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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

DESARROLLO DE TÉCNICAS COMBINADAS DE SECADO CON AIRE CALIENTE Y MICROONDAS EN LA PRODUCCIÓN DE FIBRA ALIMENTARIA A PARTIR DE SUBPRODUCTOS CÍTRICOS

Talens Vila, Clara 21 January 2016 (has links)
[EN] Sustainability is nowadays an investment for the future of any economic activity. The current situation of crisis has had an adverse impact in most industries, including the agri-food sector. However, this industry has been relatively the least affected when compared with other industrial sectors. This is mainly attributed to the fact that food products continue to be basic for consumers despite the economic downturn. Therefore, the agri-food sector is a key element in the European economy and can play a crucial role in the achievement of the objectives set in the EU's strategy for 2020: ensuring a sustainable framework of growth of a more competitive economy. The European agri-food industry has focused on energy efficiency and on reducing greenhouse gases emissions, along with better management of their resources as a way to improve its industrial competitiveness. In this sense, the search for solutions to transform the by-products generated in high value-added ingredients, is a priority. In this context, the juice industry, as fundamental sub-sector within the food sector, and large waste generator, must exploit the opportunity to transform their by-products into useful and profitable products for society. This transformation presents some difficulties which impede the profitability of the process. These difficulties are associated with the by-product, such as its compositional variability and its seasonality, and current techniques of transformation as the high energy cost in dehydration processes. This thesis represents an innovative and sustainable solution for overcoming the disadvantages associated with the high costs of stabilization, turning this by-products into high value-added ingredients, from both, nutritional and technological, points of view. The aim is to develop a microwave coupled with hot air drying technique allowing maximizing profits by using the following strategy: reducing time and operational costs, producing a new ingredient rich in dietary fiber, with interesting technological properties for the development of healthy foods, studying the proposed comprehensive process and analyzing the new generated by-products. The methodological approach of the thesis been focused, on the one hand, on studying phenomena that govern the internal transport of water and energy through the orange peel during its dehydration applying thermodynamics. On the other hand, the energy consumption of the drying process, the technological and sensory properties of the fiber obtained and its potential use as a fat substitute have been compared with the conventional hot air drying method. Finally, the integrated process, including both the combined drying technique and the pretreatments needed for colour and bitter compounds extraction, is proposed as a new route of valorization, in which the new by-products obtained, polyphenols and carotenoid rich extracts, are analysed. This study has analyzed the microwave coupled with hot air process, developing tools that allow the adequate upscaling of the drying operation by adapting it to the best standards of quality of the final product. A monitoring system that ensures these standards has been designed. The quality and the energy consumption of the dietary fiber production process has been improved. The properties associated with its inclusion in food matrices have been optimized. An innovative and sustainable process for the stabilization of industrial by-products and for their further conversion into dietary fiber and other bioactive compounds, applying microwave coupled with hot air drying, has been developed. / [ES] La sostenibilidad es una de las apuestas de futuro en cualquier actividad económica. La situación de crisis ha tenido un impacto adverso en la mayoría de las industrias, incluyendo las de ámbito agroalimentario. Sin embargo, ésta ha sido relativamente la menos afectada cuando se compara con otros sectores industriales. Esto se atribuye al hecho de que los productos alimenticios continúan siendo básicos para los consumidores a pesar de la desaceleración económica. Por lo tanto, esta industria es un pilar fundamental en la economía europea y puede jugar un papel crucial en la consecución de los objetivos marcados en la Estrategia de la UE para 2020: asegurar un marco sostenible de crecimiento de una economía más competitiva. La industria agroalimentaria europea ha apostado por la eficiencia energética y la reducción de emisiones de gases invernadero, junto con una mejor gestión de sus recursos como vía para la mejora de su competitividad industrial. La búsqueda de soluciones para transformar los subproductos generados en ingredientes de alto valor añadido, es una de las prioridades. En este contexto, la industria productora de zumos, como subsector fundamental dentro del sector alimentario, y gran generador de residuos, tiene la oportunidad de transformar sus subproductos en productos útiles y rentables para la sociedad. Esta transformación presenta algunas dificultades que impiden la rentabilidad del proceso. Estas dificultades están asociadas al subproducto, como su variabilidad composicional o su estacionalidad, y a las técnicas actuales de transformación como el elevado coste energético en procesos de deshidratación. Esta tesis se plantea como una solución innovadora y sostenible para, más allá de superar los inconvenientes asociados a los altos costes de estabilización, transformar este subproducto en un ingrediente de alto valor añadido, tanto nutricional como tecnológico. Para ello se propone desarrollar una técnica de secado combinado por aire caliente y microondas que permita maximizar beneficios mediante la siguiente estrategia: reducir el tiempo y el coste energético de la operación, produciendo un nuevo ingrediente rico en fibra dietética con propiedades tecnológicas de interés para el desarrollo de alimentos más saludables, estudiando el proceso integral propuesto y analizando los nuevos subproductos generados. El enfoque metodológico de la tesis ha estado dirigido, por una parte, a estudiar los fenómenos que gobiernan el transporte interno de agua y energía a través de la piel de naranja durante su deshidratación, aplicando termodinámica. Por otra parte, el consumo energético del proceso de secado, las propiedades tecnológicas y sensoriales de la fibra obtenida y su potencial uso como ingrediente sustituto de grasa, se han comparado con el método de secado convencional por aire caliente. Finalmente, el proceso integrado, incluyendo tanto el secado combinado como las etapas previas de extracción de color y compuestos amargos, se propone como una nueva ruta de valorización, en la que se analizan posibles subproductos de interés tales como extractos ricos en polifenoles y carotenoides. En este estudio se ha analizado el proceso combinado de secado con aire caliente y microondas, desarrollando herramientas que permiten dimensionar adecuadamente la operación de secado adaptándola a los estándares óptimos de calidad del producto final. Se ha diseñado un sistema de monitorización que asegure dichos estándares. Se ha mejorado el proceso de obtención de fibra alimentaria respecto a su calidad y a su gasto energético. Se han optimizado las propiedades asociadas a su inclusión en matrices alimentarias. Se ha desarrollado un proceso innovador y sostenible para la estabilización de subproductos vegetales de origen industrial y para su posterior conversión en fibra dietética y otros compuestos bioactivos, aplicando la tecnología de secado por aire caliente y / [CAT] La sostenibilitat és una de les apostes de futur en qualsevol activitat econòmica. L'actual situació de crisi ha tingut un impacte advers en la majoria de les indústries, incloent les d'àmbit agroalimentari. No obstant això, la indústria agroalimentària ha sigut relativament la menys afectada quan es compara amb altres sectors industrials. Açò s'atribuïx principalment al fet de que els productes alimentaris continuen sent bàsics per als consumidors a pesar de la desacceleració econòmica. Per tant, esta indústria és un pilar fonamental en l'economia europea i pot jugar un paper crucial en la consecució dels objectius marcats en l'Estratègia de la UE per a 2020: assegurar un marc sostenible de creixement d'una economia més competitiva. La indústria agroalimentària europea ha apostat per l'eficiència energètica i la reducció d'emissions de gasos d'efecte hivernacle, junt amb una millor gestió dels seus recursos com a via per a la millora del seu vaig competirtu En este sentit, la busca de solucions per a transformar els subproductes generats en ingredients d'alt valor afegit, és una de les prioritats. En este context, la indústria productora de sucs, com subsector fonamental dins del sector alimentari, i gran generador de residus, té el deure i l'oportunitat de transformar els seus subproductes en productes útils i rendibles per a la societat. Esta transformació presenta algunes dificultats que impedixen la rendibilitat del procés. Estes dificultats estan associades al subproducte, com la seua variabilitat composicional o la seua estacionalitat, i a les tècniques actuals de transformació com l'elevat cost energètic en processos de deshidratació. Esta tesi es planteja com una solució innovadora i sostenible per a, més enllà de superar els inconvenients associats als alts costos d'estabilització, transformar este subproducte en un ingredient d'alt valor afegit, tant nutricional com tecnològic. Per a això es proposa desenvolupar una tècnica de'assecat combinat per aire calent i microones que permeta maximitzar beneficis per mitjà de l'estratègia següent: reduir el temps i el cost energètic de l'operació, produint un nou ingredient ric en fibra dietètica amb propietats tecnològiques d'interés per al desenvolupament d'aliments més saludables, estudiant el procés integral proposat i analitzant els nous subproductes generats. L'enfocament metodològic de la tesi ha estat dirigit, d'una banda, a estudiar els fenòmens que governen el transport intern d'aigua i energia a través de la pell de taronja durant la seua deshidratació, aplicant termodinàmica. D'altra banda, el consum energètic del procés de d'assecat, les propietats tecnològiques i sensorials de la fibra obtinguda i el seu potencial ús com a ingredient substitut de greix, s'han comparat amb el mètode d'assecat convencional per aire calent. Finalment, el procés integrat, incloent tant l'assecat combinat com les etapes prèvies d'extracció de color i compostos amargs, es proposa com una nova ruta de valoració, en la que s'analitzen possibles subproductes d'interés com ara extractes rics en polifenoles i carotenoides. En este estudi s'ha analitzat el procés combinat d'assecat amb aire calent i microones, desenvolupant ferramentes que permeten dimensionar adequadament l'operació d'assecat adaptant-la als estàndards òptims de qualitat del producte final. S'ha dissenyat un sistema de monitorització que assegure els dits estàndards. S'ha millorat el procés d'obtenció de fibra alimentaria respecte a la seua qualitat i al seu consum energètic. S'han optimitzat les propietats associades a la seua inclusió en matrius alimentàries. S'ha desenvolupat un procés innovador i sostenible per a l'estabilització de subproductes vegetals d'origen industrial i per a la seua posterior conversió en fibra dietètica i altres compostos bioactius, aplicant la tecnologia d'assecat por aire calent i microones. / Talens Vila, C. (2015). DESARROLLO DE TÉCNICAS COMBINADAS DE SECADO CON AIRE CALIENTE Y MICROONDAS EN LA PRODUCCIÓN DE FIBRA ALIMENTARIA A PARTIR DE SUBPRODUCTOS CÍTRICOS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/54114 / TESIS
102

Adsorpce toxických kovů z odpadních vod na odpadním materiálu z potravinářského průmyslu / Adsorption of toxic metals from wastewater to waste material from the food industry

Křikala, Jakub January 2018 (has links)
This thesis was focused on the possibility of secondary utilization of waste material from the wine industry to remove heavy metals from wastewater. In the theoretical part, there were discussed mainly the problems of heavy metals pollution including methods of their removal and ICP-OES detection. Furthermore, the waste material from the wine production and the possibilities of its further processing were discussed there. The primary objective of the experimental part was to characterize the material by IR analysis, optimization of adsorption conditions, isotherms construction and determination of maximum adsorption capacities of white, red and chemically modified marc for Cd, Cr, Cu, Ni and Pb. From the parameters influencing the adsorption efficiency, the adsorbent load was optimized (m/V ratio = 0,02); pH values found were 5 for Cd, Cu, Ni, Pb and 3 for Cr and the contact time to reach the equilibrium was 15 minutes for Cd, Ni, Pb and 30 minutes for Cr and Cu. Maximum adsorption capacity for heavy metals were calculated from adsorption isotherms by applying the Langmuir model and found to be 18,829 7 mg/g for Cd; 10,664 7 mg/g for Ni; 35,602 0 mg/g for Pb (modified marc with 1M NaOH); 4,678 4 mg/g for Cu and 9,629 0 mg/g for Cr. The results of the work confirm the good adsorption potential of heavy metals on marc and the positive effect of chemical modification of natural biosorbents to improve their adsorption capacity.
103

Optimalizace adsorpce kyseliny ferulové na různých typech adsorbentů / Optimalization of ferulic acid adsorption on different types of adsorbents

Bariyeva, Aizat January 2019 (has links)
This thesis deals with optimalization processes of adsorption of ferulic acid on different types of sorbents. Specifically, was used the activated carbon as a sorbent of heterogeneous character and Amberlyst A-21 and Amberlit XAD-16 as macroporous polymer sorbents. The ferulic acid is fully characterized in the theoretical part and are discussed the problems of adsorption processes. To determination of the phenolic acid were used UV-VIS and HPLC instrumental methods. The main aim of the experimental part is to optimize various parameters of adsorption, including the construction of adsorption isotherms, determination of maximum adsorption capacity of individual sorbents, study of kinetics and mechanisms of adsorption. Determination of the influence of salt was studied to assess the impact of the inorganic salts on the ferulic acid adsorption capacity. Based on these parameters, was carried out determination of an optimal pH value on 3, with an optimal adsorbent load (m/V ratio = 0,009 gml-1) and a contact time of 50 min for all three adsorbents. Equilibrium studies described by adsorption isotherms and the Langmiur model fitted the best, and the maximum adsorption capacities were determined for all three sorbents with 150,4 mgg-1 for activated carbon, 209,1 mgg-1 for Amberlyst A-21 and 82 mgg-1 for Amberlyte XAD-16. In the study of kinetic models was selected pseudo-second model for all three adsorbents, which correlated with the results obtained by the Langmuir isotherm. The decrease in adsorption capacity in the determination of NaCl influence was 4 % for activated carbon, for macroporous polymer sorbents was decreased by 52 % and 55 % for Amberlyst A-21 and Amberlyt XAD-16 respectively. In a selectivity test under optimized conditions, adsorption strength increased in the order of sinapic acid ferulic acid p-coumaric acid for polymeric sorbent XAD-16 and activated carbon. For the A-21 sorbent the adsorption strength increased in the order of p-coumaric acid ferulic acid sinapic acid. The results of the work indicate the suitability of all three sorbents for the phenolic acid adsorption.
104

Aplicación de un método de determinación y validación de altura de isoterma 0°C en el territorio chileno, a partir de datos de radiosonda en el período 1973-2017

Miranda Cepeda, Bastian January 2019 (has links)
Memoria para optar al título de Geógrafo / El planeta se enfrenta a nuevos escenarios climáticos, y Chile no se encuentra ajeno. Aumentos de temperatura y disminución en las precipitaciones son algunos de los fenómenos que se están dando con mayor frecuencia, en donde la isoterma 0°C toma un rol importante al encontrarse vinculado estrechamente con las variaciones de temperatura. Es así como se propone un método de determinación de isoterma 0°C mediante datos de radiosonda lanzados en territorio chileno, así como también una validación de sus resultados. Los datos de radiosonda son limpiados y llevados a una macro, en donde se automatiza el cálculo de la altura de la isoterma 0°C mediante una regresión polinómica, cuyos resultados son espacializados en el territorio chileno a nivel estacional. Por otro lado, estos datos son analizados temporalmente según Makesens y contrastados con resultados arrojados por un modelo alternativo, utilizando datos de una base mundial denominada Terraclimate. La isoterma 0°C se ubica principalmente en la cordillera de Los Andes, abarcando mayor superficie en la zona norte y centro del país. A grandes rasgos, las tendencias señalan un aumento en la altura de isoterma 0°C en la zona norte, centro y sur, siendo en los meses de verano en donde existe un mayor grado de significancia. La altura de la isoterma 0°C en días de precipitación presenta un alza en la zona norte y centro del país, mientras que en la zona austral se destaca la tendencia negativa. / The planet is facing to new climate stages, and Chile isn't so far of that. Temperature increase, decrease in rainfall, are just some of the phenomenon that happens more frequently, where 0°C isotherm takes an important role to be closed linked with temperature variations. This Is how a 0°C isotherm variations method is proposed using radiosonde data launched in Chilean territory, as well as a validation of their results. The radiosonde data are cleaned and taken to a macro, where the calculation of the 0°C isotherm height is automated by a polynomial regression, the results of which are spatialized in Chilean territory at the seasonal level. On the other hand, these data are temporarily analyzed according by Makesens and contrasted with results produced by an alternative model, using data from a global database called Terraclimate. The 0°C isotherm is located mainly in the Andes mountain range, covering a larger area in the northern and central part of the country. Broadly speaking, the trends indicate an increase in the height of 0°C isotherm in the north, center and south zone, being in the summer months where there is more significance. The height of the 0°C isotherm on rainy days shows an increase in the north and center of the country, while in the southern zone the negative trend is noted.
105

Microgels as drug carriers : Relationship between release kinetics and self-aggregation of the amphiphilic drugs adiphenine, pavatrine and diphenhydramine.

Ali Mohsen, Lobna January 2021 (has links)
Abstract There has been great interest in microgels as drug carriers within the pharmaceutical industry. This includes the use of amphiphilic drugs for treating conditions such as depression, allergies, and cancer. By loading adiphenine (ADP), pavatrine (PVT), and diphenhydramine (DPH) into macrogels and observing the release, this study seeks to investigate how amphiphilic drugs can be released from microgels. There is also an interest in how aggregation behavior may vary depending on the structural components. This study utilized small angle x-ray scattering (SAXS) along with UV analysis and the measuring of the binding isotherm to investigate micelle aggregation and aggregation number. Two of the drugs adiphenine and pavatrine, have similar structures with only one bond that differentiated them. The difference in rigidity provided different results in SAXS. Adiphenine has an aggregation number of 12, diphenhydramine has a number of 13, and pavatrine has a number of 37. In contrast to pavatrine, which did not exhibit a correlation peak, adiphenine and diphenhydramine showed correlation peaks. This indicates that none of them had an ordered phase structure but pavatrine displayed an even more disordered phase structure. Nevertheless, all three drugs were in equilibrium, and so a difference between adiphenine and pavatrine could be clearly distinguished. There were significant divergences between pavatrine and adiphenine despite not being able to determine binding isotherms for all three drugs. Based on this, they should be less stable than diphenhydramine. They have an ester linkage, while diphenhydramine doesn't. As a result, it was not possible to confirm how self-aggregation of adiphenine, pavatrine, and diphenhydramine impacts drug release. Despite this, differences in the rigidity of the structural form may lead amphiphilic drugs to exhibit different behaviour in gels. Keywords: Amphiphilic drugs, small angle x-ray scattering, macrogels, binding isotherm, CMC, self-aggregation, phase structure, micelles.
106

Investigation of Adsorption and Retention of Charged Compounds In RPLC / Undersökning av adsorption och retention hos laddade substanser i RPLC

Fryxelius, Emma January 2022 (has links)
The adsorption isotherm of two weak bases, Promethazine hydrochloride and Propranolol hydrochloride, were determined with isocratic reversed-phase liquid chromatography, with a 60 w% methanol in 20 mM sodium acetate buffer pH 4 as the mobile phase, and calculated by the elution by characteristic points method. The data obtained from the method were then fitted into the Langmuir isotherm and the electrostatically modified Langmuir. Propranolol fitted reasonably good into the models while Promethazine was not as good. When Promethazine and Propranolol were together in the same sample, there was indication of competition of the adsorption sites. For comparing retention and peak shape between a C18 column and a mixed mode column, Waters XBridge C18 and Thermo Scientific Acclaim WCX-1, were tested in gradient elution with 11.32 mM sodium acetate buffer and 10–70 % methanol. The mixed-mode column gave significantly better peak shapes, while the retention time were longer compared to the C18 column. / Adsorptions-isotermerna för två svaga baser, Prometazin hydroklorid och Propranolol hydroklorid, bestämdes med isokratisk omvänd-fas vätskekromatografi, med w% 60 metanol i en 20 mM natriumacetatbuffert pH 4 som mobil fas, och beräknad med metoden elution by characteristic points.  Från metoden erhållna data passades till Langmuir isotherm och den elektrostatiskt modifierade Langmuir. Propanolen passade ganska bra till de olika isotermerna, medan Prometazin var något sämre passad. När Prometazin och Propranolol var tillsammans i samma prov, fanns det indikationer på konkurrens om adsorptionsställen. För jämförelse av topparnas form och retentionstid mellan en C18-kolonn och en mixed-mode-kolonn, användes Waters XBridge C18 och Thermo Scientific Acclaim WCX-1, som testades i gradient eluering med 11, 32 mM natriumacetatbuffert och 10–70 % metanol. Mixed-mode-kolonnen gav åtskilligt bättre toppar, medan retentionstiden var längre jämfört med C18-kolonnen.
107

Arsenic removal using biosorption with Chitosan : Evaluating the extraction and adsorption performance of Chitosan from shrimp shell waste

Westergren, Robin January 2006 (has links)
Nicaragua is a country in which the toxic metal contamination of freshwater resources has become an increasingly important problem in certain regions posing a threat to the environment as well as to human health. Among the metals found in the waters of Nicaragua, arsenic is one of the most problematic since its long time consumption is connected to serious health problems such as cancer and neurological disorders. The arsenic contamination of water recourses in Nicaragua is mostly attributable natural factors, even though anthropogenic activities including gold mining may be a contributing factor. In this work the biopolymer Chitosan was studied as a potential adsorption material for the removal of arsenic from aqueous solutions for water treatment design purposes. The Chitosan used in this study was extracted from shrimp shells with an overall yield of 40% and a deacetylation grade of 59%. The maximum adsorption capacity was determined to 20.9 mg As/g at a controlled pH of 5.5 using the Langmuir isotherm. The adsorption was found to be strongly pH dependant with a fourfold increase in adsorption capacity when pH was well under the pKa of Chitosan. The pH dependence indicates that ionic exchange was the most important mechanism. No difference in adsorption capacity with respect to the initial pH of the solution was detected in the pH range 3-7. This was attributed to the ability of Chitosan to act as a weak base in water solutions. The arsenic was desorbed from Chitosan using NaOH, (NH4) 2SO 4 and NaCl, with a 1M NaOH solution being the most efficient displaying a concentration ratio of 1.08. The NaOH and (NH4) 2SO 4 solutions displayed a steep desorption curvature with a large fraction of the arsenic being easily desorbed. The arsenic was, however, not completely desorbed from the Chitosan implying that the adsorption capacity would decrease for the coming cycles. Being a biopolymer the Chitosan is quite easily degraded in acid and alkali solutions, which might be a limiting step for the process applicability.
108

The Effects of BAM as an Adsorptive Media on Phosphorus Removal in Stormwater

Salamah, Sultan 01 January 2014 (has links)
To maintain the quality of receiving water bodies, it is desirable to remove total phosphorus (TP) in stormwater runoff. Many media filtration technologies have been developed to achieve TP and soluble reactive phosphorus (SRP) removal. Efficient media adsorption is essential to insure control of stormwater phosphorus inputs to the receiving water body. This project develops and analyzes a functionalized Biosorption Media (BAM) to remove phosphorus species from stormwater runoff. One goal of this project is to find the BAM values for coefficients such as maximum adsorption capacity (QM: 4.35E-05) for the media through SRP isotherm equilibrium experiments using the Langmuir and Freundlich models. In addition, an upflow column experiment was also performed to study BAM nutrient removal from stormwater runoff. Finally, the information from the isotherm and the column experiments are used to estimate the life expectancy or quantity required of the media, and to define the effectiveness of BAM in phosphorus removal. The result of this study shows that BAM is a feasible stormwater treatment that can remove 60% SRP and > 40% TP at temperature between 21-23°C. The media is adequately modeled by both the Langmuir and the Freundlich models over the concentration range of interest in stormwater.
109

Chemophysical Characteristics And Application Of Biosorption Activated Media (bam) For Copper And Nutrient Removal In Stormwater Management

Jones, Jamie 01 January 2013 (has links)
For high groundwater table areas, stormwater wet detention ponds are utilized as the preferred stormwater management throughout the state of Florida. Previous research has found that accumulations of nutrients, algae, heavy metals, pesticides, chlorophyll a, fecal coliform bacteria and low concentrations of dissolved oxygen (DO) are common characteristics of stormwater wet detention ponds. Although these pollutant levels are not regulated within the ponds, states are required to compute the pollutant load reductions through total maximum daily load (TMDL) programs to meet the water quality requirements addressed by the Clean Water Act (CWA). In this study, field sampling data of stormwater ponds throughout Florida are presented to identify concentration levels of the main contaminants of concern in the discharge of wet detention ponds. Sampling was done to identify possible sources, in addition to possible removal mechanisms via the use of specific sorption media. Nutrients were found as a main problematic pollutant, of which orthophosphate, total phosphorus, ammonia, nitrate, and total nitrogen were targeted whereas heavy metals exhibited minor concerns. Accumulation of high nutrient concentrations may be mitigated by the adoption of best management practices (BMPs) utilizing biosorption activated media (BAM) to remove phosphorus and nitrogen species through physical, chemical, and biological processes. This study aims to increase overall scientific understanding of phosphorus removal dynamics in sorption media systems via Langmuir and Freundlich isotherms and column studies. The removal of phosphorus (P) was proven effective primarily through chemophysical processes. The maximum orthophosphate adsorption capacities were determined under varying conditions of the media within the columns, which were found up to 0.000534 mg-P adsorbed per gram BAM with influent concentrations of 1 mg∙L -1 orthophosphate in distilled water and 1 hour hydraulic residence time (HRT). When using iv spiked pond water under the same conditions, the adsorption capacity was increased about 30 times to 0.01507 mg-P∙g -1 BAM presumably due to the properties and concentrations of ions affecting the diffusion rate regulating the surface orthophosphate reactions. These equilibrium media uptake values (q) were used to calculate the life expectancies of the media under varying HRT and influent concentrations of treatment. Chemophysical and biological removal capabilities of the media for total nitrogen, ammonia, and nitrate were effective in columns using 1100 g of BAM. In flow-through column conditions, ammonia had a consistent ~95% removal while effluent nitrate concentrations were highly variable due to the simultaneous nitrificationdenitrification processes once an aerobic-anaerobic environment was established. Batch column experiments simulating no-flow conditions within a media bed reactor resulted in orthophosphate removals comparable with the continuous flow conditions, increased total phosphorus effluents indicative of chemical precipitation of orthophosphate, decreased ammonia removal, and increased nitrate removal. Due to a biofilm’s sensitivity to even low copper concentrations and accumulation in ponds, a copper sorption media mix of "green" materials was generated. Freundlich and Langmuir isotherm tests concluded a successful mix resulting in copper removal efficiencies up to 96%.
110

PURE AND BINARY ADSORPTION OF METHANE AND NITROGEN ON SILICALITE

Vaidya, Prahar S. 25 May 2016 (has links)
No description available.

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