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Srinivasan, Priyavardhana. "NANOFIBER INCORPORATED GLASS FIBER FILTER MEDIA." University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1124903310.
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Raghavan, Bharath Kumar. "Nanofiber Filter Media for Air Filtration." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1279744866.
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Brika, Bashir. "Investigation of geometric properties of media particles for floating media filter." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5161.
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Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: In a floating medium filter, polymeric beads with a density less than that of water form a floating bed which removes suspended material. Polyolefinic beads (polypropylene and polyethylene) are commonly used as filter media in this application. The geometric properties of the beads, and to a lesser extent the surface properties, strongly influence the performance of the filter. In the case of water treatment, the primary performance requirement is the production of a filtrate with turbidity ≤ 1.0 NTU. The influence of geometric properties on the performance of existing upflow filtration systems has not been extensively researched. The aim of this thesis was therefore to investigate the effects of floating medium granule size and shape on the performance of the floating medium filter (FMF). Towards this goal a pilot plant consisting of a dosing and flocculation unit and a clear PVC column with an inner diameter of 0.3 m and height of 2.8 m was designed and constructed, allowing the effect of media type, bed depth and filtration conditions to be investigated. Artificial feed water for use during the experimental work was made up by dissolving 250 mg/L of bentonite in tap water (≈ 60 NTU). Four median grain sizes (d50 = 2.28, 3.03, 3.30, and 4.07 mm) of polypropylene plastic granules were used. Two media shapes (cubic and disc) were evaluated. The effect of filtration rising velocity, medium depth, and coagulant chemical dosage were investigated using a complete 23 full factorial experimental design. Filter performance was evaluated in terms of filtrate turbidity and headloss development. The direction of filtration was upward in all the experiments. It was found that optimal conditions for turbidity removal were low filtration rate (36.8 L/m2· min), longer media depth (0.6 m) and optimum coagulant dose (23 mg/L). At these conditions the best medium was the one with d50 = 2.28 mm, for which a minimum turbidity of 0.4 NTU was achieved, and which was able to provide 624 L of filtrate of ˂ 1.0 NTU using a bed of 0.014 m3. For this medium headloss was 109 mm H2O at breakthrough, while the other three media showed a headloss of 42 mm H2O at breakthrough. Visual observation indicated that removal of solids took place primarily in the first 0.3 m of the floating bed in the case of the smallest medium, but that solids removal took place over the full depth of the bed for the other three media. It was found that bed depth had the strongest influence on performance for a given medium type. Experimental observation showed that coagulant dosage played an important role in floc size. A higher coagulant dosage (23 mg/L) resulted in a larger floc size which gave better performance. A lower velocity gradient was favourable for the formation of larger flocs. Some effect of media shape was noted, although it appeared that media size was dominant. It is concluded that FMF show promise for application in the water treatment. FMF, however, can be applied successfully as pre-filtration unit for treatment of high turbid water. Proper medium selection in conjunction with operating conditions can enhance performance of the filter. Smaller medium would give better turbidity removal but high headloss development and more frequent backwashing becomes necessary than with larger medium.
AFRIKAANSE OPSOMMING: In ʼn dryfmediumfilter vorm polimeriese korrels met ʼn laer digtheid as dié van water ʼn dryfbedding wat swewende materiaal verwyder. Poli-olefiniese korrels (polipropileen en poliëtileen) word algemeen in hierdie toepassing as filtermedia aangewend. Die geometriese kenmerke, en in ʼn mindere mate die oppervlakkenmerke, van die korrels het ʼn groot invloed op die funksionering van die filter. In geval van waterbehandeling is die hooffunksioneringsvereiste die produksie van ʼn filtraat met ʼn troebelheid van ≤ 1.0 NTU (“nephelometric turbidity units”). Die invloed van die geometriese kenmerke van filtermedia op die funksionering van bestaande stroomop-filtreerstelsels is nog nie omvattend nagevors nie. Die doel van hierdie tesis is dus om ondersoek in te stel na die uitwerking van die korrelgrootte en -vorm van ʼn dryfmedium op die funksionering van die dryfmediumfilter (DMF). Hiervoor is ʼn proefaanleg met ʼn doseer- en uitvlokkingseenheid sowel as ʼn deursigtige pilaar van polivinielchloried (PVC) met ʼn binnedeursnee van 0.3 m en ʼn hoogte van 2.8 m ontwerp en gebou, met behulp waarvan verskillende mediumtipes, beddingdieptes en filtreeromstandighede ondersoek kon word. ʼn Kunsmatige watertoevoer vir die proefneming is vervaardig deur 250 mg/L bentoniet in kraanwater op te los (≈ 60 NTU). Polipropileenplastiekkorrels met vier verskillende deursneë (d50 = 2.28; 3.03; 3.30 en 4.07 mm) is gebruik, en twee mediumvorms (kubus- en skyfvormig) is beoordeel. Die uitwerking van filtrasiestygsnelheid, mediumdiepte en die dosis koaguleermiddel is met behulp van ʼn volledige 23-faktoriaalontwerp ondersoek. Filterfunksionering is aan die hand van filtraattroebelheid en verlies aan drukhoogte beoordeel. Alle proefnemings is teen ʼn opwaartse filtrasierigting uitgevoer. Daar is bevind dat die beste omstandighede vir die verwydering van troebelheid ʼn lae filtrasiekoers (36.8 L/m2 per minuut), ʼn groter mediumdiepte (0.6 m) en ʼn optimale dosis koaguleermiddel (23 mg/L) is. In hierdie omstandighede was die beste medium die een met ʼn d50 van 2.28 mm, waarvoor ʼn minimum troebelheid van 0.4 NTU verkry is, en wat 624 L filtraat van 1.0 NTU met behulp van ʼn bedding van 0.014 m3 kon lewer. By deurbraak het hierdie medium egter ʼn drukhoogteverlies van 109 mm H2O getoon, teenoor die ander drie media se 42 mm H2O op dieselfde punt. Visuele waarneming dui daarop dat, met die kleinste medium, vaste stowwe hoofsaaklik oor die eerste 0.3 m van die dryfbedding verwyder is, teenoor die volle diepte van die bedding vir die ander drie media. Beddingdiepte blyk dus die grootste invloed te hê op funksionering wat enige bepaalde mediumtipe betref. Proefwaarneming toon dat die dosis koaguleermiddel ʼn belangrike rol in vlokgrootte speel. ʼn Hoër dosis koaguleermiddel (23 mg/L) het ʼn groter vlokgrootte en dus beter funksionering tot gevolg. ʼn Laer stygsnelheid blyk ook die beste te wees vir die vorming van groter vlokke. Hoewel mediumvorm oënskynlik ʼn mate van ʼn rol speel, is mediumgrootte eerder die dominante faktor. Volgens die studie blyk DMF belowend vir aanwending in waterbehandeling te wees, veral as voorfiltreereenheid vir die behandeling van baie troebel water. Behoorlike mediumkeuse saam met die regte bedryfsomstandighede kan die funksionering van die filter verder verbeter. Kleiner media sal troebelheid beter verwyder, maar het ʼn groot verlies aan drukhoogte tot gevolg, en sal dus meer gereelde terugspoeling as groter media verg.
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Rautenbach, Jeremy Brian. "Improving production yields in bio-pharmaceutical filter media." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111937.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, in conjunction with the Leaders for Global Operations Program at MIT, 2017.Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, in conjunction with the Leaders for Global Operations Program at MIT, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 89-91).
This thesis presents methods to identify sources of variation in rolled goods manufacturing by defining the critical input process parameters, and the application of statistical process control. Sources of variation are prioritized according to a process control hierarchy, and reduced or eliminated through iterative cycles of rapid experimentation. This work emphasizes the value of team work, breaking down the organizational barriers between departments, knowledge sharing and the importance of a scientific approach to problem solving. FilterCo manufactures and assembles filter media catering to the ultrafiltration market growing at ~12% over the next five years. In a high growth scenario, production yield variability presents on-time delivery complications while below target yields drive significant scrap value. As FilterCo seeks to improve product lead time for its customers, while reducing WIP inventory, it must seek to maximize OEE with respect to product yield, equipment performance and availability. The variation identification, reduction and process control methodologies presented in this thesis are demonstrated to advance the goal of reducing production yield variation. The impact of the work has been verified on three filter media grades and have shown ~40% reduction in production yield variation, and rolled throughput yield improvements of ~30%. These improvements on the three membrane grades alone have resulted in an annualized saving equivalent to 60% of the total 2015 scrapped membrane value.
by Jeremy Brian Rautenbach.
S.M.
M.B.A.
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Dharmanolla, Sailaja. "A Computer Program for Filter Media Design Optimization." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1184095014.
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Arouni, Hamidreza. "Nonwoven coalescing fuel-water filter media for diesel engines." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/18692/.
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Fuel-water filters are a promising solution for the removal of water from diesel fuel and frequently rely on a depth coalescing nonwoven medium and a barrier mesh. Water is a fuel contaminant that can cause severe damage to engine injectors by promoting corrosion and microbial growth. Coalescing water out of diesel fuel has become challenging because of the increasing amount of bio-diesel and performance enhancing additives that are present to meet emission control regulations. High water content and the reduction in interfacial tension (IFT) between the water and diesel are associated with formation of more stable emulsions and the generation of smaller water droplets that are harder to remove. This research systematically investigates the characteristics of bio-diesel and surfactant (monoolein) blends with standard diesel fuel, and explores the factors affecting the efficient removal of water from fuel by means of depth coalescing media composed of poly(butylene terephthalate) (PBT) meltblown fabrics. It was established that bio-diesel and monoolein do not influence the IFT of water in fuel in a comparable manner and the resulting water droplet size distributions (DSD) are substantially different, which has implications in terms of the interpretation of results from commonly used ISO and SAE standard test methods. Fuels blended with bio-diesel exhibited higher viscosity and water content than fuel freshly blended with monoolein. Online measurement of water droplet sizes revealed substantially smaller water droplets in bio-diesel blends compared to monoolien blends at the same IFT measured using offline tensiometry. The surface wetting characteristics of PBT meltblown media were modified by alkaline hydrolysis independently of fabric geometric configuration and treated fabrics exhibited greater coalescence efficiencies (up to a 150% increase) but a lower quality factor than untreated samples due to a higher pressure drop attributed to increased water retention. The optimal wetting behaviour of fibres for achieving maximal coalescence efficiency was not the same for reference diesel and fuel containing surfactant, i.e. monoolein. A universal filter medium with a high coalescence performance cannot therefore be readily achieved if based solely on tuning fibre wetting properties. It was found that the fundamental trade-off between coalescence efficiency and pressure drop could be addressed by dynamic modification of fabric porosity (from 93% to 98%). By enabling fabric dimensions and geometric configuration to be modified in forced flow conditions, improvements in both coalescence efficiency (up to a 150% increase) and quality factor (up to 99 times greater) compared to the control flat sheet filter samples were achieved for both bio-diesel and monoolein-blended fuels.
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Hosseini, Seyed Alireza. "MODELING PARTICLE FILTRATION AND CAKING IN FIBROUS FILTER MEDIA." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/2530.
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This study is aimed at developing modeling methodologies for simulating the flow of air and aerosol particles through fibrous filter media made up of micro- or nano-fibers. The study also deals with modeling particle deposition (due to Brownian diffusion, interception, and inertial impaction) and particle cake formation, on or inside fibrous filters. By computing the air flow field and the trajectory of airborne particles in 3-D virtual geometries that resemble the internal microstructure of fibrous filter media, pressure drop and collection efficiency of micro- or nano-fiber filters are simulated and compared with the available experimental studies. It was demonstrated that the simulations conducted in 3-D disordered fibrous domains, unlike previously reported 2-D cell-model simulations, do not need any empirical correction factors to closely predict experimental observations. This study also reports on the importance of fibers’ cross-sectional shape for filters operating in slip (nano-fiber filters) and no-slip (micro-fiber filters) flow regimes. In particular, it was found that the more streamlined the fiber geometry, the lower the fiber drag caused by a nanofiber relative to that generated by its micron-sized counterpart. This work also presents a methodology for simulating pressure drop and collection efficiency of a filter medium during instantaneous particle loading using the Fluent CFD code, enhanced by using a series of in-house subroutines. These subroutines are developed to allow one to track particles of different sizes, and simulate the formation of 2-D and 3-D dendrite particle deposits in the presence of aerodynamic slip on the surface of the fibers. The deposition of particles on a fiber and the previously deposited particles is made possible by developing additional subroutines, which mark the cells located at the deposition sites and modify their properties to so that they resemble solid or porous particles. Our unsteady-state simulations, in qualitative agreement with the experimental observations reported in the literature, predict the rate of increase of pressure drop and collection efficiency of a filter medium as a function of the mass of the loaded particles.
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Andersen, Erin R. "Thallium Removal from Drinking Water Using Pyrolusite Filter Media." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7399.
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Thallium (Tl) is a rare heavy metal in drinking water, but its extreme toxicity makes its removal crucial to consumer health. Traditional treatment methods do not work for Tl in sources with high concentrations of ions like calcium (Ca+2) and potassium (K+), as they are removed preferentially to Tl. A treatment method that specifically targets Tl must be applied. Pilot studies conducted in Park City Utah found that pyrolusite, a manganese oxide ore, will remove Tl to very low concentrations in the presence of competing ions but because this method is not common, further study was required. This study investigated the mineral composition of the pyrolusite and where, within the material, Tl was held. Calcite is known to accumulate Tl so tests were done looking at Tl accumulation onto pyrolusite with and without calcite on the surface in three water qualities: one with high pH and chlorine (Cl2) and low concentrations of the interfering ions Ca, K, chloride (Cl-) predicted to promote Tl removal, one with low pH and Cl2 and high concentrations of interfering ions predicted to limit Tl removal, and one with a moderate pH used for comparison. The likelihood of this Tl to stay on the media surface with changes in water chemistry was also tested. It was seen that Tl does accumulate in calcite on the media surface. Both pyrolusite media showed a high capacity for Tl and media without calcite exhibited a preference for Tl over K. Calcite dissolved with changes in pH which led to the conclusion that its formation on the media surface must be closely monitored as it may increase the risk Tl release into the drinking water system.
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Moorthy, Kavitha. "EFFECT OF SURFACE ENERGY OF FIBERS ON COALESCENCE FILTRATION." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1185554340.
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Cescon, Anna. "Assessment of alternative filter media in single and dual media configuration for drinking water treatment." Thesis, Glasgow Caledonian University, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.743902.
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Cucarella, Cabañas Victor. "Phosphorus recycling from wastewater to agriculture using reactive filter media." Licentiate thesis, KTH, Land and Water Resources Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4449.
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This thesis focused on testing the suitability of reactive filter media used for phosphorus (P) removal from wastewater as fertilizers, thus recycling P to agriculture. The work compared the P sorption capacity of several materials in order to assess their suitability as a source of P for plants. The selected materials (Filtra P, Polonite and wollastonite) were saturated with P and used as soil amendments in a pot experiment. The amendments tended to improve the yield of barley and ryegrass compared with no P addition. The amendments also increased soil pH, P availability and cation exchange capacity in the studied soils. The substrates studied here can be of particular interest for acid soils. Of the materials studied, Polonite appears to be the most suitable substrate for the recycling of P from wastewater to agriculture
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Cucarella, Cabañas Victor. "Phosphorus recycling from wastewater to agriculture using reactive filter media /." Stockholm : Mark- och vattenteknik, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4449.
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Kent, Tanya Denise. "The effect of media size on biological aerated filter performance." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287176.
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Davies, Phillip D. "Alternative filter media in rapid gravity filtration of potable water." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/12183.
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Sand has been the main filter media used in rapid gravity filtration since their emergence in the 19th century. This dominance is due to its low cost, availability and extensive experience which has led to dependable and predictable performance. Over recent years multi-media filters have become the typical filter arrangement. Sand still remains the preferred filter medium in the lower layer with typically anthracite used in the upper layer. A limitation to match previous work has been the emphasis on overall performance but mechanistic analysis as to the reasons for the variations compared to sand has been rare. The fundamental effects of particle size and consolidation on filtration performance and headloss are known but were not often accounted for in the reported research. This has limited the academic contribution of previous work and made it more difficult to compare with the data for this thesis. At an average treatment works the highest costs are associated with the use of chemicals (30 %) and power (60 %) required mainly for pumping. Rapid gravity filters are one of the least energy demanding stages in this system, only requiring pumping for backwashing and air scour, assuming gravity feed was incorporated into the design. Energy efficiency of water treatment has become more important and the research was conducted to determine if the use of novel new media could be used to improve the performance of the filters with regards to turbidity and headloss. For example, the result presented within this thesis demonstrates through the use of angular media improved performance to benefit both turbidity and headloss performance. This was obtained from slate having a sphericity of 0.49 compared to sand at 0.88. In addition the use of novel materials with different physical properties has allowed an extension to analysis of performance using fundamental filtration mechanisms. The greater range of properties available from the novel media used in this thesis compared to sand has suggested additions to this theory. The use of surface reactive materials, including limestone, has shown the removal of additional contaminants such as phosphorus, iron, aluminium and manganese not typically associated with rapid gravity filtration. An assessment of the impact these reactions had on typical filter performance criteria, for example turbidity, headloss and life expectancy. The results showed an 97 % removal of Fe in the limestone compared to 13 % for sand. This was brought about by the precipitation of hydroxide, coagulation, a pH change and consequent co-precipitation. In the case of iron and aluminium removal this pH induced change was theorized as the most likely cause of coagulation within the filter bed itself leading to improved turbidity removal performance. Filter media chosen for laboratory and pilot study in this work was firstly assessed using British Standards tests, but additional tests were added that could provide additional characterisation data. The media were selected based on an individual fundamental property that differed from the other media selected whilst retaining the standard RGF size. Filtralite for example offered a high surface area, limestone a more active surface and slate a plate-like particle shape. Glass had a very smooth surface texture and as a recycled material better sustainability. Four of these filter media (Sand (control), Glass, Filtralite and Slate) were then selected for further on-site pilot plant studies, based on results from the laboratory work. Both the laboratory and pilot study suggested that turbidity and headloss performance could be improved by changes in media specification. The results showed that after particle size, angularity of the media was the most important factor affecting turbidity and headloss performance. A greater angularity led to improvements in filter run time with for example a doubling of filter run time with the slate compared to sand for the same turbidity removal in the pilot plant. Previous literature had suggested an improvement in turbidity performance but that head loss would deteriorate but this was not seen in the data from this research, with slate (sphericity of 0.49) offering improved headloss performance. This improvement was attributed to the varied packing of the filter bed and associated porosity variations throughout the filter. The objectives of the pilot study were to provide understanding of scale-up factors and adjust these theories with real variable clarified water. Real water chemistry is too complex to model and enabled experiments more typical of the variation that a rapid gravity filter would encounter. The pilot plant is 0.07 % the plan area of a full scale filter compared to the 0.01 % of the laboratory columns. Results corroborated the laboratory work on the effect of extreme particle shapes on filter performance. The pilot study also highlighted problems from floc carry over with the use of clarified water and quantified the impact it had on filtration performance. In this case floc carryover changed the performance of the pilot plant results significantly. Thus an overall conclusion from the work was that an integrated design approach to filters, to account for the clarifier type the likelihood of floc carryover and raw water anticipated could be further researched. There were also limitations to the current monitoring equipment that could not quantitatively measure the floc carryover because of large particle size.
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DePalma, Julia E. "The Filter: Social Media and Their Effects on Human Interaction." Kent State University Honors College / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1525694435239416.
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Vafai, Fereydoon. "Analytical modelling and laboratory studies of particle transport in filter media." Online version, 1996. http://bibpurl.oclc.org/web/23534.
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Volooj, Shinenemekh. "Investigation into the wet processing of keratin fibres and filter media." Thesis, University of Manchester, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501954.
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The aim of this research was to minimise the damage of keratin fibres during wet chemical processing including dyeing and bleaching, and to recycle the bleach and dyebath water using microfiltration technique. Low temperature dyeing of cashmere fibres using Miralan TOP process provided sufficient dye exhaustion at lower temperatures compared to conventional Lanaset dyeing system, which resulted in superior strength properties of fibres dyed by Miralan TOP process.
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Hamisi, Rajabu. "Modelling phosphorus dynamics in constructed wetlands upgraded with reactive filter media." Licentiate thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-207613.
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Developing low-cost and effective technologies to upgrade phosphorus (P) removal from the catchment runoffs and rural wastewater treatment facilities is one of the main research agendas to save the Baltic Sea from eutrophication. In Sweden, the construction of the constructed wetlands has been one of the environmental objectives for wastewater quality improvement in the small communities. However, the insufficiently understanding of the mechanisms underlying the process of phosphorus mobility and sorption in the constructed wetlands has limited design of the effective constructed wetlands. To provide the better understanding of sorption process in the catchment and constructed wetland system, this thesis used the GIS-based Soil and Water Assessment Tool (SWAT) to predict phosphorus mobility and identify the critical diffusing sources of phosphorus loss in the Oxunda catchment (Paper I). Then, the study developed the three-dimensional numerical Reactive TRAnsPort Model (RETRAP - 3D) in the COMSOL Multiphysics® for evaluating the long - term sorption processes and removal efficiencies of the porous reactive media for upgrading the performance of constructed wetlands (Paper II and III). The latter model coupled many physics equations to solve process of water flow, reaction kinetics and solute transport in the porous reactive adsorbent media for application in the constructed wetlands. The data from the field measurements and column experiments have been used to demonstrate the model simulation accuracy to capture the process of phosphorus sorption in the real environment. Modeling results ranked the phosphorus removal efficiency of the adsorbent media as follows: Polonite® (88 %), Filtralite P® (85%), BFS (62%), Wollastonite (57 %). The satisfactory agreement which obtained between the simulated outputs and measured data confirmed that the SWAT and RETRAP-3D are useful tools for describing various processes in the complicated system. However, further study is required to generate and validate more experimental data to evaluate the sensitivity of local parameters.This reserch project was finacially supported by Lars Erik Lundberg scholarship foundation for projectnumber (2015/34 and 2016/12), ÅkeochGreta Lissheds Stiftelsen for project number (2015-00026), J.Gust. Richert Stiftelsen and Ecopool researchproject for smart and sustainable environment. QC 20170523
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Bowerman, Alexander Scott. "PERFORMANCE OF A STORMWATER FILTER AND BACTERIA INACTIVATION USING BIOCIDAL MEDIA." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/260.
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There are many possible ways to mitigate stormwater pollution, but this study focused on the DrainPacTM catchment basin insert and the feasibility of integrating N-halamine biocidal brominated beads into the filter system. This study was divided into three sections. The first section involved testing a DrainPacTM filter for treatable flow rates, head loss, and removal of solids, oil, and bacteria. The DrainPacTM filter is designed to be installed in a stormwater catch basin. The filter is composed of a 12 x 41 inch metal frame with textile filter media attached to it in a basket shape. The upper portion of one panel of the filter basket is made from a plastic mesh to allow overflow if the filter is overloaded. The second section of this study involved testing N-halamine brominated biocidal beads in laboratory-scale columns, and the third section involved integrating the beads into the DrainPacTM filter and testing it full scale.
For the DrainPacTM filter tests, the unit was installed into a custom-built test flume which was designed to mimic the conditions that would be encountered in a real stormwater application. The flume was supplied with a gravity-fed stream of water from a retention pond located on the Cal Poly, San Luis Obispo campus. The initial tests were conducted to determine the amount of head loss produced by the filter. First, the clean filter was subjected to flow rates between 20 and 200 GPM. The filter showed very minimal head loss (0.5 to 9.1 cm for 20 to 200 GPM) when not loaded with solids. Next, the filter was subjected to 200 GPM flow with a solids concentration of between 80 and 100 mg/L until it failed (overflowed). This occurred after 625 g of solids had been added to the filter. After the filter had been loaded with solids to the point of overflow at 200 GPM, it was tested to determine what flow rate could be filtered with the solids present. The fully loaded filter was able to pass a flow rate of up to 80 GPM before overflowing.
The DrainPacTM filter removed solids at a range of efficiencies from 83 to 91% at flow rates between 20 and 200 GPM. The higher removal efficiencies were achieved at the lower flow rates. The filter removed oil at efficiencies ranging between 40 and 80%. The oil removal efficiency did not appear to depend on the flow rate. The DrainPacTM filter did not remove bacteria under the test conditions.
Following the DrainPacTM experiments, 0.3 mm and 0.8 mm diameter N-halamine brominated biocidal beads were tested in the lab using a laboratory glass column. At flow rates between 0.28 and 1.4 mL/sec, a 1 cm bed height of the 0.3 mm beads was found to produce head losses between 19 and 51.7 cm. The 0.8 mm beads produced head losses ranging from 11.9 to 47.7 cm when tested over the same range of flow rates. These flow rates represent nominal velocities between 0.36 and 1.8 cm/sec which would be expected in the DrainPacTM filter. The beads were then tested to determine how effectively they inactivate bacteria in a stream of water. Contact time after flowing through the column was found to be the key factor in how efficiently the beads worked. When the effluent samples were instantly quenched with sodium thiosulfate, the bacteria removal results matched those observed for the control (beads without bromine). When the samples were quenched directly after collection by adding the sodium thiosulfate to the sample as soon as the desired sample volume had been collected (95 to 285 seconds depending on flow rate), between 95 and over 99 percent of the bacteria were inactivated. After 10 minutes, all of the bacteria were inactivated.
The final test involved integrating the N-halamine brominated beads into the DrainPacTM filter for a full scale test. Two sleeves containing 1400 grams of beads were laid into a DrainPacTM filter which was custom built to concentrate the flow through the beads. This system was tested using pond water with an average of 298 CFU/100 mL coliform bacteria at a flow rate of 36 GPM. The results of this test were very similar to the results of the lab scale testing. Contact time again proved to be necessary for bacteria inactivation. The filter with integrated N-halamine beads removed between 72 and 100% of bacteria with contact time between 30 seconds and 10 minutes.
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Walter, Sandra L. "Optimizing the efficiency and filter area of the SurgiBox Environmental System by redistributing effective media area across filter length." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127866.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, May, 2020Cataloged from the official PDF of thesis.
Includes bibliographical references (page 46).
Across the globe, billions of people lack access to safe surgery. SurgiBox is working to lower that number by creating a portable surgical environment for patients in need. To do this, they are working to improve their air filtration system by better utilizing filter media to create a more efficient system. To help SurgiBox achieve this goal, Solidworks Flow Simulation Models were created and analysed to determine what parameters would be necessary to achieve a goal of a uniform velocity profile while meeting volumetric flow rate specifications. These models show that it is possible to achieve a uniform velocity distribution by using filters with varied resistances to air flow. It was found that, neglecting edge effects, the pressure drops (at a defined velocity) of the filter follow a linear trend across the length of the filter. However, these models also show that edge effects lead to significant air flow inconsistencies revealing that if these edge effects are not addressed, the system may quickly fall out of specification. Numerically generated "ideal" system centerline velocity and pressure curves were created to be used as comparative tools while conducting experiments on the SurgiBox system. These, in combination with the SolidWorks models will inform design changes to the SurgiBox system and help the SurgiBox team quantitativly assess the quality of their designs.
by Sandra L. Walter.
S.B.
S.B. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Yamashita, Hiroshi, Hiroyoshi Yane, Masamichi Nakamura, and Kazuhiro Yamamoto. "Simulation on catalytic reaction in diesel particulate filter." Elsevier, 2010. http://hdl.handle.net/2237/20048.
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Mofokeng, Teboho. "Full-scale trials of external nitrification on plastic media nitrifying trickling filter." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5024.
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Includes abstract.Includes bibliographical references.
In South Africa, many wastewater treatment plants (WWTP) still make us of their rock filled trickling filters. Instead of using them for organics removal and nitrification, there is growing interest in integrating them with biological excess P removal activated sludge (BEPRAS) systems in an external nitrification flow scheme (Hu et al., 2000). In such a scheme, the full influent flow (after primary settling) is discharged to the anaerobic reactor of the BEPRAS system, after which the activated sludge is separated from the water by internal settling tanks. The clarified supernatant is pumped to the trickling filter for nitrification and the activated sludge to the anoxic reactor of the BEPRAS system, where the nitrified water rejoins the main BEPRAS system. This external nitrification BEPRAS system has several advantages over continuing to use the trickling filters for organics removal and nitrification, such as significantly reduced oxygen demand (~50%) and biological N and P removal on the full wastewater flow. To date full-scale studies in South Africa have been performed only with rock media trickling filters, for example that at Daspoort WWTP (Muller et al., 2004, 2006a, b). This report describes an investigation on the full-scale operation of a plastic media nitrifying trickling filter (NTF) at the 1 Ml/d Citrusdal WWTP.
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Daido, S., H. Yamashita, S. Oohori, and K. Yamamoto. "Simulation on soot deposition and combustion in diesel particulate filter." Elsevier, 2009. http://hdl.handle.net/2237/20033.
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Ochi, Fumihiro, and Kazuhiro Yamamoto. "Soot accumulation and combustion in porous media." Maney Publishing, 2006. http://hdl.handle.net/2237/20054.
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Kulkarni, Prashant S. "Mixed Hydrophilic/Hydrophobic Fiber Media for Liquid-Liquid Coalescence." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1310686055.
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O'Connor, Caleb S. "Measurement of Dispersion and Attenuation in Granular Media using a Filter-Correlation Method." Thesis, University of Louisiana at Lafayette, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1592420.
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A wideband technique for measuring sound dispersion and frequency-dependent attenuation in granular media is presented. The measurements were done on a mono-disperse medium of 2-cm solid polypropylene balls, over the frequency range of 500 Hz-20 kHz, enough to cover both weak and strong scattering regimes. A horn driver was used to launch sound into a foam-lined bucket containing the granular medium. The latter was mechanically isolated from the driver so as to minimize direct-contact coupling. The foam isolation was not enough, especially at resonances of the bucket-granular system. In the effort to simulate a free-granular medium, the bucket was replaced with a mesh bag hanging in free space. The frequency-dependent wavenumber of the granular is obtained by a filter-correlation method. After successive bandpass filtering, the phase speed and attenuation are obtained within each band, respectively, by signal alignment and amplitude log ratio. The attenuation coefficient yielded reasonable results, illustrating the transition from ``piston-like" dynamics to the strong scattering regime, as the frequency increased. The phase speed results where more sporadic, qualitatively there is a decrease in sound speed as the frequency increases.
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Ochieng, GMM, FAO Otieno, TPM Ogada, SM Shitote, and DM Menzwa. "Performance of multistage filtration using different filter media against conventional water treatment systems." Water SA, 2004. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001748.
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Abstract
This study was aimed at introducing multistage filtration (MSF) (a combination of slow-sand filtration (SSF) and pretreatment
system - horizontal flow roughing filter (HRF)) as an alternative water treatment technology to the conventional one. A pilot- plant
study was undertaken to achieve this goal. Evaluating the MSF performance vs. the existing conventional system in removing
selected physical and chemical drinking water quality parameters together with the biological water quality improvement by the
MSF without chemical use was done. Evaluation of the effectiveness of the MSF system utilizing locally available material, i.e.
gravel, improved agricultural waste (charcoal maize cobs) and broken burnt bricks as pretreatment filter material was also done
The benchmark was the Kenya Bureau of Standards (KEBS) values for the selected parameters. Results showed that with proper
design specifications, MSF systems perform better than conventional systems under similar conditions of raw water quality and
environmental conditions. The tested locally available materials can also be effectively used as pretreatment media with each
allowing a filter run greater than 82 d and therefore could serve as alternatives where natural gravel is not readily available. With
special reference to the bacteriological quality improvement, the MSF greatly improved the bacteriological quality of the water
recording removal efficiencies of over 99% and 98% respectively for E. coli and total coliforms. Despite the observed performance,
MSF should be complemented with chlorination as a final buffer against water-borne diseases. However, in this case, the dosing
will be greatly reduced when compared to the conventional system.
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Hungate, Robert W. "Adsorption kinetics for the removal of soluble manganese by oxide- coated filter media." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43861.
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This study was conducted to examine the kinetics of
manganese sorption on oxide-coated filter media. Initial
experimentation confirmed the findings of other investigators,
the Mn2+ sorption capacity of oxide-coated media
increases as solution pH increases. Further study revealed
that uptake rate kinetics could be described by first order
kinetics and also increased with increasing solution pH.
The addition of free chlorine (HOCl) to solution greatly
enhanced Mn2+ uptake rate kinetics. Later studies indicated
that the oxide coating had very little impact on the
physical properties of the media tested.
Actual data from a water treatment plant filter confirmed laboratory experimental results by showing that sorption of soluble manganese does indeed occur on oxidecoated filters. The water treatment plant data also suggested that the sorption kinetics were relatively rapid, again upholding laboratory findings.
Results from the manganese kinetics and sorption
experiments were combined to formulate a theoretical model
which would predict manganese breakthrough in a filter,
given a known set of loading parameters. Preliminary use of
the model indicated that oxide-coated filters could sorb significant quantities of soluble manganese before
detectible levels of manganese appear in the effluent.
Master of Science
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Lachendro, Edward J. "Inactivation of surrogate bioaerosols on clean filter media by low-current electric fields." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1453568.
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Takada, Naoki, and Kazuhiro Yamamoto. "LB simulation on soot combustion in porous media." Elsevier, 2006. http://hdl.handle.net/2237/20044.
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Blackford, Marie. "Étude de nouveaux media granulaires et non tissés pour la filtration du vin." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0792.
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Les membranes et les adjuvants de filtration sont très utilisés pour la filtration des vins. Les adjuvants de filtration forment un dépôt filtrant assurant l’efficacité du filtre. Cependant ces particules ne sont pas régénérables. L’objectif de ces travaux est de proposer un media filtrant régénérable et disponible en plusieurs granulométries, afin d’être utilisé lors des différentes étapes de l’élaboration des vins. Les Rilsan® en polyamide 11 biosourcé sont étudiés et caractérisés en tant qu’alternative aux diatomites. Les résultats montrent qu’avec la gamme de Rilsan® existante il est possible d’obtenir les différents grades nécessaires pour la filtration du vin. Les distributions de tailles de particules, la formation des dépôts ainsi que les efficacités de filtration ont été déterminées. Lors de la filtration sur précouche de Rilsan® les mécanismes de rétention suivent une loi de colmatage intermédiaire des pores. Du fait de la structure non poreuse du matériau par rapport aux diatomites, leur régénération est possible et a été étudiée par hydrocyclonage. Les non-tissés ont l’avantage d’avoir de très fortes porosités ; ce qui est un atout pour obtenir des débits de filtration importants. De nouveaux media en polyamide 11 fabriqués par Electrospinning sont testés comme une alternative aux membranes actuelles, de plus faible porosité. Les diamètres de pores obtenus de l’ordre de 1,5 μm sont encore trop élevés pour envisager une stabilisation microbiologique du vin. La faible résistance mécanique des media est un frein à leur développement pour la filtration des liquides. Les perméabilités sont peu dépendantes de la dimension des pores dans la gamme testée et dépendent principalement de l’épaisseur du matériau et d’autres paramètres de fabricationMembranes and filter aids are classically used filter media throughout the wine making process. During filtration, filter aids form a precoat inducing the retention efficiency of the filter. However, these particles are not regenerable. The aim of this study is to find a cleanable and reusable alternative to existing filter aids, available in various grain-size distributions, in order to perform the different types of wine filtration. The Rilsan® powder, made of biobased polyamide 11, are characterized and studied as an alternative to diatomaceous earth mainly used for enology applications. Results showed that the range of Rilsan® allowed performing both rough and clarifying filtration. The particle size distribution, the granular bed deposition and the filtration efficiency were determined. During filtration using Rilsan® precoat, the fouling mechanisms follow an intermediate pore blocking law. According to their non-porous structure compared to diatomite, these particles are cleanable. Hydrocyclone process is studied in order to achieve this regeneration. Nonwovens have important porosities which is an asset to have high filtration flow rates. New filter media made by electrospinning process of polyamide 11 are tested as an alternative to currently used filtration membranes. The pore diameters measured of 1.5 μm are still too large to be used for wine microbiological stabilization. Their mechanical weakness is a brake to their use in liquid filtration applications. Water permeability is little influenced by the pore size, in the range of media tested, and depends mainly on the thickness of the media and other fabrication processes
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MacLure, Ryan Scott. "Performance of a Catch Basin Filter and Leachate from Biocidal Media for Stormwater Treatment." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/47.
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The feasibility of installing biocidal beads into a catch basin filter insert for simultaneous stormwater disinfection and contaminant removal was tested. The catch basin filter insert (DrainPac®) was tested for its sediment, oil and grease, and coliform bacteria removal efficiency in conjunction with bench-scale testing of biocidal polymer beads. DrainPac® catch basin filters are composed of a metal frame, polypropylene filter fabric, and a high-density polymer support basket, and are installed below storm drains. A 12 x 41 in. DrainPac® filter (United Stormwater, Inc.) insert was set in a flume that simulated a large-scale catchment basin. Pond water was gravity fed to the flume at flow rates up to 200 gpm. The pond water contained fine sediments at concentrations ranging from 30-50 mg/L. The biocidal beads were tested in a small laboratory column for potential application to stormwater treatment. The head loss through the clean filter insert varied from 0.5 cm at 20 gpm to 9.1 cm at 200 gpm. Head loss of 21.5 cm occurred after 625 g of solids were added to the filter at 200 gpm at which point water began bypassing the filter fabric and flowing through the mesh screen. The highest flow rate that could be filtered through the loaded filter was 80 gpm. The DrainPac® filter removed total suspended solids with efficiencies ranging from 83% to 91% at flow rates of 20 to 200 gpm, with higher removal efficiencies at lower flow rates. The oil and grease removal efficiency of the DrainPac® filter ranged from 40% to 82%. The DrainPac® filter exhibited no removal of coliform bacteria under these test conditions. Biocidal brominated polystyrene beads, developed by Dr. S. D. Worley at Auburn University, were tested in a 1-cm diameter laboratory column apparatus for leaching of bromine compounds, which is important for determining if the filters will meet water quality regulations of the receiving waters. Removal efficiencies of coliform bacteria were tested in a companion study by Cal Poly graduate student Alex Bowerman. Pond water was passed through a 1-cm thick bed of beads in an up-flow direction. Leachate was analyzed for bromine, bromide, and bromoform. Leaching from both 0.3-mm and 0.8-mm biocidal beads was tested in the column apparatus. Samples collected for bromoform analysis were quenched with sodium thiosulfate, and the time before samples were quenched had a drastic effect on bromoform concentrations. Samples quenched after the collection of the total sample were assumed to be the most realistic for stormwater conditions since stormwater entering catch basins isn’t immediately discharged into its receiving waters. Effluent from a 1-cm bed of 0.3-mm beads at 0.56 mL/sec contained the following average concentrations: 0.47 mg/L bromine, 2.45 mg/L bromoform, and 0.53 mg/L bromide. The same conditions for 0.8 mm beads resulted in effluent containing the following average concentrations: 0.27 mg/L bromine, 0.06 mg/L bromoform, and 0.50 mg/L bromide. The much lower concentrations of bromine measured in the 0.8-mm bead leachate was likely due to the greater surface area of the smaller beads. The greater leaching of bromoform from the 0.3 mm beads may be partly attributed to the greater surface area of the smaller beads, but also the manufacturer of the beads reported that different production methods were used for the 0.3 mm beads. Higher bromine compound concentrations were found at lower flow rates, due to the longer contact times with the beads. Deionized (DI) water that was used to initially wet the biocidal beads before passing pond water through the column was also analyzed for bromoform. The DI flush water from the 0.3 mm beads contained 1.25 mg/L bromoform at a flow rate of 0.28 mL/sec. Bromoform concentrations in the DI flush water from the 0.8 mm beads at the same flow rate were below detection. Bromoform is expected to be formed as bromine is reduced to bromide by the presence of organics. Since there are no organics present in DI water to form such high concentrations of bromoform as those found from the 0.3-mm bead DI flush water, it appears that bromoform could have leached from the surface of the 0.3 mm beads. The longevity of the bromine treatment of the biocidal beads was tested on one set of 0.3-mm beads by simulating five use cycles, and also by testing another set of beads after dry storage. Each use cycle was simulated by pumping pond water through a 1-cm bed of 0.3 mm beads at 0.56 mL/sec for one hour and then connecting the column to an air pump to dry for 23 hours. After five simulated uses, leachate from the beads showed only a slight reduction in concentrations of bromine and bromide (21% and 4% less than fresh beads, respectively), while the concentration of bromoform was nearly 100 times less. The drastic decrease in bromoform concentration suggests that after five simulated uses, much of the bromoform was exhausted or conditions for the formation of bromoform were no longer present. For the dry storage test, 0.3 mm beads were wetted with 1-L DI water and then stored dry for 162 days. Then pond water was pumped through the column at 0.56 mL/sec and the leachate was analyzed. After dry storage for 162 days, the leachate showed no reduction in bromine concentrations compared to fresh beads, a 97% reduction in bromoform, and a 30% increase in bromide concentrations. This significant reduction in bromoform could be due to the volatilization of bromoform off the surface of the 0.3 mm beads during dry storage. The 0.3 mm beads are no longer being manufactured, and leachate from the 0.8 mm beads contained bromoform at concentrations below the potable drinking water maximum contaminant level of 80 µg/L. Under all tested conditions, bromine, bromide, and bromoform are present in the leachate from the biocidal beads, and thus their applicability for stormwater disinfection depends on the longevity of the bromine compounds in receiving waters, and on the regulations governing these compounds.
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Tam, Ka-man. "Autotrophic denitrification of synthetic wastewater in biological activated filter (BAF) reactors with sulfur media." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B3878922X.
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Tam, Ka-man, and 譚家雯. "Autotrophic denitrification of synthetic wastewater in biological activated filter (BAF) reactors with sulfur media." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B3878922X.
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Park, Soo-Jin. "Catalytic Decomposition of Nitric Oxide and Carbon Monoxide Gases Using Nanofiber Based Filter Media." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1216931978.
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BARTON, JOHN M. H. "EFFECT OF MEDIA GRAIN SHAPE ON PHYSICAL CAPTURE OF PARTICLES IN A FILTER BED." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1092931427.
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Barton, John M. H. "Effect on media grain shape on physical capture of particles in a filter bed." Cincinnati, Ohio : University of Cincinnati, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1092931427.
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Wang, Qiang. "FILTER PERFORMANCE UNDER SIMULATED REAL-WORLD CONDITIONS." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4464.
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Evaluating the performance of filter media for filtration applications is essential to assure design engineers and users that filter device will deliver promised performance for specific applications under the environmental stress. The study of particle loading characteristics of filter media in the laboratory setting is typically performed under the steady flow conditions, i.e., at the constant particle concentration and flow rate. In reality, filtration products are operated under the situations that the flow rate and mass concentration of particles are varied in time. The success of translating the laboratory data to estimate the performance of filter media in the fields is thus limited. It is necessary to investigate the performance of filter media under the real-world conditions, i.e., unsteady flow rate and mass concentration to bridge the gap.
The overall goals of this research are (1) to study the performance of filter medium under unsteady conditions (i.e., the performance of respirator filter media under simulated breathing conditions); and (2) to investigate the issue of non-uniform particle deposition on HVAC filter panels. A new experimental setup was developed to accomplish the former goal. Numerical modeling tool, Computational fluid dynamics (CFD), was applied to achieve the latter objective……
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Nakamura, Masamichi, and Kazuhiro Yamamoto. "Simulation on Flow and Heat Transfer in Diesel Particulate Filter." ASME (American Society of Mechanical Engineers), 2011. http://hdl.handle.net/2237/19976.
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Davoudi, Masoume. "Aerosol Droplet Migration in Fibrous Media." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1509120181801687.
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Moberg, Mikhal. "THE EFFECTIVENESS OF SPECIFICALLY DESIGNED FILTER MEDIA TO REDUCE NITRATE AND ORTHOPHOSPHATE IN STORMWATER RUNOFF." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3677.
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Throughout Central Florida surface water and ground water are decreasing in quantity and quality in part because of excess Nitrate and Phosphorus nutrients. Stormwater runoff serves as a medium for transport of Nitrate and Phosphorus to surface water and ground water. The goal of this experiment is assess the Nitrate and Phosphorus removal in stormwater using select media. The results of a literature search, batch test experimentation and column test experimentation are used to determine an optimal media blend that may be implemented in detention ponds to reduce Nitrate and Phosphorus. The extensive literature search revealed 32 different media that may be used to remove Nitrate and Phosphorus. Each potential media was qualitatively and quantitatively evaluated based on 5 criteria: 1) relevance, 2) permeability, 3) cost, 4) availability in Florida, and 5) additional environmental benefit. The top 7 performing media: Florida peat, sandy loam, woodchips, crushed oyster shell; crushed limestone, tire crumb and sawdust were selected for batch test experimentation. The aerobic conditions in batch test experimentation prohibited the growth of denitrifying bacteria, therefore media mixes were selected for column test experimentation based on Ammonia and Orthophosphate concentrations. Batch test experimentation showed the most effective media to be 50% sand, 30% tire crumb, 20% sawdust by weight (media mix 1) and 50% sand, 25% sawdust, 15% tire crumb, 10% limestone by weight (media mix 2). Media mix 1, media mix 2 and a control are tested in column test experimentation, where the control is site soil from Hunters Trace development in Ocala, Florida. Column test experimentation models a dry detention pond where water passes through a 48 inch unsaturated zone then a 48 inch saturated zone. To test Nitrate and Orthophosphate removal potential, pond water augmented with Nitrate (0.38, 1.26, 2.5 mg/L NO3-N) and Orthophosphate (0.125, 0.361, 0.785 mg/L PO4-P) was pumped into the columns. Media mix 1 and media mix 2 outperformed the control in both Nitrate and Orthophosphate removal. Media mix 1 and media mix 2 had Nitrate removal efficiencies ranging from 60% to 99% and the control had Nitrate removal efficiencies ranging from 38%-80%. Media mix 1 and media mix 2 averaged Orthophosphate removal efficiencies ranging from approximately 42% to 67%. For every run in every influent Orthophosphate concentration the saturated control added Orthophosphate to the water. The Nitrate and Orthophosphate removal performances for media mix 1 and media mix 2 could not be directly compared because of different influent saturated nutrient concentrations.M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engr MSEnvE
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Lundgren, Lovisas. "Metal Removal Efficiency of Five Filter Media Intended for use in Road Stormwater Treatment Facilities." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292146.
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Roads, buildings, vehicles, and human activities cause spreading of pollutants, which partly end up in stormwater. The pollutant load contains solid particles of various size, hydrocarbons, organics, metals, nutrients, and microorganisms, which can have negative effects on water quality of surface-, coastal- and ground waters. Furthermore, urban development causes hardening of ground and reduced soil permeability that promotes rapid runoff during precipitation. The conversion from permeable to impermeable surfaces therefore lead to increased volumes stormwater but also decrease in stormwater water quality. Stormwater runoff metals are bound to various particles or occur in the dissolved fraction which is more toxic to aquatic life. Infiltration to soil, sand or other media is common practice to reduce runoff and filtrate metals and many treatment facilities and filter media have therefore been assessed for their metal removal efficiencies. High metal removal is often achieved for total metals, but removal of dissolved fraction remains elusive in many studies. Hence the importance of evaluate removal of dissolved metals before application to stormwater treatment facilities. The experimental column study of metal removal using commercially available reactive filter media showed that all filter media removal efficiencies in the order of zinc > copper > nickel. Removal efficiencies of chromium and lead were not considerably higher in tested filter media compared to the reference filter sand. Two filter media also leached chromium during the initial part of the experiment.Vägar, byggnader, fordon och mänskliga aktiviteter orsakar spridning av föroreningar av vilka en del förekommer i dagvatten. Urban bebyggelse orsakar också hårdgörande av ytor och reducerar jordens permeabilitet vilket skapar snabb avrinning vid nederbörd. Avrinningen innehåller bland annat partiklar, kolväten och andra organiska ämnen, metaller, näringsämnen och mikroorganismer vilka kan ha negativa effekter på yt-, kust- och grundvatten. Omvandlingen till hårdgjorda ytor orsakar därför både ökade volymer avrinning och sämre vattenkvalité. Metaller i dagvatten är ofta bundna till olika partiklar eller förekommer i löst form där den lösta formen anses vara mest miljöfarlig. Infiltration i jord, sand eller annan media är vanliga sätt att reducera avrinning och filtrera metaller. Hög förmåga att avskilja metaller kan ofta hittas för totala koncentrationen av metall men avskiljning av den lösta formen är ofta oklar. Utvärdering av olika filtermaterials förmåga att reducera lösta metaller är därför av särskilt intresse. Kolonnförsöken gjorda för att utvärdera metallavskiljningskapacitet med kommersiellt tillgängliga reaktiva filtermaterial har i denna uppsats visat att filtermaterialen har högst procentuell avskiljning för zink följt av koppar och därefter nickel. Krom och bly avskiljs inte mer i dessa filtermaterial än vad de gör i sandfilter. Två av filtermaterial läckte dessutom initialt höga koncentrationer krom.
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Morsch, Patrick [Verfasser], and H. [Akademischer Betreuer] Nirschl. "Detachment of fine-grained thin particle layers from filter media / Patrick Morsch ; Betreuer: H. Nirschl." Karlsruhe : KIT-Bibliothek, 2021. http://d-nb.info/123814795X/34.
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Merkle, Peter B. "Characterization and modeling of soluble manganese removal from drinking water by oxide-coated filter media." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-162507/.
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Qin, Hongye. "Investigation of Direct-Reduced Iron as a Filter Media for Phosphorus Removal in Wastewater Applications." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39973.
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Passive reactive filters have the potential to provide effective phosphorus (P) removal from stormwater or agricultural drainage, or to act as an add-on P-removal technology for decentralized or small community wastewater treatment systems. Passive filters require minimal energy consumption and human maintenance. Direct-reduced iron (DRI), a steel-making intermediate, was investigated as a passive filter media for wastewaters phosphorus reduction.
Phosphorus is a biologically active element that is in excess in many natural waterways due to intensive human activity. Eutrophication can occur when P concentrations exceed 0.02 mg/L in freshwater lakes and rivers. The harmful consequence of this phenomenon includes oxygen deprivation, fish death and cyanobacteria-produced toxins. There is a pressing need to limit phosphorus over-discharge into natural waterways.
DRI is a novel media in the application of wastewater treatment and was characterized to have a porous structure with high metallic iron content. The phosphorus retaining mechanisms in batch and column studies suggest a combination of adsorption and surface crystal formation as the dominant removal mechanisms. Batch studies demonstrated increasing removal capacity with P concentration with a plateau observed at 21 mg P/g DRI relating to initial 3000 mg P/L. Media rejuvenation was investigated through chemical treatment with two iron solutions (Fe2(SO4)3, FeCl3) and two acidic solutions (H2SO4 and HCl) at varying molarity. P removal capacity could be fully recovered with 0.05 M Fe3+ or 0.4 N H+ (HCl/H2SO4), while a 37.6% P recovery was also achieved in an acidic solution at 1.2 N H+ (HCl/H2SO4).
A column study utilizing three media sizes of DRI (3.5, 11, 19 mm) and one media size of activated alumina (AA) (7.5 mm) was conducted for 315 days using synthetic P solution varying from 2 to 10 mg/L and hydraulic retention times (HRTs) varying from 0.7 – 15 h. The results demonstrated that removal efficiency increased with HRT and decreased with increasing media size and concentration with minimum HRTs to maintain an 80% removal efficiency varying from 4.4 to 15 hrs for DRI and 3.9 hrs for AA for influent P concentrations of 10 mg/L and below. After 1 year of column operation, the DRI media had demonstrated a minimum removal capacity of 1.82 mg P/g DRI, which can be used as a conservative design parameter. A short duration column study (34 days) utilizing municipal lagoon effluent exhibited similar removal efficiencies to the synthetic column study under the same operational conditions. The 10 years lifespan DRI filter with 80% removal rate in the treatment of stormwater, municipal lagoon effluent, septic tank effluent and dairy wastewater application would have been estimated to have filter volumes of 0.24, 4.69, 15.3 and 36.2 m3, respectively.
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Yamashita, Hiroshi, Shingo Satake, and Kazuhiro Yamamoto. "Microstructure and particle-laden flow in diesel particulate filter." Elsevier, 2009. http://hdl.handle.net/2237/20047.
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MISAWA, MASAKI, NAOKI TAKADA, HIROSHI YAMASHITA, SHINGO SATAKE, and KAZUHIRO YAMAMOTO. "LATTICE BOLTZMANN SIMULATION ON FLOW WITH SOOT ACCUMULATION IN DIESEL PARTICULATE FILTER." World Scientific Publishing, 2007. http://hdl.handle.net/2237/20052.
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Rufianto, Muhammad Haky. "State Prediction for Haptic Remote Teleoperation - A Kalman Filter ApproachState Prognos för haptisk Remote teleoperation – en metod baserad på Kalman-filter." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-189155.
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Teleoperation system is an important tool to control a device or model in an isolated area remotely where the operator cannot perform the task locally. The vast majority of teleoperation systems provides the operator with visual and haptic control to accomplish the assignment as naturally as possible. However, on a teleoperation system with considerable distance, the time delay could cause a drop in performance. This thesis aims to minimize delay problem by implementing a prediction approach using Kalman Filter. Kalman Filter algorithm has been widely used to estimate user movement for tracking systems. Kalman filter provides an efficient mechanism to predict future state based on Bayesian estimation to sequentially predict future states and measure an actual system to update system parameters. The primary objective of this work is to extract information generated by our prototyping model and visualizing the data to reflect the performance of the system. We use Phantom Omni devices and 3D arm as a model. Different type of Kalman filter algorithms is used to test the accuracy and performance of predicted state generated by the filter. The result shows that the implementation of Extended Kalman Filter (EKF) and smoothing function could overcome the networking delay on certain degrees. The comparison shows that the EKF has better accuracy and performance compared to Unscented Kalman Filter (UKF) when estimating the future state. Additionally, the implementation of smoothing function could improve the stability of teleoperation system.Teleoperation systemet är ett viktigt verktyg för att styra en enhet eller modell i ett isolerat område på distans där operatören inte kan utföra uppgiften lokalt. De allra flesta av teleoperation system ger föraren visuell och haptisk kontroll för att utföra uppdraget så naturligt som möjligt. Men på en teleoperation system med stort avstånd, kan tidsfördröjningen medföra en nedgång i prestanda. Denna avhandling syftar till att minimera förseningar problem genom att implementera en förutsägelse tillvägagångssätt med Kalman Filter. Kalman filteralgoritm har i stor utsträckning används för att uppskatta användarens rörlighet för spårning. Kalman filter ger en effektiv mekanism för att förutsäga framtida stat grundad på Bayesian uppskattningen att sekventiellt förutsäga framtida tillstånd och mäta ett verkligt system för att uppdatera systemparametrar. Det primära syftet med detta arbete är att extrahera information som genereras av vår prototypmodell och visualisera data för att återspegla systemets prestanda. Vi använder Phantom Omni enheter och 3D-arm som en modell. Olika typer av Kalman filter algoritmer används för att testa riktigheten och prestandan hos förutsagda tillståndet genereras av filtret. Resultatet visar att genomförandet av Extended Kalman filter (EKF) och utjämningsfunktionen kan övervinna nätverk dröjsmålsvissa grader. Jämförelsen visar att EKF har bättre noggrannhet och prestanda jämfört med Unscented Kalman Filter (UKF) vid bedömningen av framtida tillstånd. Dessutom, genomförandet av utjämningsfunktionen skulle kunna förbättra stabiliteten hos teleoperation systemet.
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Heleva-Ponaski, Emily. "Removal Efficiencies, Uptake Mechanisms and Competitive Effects of Copper and Zinc in Various Stormwater Filter Media." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4556.
Full textAbstract:
Polluted stormwater, if not treated, can compromise water quality throughout our hydrologic cycle, adversely affecting aquatic ecosystems. Common stormwater pollutants, copper and zinc, have been identified as primary toxicants in multiple freshwater and marine environments. For small-scale generators, stormwater management can be cumbersome and implementation of common BMPs impractical thus catch basins are popular though not the most environmentally conscious and sustainable option. This study aims to characterize the potential of a mobile media filter operation for the treatment and on-site recycling of catch basin stormwater. The removal capacities of various commercially available filter media (e.g. a common perlite; Earthlite™, a medium largely composed of biochars; and Filter33™, a proprietary porous medium) were measured using binary injection solutions modeled after local catch basin stormwater characteristics. The results of filtration experiments, rapid small-scale column tests (RSSCTs), indicate that the transport of metals in Perlite is primarily impacted by nonspecific sorption whereas in Earthlite™ and Filter33™ both nonspecific and specific sorption are present. For all media and experimentation, there was a consistent preferential uptake of copper such that copper displayed delayed arrival and/or greater removal than zinc. Moreover, the observed snow plow effects and concentration plateaus in Earthlite™ and Filter33™ RSSCTs suggest rate limited ion exchange and specific sorption in addition to ion competition. Earthlite™ exhibited an approach velocity dependent removal efficiency in the RSSCTs and pseudo second order uptake behavior for zinc in kinetic batch experiments. At the lab scale equivalent of the proposed field scale flow rate, Filter33™ displayed the greatest average zinc removal of 8.6 mg/g. In all, this research indicates that test parameters (i.e. pH, competitive ions solutions, empty bed contact time, flow rate) based on the natural environment and field scale operation can greatly impact removal efficiency in filter media.
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Robertsson, Filip. "Facebook as News Medium: A Qualitative Study on Reliability in Social Media." Thesis, Malmö högskola, Fakulteten för teknik och samhälle (TS), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-20193.
Full textAbstract:
Sociala medier blir en allt viktigare nyhetskanal för unga vuxna. Denna utveckling har gjort att medieforskare ifrågasätter huruvida sociala medier är kapabla att utbilda och informera på samma sätt som de fysiska formaten gjort med tidigare generationer. Vissa har funnit att möjligheten att filtrera nyhetsflödet innebär en risk att användaren försätter sig i en filterbubbla där endast åsikter och tankar som stämmer överens med deras egna kommer igenom. Andra menar istället att sociala medier ger ett rikare utbud med större variation. Klart står att journalistens roll som grindvakt för vad som publiceras blir mindre viktig och att vem som helst numera kan yttra sina åsikter och potentiellt nå ut till en stor massa med dessa. Denna studie undersöker och ger insikter om hur unga vuxna sållar i sitt Facebookflöde, hur de definierar tillförlitlighet i nyhetsmedia och hur de utifrån detta avgör vad som är tillförlitligt och inte i sitt flöde. Studien består av kvalitativa intervjuer och ett observationsexperiment där respondenterna får scrolla igenom ett fiktivt Facebookflöde. Resultaten visar att bedömningen som görs ofta är medveten och går mycket snabbt, samt att det är få inlägg som anses leva upp till deras definition av tillförlitliga. Även om Facebook visar sig vara en vanlig nyhetskälla är det få av respondenterna som anser den vara bra och tillförlitlig.Social media is becoming a more and more important news medium for young adults. This development has lead media researchers to question whether social media is as capable of educating and informing these young adults as the legacy media did the generations before them. Some argue that social media, with its ability to filter the news feed, might place users in a filter bubble lacking any challenging views. Others argue that social media encourages a diverse news and information feed. What's clear is that the role of the journalist as gatekeeper has diminished, and that anyone is now able to voice their opinions to a big audience. This study investigates how young adults sift through their Facebook feed, how they define reliability in news media, and how they assess their social news feed based on this. The study consists of qualitative interviews and an observational experiment where the respondents scrolled through a fictive Facebook feed. The results show that the assessment made is often very quick and deliberate, and that few news posts live up their definition of reliable, namely objective and transparent. Although Facebook is a common news source, few consider it to be a good and reliable one.