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.
Results
Showing 1 to 14 of 14 for “"pore blockage"”.
-
Roles of Background Compound Molecular Size and Adsorbent Pore Size Distribution in Competitive Adsorption on Activated Carbon
… which consisted of extensive secondary micropore and mesopore volumes, labeled as Pellet II, were evaluated for atrazine adsorption in the presence of CR in order to assess the role of PSD on competitive adsorption. The capacity for CR adsorption correlated well with pore volume between 13 …
-
Microscopic study of salt precipitation dynamics during the injection process of CO2 storage in saline aquifers
… salt precipitation during injection can clog pores and reduce permeability. Understanding the dynamics of this process, influenced by injection flow rate, pore structure, and brine properties, is crucial for optimizing CCUS strategies. This thesis examines the impact of salt precipitation on …
-
The deactivation of Zeolite-Y and mordenite during hexane cracking and propene oligomerisation
… HY and HM were chosen because of their different pore structures and acid site distributions. Hexane cracking at 1 atmosphere and high pressure propene oligomerisation provided two different reaction types. The transport properties of the catalysts were compared by measuring adsorption and …
-
Development of a Multi-Component Competitive Adsorption Model for GAC Systems and Application to Improve Hybrid Sorption -Membrane Processes
… NOM fractions- a strongly competing and a pore blocking fraction. To accurately describe GAC column adsorption, three competitive effects were needed: direct competition for sites, intraparticle pore blockage, and external surface pore blockage. COMPSORB-GAC is the first model to …
-
Interaction between membrane and protein properties on flux decline during sterile microfiltration
… these conditions was analyzed using classical pore blockage models. In general, flux decline was found to be caused by complete pore blocking. In the case of ovalbumin filtered through PVA coated PTFE, the flux decline was first caused by pore blockage and then later transitioned to cake …
-
Mechanisms of competitive adsorption between trace organic contaminants and natural organic matter on activated carbon
… capacity for target compounds, blocking of pore entrance which reduces diffusion rate of the target compounds, and covering of surface sites which may actually enhances diffusion rate of the target compounds. The objective of this dissertation study was to further elucidate the individual …
-
STUDYING THE EFFECTS OF NEW ADDITIVE MATERIALS FOR THE IMPROVEMENT OF THE CAPACITY AND CYCLE LIFE PERFORMANCE OF THE LEAD-ACID BATTERY
… due to poor active mass utilization and PbSO4 pore blockage, and the longevity of the batteries is hampered by secondary reactions during the cycle life such as corrosion and gassing.</p> <p>Lead-acid batteries were investigated and improved through several different approaches: an alternative …
-
The effect of calcium and magnesium on carbonate mineral precipitation during reactive transport in a model subsurface pore structure
… result in physical and chemical changes in the pore network. This can affect the effectiveness of various applications including carbon sequestration and in situ remediation. In this work we evaluate the precipitation kinetics of carbonates in a microfluidic pore network when carbonate in water …
-
Fouling mechanisms in the membrane filtration of single and binary protein solutions
… resistance and the membrane wall concentration. Pore blockage and narrowing occurred at somewhat higher fluxes as indicated by increases in the observed rejection. Fouling was not influenced greatly by the addition of electrolytes for microfiltration membranes but observed transmissions were …
-
Mechanism study of virus removal in membrane filtration and the application to improve virus removal
… By fitting the permeate flux decrease with the pore blockage-cake filtration model, it was determined that HAdV-2 fouled the membrane and decreased the effective membrane pore size, leading to the enhanced virus removal and the decreased permeate flux. It was also found that, the aim of high …
-
Zeolite deactivation during hydrocarbon reactions: characterisation of coke precursors and acidity, product distribution
… is due to the poisoning of the acid sites and/or pore blockage. The formation of coke on hydrocarbon processing catalysts is of considerable technological and economic importance and a great deal of work has been carried out to this study. The main aim of this work is to understand the …
-
Influence of basicity in Fischer-Tropsch synthesis over supported iron-based catalysts
… amine groups in the APTeS-modified silica. The pore radius distribution of silica is slightly shifted towards higher pore radii in comparison to APTeS-modified silica. It might thus be stated that aminopropyltriethoxysilane covers the pore walls and does not seem to result in pore blockage. …
-
Matrix Effects on Electrochemical Oxidation of PFAS in Real Wastewater Systems
… local pH near the cathode. This scaling led to pore blockage, membrane fouling, and increased internal resistance. In parallel, high chloride levels promoted the formation of reactive chlorine species (Cl2, ClO2⁻, ClO3⁻, ClO4⁻), with total ClOx⁻ concentrations reaching 0.54 mM and a free …
-
Modelling and Simulation of Membrane Bioreactors for Wastewater Treatment
… suspended solids (MLSS), SMP and EPS which cause pore blockage, cake formation, pore diameter constriction, and affect the specific cake resistance (SCR). The membrane, on the other hand, has a direct effect on the bulk liquid SMP concentration due to its SMP rejection properties. SMP are assumed …