The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
José A. Peres - One of the best experts on this subject based on the ideXlab platform.
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Characteristics of p-Hydroxybenzoic Acid oxidation using Fenton's reagent.
Journal of environmental science and health. Part A Toxic hazardous substances & environmental engineering, 2004Co-Authors: José A. Peres, Luis M. Carvalho, Rui A.r. Boaventura, Carlos A. V. CostaAbstract:Abstract The objective of this work was to investigate the oxidation of p-Hydroxybenzoic Acid by the Fenton's reagent. Batch experiments were carried out to investigate the influence of the most important process variables: hydrogen peroxide and ferrous salt concentrations, pH, and temperature. The optimal results obtained indicate that p-Hydroxybenzoic Acid can be effectively degraded using Fenton's oxidation within 10-min reaction time by using a molar ratio H2O2: p-Hydroxybenzoic Acid of 4:1 and H2O2:Fe2+ of 15:1, at 30°C and pH = 3.0. The behavior of ORP and pH along the reaction time for different values of R (molar ratio H2O2: p-Hydroxybenzoic Acid) was also discussed. A pseudo-first order model was applied to describe the oxidation kinetics of p-Hydroxybenzoic Acid by Fenton's reagent.
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oxidation of p Hydroxybenzoic Acid by uv radiation and by tio2 uv radiation comparison and modelling of reaction kinetic
Journal of Hazardous Materials, 2001Co-Authors: Jesus Beltran De Heredia, Joaquin Torregrosa, Joaquin R Dominguez, José A. PeresAbstract:Abstract The phenolic compound p -Hydroxybenzoic Acid is very common in a great variety of agroindustrial wastewaters (olive oil and table olive industries, distilleries). The objective of this work was to study the photocatalytic activity of TiO 2 towards the decomposition of p -Hydroxybenzoic Acid. In order to demonstrate the greater oxidizing power of the photocatalytic system and to quantify the additional levels of degradation attained, we performed experiments on the oxidation of p -Hydroxybenzoic Acid by UV radiation alone and by the TiO 2 /UV radiation combination. A kinetic model is applied for the photooxidation by UV radiation and by the TiO 2 /UV system. Experimental results indicated that the kinetics for both oxidation processes can be fitted well by a pseudo-first-order kinetic model. The second oxidation process can be explained in terms of the Langmuir–Hinshelwood kinetic model. The values of the adsorption equilibrium constant, K pHB , and the second order kinetic rate constant, k c , were 0.37 ppm −1 and 6.99 ppm min −1 , respectively. Finally, a comparison between the kinetic rate constants for two oxidation systems reveals that the constants for the TiO 2 /UV system are clearly greater (between 220–435%) than those obtained in the direct UV photooxidation.
Gautam R Desiraju - One of the best experts on this subject based on the ideXlab platform.
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synthon polymorphism and pseudopolymorphism in co crystals the 4 4 bipyridine 4 Hydroxybenzoic Acid structural landscape
Chemical Communications, 2011Co-Authors: Arijit Mukherjee, Gautam R DesirajuAbstract:Co-crystals of 4,4′-bipyridine and 4-Hydroxybenzoic Acid (1 ∶ 2) show synthon polymorphism with the former being more stable. A 2 ∶ 1 co-crystal is pseudopolymorphic within the same structural landscape with the structural roles of the two bipyridine N-atoms being distinct, as evidenced by mimicry by 4-phenylpyridine.
Jesus Beltran De Heredia - One of the best experts on this subject based on the ideXlab platform.
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oxidation of p Hydroxybenzoic Acid by uv radiation and by tio2 uv radiation comparison and modelling of reaction kinetic
Journal of Hazardous Materials, 2001Co-Authors: Jesus Beltran De Heredia, Joaquin Torregrosa, Joaquin R Dominguez, José A. PeresAbstract:Abstract The phenolic compound p -Hydroxybenzoic Acid is very common in a great variety of agroindustrial wastewaters (olive oil and table olive industries, distilleries). The objective of this work was to study the photocatalytic activity of TiO 2 towards the decomposition of p -Hydroxybenzoic Acid. In order to demonstrate the greater oxidizing power of the photocatalytic system and to quantify the additional levels of degradation attained, we performed experiments on the oxidation of p -Hydroxybenzoic Acid by UV radiation alone and by the TiO 2 /UV radiation combination. A kinetic model is applied for the photooxidation by UV radiation and by the TiO 2 /UV system. Experimental results indicated that the kinetics for both oxidation processes can be fitted well by a pseudo-first-order kinetic model. The second oxidation process can be explained in terms of the Langmuir–Hinshelwood kinetic model. The values of the adsorption equilibrium constant, K pHB , and the second order kinetic rate constant, k c , were 0.37 ppm −1 and 6.99 ppm min −1 , respectively. Finally, a comparison between the kinetic rate constants for two oxidation systems reveals that the constants for the TiO 2 /UV system are clearly greater (between 220–435%) than those obtained in the direct UV photooxidation.
David J W Grant - One of the best experts on this subject based on the ideXlab platform.
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improved tableting properties of p Hydroxybenzoic Acid by water of crystallization a molecular insight
Pharmaceutical Research, 2004Co-Authors: Changquan Calvin Sun, David J W GrantAbstract:Purpose. To understand the influence of water in the crystal structure on the compaction properties of otherwise structurally similar crystals, p-Hydroxybenzoic Acid anhydrate (HA) and the monohydrate (HM) were used as model compounds.
Arijit Mukherjee - One of the best experts on this subject based on the ideXlab platform.
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synthon polymorphism and pseudopolymorphism in co crystals the 4 4 bipyridine 4 Hydroxybenzoic Acid structural landscape
Chemical Communications, 2011Co-Authors: Arijit Mukherjee, Gautam R DesirajuAbstract:Co-crystals of 4,4′-bipyridine and 4-Hydroxybenzoic Acid (1 ∶ 2) show synthon polymorphism with the former being more stable. A 2 ∶ 1 co-crystal is pseudopolymorphic within the same structural landscape with the structural roles of the two bipyridine N-atoms being distinct, as evidenced by mimicry by 4-phenylpyridine.
