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Yanjun Xie - One of the best experts on this subject based on the ideXlab platform.

  • degradation of wood veneers by fenton reagents effects of 2 3 Dihydroxybenzoic Acid on mineralization of wood
    Polymer Degradation and Stability, 2012
    Co-Authors: Yanjun Xie, Lothar Klarhofer, Carsten Mai
    Abstract:

    Pine sapwood veneer strips were subjected to Fenton's reagent (hydrogen peroxide and iron ions) without and in the presence of the iron chelator 2,3-Dihydroxybenzoic Acid (DHBA). Incubation was carried out in water (unbuffered) and in acetate buffer in order to assess the effect of the oxidising systems on the weight loss and tensile strength loss as well as on the mineralisation of wood. A great amount of carbon dioxide was produced during the incubation and revealed that organic substances (wood, DHBA, and acetate buffer) were mineralized due to Fenton's reaction. The degree of oxidative wood degradation by Fenton's reagent was greater in the buffered solutions than in the aqueous solutions. DHBA accelerated the decomposition of H2O2 in the solution but reduced the loss in weight and tensile strength and the degrees of mineralization of wood as compared to the system without DHBA.

Carsten Mai - One of the best experts on this subject based on the ideXlab platform.

  • degradation of wood veneers by fenton reagents effects of 2 3 Dihydroxybenzoic Acid on mineralization of wood
    Polymer Degradation and Stability, 2012
    Co-Authors: Yanjun Xie, Lothar Klarhofer, Carsten Mai
    Abstract:

    Pine sapwood veneer strips were subjected to Fenton's reagent (hydrogen peroxide and iron ions) without and in the presence of the iron chelator 2,3-Dihydroxybenzoic Acid (DHBA). Incubation was carried out in water (unbuffered) and in acetate buffer in order to assess the effect of the oxidising systems on the weight loss and tensile strength loss as well as on the mineralisation of wood. A great amount of carbon dioxide was produced during the incubation and revealed that organic substances (wood, DHBA, and acetate buffer) were mineralized due to Fenton's reaction. The degree of oxidative wood degradation by Fenton's reagent was greater in the buffered solutions than in the aqueous solutions. DHBA accelerated the decomposition of H2O2 in the solution but reduced the loss in weight and tensile strength and the degrees of mineralization of wood as compared to the system without DHBA.

Martin R Roop - One of the best experts on this subject based on the ideXlab platform.

C M Suter - One of the best experts on this subject based on the ideXlab platform.

Sekh Mahiuddin - One of the best experts on this subject based on the ideXlab platform.

  • Adsorption of substituted benzoic Acids onto α-Al2O3 surface in mixed-adsorbate mode: 2,4-Dihydroxybenzoic Acid, 2,6-Dihydroxybenzoic Acid and 1,2,4-benzenetricarboxylic Acid (trimellitic Acid)
    Journal of Environmental Chemical Engineering, 2017
    Co-Authors: Jyotirmoy Sarma, Sekh Mahiuddin
    Abstract:

    Abstract Influence of position and type of functional groups ( COOH and phenolic OH groups) in a benzene ring on the adsorption of three natural organic matter (NOM) analogues e.g. 2,4-Dihydroxybenzoic Acid (2,4-DHBA), 2,6-Dihydroxybenzoic Acid (2,6-DHBA) and trimellitic Acid (1,2,4-benzenetricarboxylic Acid) onto α-alumina surface are explored in terms of adsorption kinetics and isotherms in single- and mixed-adsorbate mode. Focusing at the positional functional groups, adsorption profile of 2,4-DHBA and 2,6-DHBA is compared in single- and mixed-adsorbate mode. 2,4-DHBA produces higher adsorption density than 2,6-DHBA in both single- and mixed-adsorbate mode, governing factor is the ortho-para position of phenoilc OH group in 2,4-DHBA for higher adsorption density. Concerning type of functional groups, adsorption profile of 2,4-DHBA is also compared with trimellitic Acid. Here again 2,4-DHBA produces higher adsorption density than trimellitic Acid in single-adsorbate mode. In contrast, in mixed-adsorbate mode both adsorbates exhibit roughly equal adsorption densities indicating competition of co-operative nature, which is also supported by their activation energy values in mixed-adsorbate mode. Nevertheless, there exists a competition for the same surface sites of α-alumina that results in reduction of adsorption densities in mixed-adsorbate mode than that of the single-adsorbate mode.

  • Specific ion effect on the point of zero charge of α-alumina and on the adsorption of 3,4-Dihydroxybenzoic Acid onto α-alumina surface
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014
    Co-Authors: Jyotirmoy Sarma, Sekh Mahiuddin
    Abstract:

    Abstract In the scope of adsorption of simple organic Acid at the mineral oxide–water interface that represent natural ecosystem, adsorption of 3,4-Dihydroxybenzoic Acid onto α-alumina is explored in the presence of different salts at pH 5 and 7. The adsorption isotherms showed a critical salt concentration (in the present system it is 0.025 mM) that demarcates positive and negative effects of different salts on the adsorption densities of 3,4-Dihydroxybenzoic Acid onto α-alumina surface. The theoretical origin of specific ion effects below and above the critical salt concentration is likely to be different. Nevertheless, at higher salt concentration the polarizability of ions is reasonably accounted for the specific ion effects.

  • adsorption comparison at the α alumina water interface 3 4 Dihydroxybenzoic Acid vs catechol
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011
    Co-Authors: Jayanta M Borah, Jyotirmoy Sarma, Sekh Mahiuddin
    Abstract:

    Abstract Adsorption kinetics and isotherms and the surface complexation of 3,4-Dihydroxybenzoic Acid (3,4-DHBA) and catechol at the α-alumina/electrolyte interface were investigated. The state of equilibrium for adsorption of 3,4-DHBA onto α-alumina surface at pH 5 was attained at 120 min, whereas it was 90 min for catechol, but at pH 10 the state of equilibrium for the both the systems was same (∼60 min). The pseudo-second-order kinetic equation of nonlinear form (Eq. (3) ) fits the experimental kinetic data significantly better than the linear form (Eq. (2) ) in the entire time duration. The adsorption density of 3,4-DHBA onto the α-alumina surfaces at pH 10 and at similar experimental conditions is equivalent to catechol. DRIFT spectra indicate that 3,4-DHBA forms both outer- and inner-sphere complexes and catechol forms bidentate mononuclear complex with the α-alumina surface.