As the economy has been growing fast in China, Chinese people have more incomes and then higher standard of living. In the case of household water treatment, more and more urban residents in China use bottled water or water filtration system instead of tap water because people start to worry about polluted tap water. According to a survey from China Water Supply Services Promotion Alliance in 2014, 59% of urban residents drinking water is from tap water (after being boiled), 41% from bottled water and water filtration system. The 41% participants prefer bottled water as the first choice over a water filtration system. The comparative advantages and disadvantages of home water filtration system and bottled water are analyzed using comparative analysis. The reasons why home water filtration industry has grown slowly in urban China even though it is less expensive and has environmental benefits are analyzed using a system dynamics model. The model focuses on the physical system of home water filtration industry. The study shows that order delivery delay and service time are key factors to the adoption rate of home water filtration system. However, initial cost becomes a limiting factor to the growth of the market of home water filtration system. The study proposes the according market policy, demand policy, and supply policy to improve the current scenario.

Ce travail de thèse propose une nouvelle approche pour la préparation de membranes à matrice mixte basée sur l’utilisation de copolymères à blocs et de nanoparticules inorganiques disposant de propriétés magnétiques. Des aggrégats de copolymères ont été préparés avec une morphologie variée (sphères, cylindres et vésicules) à partir du copolymère poly(acide méthacrylique)-b-poly(méthacrylate de méthyle). Ce dernier a été synthétisé par polymérisation radicalaire contrôlée par transfert de chaîne réversible par addition-fragmentation (RAFT) dans l’éthanol à 70°C. Des particules d’oxyde de fer ont, quant à elles, été préparées en présence de différents stabilisants à température variée pour permettre d’atteindre la charge de surface et les propriétés magnétiques recherchées. La structure des copolymères à bloc a permis d’obtenir à la fois des membranes hydrophobes via le procédé de séparation de phase induite par un non-solvant, ainsi que des membranes hydrophiles lorsque que la technique de spin-coating était appliquée aux aggrégats formés par auto-assemblage induit lors de la polymérisation. Grâce à l’étude détaillée des propriétés de filtration des membranes obtenues, la relation structure-propriété a été discutée sous l’action d’un champ magnétique externe. Enfin, la sensibilité au colmatage a été vérifiée via la filtration de solutions de protéines. Il a ainsi été démontré une diminution notable du colmatage sous champ magnétique, ouvrant de belles perspectives pour ces nouvelles membranes. / This thesis presents a new approach to produce mix matrix membranes using block copolymers and inorganic nanoparticles having magnetic properties. The polymeric nanoparticle with different morphologies (linear, Spheres, worms, and vesicles), from poly (methacrylic acid)-b-(methyl methacrylate) diblock copolymer, were synthesized using Reversible addition−fragmentation chain transfer polymerization (RAFT) in ethanol at 70 ֠C. The inorganic counterpart, iron oxide nanoparticles were prepared using different stabilizers at various temperatures to acquire the necessary surface charge and magnetic properties. The chemistry of the particles leads to form both hydrophobic membranes using non-solvent induced phase separation as well as a hydrophilic membrane by using the simple spin coating technique with the particles from polymerization induced self-assembly. By a detailed experimental study of the membrane filtration, the influence of different parameters on the process performance has been investigated with and without magnetic field. Finally, membrane fouling has been studied using protein solution. Also, the membrane performance was examined under magnetic field revealing the successful reduction in the fouling phenomenon making them new performant membranes in the area of membrane technology.

Tendo em vista a existência de muitas comunidades no Estado de São Paulo (e em outros estados do Brasil), que utilizam água muitas vezes com qualidade imprópria ao consumo humano, o presente trabalho visa o desenvolvimento de uma instalação de filtração utilizando Carvão Ativado Impregnado com Prata (CAIP) com o intuito de eliminar alguma contaminação na água tratada devido à problemas tais como anomalias operacionais na ETA, tecnologia de tratamento inadequada, contaminação da rede de distribuição, reservação, dentre outros. Para a investigação experimental foram preparados três tipos de água de estudo, com baixos valores de turbidez e cor aparente. A água tipo I era isenta de contaminação, as águas tipo II e III apresentaram coliformes totais e fecais, sendo que a água tipo III utilizada na simulação da instalação como filtro domiciliar. Os ensaios realizados apresentaram taxa de filtração entre 200 e 250 m3/m2*d. Os resultados indicam que o CAIP apresentou propriedades adsorventes e é um poderoso agente desinfetante, reduzindo significativamente o NMP de coliformes totais e fecais de águas contaminadas. Porém, a desinfecção não foi completa e ocorreu excessivo desprendimento da prata do CAIP, inviabilizando o uso deste CAIP nesta instalação desenvolvida. / Minding the existence of many communities within the state of São Paulo (and other Brazilian states) which often use water unfit for human consumption, this work aims at the development of a filtering installation that uses Activated Carbon supporting Silver (AC(Ag)) in an attempt to eliminate any contamination in treated water. Such water contamination problems include, operational anomalies in the WTP, inadequate treatment technologies, contamination in the distribution net, and other filter specific problems. For the experimental investigation three types of test water were prepared, with low turbidity and apparent color values. Water type I was contarnination-free, water type II and III had total and fecal coliforms, and water type III was used in the simulation of domestic filtering installation. Tests showed a filtering rate between 200 and 250 m3/m2*d. Results point that AC(Ag) has adsorbent capabilities, in addition to being a powerful disinfection agent, and reduced significantly the number of total and fecal coliforms of contaminated waters. However, disinfection was not thoroughly, and silver was excessively dragged away, from the Activated Carbon, thus rendering the use of AC(Ag) unadvisable in the developed installation.

Benzodiazepines (Benzos) and ketamine (K) are compounds that have been encountered in Drug-Facilitated Sexual Assault (DFSA) cases. Due to the intimate nature of these crimes, evidence collection is often postponed due to delays and/or reluctance in reporting these crimes. Further delays in analysis may be encountered in laboratories with large caseloads and/or backlogs. Drug identification in biological samples is important to determine whether victims knowingly or unknowingly took an impairing substance, however, the results could be negative due to chemical degradation over a long storage period. The purpose of this project was to study if degradation could be prevented with a new preservation method at the time of collection. Urine samples were prepared by the addition of K and metabolites and selected benzos and metabolites that were subjected to different sample pre-treatment techniques, and were analyzed after storage at room temperature (25°C), refrigerator (4°C) and freezer (-20°). The samples were either pre-treated with preservative (0.5% toluene) or filtration sterilization (sterile filter kit) within two hours after sample collection, and a control group with no pre-treatment was incorporated into the study for comparison. The changes in concentrations over 50 days (Benzos group) and 210 days (K group) were evaluated between different pre-treated methods and different temperature conditions. Sample that were treated with 0.5% toluene showed the most degradation: 44% of oxazepam and 96% of diazepam degraded over 10 days, and 80% of dehydronorketamine degraded after storage of 150 days regardless the temperature conditions. Clonazepam and flunitrazepam concentrations were reduced by 80% of the original concentration when stored at room temperature for 10 days. The major benzodiazepines evaluated in this study were stable when stored in the freezer. In K group, ketamine and norketamine that were stored at room temperature and refrigerated over 210 days were stable, however, degradation was observed after 150 days when the samples were stored in the freezer. There was no statistically different change observed among the samples pre-treated with or without filtration sterilization. Each sample pH was measured and it was determined that those stored at room temperature had an average pH of 8.5, while samples stored in the refrigerator and freezer had an average pH of 6.7 and 6.5, respectively. This finding revealed that pH could be the major factor affecting compound degradation rather than the bacterial contamination with high pH contributing to degradation, and low pH potentially preventing sample lost.

The transesterification of lipids extracted from algae makes up the third generation of biodiesel production. The city of Logan, Utah, proposes that the algae used from the 460-acre wastewater pond could potentially be used for the production of biofuel that could serve as transportation fuel for the City solid waste vehicles. Separating the algae from the Logan Lagoon wastewater is the most expensive portion of the biodiesel process and the application of chemical flocculation can significantly increase costs and potentially interfere with biodiesel production. Cross flow filtration has been identified for algae harvesting, and experiments were conducted to evaluate materials and operating conditions for separating and harvesting algae from the Logan Lagoon system. Two cross flow filtrations units were used to conduct experiments. A pilot-scale cross flow filtration unit provided by WesTech, Inc., Engineering (Salt Lake City) with a 0.2-micron nylon membrane mesh was used for mixed-culture algae harvesting. In addition, a bench scale cross flow filtration unit was provided, and tests were conducted to further examine the effectiveness of cross flow filtration on pure-culture algae harvesting. A 1-micron nylon, 5-micron nylon and 5-micron polyester mesh were used with this system. The WesTech, Inc., Pilot Scale System demonstrated that the type of membrane used was critical for effective algae harvesting. Test results showed that the algal cake that developed on the membrane and that the amount of algae harvested decreased with flux. The bench scale unit demonstrated that more algal cells were collected when a membrane of a larger pore size was used. The 1-micron nylon mesh proved to be the most effective at concentration algae. The 5-micron polyester mesh was shown to be more effective than the 5-micron nylon mesh. The results in this thesis show that cross flow filtration is a feasible option for the City of Logan Environmental Department and is a technical option for algal harvesting for biofuel production.

In order to meet increasing water demands and more stringent regulations drinking water treatment plant managers must continually look to new treatment strategies and optimization techniques. One such strategy is to eliminate chlorine residual before filtration, allowing indigenous bacteria already present in the source water to grow on the filter media. These microorganisms help improve effluent water quality by increasing organic and inorganic contaminant removal. The process is known as biological filtration, or biofiltration. The implications of converting a conventional filtration plant (not specifically designed for biofiltration) to a biofiltration plant are still not well understood. Therefore, the purpose of this study was to evaluate water quality and operational trends of a side-by-side full-scale biofiltration conversion at the Quail Creek Water Treatment Plant (QCWTP), located in Hurricane, Utah, and to determine the impact of pre-chlorination elimination on filter performance. Four of twelve filters at the QCWTP were used to test the plant’s ability to operate in biological mode. One acted as a control and ran similar to the other eight filters in the treatment plant. The other three were converted to biofilters by quenching the influent chlorine residual with thiosulfate. The experiment lasted one year, so filter performance could be evaluated in each season. The results from the study indicated that the influent water was low in organic carbon (i.e. food for microorganisms), which resulted in small differences in biological activity between filters. Disinfection by-products (DBPs) (i.e. cancer causing agents created from the combination of chlorine and organic matter) were lower in the biofilters relative to the control. Biological conversion resulted in slightly higher and more variable final effluent turbidity values (though still within EPA drinking water standards and operational goals) compared to the non-biological filters; however, filter run times were unaffected.

<p>Cake filtration is a unit operation to separate solids from fluids in industrial processes. The build up of a filter cake is usually accompanied with a decrease in overall permeability over the filter leading to an increased pressure drop over the filter. For an incompressible filter cake that builds up on a homogeneous filter cloth, a linear pressure drop profile over time is expected for a constant fluid volume flow. However, experiments show curved pressure drop profiles, which are also attributed to inhomogeneities of the filter (filter medium and/or residual filter cake).</p><p>In this work, a mathematical filter model is developed to describe the relationship between time and overall permeability. The model considers a filter with an inhomogeneous permeability and accounts for fluid mechanics by a one-dimensional formulation of Darcy's law and for the cake build up by solid continuity. The model can be solved analytically in the time domain. The analytic solution allows for the unambiguous inversion of the model to determine the inhomogeneous permeability from the time resolved overall permeability, e.g. pressure drop measurements. An error estimation of the method is provided by rewriting the model as convolution transformation.</p><p>This method is applied to simulated and experimental pressure drop data of gas filters with textile filter cloths and various situations with non-uniform flow situations in practical problems are explored. A routine is developed to generate characteristic filter cycles from semi-continuous filter plant operation. The model is modified to investigate the impact of non-uniform dust concentrations.</p>

Cost-effective processing of dairy whey permeates is important to the environment and economics of the agriculture industry in Canada. Bioconversion of whey permeates is an attractive means of obtaining value-added adjuncts with improved nutritional and functional properties. In the past, cost-effective technologies to recover additional value from whey permeates at a low cost were lacking. Currently, such a technological platform is now feasible with the introduction of new modern bioconversion technologies that incorporate batch or continuous bioreactors, and use ultra- and nano-filtration membranes for the separation of whey permeate components. In this dissertation, a novel processing methodology is described. This methodology, which is a desirable configuration for food manufacturers includes a stirred batch nanomembrane bioreactor equipped with a crossflow nanomembrane and offers lactose bioconversion with an immobilized biocatalyst, product separation, and biocatalyst recovery in a batch operation. The major focus of this research was on: a) the development of a new analytical methodology for carbohydrate measurement during the lactose bioconversion process, b) the selection, testing and integration of highly selective nanomembranes to separate the desired substrates, whey permeate carbohydrates, from the reaction mixture, and c) the production of a stable and highly active and specific immobilized biocatalyst. Noticeably, this methodology was designed, developed and tested for the bioconversion of lactose, but could also be used for the bioconversion of other carbohydrate feedstocks. The food industry in Canada needs an integrated approach to achieve complete lactose reclamation and use. This research project offers such a solution. The research described in this dissertation presents an integrated model of a stirred batch bioreactor that may support not only current, but also future research, and may economically impact the development and bioconversion of whey permeates containing lactose. This may lead to the development of a continuous processing methodology for low cost recovery of lactose from whey permeates and simultaneous conversion to value-added products. / Bioresource and Food Engineering

The influence of particle shape of coating pigments on theirpacking ability and on the flow properties of coating colourshas been investigated. The particle shapes considered werespherical, flaky and acicular (needle-shaped). In the case ofsuspensions containing monodisperse spherical polystyreneparticles, a concentration gradient appeared in the filter cakeforming during filtration under static conditions. Such agradient, monitoredby non-destructive magnetic resonanceimaging (MRI), is not accounted for in the traditionalfiltration theory used in coating technology. Good agreementwas found between a literature model describing filtrationthrough a compressible filter cake and the concentrationgradients measured by MRI. According to this model, the scaledconcentration gradient was the same at all times. For flaky (mainly kaolin) and acicular (aragonite)particles, a rapid method was evaluated to estimate a shapefactor of the pigment particle. Generalised mathematical modelsof oblate and prolate spheroids were applied to reduce thethree geometrical dimensions of the particle to two, the majoraxis and the minor axis. The shape factor, which is mass-based,was derived from a comparison between the results obtained bytwo different size-assessment instruments, viz. the Sedigraphand an instrument using light scattering. This yields a shapefactor distribution as a function of equivalent sphericalparticle size, but the results are uncertain for small particlediameters, below 0.2 µm. Good agreement was obtainedbetween the shape factor and a mass-based aspect ratio obtainedby image analysis, but the rapid method is generally moreaccurate for flaky than for acicular particles. Results obtained by capillary viscometry showed that therewas a relationship between the viscosity at high shear rates(&gt;105s-1) and the shape factor, but that it was notsufficient to use the median value of the shape factor toachieve proper information. A more complete evaluation requiresknowledge of the shape factor distribution, which is also givenin part by the method mentioned above. However, a large medianshape factor was related to a high high-shear viscosity.Non-Newtonian entrance pressure losses were sometimessignificant in capillary viscometry, indicating that it wasinappropriate to measure the shear viscosity with only onecapillary. Such effects were however relatively much morepronounced in slit die viscometry, especially in the case ofacicular particles, where the aspect ratio was a crucialparameter. The influence of the shape factor of kaolinparticles on the non-Newtonian entrance pressure losses over aslit die was surprisingly small. The high-shear viscosity ofcoating suspensions based on different pigments correlated withthe median pore size of the corresponding coating layer ratherthan with the porosity. <b>Keywords</b>: Aspect ratio, capillary viscometry, coatingcolour, filtration, particle packing, pigment, pore structure,rheology, shape factor, slit die viscometry, spheroid.

Cake filtration is a unit operation to separate solids from fluids in industrial processes. The build up of a filter cake is usually accompanied with a decrease in overall permeability over the filter leading to an increased pressure drop over the filter. For an incompressible filter cake that builds up on a homogeneous filter cloth, a linear pressure drop profile over time is expected for a constant fluid volume flow. However, experiments show curved pressure drop profiles, which are also attributed to inhomogeneities of the filter (filter medium and/or residual filter cake). In this work, a mathematical filter model is developed to describe the relationship between time and overall permeability. The model considers a filter with an inhomogeneous permeability and accounts for fluid mechanics by a one-dimensional formulation of Darcy's law and for the cake build up by solid continuity. The model can be solved analytically in the time domain. The analytic solution allows for the unambiguous inversion of the model to determine the inhomogeneous permeability from the time resolved overall permeability, e.g. pressure drop measurements. An error estimation of the method is provided by rewriting the model as convolution transformation. This method is applied to simulated and experimental pressure drop data of gas filters with textile filter cloths and various situations with non-uniform flow situations in practical problems are explored. A routine is developed to generate characteristic filter cycles from semi-continuous filter plant operation. The model is modified to investigate the impact of non-uniform dust concentrations.