scholarly journals Bench-Scale Study of Aqueous MTBE Degradation by Combined Advanced Oxidation and Biological Processes

2021 ◽  
Author(s):  
Azadeh Asadi
Keyword(s):  
Biological Treatment ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Methyl Tert Butyl Ether ◽  
Molar Ratio ◽  
Second Phase ◽  
Biological Processes ◽  
Butyl Ether ◽  
Pre Treatment ◽  
Total Residence Time

The oxidation of methyl tert-butyl ether (MTBE) by advanced oxidation processes in conjunction with biological treatment in investigated. Firsst, the degradation of MTBE by UV/H2O2 and UV/TiO2 is studied. It is found that the optimum molar ratio or H2O2/MTBE is about 14 while the optimum concentration of TiO2 is 1.5 g/L. In addition, it is observed that a combined process of UV/H2O2 and UV/TiO2 does not have any advantage over each of these processes alone. In the second phase, biodegradability of MTBE by aerobic microorganisms is evaluated in three different approaches including BODu assessment, removal of MTBE by non-acclimated, and acclimated microorganisms. It is shown that the acclimatization of microorganisms enhances the rate of biodegradation of MTBE. Finally, it is observed that the rate of bioreaction is not improved after a photochemical pre-treatment. It is also found that using the integration of photochemical and biological treatment reduced the total residence time.

scholarly journals Bench-Scale Study of Aqueous MTBE Degradation by Combined Advanced Oxidation and Biological Processes

2021 ◽  
Author(s):  
Azadeh Asadi
Keyword(s):  
Biological Treatment ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Methyl Tert Butyl Ether ◽  
Molar Ratio ◽  
Second Phase ◽  
Biological Processes ◽  
Butyl Ether ◽  
Pre Treatment ◽  
Total Residence Time

The oxidation of methyl tert-butyl ether (MTBE) by advanced oxidation processes in conjunction with biological treatment in investigated. Firsst, the degradation of MTBE by UV/H2O2 and UV/TiO2 is studied. It is found that the optimum molar ratio or H2O2/MTBE is about 14 while the optimum concentration of TiO2 is 1.5 g/L. In addition, it is observed that a combined process of UV/H2O2 and UV/TiO2 does not have any advantage over each of these processes alone. In the second phase, biodegradability of MTBE by aerobic microorganisms is evaluated in three different approaches including BODu assessment, removal of MTBE by non-acclimated, and acclimated microorganisms. It is shown that the acclimatization of microorganisms enhances the rate of biodegradation of MTBE. Finally, it is observed that the rate of bioreaction is not improved after a photochemical pre-treatment. It is also found that using the integration of photochemical and biological treatment reduced the total residence time.

Degradation of chlorpyriphos in water by advanced oxidation processes

2010 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Murillo ◽  
J. Sarasa ◽  
M. Lanao ◽  
J. L. Ovelleiro
Keyword(s):  
Reaction Time ◽  
Light Source ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
The Other ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Other Hand ◽  
Initial Ph

The degradation of chlorpyriphos by different advanced oxidation processes such as photo-Fenton, TiO2, TiO2/H2O2, O3 and O3/H2O2 was investigated. The photo-Fenton and TiO2 processes were optimized using a solar chamber as light source. The optimum dosages of the photo-Fenton treatment were: [H2O2]=0.01 M; [Fe3 + ]=10 mg l−1; initial pH = 3.5. With these optimum conditions total degradation was observed after 15 minutes of reaction time. The application of sunlight was also efficient as total degradation was achieved after 60 minutes. The optimum dosage using only TiO2 as catalyst was 1,000 mg l−1, obtaining the maximum degradation at 20 minutes of reaction time. On the other hand, the addition of 0.02 M of H2O2 to a lower dosage of TiO2 (10 mg l−1) provides the same degradation. The ozonation treatment achieved complete degradation at 30 minutes of reaction time. On the other hand, it was observed that the degradation was faster by adding H2O2 (H2O2/O3 molar ratio = 0.5). In this case, total degradation was observed after 20 minutes.

Combined Advanced Oxidation Processes and Aerobic Biological Treatment for Synthetic Fatliquor Used in Tanneries

2012 ◽  
Vol 51 (50) ◽  
pp. 16171-16181 ◽  
Author(s):  
Chitra Kalyanaraman ◽  
Sri Bala Kameswari Kanchinadham ◽  
L. Vidya Devi ◽  
S. Porselvam ◽  
J. Raghava Rao
Keyword(s):  
Biological Treatment ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Oxidation Processes

Effect of advanced oxidation processes on the toxicity of municipal landfill leachates

2004 ◽  
Vol 49 (4) ◽  
pp. 273-277 ◽  
Author(s):  
B. Slomczynska ◽  
J. Wasowski ◽  
T. Slomczynski
Keyword(s):  
Organic Compounds ◽  
Advanced Oxidation Processes ◽  
Vibrio Fischeri ◽  
Advanced Oxidation ◽  
Optimal Conditions ◽  
Toxicity Evaluation ◽  
Landfill Leachates ◽  
Oxidation Processes ◽  
Municipal Landfill ◽  
Pre Treatment

The aim of the present study was to assess the effect of advanced oxidation processes (AOPs) (oxidation ozone and peroxide/ozone) on the toxicity of leachates from municipal landfill for Warsaw, Poland, using a battery of tests. AOPs used to pre-treat leachates were carried out in laboratory conditions after their coagulation with the use of FeCl3. The effects of the pre-treatment of leachates using the method of coagulation with FeCl3 depended on the concentration of organic compounds and with optimal conditions of the process ranged from 40 to 70%. Further pre-treatment of the leachates after coagulation, involving the use of oxidation with O3 and H2O2/O3, did not cause significant decrease of leachate toxicity. The data of this study demonstrated the usefulness of the battery of tests using Daphnia magna, Artemia franciscana, Scenedesmus quadricauda and Vibrio fischeri for the toxicity evaluation of raw and pre-treated leachates.

scholarly journals Organic Degradation Potential of Real Greywater Using TiO2-Based Advanced Oxidation Processes

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2811
Author(s):  
Dheaya Alrousan ◽  
Arsalan Afkhami ◽  
Khalid Bani-Melhem ◽  
Patrick Dunlop
Keyword(s):  
Advanced Oxidation Processes ◽  
Low Cost ◽  
Advanced Oxidation ◽  
Molar Ratio ◽  
Organic Fraction ◽  
Viable Option ◽  
Oxidation Processes ◽  
Toc Removal ◽  
Uva Irradiation ◽  
Efficiency Parameter

In keeping with the circular economy approach, reclaiming greywater (GW) is considered a sustainable approach to local reuse of wastewater and a viable option to reduce household demand for freshwater. This study investigated the mineralization of total organic carbon (TOC) in GW using TiO2-based advanced oxidation processes (AOPs) in a custom-built stirred tank reactor. The combinations of H2O2, O3, and immobilized TiO2 under either dark or UVA irradiation conditions were systematically evaluated—namely TiO2/dark, O3/dark (ozonation), H2O2/dark (peroxidation), TiO2/UVA (photocatalysis), O3/UVA (Ozone photolysis), H2O2/UVA (photo-peroxidation), O3/TiO2/dark (catalytic ozonation), O3/TiO2/UVA (photocatalytic ozonation), H2O2/TiO2/dark, H2O2/TiO2/UVA, H2O2/O3/dark (peroxonation), H2O2/O3/UVA (photo-peroxonation), H2O2/O3/TiO2/dark (catalytic peroxonation), and H2O2/O3/TiO2/UVA (photocatalytic peroxonation). It was found that combining different treatment methods with UVA irradiation dramatically enhanced the organic mineralization efficiency. The optimum TiO2 loading in this study was observed to be 0.96 mg/cm2 with the highest TOC removal (54%) achieved using photocatalytic peroxonation under optimal conditions (0.96 mg TiO2/cm2, 25 mg O3/min, and 0.7 H2O2/O3 molar ratio). In peroxonation and photo-peroxonation, the optimal H2O2/O3 molar ratio was identified to be a critical efficiency parameter maximizing the production of reactive radical species. Increasing ozone flow rate or H2O2 dosage was observed to cause an efficiency inhibition effect. This lab-based study demonstrates the potential for combined TiO2-AOP treatments to significantly reduce the organic fraction of real GW, offering potential for the development of low-cost systems permitting safe GW reuse.

Phenol wastewater remediation: advanced oxidation processes coupled to a biological treatment

2007 ◽  
Vol 55 (12) ◽  
pp. 221-227 ◽  
Author(s):  
A. Rubalcaba ◽  
M.E. Suárez-Ojeda ◽  
F. Stüber ◽  
A. Fortuny ◽  
C. Bengoa ◽  
...  
Keyword(s):  
Biological Treatment ◽  
Advanced Oxidation Processes ◽  
Treatment Plant ◽  
Advanced Oxidation ◽  
Industrial Effluents ◽  
Coupled Processes ◽  
Catalytic Wet Air Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Oxidation Processes

Nowadays, there are increasingly stringent regulations requiring more and more treatment of industrial effluents to generate product waters which could be easily reused or disposed of to the environment without any harmful effects. Therefore, different advanced oxidation processes were investigated as suitable precursors for the biological treatment of industrial effluents containing phenol. Wet air oxidation and Fenton process were tested batch wise, while catalytic wet air oxidation and H2O2-promoted catalytic wet air oxidation processes were studied in a trickle bed reactor, the last two using over activated carbon as catalyst. Effluent characterisation was made by means of substrate conversion (using high liquid performance chromatography), chemical oxygen demand and total organic carbon. Biodegradation parameters (i.e. maximum oxygen uptake rate and oxygen consumption) were obtained from respirometric tests using activated sludge from an urban biological wastewater treatment plant (WWTP). The main goal was to find the proper conditions in terms of biodegradability enhancement, so that these phenolic effluents could be successfully treated in an urban biological WWTP. Results show promising research ways for the development of efficient coupled processes for the treatment of wastewater containing toxic or biologically non-degradable compounds.

Degradation and changes in toxicity and biodegradability of tetracycline during ozone/ultraviolet-based advanced oxidation

2014 ◽  
Vol 70 (7) ◽  
pp. 1229-1235 ◽  
Author(s):  
Huyen Trang Luu ◽  
Kisay Lee
Keyword(s):  
Escherichia Coli ◽  
Biological Treatment ◽  
Advanced Oxidation Processes ◽  
Vibrio Fischeri ◽  
Oxygen Demand ◽  
Advanced Oxidation ◽  
Uv Treatment ◽  
Experimental Conditions ◽  
Oxidation Processes ◽  
Complete Mineralization

Advanced oxidation processes (AOPs) composed of O3, H2O2 and ultraviolet (UV) were applied to degrade tetracycline (TC). Degradation efficiency was evaluated in terms of changes in absorbance (ABS) and total organic carbon (TOC). The change in biotoxicity was monitored with Escherichia coli and Vibrio fischeri. The improvement in biodegradability during oxidation was demonstrated through 5-day biochemical oxygen demand/chemical oxygen demand ratio and aerobic biological treatment. The combination of O3/H2O2/UV and O3/UV showed the best performance for the reductions in ABS and TOC. However, mineralization and detoxification were not perfect under the experimental conditions that were used in this study. Therefore, for the ultimate treatment of TC compounds, it is suggested that AOP treatment is followed by biological treatment, utilizing enhanced biodegradability. In this study, aerobic biological treatment by Pseudomonas putida was performed for O3/UV-treated TC. It was confirmed that O3/UV treatment improved TOC reduction and facilitated complete mineralization in biological treatment.

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