Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 8 of 8 for “"Intraparticle diffusion"”.
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Organic-inorganic hybrid materials for arsenic adsorption : surface complexation and intraparticle diffusion
… the adsorption kinetics data, and estimate the diffusion coefficients. This study aims to develop and explore new high-performance organic-inorganic hybrid adsorbents for arsenic adsorption and evaluate the adsorption performance of the developed materials. The focuses of the study include: 1. …
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Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics
… that occur during char conversion (external diffusion, chemical reactions, and intraparticle diffusion) to determine which process limits the rate of the reaction under a range of conditions. It was determined that at most FBBG operating points, the rate of char conversion will be limited by …
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Predicting thermodynamic and transport parameters for metal contaminant sorption to hydrated metal oxides in aquatic systems
… to the external surface followed by slow intraparticle diffusion along the micropore walls. Adsorption is an endothermic physical reaction that can be represented by one average mechanism or site independent of pH and adsorbate concentration. Accordingly, the sorbed ions retain their …
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Remediation of acid mine drainage using natural zeolite
… The rate limiting step for this process was intraparticle diffusion. Column studies showed that natural zeolite was capable of removing heavy metals from a continuously flowing solution. The breakthrough time increased with a longer bed height and slower flow rate. The bed depth service time …
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Heterogeneous catalyzed macromolecular hydrogenations in oscillating systems
… mass transfer; rather it arised from improved intraparticle mass transfer limitations or surface wetting. Sereo-selectivity was largely unaffected by the reactor system but was instead dependent on intraparticle diffusion lengths.
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Modeling contaminant transport and fate and subsequent impacts on ecosystems
… as well as oxide coatings, demonstrated that intraparticle diffusion is the rate-limiting mechanism in the sorption process, where best-fit surface diffusivities ranged from 10^{-18} to 10^{-15} cm^2 s^{-1} Intraparticle surface diffusion was incorporated into the Groundwater Modeling System …
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Characteristics and mechanisms of atrazine sorption to biochar for land remediation
… transported to adsorption sites, although poor intraparticle diffusion for softwood and oil seed rape biochars can prevent efficient transport. Wheat straw and rice husk biochars showed effective pore diffusion, resulting in high sorption capacities. Partitioning was associated with poor …
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Formation and Characterisation of Nanostructured Polypyrrole Films: Their Growth on Membrane Supports and Application in Heavy Metal Remediation
… to the Morris- Weber model indicated that intraparticle diffusion may also play a role in the adsorption process.