Phenol degradability

Phenolic networks are well known for their excellent thermal and thermo-oxidative stabilities. The mechanisms for high-temperature phenolic degradation include dehydration, thermal crosslinking, and oxidation, which eventually lead to char. 

Phenolic degradation, thermal and thermo-oxidative, 418-425 Phenolic-epoxy networks, 413 Phenolic monomers, second-order reaction rate constants of formaldehyde with, 403... 

Phenol is an important intermediate in the anaerobic degradation of many complex and simple aromatic compounds. Tschech and Fuchs proposed that the carboxylation of phenol to 4-hydroxybenzoate is the first step in the degradation of phenol under denitrifying conditions. However, 4-hydroxybenzoate is not detected in the cultures or cell extracts of the denitrifying Pseudomonas species in the presence of CO2 and phenol, but it is detected if phenol is replaced by phenolphosphate. In contrast, 4-hydroxybenzoate is readily detected as an intermediate of phenol degradation in the iron-reducing bacterium GS-15, and 4-hydroxybenzoate may prove to be a common intermediate in the anaerobic transformation. Thus, in anaerobic degradation of phenolic compounds, it has been postulated that carboxylation reactions may play important roles. 

Liu YJ, XZ Jiang (2005) Phenol degradation by a nonpulsed diaphragm glow discharge in an aqueous solution. Environ Sci Technol 39 8512-8517. 

A phenol-degrading community was examined using phenol followed by analysis of the stable-isotope-labeled RNA by equilibrium density centrifugation, and complemented... 

DeRito CM, GM Pnmphrey, EL Madsen (2005) Use of field-based stable isotope probing to identify adapted popnlations and track carbon flow throngh a phenol-degrading soil microbial conunnnity. Appl Environ Microbiol 71 7858-7865. 

Watanabe K, M Teramoto, H Eutamata, S Harayama (1998b) Molecular detection, isolation, and physiological characterization of functionally dominant phenol-degrading bacteria in activated sludge. Appl Environ Microbiol 64 4396-4402. 

Watanabe K, S Yamamoto, S Hino, S Harayama (1998a) Population dynamics of phenol-degrading bacteria in activated sludge determined by gyrB-targeted quantitative PGR. Appl Environ Microbiol 64 1203-1209. 

G. D. Bending and D. J. Read, Lignin and soluble phenolic degradation by cctomy-corrhizal and ericoid fungi. Mycol. Res. /Of 1348 (1997). 

Weavers LK, Malmstadt N, Hoffmann MR (2000) Kinetics and mechanism of pentachloro-phenol degradation by sonication, ozonation and sonolytic ozonation. Environ Sci Tech 34 1280-1285... 

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. 

Many workers have since tried ultrasound induced Fenton s reagent methods to degrade phenol. Papadaki et al. [83] reported the lower efficiency of Fenton s reagent for phenol degradation due to competition of both Fe2+ and ultrasound for H202, resulting in the reduction of concentration of Fenton s reagent in solution. 

In the experiment involving oxidative enzyme HRP (EC 1.11.1.7, RZ 1.9, 240 purpuro gallin (units/mg)) [89] for the enzymatic treatment and ultrasonic waves of 423 kHz and 5.5 W, the phenol degradation rate was found to increase. The ultrasound assisted biodegradation method has been found to be more efficient method than the sonolysis and enzyme treatment when operated individually. 

The rare earth oxides of lanthanum, samarium and gadolinium were converted into soluble nitrate salts by dissolving them in the minimum amount of concentrated nitric acid. Then two sets were prepared by adding 2.0 ml of aqueous solution of La(N03)3.6H20 [0.2 M] and 0.01 ml of (n-BuO)4Ti to 25 ml of aqueous solution of Cu(N03)2 [1.0 M]. Similarly, two sets were prepared with Co(N03)3. Same procedures were followed for Sm(N03)3 [0.2 M] and Gd(N03)3 [0.2 M], One set of all these solutions were sonicated under ultrasonic bath (Model - Meltronics, 20 kHz, 250 W) for half an hour. The solutions prepared in normal and sonicated conditions were kept in muffle furnace (Model - Deluxe Zenith) first at 100°C for 2 h and then the temperature of the furnace was raised up to 900°C and calcined for 2 h. The solid composites prepared were then cooled to room temperature and treated as catalyst for phenol degradation. 

Lurascu B, Siminiceanu I, Vione D, Vicente MA, Gil A (2009) Phenol degradation in water through a heterogeneous photo-Fenton process catalyzed by Fe-treated laponite. Water Res 43 1313-1322... 

Karunakaran C, Dhanalakshmi R (2009) Phenol degradation on Pr6On surface under UV-A light. Synergistic photocatalysis by semiconductors. Radiat Phys Chem 78 8-12... 

Esplugas S, Gimlenez J, Contreras S, Pascual E, Rodriguez M (2002) Comparison of different advanced oxidation processes for phenol degradation. Water Res 36 1034—1042... 

Chand R, Ince NH, Gogate PR, Bremner DH (2009) Phenol degradation using 20, 300 and 520 kHz ultrasonic reactors with hydrogen peroxide, ozone and zero valent metals. Sep Purif Technol 67 103-109... 

Figure 4.4 High aspect ratio (high length to P25) in phenol degradation, thusevidencingthe...

Cr- and N-doped titania showed improved activity under visible light in the degradation of methylene blue and isopropyl alcohol [89]. I-doped Ti02 showed better activity than Degussa P25 for methylene blue degradation. The sample composed of anatase and rutile showed better activity than that with only anatase [90] for phenol degradation [91]. 

A = ethanol production B - solvent fermentation C - phenol degradation D - 3 4 dlchloroanaline degradation E = denitrification... 

Etzensperger, M., Thoma, S., Petrozzi, S., and Dunn, I. J., Phenol Degradation in a Three-Phase Biofilm Fluidized Sand Bed Reactor, Bioproc. Eng., 4 175... 

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