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Theoretical and Empirical Modeling of Flow, Strength, Leaching and Micro-Structural Characteristics of V Shaped Porous Ceramic Water Filters
Plappally, Anand Krishnan

2010, Doctor of Philosophy, Ohio State University, Food, Agricultural and Biological Engineering.
Clay based ceramic materials have been used in various parts of the world as a medium to purify and store water at points of use. United Nations and several other non governmental agencies are distributing these sustainable clay ceramic filters with embedded organic or carbonaceous materials to areas with scarcity of potable water. For example, rural areas in developing low income economies, disaster relief operation during flooding and many more on the list.
Several studies have taken place on these clay ceramic filters. There is a large amount of literature documented on the flow behavior through these clay ceramic filters, field studies on microbial removal effectiveness, structural damage of filters while in use and during transport, people/societies satisfaction and health impact of using these ceramic filters.
Here gravity operated frustum shaped clay ceramic filter have been manufactured using distinct volume ratios of clay and sawdust (organic material). This study has been done in order to individually assess the material parameter influencing flow, leaching and strength of these clay composite filters.
Reduction in flow is seen with time and filtration events imposing the need for scrubbing/cleaning of these filters. Similarly with fractional changes in embedded organic / carbonaceous material, there is a change in micro-structural and mechanical properties. Micro-structural, flow and mechanical characteristics change geo-spatially due to non availability of similar raw material constituents at different locations around the globe.
Functional challenges such as water contaminants, material composition are not the same everywhere. In this situation it is a must to investigate the stochastic effects on micro-structural, filtration flow/percolation and mechanical properties of these ceramic clay materials.
The cumulative flow has been modeled using a multi-parameter stochastic multiplicative model with time and volume fraction of the organic raw material used in the initial manufacture of the filter. The asymptotic regimes of cumulative discharge have been mathematically simulated using a predictor transformation for each of the different types of samples discussed. Material studies also confirmed a linear relationship between porosity and volumetric content of organic material used in the manufacture of these clay ceramics.
Mechanical properties of materials depend on the micro-structural features, compositional ratios as well as loading rates which they bear. Tensile fracture toughness development is found to follow a multiplicative behavior with respect to predictor variables like amount of organic material used for manufacturing, micro-structural porosity and applied force. Plastic flow during manufacture is found to influence mechanical properties in clay ceramics.
The alkalinity of the filtrate and its changes with time and material has been studied. Stochastic multivariate regression analysis on the principles of non equilibrium processes with respect to flow taking place through the filters has been used to provide extension to regression hypothesis proposed by Onasager for aqueous solution and porous flow mechanics. It was found that transport processes were dependent on each other but they also varied with time without losing their interdependence.
It is to be noted that microbial transport though these micro-nano porous ceramic filters are negligible. These filters showed similar microbial removal as confirmed by different authors earlier. This phenomenon may help in reduction of health problems due to drinking water. So in order to test these filters in an economically low income society setting, these filters were introduced in Eweje Village, Ogun State, Nigeria. A nine month survey was conducted with an objective to find the independent variables which may influence health in areas where these filter are being utilized. It was found that time of filter usage, traditional medicinal knowledge/medical facility access and money were the top influencers of health in Eweje Village, Ogun State, Nigeria.
Alfred Soboyejo, PhD (Advisor)
Larry Brown, PhD (Advisor)
Winston Soboyejo, PhD (Advisor)
Ann Christy, PhD (Committee Member)
Lingying Zhao, PhD (Committee Member)
243 p.

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Plappally, A. (2010). Theoretical and Empirical Modeling of Flow, Strength, Leaching and Micro-Structural Characteristics of V Shaped Porous Ceramic Water Filters. (Electronic Thesis or Dissertation). Retrieved from https://etd.ohiolink.edu/

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Plappally, Anand. "Theoretical and Empirical Modeling of Flow, Strength, Leaching and Micro-Structural Characteristics of V Shaped Porous Ceramic Water Filters." Electronic Thesis or Dissertation. Ohio State University, 2010. OhioLINK Electronic Theses and Dissertations Center. 19 Nov 2018.

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Plappally, Anand "Theoretical and Empirical Modeling of Flow, Strength, Leaching and Micro-Structural Characteristics of V Shaped Porous Ceramic Water Filters." Electronic Thesis or Dissertation. Ohio State University, 2010. https://etd.ohiolink.edu/

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