Sökning: "retention time distribution"

Visar resultat 1 - 5 av 48 avhandlingar innehållade orden retention time distribution.

1. 1. Hydrodynamic control of retention in heterogeneous aquifers and fractured rock

   Författare :Hua Cheng; Vladimir Cvetkovic; Chin-Fu Tsang; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aquifer; Fracture; groundwater; First-order solution; Monte-Carlo simulation; Nu-clear waste; Heterogeneity; Retention processes; Matrix diffusion; Prediction; Evaluation; Travel time; Flow rate; ; Water engineering; Vattenteknik;

   Sammanfattning : In this thesis, fluid flow and solute transport in heterogeneous aquifers and particularly in frac-tured rock have been investigated using Lagrangian Stochastic Advective-Reaction (LaSAR) framework. The heterogeneity of the aquifer structure or fracture configuration, as well as the various reaction/retention processes have been considered in the modelling approach. LÄS MER

3. 2. Effects of Flow Structure on Particle Separation in Dissolved Air Flotation

   Författare :Måns Lundh; Institutioner vid LTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; plasma; Environmental technology; pollution control; Miljöteknik; kontroll av utsläpp; Gases; fluid dynamics; plasmas; Gaser; fluiddynamik; Teknik; Technological sciences; modelling; retention time distribution; acoustic doppler velocimeter; flow structure; separation; water treatment; wastewater treatment;

   Sammanfattning : Dissolved Air Flotation (DAF) is a separation process in water and wastewater treatment. The removal function is based on reducing the density of the particle by producing aggregates of the particles and added micro-bubbles of air, thus lifting the aggregates to the water surface, where they can be removed as sludge. LÄS MER

4. 3. Metal accumulation by plants : evaluation of the use of plants in stormwater treatment

   Författare :Åsa Fritioff; Maria Greger; Lena Kautsky; Bert Wolterbeek; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Elodea canadensis; Potamogeton natans; uptake; translocation; distribution; toxicity; salinity; temperature; and leakage; Plant physiology; Växtfysiologi;

   Sammanfattning : Metal contaminated stormwater, i.e. surface runoff in urban areas, can be treated in percolation systems, ponds, or wetlands to prevent the release of metals into receiving waters. Plants in such systems can, for example, attenuate water flow, bind sediment, and directly accumulate metals. LÄS MER

5. 4. Long-term metal retention processes in a peat bog : Field studies, data and modelling

   Författare :Kristina Syrovetnik; Ivars Neretnieks; Bert Allard; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Peat; heavy metals distribution; sequential extraction; binding mechanisms; modelling; metal sulphide oxidation; aqueous composition; sorption; humic substances; ferric oxyhydroxide; Chemical engineering; Kemiteknik;

   Sammanfattning : The study was inspired by the need to assess long-term metal retention in municipal solid waste (MSW) landfills. The long-term processes in landfills are poorly known due to the relatively short time that such landfills have been in existence. Natural analogues where similar metal binding processes could be expected were therefore sought for. LÄS MER

7. 5. An Analytical Solution Applied to Heat and Mass Transfer in a Vibrated Fluidised Bed Dryer

   Författare :Apolinar Picado; Joaquín Martínez; Göran Lindbergh; Ivars Neretnieks; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Analytical solution; Heat and mass transfer; Temperature and moisture distribution; Drying modelling; Multicomponent drying; Drying selectivity; Volatile retention; Ternary mixture; Drying of particulate materials; Vibrated fluidised bed dryer; Chemical engineering; Kemiteknik;

   Sammanfattning : A mathematical model for the drying of particulate solids in a continuous vibrated fluidised bed dryer was developed and applied to the drying of grain wetted with a single liquid and porous particles containing multicomponent liquid mixtures. Simple equipment and material models were applied to describe the process. LÄS MER