-H. Hung
Keyword(s):  
Light Intensity ◽  
Degradation Rate ◽  
Reaction Rate ◽  
Experimental Results ◽  
Methyl Tert Butyl Ether ◽  
H2o2 Concentration ◽  
Pseudo First Order Reaction ◽  
Butyl Ether ◽  
Solution Ph ◽  
Degradation Rates

This study investigated photocatalysis of MTBE via both UV/TiO2 and H2O2-UV/TiO2 processes. Several experimental parameters including pH level, H2O2 concentration, TiO2 dosage and light intensity were investigated. The experimental results demonstrated the degradation of MTBE following a pseudo first-order reaction in both reaction systems. Faster degradation rates were observed in alkaline solution for the UV/TiO2 system, but for the H2O2-UV/TiO2 system, faster degradation rates were detected in acidic solution. More dosage of TiO2 and irradiated light intensity were beneficial for the photocatalysis of MTBE. However, a peak reaction rate was observed at a TiO2 concentration of about 500 mg/L. The experimental results also indicated that the degradation rate of MTBE was enhanced by the addition of H2O2. H2O2 could be a more efficient electron acceptor than oxygen for retarding recombination of electron–hole pairs. The degradation rate in the H2O2-UV/TiO2 system was about 2.8 times faster than that in the UV/TiO2 system for solution pH below 5, and the rate increased 30% for solution pH above 6. In addition, it is observed that the reaction rate of MTBE increased quickly with H2O2 concentration at low H2O2 dosages, but the rate was independent of H2O2 dosage when adding too much H2O2.

scholarly journals Photoreduction of Cr(VI) Ions in Aqueous Solutions by UV/ Photocatalytic Processes

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Chih Ming Ma ◽  
Yung Shuen Shen ◽  
Po Hsiang Lin
Keyword(s):  
Aqueous Solutions ◽  
Reaction Rate ◽  
Removal Rate ◽  
Experimental Results ◽  
Order Kinetic ◽  
Solution Ph ◽  
Relationship Of ◽  
The Relationship ◽  
Photocatalytic Processes ◽  
Order Kinetic Equation

This study discussed the photoreduction of Cr(VI) ions in aqueous solutions by UV/TiO2photocatalytic processes under various operational factors. Experimental results showed that the removal rate of Cr(VI) increased with decreasing solution pH values and with increasing dosages of organic compounds, indicating that the recombination rate of electrons and h+can be retarded in the reaction systems by the addition of the scavenger, thus raising the reaction rate of Cr(VI). The relationship of the chemical reaction rate of Cr(VI), TiO2dosage, and changes of Cr(VI) concentration was expressed by the pseudo-first-order kinetic equation. Comparing the experimental results of two different doping metals in modified TiO2photoreduction systems, the removal rate of Cr(VI) by the Ag/TiO2process is larger, possibly because the electron transferring ability of Ag is superior to that of Cu. However, the photoreduction rates of Cr(VI) by modified UV/TiO2processes are worse than those by a nonmodified commercial UV/TiO2process.

Photocatalytic degradation of azo dye in TiO2 suspended solution

2001 ◽  
Vol 43 (2) ◽  
pp. 313-320 ◽  
Author(s):  
C.-H. Hung ◽  
P.-C. Chiang ◽  
C. Yuan ◽  
C.-Y. Chou
Keyword(s):  
Reaction Time ◽  
Light Intensity ◽  
Photocatalytic Degradation ◽  
Azo Dye ◽  
Batch Reactor ◽  
Reaction Rates ◽  
Pseudo First Order Reaction ◽  
Degradation Rates ◽  
Orange G ◽  
Degradation Of Azo Dye

The photocatalysis of azo dye, Orange G, by P-25 anatase TiO2 was investigated in this research. The experiments were conducted in a batch reactor with TiO2 powder suspension. Four near-UV lamps were used as the light source. The experimental variables included solution pH level, amount of TiO2, illumination light intensity, and reaction time. A pseudo-first order reaction kinetic was proposed to simulate the photocatalytic degradation of Orange G in the batch reactor. More than 80% of 10 mg/L Orange G decomposition in 60-minute reaction time was observed in this study and fast decomposition of Orange G only occurred in the presence of both TiO2 and suitable light energy. Faster degradation of Orange G was achieved under acid conditions. The degradation rates of Orange G at pH = 3.0 were about two times faster than those at pH = 7.0. Faster degradation of azo dye was observed for greater irradiated light intensity and more TiO present during the reaction. The reaction rates were proportional to TiO2concentration and light intensity with the power order of 0.726 and 0.734, respectively.

scholarly journals Removal of MTBE From Groundwater Using A PRB of ZVI/Sand Mixtures: Role of Nitrate And Hardness

2021 ◽  
Author(s):  
Farhad Ghayurdoost ◽  
Ali Assadi ◽  
Mohammad Reza Mehrasbi
Keyword(s):  
Reaction Rate ◽  
Considerable Effect ◽  
Reaction Rate Constant ◽  
Permeable Reactive Barrier ◽  
Process Efficiency ◽  
Methyl Tert Butyl Ether ◽  
Reactor Performance ◽  
Butyl Ether ◽  
Sand Mixture ◽  
Hydraulic Conditions

Abstract In this study, the efficiency of the permeable reactive barrier (PRB) in a column reactor using zero-valent iron (ZVI) particles and sand mixture in the removal of methyl tert-butyl ether (MTBE) from aquatic phases was investigated. The main operating parameters influence reactor performance such as pH, reaction time, pollutant content, catalyst load, hydraulic loading rate, and the reaction rate constant was evaluated. The results showed that the efficiency of process decreased with increasing pH, inflow, and pollutant concentration. In this case, the optimal conditions were obtained at pH=7, flow rate=0.23 m3/m2.d and C0=1 mg/L, which achieved a remarkable removal efficiency up to 90.32%. The being of high nitrate and hardness concentrations as intervening factors were led to reduce process efficiency to less than 44.61% and 51.4%, respectively. Lack of interfering factors had a considerable effect on the reaction rate of MTBE reduction that is approximately 2.65 and 4.11 times higher than in the presence of calcium hardness and nitrate, respectively. The PRB can be operated to remediate groundwater containing hydrocarbons based on filling media and hydraulic conditions.

Study on Limonite/TiO2 Microspheres Photolysising Phenol in Source Water

2012 ◽  
Vol 518-523 ◽  
pp. 116-120
Author(s):  
Qi Hong Zhu ◽  
Hong Xia Xia
Keyword(s):  
Reaction Time ◽  
Light Intensity ◽  
Removal Rate ◽  
Experimental Results ◽  
Source Water ◽  
Solution Ph

The Limonite/TiO2 combined microspheres are prepared and used to treat phenol in source water. The experimental results show that Limonite -TiO2 combined microspheres have high purifying effect on phenol in source water. When the dosage of Limonite/ TiO2 combined microspheres is 1.5g,solution pH is 4.5,reaction time is 90min,light intensity is 1600(x10 lux), the removal rate of phenol in water is the best,and reaches 87.77%.So, Limonite/TiO2 combined microspheres can be used to treat phenol in source water.

scholarly journals Biodegradation of methyl tert-butyl ether by Kocuria sp.

2012 ◽  
Vol 66 (5) ◽  
pp. 717-722 ◽  
Author(s):  
Blazo Lalevic ◽  
Jelena Jovic ◽  
Vera Raicevic ◽  
Igor Kljujev ◽  
Dragan Kikovic ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Bacterial Isolate ◽  
Methyl Tert Butyl Ether ◽  
Wastewater Sample ◽  
Butyl Ether ◽  
Isolation And Identification ◽  
Toxic Compounds ◽  
Tert Butyl ◽  
Degradation Rates ◽  
Intensive Use

Methyl tert-butyl ether (MTBE) has been used to replace the toxic compounds from gasoline and to reduce emission of air pollutants. Due to its intensive use, MTBE has become one of the most important environment pollutants. The aim of this paper is isolation and identification of the bacteria from wastewater sample of ?HIP Petrohemija? Pancevo (Serbia), capable of MTBE biodegradation. The results of the investigation showed that only the bacterial isolate 27/1 was capable of growth on MTBE. The result of sequence analyzes of 16S rDNA showed that this bacterial isolate belongs to the Kocuria sp. After the incubation period of 86 days, the degradation rates of initial MTBE concentration of 25 and 125 ?g/ml were 55 and 36%, respectively. These results indicated that bacteria Kocuria sp. is successfully adapted on MTBE and can be potentially used in bioremediation of soils and waters contaminated with MTBE.

Experimental Study of Photosynthetic Bacterial Degradation of Direct Red 4BS Wastewater

2013 ◽  
Vol 329 ◽  
pp. 61-65
Author(s):  
Zheng Fan ◽  
Guo Liang Zhang ◽  
Zhi Yang Wang ◽  
Zhi Yan Pan ◽  
Yan Li
Keyword(s):  
Light Intensity ◽  
Sodium Acetate ◽  
Degradation Rate ◽  
Inoculum Size ◽  
Bacterial Degradation ◽  
Solution Ph ◽  
Initial Concentration ◽  
First Order Kinetics ◽  
Low Concentrations ◽  
Degradation Reaction

The photosynthetic bacteria direct red 4BS solution pH, light intensity, inoculum size, the concentration of sodium acetate, and the initial concentration of direct red 4BS degradation rate. The results show that: the initial concentration of 80 mg / L, the inoculation amount of 25% (v / v), pH 8.0, the light intensity 3000lx, sodium acetate, 1.6mg / L under the conditions, after 96 hours of direct red 4BS degradation rate up to 87.5%. Sodium acetate in the reaction can increase the degradation rate, experiments show that: the process of degradation of sodium acetate and direct red 4BS ratio of 20: 1 (m / m) the degradation rate is better. Direct Red 4BS low concentrations, the reaction kinetics of the degradation reaction are first-order kinetics.

scholarly journals A Multi-Criteria Decision-Making Approach to Evaluate Different UVC/H2O2 Systems in Wastewater Treatment

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2252
Author(s):  
Isadora Luiza Climaco Cunha ◽  
Jose Geraldo Vidal Vieira ◽  
Luiz Kulay
Keyword(s):  
Decision Making ◽  
Environmental Impacts ◽  
Degradation Rate ◽  
Industrial Applications ◽  
Design Stage ◽  
Multi Criteria Decision Making ◽  
Treatment Technology ◽  
Pseudo First Order Reaction ◽  
Experimental Conditions ◽  
Degradation Rates

High azoxystrobin (AZO), difenoconazole (DFZ), and imidacloprid (IMD) pesticide removal rates in sixteen bench-scale experiments concerning tomato washing water treatment were obtained through a UVC/H2O2 advanced oxidative process. Experimental conditions ([H2O2]0) and irradiance (EUVC) were optimized for higher degradation rates (pseudo-first-order reaction). To consider both economic aspects and environmental impacts when defining the treatment technology, as well as technological requirements, this study applied a multi-criteria decision-making method (MCDM) to assess and differentiate similar UVC/H2O2 process configurations. This allowed for the identification of the cheapest experimental arrangement with the lowest associated environmental impacts, coupled to the highest degradation rate (kIMD). After consulting experts to determine the importance of the applied criteria and measuring alternative performances, experiment E7 ([H2O2]0 = 43.5 mg L−1; EUVC = 15.0 W m−2; kIMD = 0.236 s−1) was determined as meeting the three criteria in a balanced manner. Although E7′s technological performance regarding degradation rate did not achieve the best individual result, it presented the lowest impacts and costs among the analyzed series, although alternatives are sensitive to decision-maker priorities. This study considered different factors of a process displaying potential industrial applications still in the design stage to achieve a more efficient and balanced solution.

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