Monitoring the influence of toxic compounds on microbial denitrifying biofilm processes

2003 ◽  
Vol 47 (5) ◽  
pp. 211-216 ◽  
Author(s):  
J. Li ◽  
P.L. Bishop
Keyword(s):  
Organic Compound ◽  
Redox Potential ◽  
Organic Compounds ◽  
Acid Orange 7 ◽  
Toxic Compounds ◽  
Acid Orange ◽  
Anoxic Layer ◽  
Anaerobic Zone ◽  
Microelectrode Measurements

Microelectrode measurements were conducted to obtain nitrate, pH and redox potential profiles within anoxic denitrifying biofilms. The influence of a toxic organic compound (acid orange 7) on biofilm microprofiles was also monitored using microelectrodes. The data provide evidence that the denitrifying biofilms were stratified into an anoxic layer and an anaerobic layer. The anaerobic zone might provide a niche for the biodegradation of recalcitrant organic compounds in biofilms. It was found that acid orange 7 and its biodegradation byproducts had only a slight impact on biofilm nitrate, pH and redox potential profiles.

Adsorption mechanism of acid orange 7 on photocatalytic materials based on TiO2

MRS Advances ◽  
2019 ◽  
Vol 4 (61-62) ◽  
pp. 3399-3405
Author(s):  
A. Arteaga-Jiménez ◽  
A. I. Caudana-Campos ◽  
A. L. García-García ◽  
E. Hernández-Zapata ◽  
M. A. Vidales-Hurtado
Keyword(s):  
Chemical Composition ◽  
Organic Compound ◽  
Titanium Tetrachloride ◽  
Adsorption Mechanism ◽  
Organic Molecules ◽  
Heterogeneous Photocatalysis ◽  
Acid Orange 7 ◽  
No Adsorption ◽  
Acid Orange ◽  
Catalytic Material

ABSTRACTThe degradation of organic molecules in an aqueous medium using heterogeneous photocatalysis depends on the chemical composition and concentration of the organic compound, the crystalline and morphological nature of the photocatalyst, the pH of the dye dilution, and the reaction temperature. Since photocatalytic degradation is a process that occurs on the surface of the catalytic material, it is desirable to induce maximum adsorption of the organic compound. One strategy to achieve this is to functionalize the surface of the catalyst to retain the molecule of interest. In this work, we studied the interaction of acid orange 7 (AO7) with commercial TiO2-anatase powder catalyst, and with a catalyst synthesized in house using titanium tetrachloride and ethanolamine (TiO2-et). Our results indicate that there is no adsorption of the AO7 dye on the TiO2-et particles. The infrared spectrum of the TiO2-et particles is presented.

scholarly journals A MEMS µ-Preconcentrator Employing a Carbon Molecular Sieve Membrane for Highly Volatile Organic Compound Sampling

Chemosensors ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 104
Author(s):  
Hung-Yang Kuo ◽  
Wei-Riu Cheng ◽  
Tzu-Heng Wu ◽  
Horn-Jiunn Sheen ◽  
Chih-Chia Wang ◽  
...  
Keyword(s):  
Organic Compound ◽  
Organic Compounds ◽  
Volatile Organic Compound ◽  
Molecular Sieve ◽  
Amplification Factor ◽  
Microfluidic Channel ◽  
Carbon Molecular Sieve ◽  
Volatile Organic ◽  
Chromatographic Peaks ◽  
Gaseous Toluene

This paper presents the synthesis and evaluation of a carbon molecular sieve membrane (CMSM) grown inside a MEMS-fabricated μ-preconcentrator for sampling highly volatile organic compounds. An array of µ-pillars measuring 100 µm in diameter and 250 µm in height were fabricated inside a microfluidic channel to increase the attaching surface for the CMSM. The surface area of the CMSM was measured as high as 899 m2/g. A GC peak amplification factor >2 × 104 was demonstrated with gaseous ethyl acetate. Up to 1.4 L of gaseous ethanol at the 100 ppb level could be concentrated without exceeding the capacity of this microchip device. Sharp desorption chromatographic peaks (<3.5 s) were obtained while using this device directly as a GC injector. Less volatile compounds such as gaseous toluene, m-xylene, and mesitylene appeared to be adsorbed strongly on CMSM, showing a memory effect. Sampling parameters such as sample volatilities, sampling capacities, and compound residual issues were empirically determined and discussed.

Preparation of cationic waste paper and its application in poisonous dye removal

2013 ◽  
Vol 67 (11) ◽  
pp. 2560-2567 ◽  
Author(s):  
Fan Yang ◽  
Xiaojie Song ◽  
Lifeng Yan
Keyword(s):  
Low Cost ◽  
Aqueous Suspension ◽  
Order Kinetic ◽  
Acid Orange 7 ◽  
Anionic Dyes ◽  
Experimental Conditions ◽  
Adsorption Models ◽  
Acid Orange ◽  
Initial Ph ◽  
Pseudo Second Order

Cationic paper was prepared by reaction of paper with 2,3-epoxypropyltrimethylammonium chloride in aqueous suspension, and tested as low-cost adsorbent for wastewater treatment. The experimental results revealed that anionic dyes (Acid Orange 7, Acid Red 18, and Acid Blue 92) were adsorbed on the cationic paper nicely. The maximum amount of dye Acid Orange 7 adsorbed on cationic paper was 337.2 mg/g in experimental conditions. The effects of initial dye concentration, temperature, and initial pH of dye solution on adsorption capacity of cationic paper were studied. The pseudo-first-order and pseudo-second-order kinetic models were applied to describe the kinetic data. The Freundlich and Langmuir adsorption models were used to describe adsorption equilibrium. The thermodynamic data indicated that the adsorption process of dye on cationic paper occurred spontaneously.

Fabrication of monoclinic BiVO4 photocatalyst film and its photocatalytic activity for organic pollutant removal

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Saranyoo Chaiwichian ◽  
Buagun Samran
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Average Particle Size ◽  
Pollutant Removal ◽  
Light Irradiation ◽  
Average Particle ◽  
Film Sample ◽  
Acid Orange 7 ◽  
Acid Orange ◽  
X Ray

Abstract Monoclinic BiVO4 photocatalyst films decorated on glass substrates were successfully fabricated via a dip-coating technique with different annealing temperatures of 400 °C, 450 °C, 500°C, and 550 °C. All of the physical and chemical properties of as-prepared BiVO4 photocatalyst film samples were investigated using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectra techniques. The results revealed that the as-prepared BiVO4 photocatalyst film samples retained a monoclinic phase with an average particle size of about 50 – 100 nm. Moreover, the BiVO4 photocatalyst film samples showed a strong photoabsorption edge in the range of visible light with the band gap energy of 2.46 eV. The photocatalytic activities of all the film samples were tested by the degradation of model acid orange 7 under visible light irradiation. The BiVO4 photocatalyst film sample annealed at a temperature of 500 °C showed the highest photoactivity efficiency compared with other film samples, reaching up to 51%within 180 min. In addition, the stability and reusability of BiVO4 photocatalyst film sample made with an annealing temperature of 500 °C did not show loss of photodegradation efficiency of acid orange 7 after ten recycles. A likely mechanism of the photocatalytic process was established by trapping experiments, indicating that the hydroxyl radical scavenger species can be considered to play a key role for acid orange 7 degradation under visible light irradiation.

Degradation of C.I. Acid Orange 7 by ultrasound enhanced ozonation in a rectangular air-lift reactor

2008 ◽  
Vol 138 (1-3) ◽  
pp. 231-238 ◽  
Author(s):  
Hui Zhang ◽  
Yujuan Lv ◽  
Fang Liu ◽  
Daobin Zhang
Keyword(s):  
Acid Orange 7 ◽  
Acid Orange ◽  
Air Lift Reactor ◽  
Air Lift
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