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Initial Phenol Concentrations (initial + phenol_concentration)

Distribution by Scientific Domains

Chemistry	100%

Selected Abstracts

Catalytic wet air oxidation of phenol using active carbon: performance of discontinuous and continuous reactors

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 7 2001
Frank Stüber
Abstract Catalytic wet air oxidation (CWAO) of an aqueous phenol solution using active carbon (AC) as catalytic material was compared for a slurry and trickle bed reactor. Semi-batchwise experiments were carried out in a slurry reactor in the absence of external and internal mass transfer. Trickle-bed runs were conducted under the same conditions of temperature and pressure. Experimental results from the slurry reactor study showed that the phenol removal rate significantly increased with temperature and phenol concentration, whereas partial oxygen pressure had little effect. Thus, at conditions of 160,°C and 0.71,MPa of oxygen partial pressure, almost complete phenol elimination was achieved within 2,h for an initial phenol concentration of 2.5,g,dm,3. Under the same conditions of temperature and pressure, the slurry reactor performed at much higher initial rates with respect to phenol removal than the trickle bed reactor, both for a fresh active carbon and an aged active carbon, previously used for 50,h in the trickle bed reactor, but mineralisation was found to be much lower in the slurry reactor. Mass transfer limitations, ineffective catalyst wetting or preferential flow in the trickle bed alone cannot explain the drastic difference in the phenol removal rate. It is likely that the slurry system also greatly favours the formation of condensation polymers followed by their irreversible adsorption onto the AC surface, thereby progressively preventing the phenol molecules to be oxidised. Thus, the application of this type of reactor in CWAO has to be seriously questioned when aiming at complete mineralisation of phenol. Furthermore, any kinetic study of phenol oxidation conducted in a batch slurry reactor may not be useful for the design and scale-up of a continuous trickle bed reactor. © 2001 Society of Chemical Industry [source]

Phenol Removal through Chemical Oxidation using Fenton Reagent

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 5 2007
Y. Yavuz
Abstract In this study, phenol, aromatic, and non-biodegradable organic matter were investigated and found to be removed from the model solution through chemical oxidation using Fenton reagent. The effects of the initial phenol concentration, hydrogen peroxide, and ferrous sulfate concentrations on the removal efficiency were investigated. Performance of the chemical oxidation process was monitored with phenol and COD (Chemical Oxygen Demand) analyses. In the experimental studies, phenol removal of over 98,% and COD removal of nearly 70,% were achieved. The optimum conditions for Fenton reaction both for initial phenol concentrations of 200 and 500,mg/L were found at a ratio [Fe2+]/[H2O2] (mol/mol) equal to 0.11. According to the results, chemical oxidation using Fenton reagent was found to be too effective, especially for phenol removal. However, this method has limited removal efficiency for COD. [source]

Modeling for batch phenol biodegradation with immobilized Alcaligenes faecalis

AICHE JOURNAL, Issue 4 2006
Xiaoqiang Jia
Abstract Intrinsic cell growth and phenol biodegradation kinetics of Alcaligenes faecalis were studied in shaking flasks. Batch phenol biodegradation experiments were carried out in a 7.5 L fermentor with immobilized Alcaligenes faecalis in polyurethane foams. A double-layer reaction-diffusion model was developed to describe the dynamic behaviors of batch phenol biodegradation processes. Phenol degradation (within the cell-immobilized polyurethane foams as well as in the main liquid phase) and cell growth (within the cell-immobilized polyurethane foams only) at different initial phenol concentrations were simulated and analyzed in terms of both biodegradation time and layer radius course. The good agreement between the model simulations and the experimental measurements for phenol degradation in the main liquid phase validates the proposed double-layer reaction-diffusion model. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source]

Modélisation de la cinétique de biodégradation de phénol par granules aérobies

THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2008
Claudia Calvario-Rivera
Abstract Ce travail est consacré à la modélisation de la cinétique de biodégradation de phénol par granules aérobies. Ceux-ci ont été obtenus à partir de la culture à alimentation séquentielle d'un surnageant de boues activées sur une eau usée synthétique,; puis ils ont été acclimatés au phénol (100 mg/L). La biodégradation de différentes concentrations de phénol (40,1112 mg/L) a été étudiée en fioles agitées ensemencées avec des granules acclimatés. Un modèle de type Haldane a été sélectionné, qui permet de décrire de manière adéquate l'évolution de la concentration de phénol avec un seul jeu de paramètres. Ce modèle pourrait permettre de mieux comprendre la biodégradation de molécules toxiques telles que le phénol dans des réacteurs granulaires aérobies. This work describes a model of the biodegradation of phenol carried out by aerobic granules. These granules were obtained by culturing an activated sludge supernatant in a sequencing batch reactor fed with a synthetic waste water and subsequently, by acclimation to phenol (100 mg/L). The kinetics of phenol biodegradation by the aerobic granules was investigated over a wide range of initial phenol concentrations (40,1112 mg/L) in shake-flask cultures. A Haldane-type model was adjusted to the experimental results, which depicts successfully the phenol biodegradation profiles in the entire range of initial concentrations studied by using only one set of parameters. It is our view that the proposed model could contribute to the knowledge about the ability of aerobic granular systems to biodegrade toxic, inhibitory compounds such as phenol. [source]