Phenolic decomposition

Li et al. [76] confirmed that efficacy of phenol degradation depends on microbubble formation. In their experiments, they observed no change in phenol concentration if micro-bubble formation was stopped. The phenol decomposition rate was found maximum in the case when O2 was passed in the solution due to highest micro-bubble formation followed by air and N2 respectively. 

Balazs, N., Mogyorosi, K., Sranko, D.F., Pallagi, A., Alapi, T., Oszko, A., Dombi, A., and Sipos, P. (2008) The effect of particle shape on the activity of nanocrystalline Ti02 photocatalysts in phenol decomposition. Applied Catalysis B Environmental, 84 (3-4), 356—362. 

Dufek P, Cemohorsky I, Pacakova V. 1982. Gas chromatography as a tool for the study of the products of photosensitized phenol decomposition. J Chromatogr 241 19-28. 

TOC and phenol concentration decreased same trend and the forming of by product was determined by mass spectrum. It was shown that formed by product was not stabile, whereas it immediately decomposes to different products. It was also determined that the amounts of ozone were sufficient for phenol decomposing. As a result of kinetic investigation of phenol, decomposition reaction was found first order because of obtaining almost constant k values (Fig. 24.2a-f). As expected... 

Bodzek M, Bohdziewicz J, Kowalska M. Preparation of membrane-immobilised enzymes for phenol decomposition. J Chem Technol Biotechnol 1994 61 231-239. 

Brezova V, Blazkova A, Karpinsky L, et al. Phenol decomposition using Mn+/Ti02 photocatalysts supported by the sol-gel technique on glass fibres. J Photochem Photobiol A Chem 1997 109 177-83. 

The results of the library search for these compounds are summarized in Table III. Generally, the phenols were correctly identified. The conjugates wore not present in the mass spectral library. However, they were consistently identified as their aglycone or phenol decomposition product. 

A large amount of phenols is released in wastewater and can be lost to waste streams. A rapid increase in the distribution and abundance of plastic debris in the ocean around the world was reported, and the adverse influence of plastic s phenol residues has been of great interest Polluted water disinfection, enzymatic oxidation of chlorinated phenols, decomposition of alkylphenol polyethoxylates and combustion of phenols can lead to the formation of highly toxic compounds. High adsorption of phenols on sludge and sediments requires that their distribution in these systems also be followed. All of these facts have promoted extensive research on phenolic compounds and their fate in the environment. 

Kimmig J and Schulz KH Occupational chloracne caused by aromatic cyclic ethers. Dermatologies 115 540-546, 1957. Goldman PJ Critically acute chloracne caused by trichloro-phenol decomposition products. Arbeitsmed Sozialmed Arbeit-shygiene 7 12-18, 1972. 

To prepare the hormone, the adrenal glands are extracted with acetone, after which the acetone is removed by distillation in vacuo at 35° to 40° C. The remaining aqueous concentrate, after being filtered and adjusted to pW 7.0 with sodium hydroxide, is shaken with activated carbon to adsorb the hormone. To get rid of impurities incidentally adsorbed on the carbon, it is washed successively with dilute alkali, hydrochloric acid, and alcohol. The alkali removes products of phenolic decomposition the acid elutes epinephrine and the alcohol dissolves certain lipoidal impurities. 

An alternative or complimentary theory for the mode of action of simple phenolic compounds is that they are converted to much more toxic quinones. Pillinger et al. [69] found that various phenolic decomposition products of barley straw were most toxic under conditions favorable for oxidation of the compounds to quinones, and that quinones were up to one thousand-fold more toxic to algae than the parent compounds. The most likely route to conversion to a quinone is enzymatic. Peroxidases and polyphenol oxidases can perform such a reaction, depending on the substrate. However, polyphenol oxidase cannot be detected in most green algae [139] and has not been reported in cyanobacteria. 

Additional information can be obtained from certain special tests. Thus, the Gibbs indophenol test is positive with PEEK, PAR, and PEI (see Section 6.1.3). Using the color reaction with jo-dimethylamino benzaldehyde (Section 6.1.2), one can differentiate HT-polyamides, such as PA 6-3-T, from polymers that develop phenolic decomposition products during pyrolysis. While with polyamides, the red coloration obtained after the addition of concentrated hydrochloric acid remains, with polycarbonates it turns blue. 

B13 Aqueous phenol decomposition Phenol removal from industrial n02 on silica beads, Ni or Co on Wastewater treatment [27]... 

Mungmart M, Kijsirichareonchai U, Tonanon N, Prechanont S. Panpranot J, Yamamoto T, Eiadua A, Sano N, Tanthapanichakoon W, Charinpanitkul T. Metal catalysts impregnated on porous media for aqueous phenol decomposition within three-phase fluidized-bed reactor. J. Hazard. Mater. 2011 185 606-612. 

FIGURE 3.18 Changes in photoactivity nnder ultraviolet (UV) rays measured by phenol decomposition (a), turbidity (b), and practical efficiency (c) with carbon content for carbon-modified Ti02 prepared at different temperatures. 

A marked acceleration of phenol decomposition in the presence of H2O2 was observed by modihcation of carbon-coated Ti02 with iron this will be discussed in Section 3.5.3. 

Tryba, B., A.W. Morawski, M. Inagaki, and M. Toyoda, Mechanism of phenol decomposition on Fe-C-Ti02 and Fe-TiOj photocatalysts via photo-Fenton process. J. Photochem. Photobiol. A. 179 (2006) 224-228. 

Balazs N, Mogyorosi K, Sranko DF, Pallagi A, Alapi X, Oszko A, Dombi A, Sipos P (2(X)8) Xhe effect of particle shape on the activity of nanocrystalline Xi02 photocatalysts in phenol decomposition. Appl Catal Environ 84(3) 356-362... 

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