Academic literature on the topic 'Industrie de granulat'

Aus Polyethen aus Haushalt und Industrie wird erstmals auf Zypern ein hochwertiges Granulat frei von Lufteinschlüssen zur Wiederverwertung hergestellt. Dies ist auf dem Inselstaat ein großer Schritt in Richtung Kreislaufwirtschaft.

Granular products are widely used in many industries for the production of catalysts in oil refining and organic synthesis, drugs, food products, fertilizer production, etc. The main advantages of granular products are ease of operation and storage. Depending on the morphological structure, the granules obtained as a result of the technological process are divided into one-component, single-layer, composite-coated granule, multilayer granule, frame granule, and combinations thereof. In this paper, we consider, as an example, the technological basis of granulation of aqueous solutions of ammonium sulfate with impurities of humates, calcium carbonate and other substances with the formation of multilayer composite granules in a fluidized bed granulator. The processes of dehydration and mass crystallization during granulation, namely the influence of the drying rate and impurities on the kinetics of the evaporation process of the dispersed heterogeneous solution on solid particles have been studied. In the process of mass crystallization, when the saturation concentration is reached by removing the solvent, the processes of nucleation and crystal growth occur with the formation of a crystalline framework of ammonium sulfate crystals between, which impurities of organic matter and other components are evenly distributed in the volume of the formed micro layer. It was confirmed that the obtained granules of the composite granular fertilizer have a composite multilayer structure with a uniform distribution of suspended particles in the volume of the granule. Bibl. 14, Fig. 4.

Granulate material sorting is a mature and well-developed topic, due to its presence in various fields, such as the recycling, mining, and food industries. However, sorting can be improved, and artificial intelligence has been used for this purpose. This paper presents the development of an efficient sorting system for transparent polycarbonate plastic granulate, based on machine vision and air separation technology. The developed belt-type system is composed of a transparent conveyor with an integrated vision camera to detect defects in passing granulates. The vision system incorporates an industrial camera and backlight illumination. Individual particle localization and classification with the k-Nearest Neighbors algorithm were performed to determine the positions and conditions of each particle. Particles with defects are further separated pneumatically as they fall from the conveyor belt. Furthermore, an experiment was conducted whereby the combined performances of our sorting machine and classification method were evaluated. The results show that the developed system exhibits promising separation capabilities, despite numerous challenges accompanying the transparent granulate material.

The research aims to establish the eff ectiveness of granular chalk use produced by «Slavuta-Calcium» Ltd. under growing Poliska–90 winter wheat variety, changing the physicochemical properties of grey forest soil and the wheat productivity. It also aims to establish optimal dosis of «Slavuta-Calcium» granular chalk as the meliorant and mineral fertilizer for grey forest soil in the system of winter wheat fertilization. In the temporary fi eld studies, various doses of nutrients N60–90–120P30–45–60K60–90–120 combined with «Slavuta–Calcium» granular chalk in a dose of Ca230–460–690 kg/ha of the active substance were studied against the background of secondary plowing of rotation products – soybean biomass that averaged 2.34 t/ha. Granular chalk is a modern complex highly eff ective meliorant with the content of Ca – 37.7 and Mg – 0.2 %, the mass fraction of carbonates (CaCO3 + MgCO3) makes at least 95 %. It is characterized by a high level of solubility when interacting with moisture in soil. It has a form of white granules, the mass fraction of 4.0–6.0 mm in size granules makes not less than 90 % and the one of 1.0 mm in size makes less than 5 %. Reactivity – 97 %. The granular chalk is advisable to apply on acidic soils, as a highly concentrated calcium-magnesium fertilizer, with the former as the dominant fertilizer, to optimize the physicochemical properties of the soil, as well as the plant nutrition system, in particular, increasing the availability of an element for assimilation by plants and as long-term ameliorants. The eff ectiveness of the use of mineral fertilizers, in particular acidic nitrogen on highly and medium acidic soils, after chemical reclamation is increased by 30–50 %, and slightly acidic by 15–20 %. The increase in productivity of crops from the combined eff ects of nutrients and chalk granulated is usually higher than when separately applied. The eff ectiveness of the integrated action of these elements is manifested in the growth of plant productivity and the quality of the resulting products, as well as the optimization of physical chemical properties and soil buff ering in the long term. In order to optimize the physicochemical properties of the arable layer of gray forest soil and the productive nutrition of agricultural crops, winter wheat, in particular, biogenic elements should be used in doses N60-90-120P30-45- 60K60-90-120 with granulated chalk «Slavuta-Calcium» in doses of Ca230-460-690 kg/ha of active substance. Granulated chalk obtained as a result of industrial grinding of solid sedimentary carbonate rocks of natural origin, subsequently under the infl uence of the granulation process of the starting material contains Ca and Mg carbonates of at least 95 %, dense granules which facilitates convenient mechanized application, as well as chalk suitable for accurate metered application on the quest map. Key words: granular chalk, gray forest soil, chemical reclamation, crop productivity.

This work concerns non-pressure granulation of mineral materials used for the production of agricultural fertilizers for soil deacidification. In order to expand the product range of Nordkalk Poland sp. z o. o. located in Poland, the granulation conditions of the gypsum–lime mix were examined with the use of various granulation methods. The processed mixture was Jurassic lime flour mined in the Sławno mine (Poland) and waste gypsum (sulfogypsum) obtained from the largest coal-fired power plant in the EU, Bełchatów Power Plant (Poland). This paper presents the results of the optimization of the gypsum–lime fertilizer granulation process. The results of the study of granulation of gypsum–lime mixture realized in one-stage technology in a disc granulator were compared with the effects of two-stage agglomeration. During the research, a mixture (in a 1:1 ratio) of waste sulfogypsum and lime flour was used. Such a weight ratio provides maximum use of the sulfogypsum waste while maintaining good mechanical properties of the granulate. The granulated bed was moistened with a lignosulfonate solution. The process was carried out periodically. After the experiment, the grain composition of the granulate obtained was determined and tests were performed to determine the strength of the product. The test results were compared with analogous ones obtained during granulation with the use of molasses (waste from sugar production). The results obtained were verified during a trial carried out on an industrial scale.

Plastic film granulating machine is an industrial machine used for reducing plastic materials, mostly for grinding plastic into granules of uniform sizes for further processing either into new plastic shapes or recycled back to its parental source. This paper presents the use of locally sourced materials for realising the same machine; reducing its size and cost, while maintaining high efficiency, as well as decrease in vibration and increased shear efficiency with uniform size of granules. The machine consists of the hopper, the grinding chamber in which contains the shaft and cutting blades with a discharge unit. The plastic film granulator has a capacity of granulating 1kg of recycled plastic in 1h at 75% efficiency, a working revolution of 3000rpm, and power rating of 5.5hp engine. The machine works by principle of shearing, power is transferred from the motor to the granulating shaft with the aid of a transmission coupler that connects them. The inlet plastics are granulated until the desired size is achieved, small enough to pass through the discharge screen.

When preparing the polyamide-6 granulate for treatment proceses, its properties such as the content of low-molecular compounds (caprolactam and oligomers, LMC) and relative viscosity are normalized. Two alternative methods of preparing the polyamide-6 granulate for proceesing are used: 1) currently, the industry uses a method consisting of stages of aqueous extraction of low-molecular compounds from PA-6 granules, followed by drying of the latter and separation of LMC from extraction solutions by evaporation; 2) an alternative process is being developed, which consists in simultaneously carrying out the drying and demonomerization of polyamide-6 granulate. Through of these methods samples of granulate of polyamide-6 of 2 kinds were prepared: 1) equilibrium matted granulate of industrial production; 2) granules after solid-phase dopolyamination in a superheated steam environment. These samples were conversed by the re-melting method, which consists in melting the polyamide-6 granulate at T = 270 °C. The properties of these samples were determined before and after the conversion using the following methods: the content of low molecular weight compounds is determined by their extraction from granules. The content of caprolactam is determined by its sublimation from granules; the value of the relative viscosity is determined by viscometry. It is shown that during the process of conversion of the polyamide-6 granulate, the polymer acquires practically the same properties, regardless of the preparation method. Thus, it is proved that the process of combined drying-demonomerization is more advantageous in terms of energy and material costs than the process of extraction of low-molecular compounds from the polyamide-6 granulate.Forcitation:Barannikov M.V., Bazarov Yu.M. Influence of methods of preparing polyamide-6 to processes of treatment on properties of finished product. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 72-75

Today there is the problem of fine water purification during its consumption and disposal in industry from impurities of water-soluble organic compounds that enter it with pharmaceutical, cosmetic preparations, food waste, waste from the textile and chemical industries. Diatomite is a good raw material for the production of these adsorbents. It is found that diatomite is the mesoporous sorbent. The permeability of diatomite can be increased by granulating of the rock. It is found that heat treatment is necessary to obtain more durable granules from diatomite: when the increasing in the temperature of heat treatment of granules the compressive strength of granules increases too. At the same time, when the temperature of the heat treatment is increasing, the equilibrium adsorption of methylene blue on diatomite granules is decreasing. The optimum temperature for the heat treatment of granules is 550 °C. It is found that the heat treatment and granulation of diatomite do not have a significant impact on the adsorptive-structural properties of the rock: up to 70 % of the pore volume of granules is the volume of mesopores. The powdered adsorbent from diatomite which can be obtained by the developed laboratory method can be used in industrial water purification schemes where static adsorption is used for fine water purification. Using the developed laboratory method for producing granular adsorbent from diatomite, it is possible to produce an adsorbent for water purification under dynamic adsorption conditions, where a high value of the sorbent permeability is important.

An autotrophic denitrification system was developed for nitrate contaminated industrial wastewater whose C/N ratio was very low. The microbes containing Thiobacillus denitrificans as a dominant species were attached on the surface of granular elemental sulfur packed in a column. Elemental sulfur was used as an electron donor for autotrophic denitrification. The granules of limestone were mixed with the granular sulfur to moderate the decrease of alkalinity during autotrophic denitrification. The stoichiometry and basic kinetics of denitrification were studied in column runs. The effects of minerals such as phosphorus on treatment performance were clarified. The wastewater from steel production plants was treated by the present biofilm process. Low extent of nitrogen removal was caused by the lack of minerals.

Abstract Polymeric materials, which are currently very often used in various industries, are often transported and stored in the form of granules before processing. This method has several advantages, but in most studies the test samples are modified to different shapes and dimensions. This paper is therefore focused on the initiation of selected granular plastics. Samples of five polymeric materials were exposed to an external heat flux from 20 kW.m−2 to 40 kW.m−2. A spark initiator was used to ignite the released gaseous products of thermal decomposition of the polymer sample. FTP (flow-time product) method was applied to the obtained parameter - time to ignition, from which other initiation parameters were determined. The critical heat flux was determined in the range of 5.0 kW.m−2 - 11.8 kW.m−2. Despite the relatively small thickness (4 mm), the samples behaved as thermally thick. During the measurement, thin surface layer melted, and the rest of the polymer remained in its original granulated form. Ignition temperatures were calculated according to the Stefan-Boltzmann’s law between 273 °C - 402 °C.

Les floculants à base de polyacrylamide (PAM) sont produits à partir du monomère toxique : l’acrylamide (AMD) et peuvent en contenir des quantités résiduelles (jusqu’à 0,1% en Europe). Après utilisation pour faciliter la séparation solide/liquide des eaux de procédés dans les industries de granulat, ces floculants sont stockés avec les boues de décantation dans des lagunes à partir desquelles une dissémination de l’AMD et du PAM vers les eaux de surface ou les eaux souterraines peut avoir lieu. Dans ces travaux de thèse, les interactions du PAM et de l’AMD avec des particules de boue et des phases argileuses (kaolinite et illite, utilisées pour étanchéifier les lagunes de décantation) ont été étudiées. Pour pouvoir quantifier correctement l’AMD, une méthode d’analyse basée sur la HPLC/MS/MS en injection directe a été développée. Cette méthode a été validée avec les normes Afnor NF T 90-210 et NF T 90-220 avec une limite de quantification égale à 1 µg/L. L’étude de l’interaction de l’AMD avec des particules de boue d’un site de granulat et deux argiles (kaolinite et illite) a mis en évidence une faible adsorption de l’AMD sur ces phases solides (<10%), indépendante du temps, de la concentration en AMD et du pH. Inversement, le PAM s’adsorbe fortement et irréversiblement sur la boue, la kaolinite et l’illite avec une cinétique rapide de 1er ordre. Les isothermes d’adsorption sont bien corrélées avec les modèles de Langmuir et de Freundlich. Les quantités d’adsorption du PAM sont indépendantes du pH des suspensions mais fortement impactées par la force ionique qui influence les interactions électrostatiques entre le PAM et les surfaces solides
Polyacrylamide (PAM) based floculants are produced from the highly toxic acrylamide (AMD) monomer and can contain residual amounts (up to 0.1% in Europe) of AMD. After they are used to facilitate liquid/solid separation of process water in aggregate quarries, PAM floculants are stored, with the sewage sludge, in decantation lagoons. Dissemination of AMD and PAM to groundwater and surface water from these lagoons can occur. In this work, we aimed to study the interactions of AMD and PAM with sludge particles and clays (kaolinite and illite used for decantation lagoon sealing) from aggregate quarry. To correctly quantify the AMD, analytical method based on HPLC/MS/MS with direct injection was developed. This method was validated according to the Afnor guidelines (NF T 90-210 and NF T 90-220) with a limit of quantification of 1 µg/L. Results of AMD adsorption experiments showed a low adsorption of AMD to sludge and clay (kaolinite and illite) particles, which is independent of time, AMD concentration and pH. Inversely, PAM was found to adsorb strongly and irreversibly to sludge, kaolinite and illite with a rapid kinetic of adsorption which consists of first order kinetic. Adsorption isotherms are well correlated with Langmuir and Freundlich models. PAM adsorption quantities are independent on the pH of suspensions, but are strongly impacted by the ionic strength which affects electrostatic interactions between PAM and solid surfaces

El presente estudio tiene por finalidad determinar la viabilidad de la instalación de una planta de producción de panela granula en la región de Lima a través del desarrollo de los principales aspectos comerciales, tecnológicos y financieros. Se desarrolló el estudio de mercado para definir el mercado meta al cual irá el producto, que está conformado por los habitantes de Lima Metropolitana de 18 a 60 años de edad del sector socioeconómico A con un estilo de vida sofisticado1. Utilizando esta segmentación y las encuestas realizadas para medir la intención e intensidad de compra del producto se determinó que la demanda del proyecto será de 177 toneladas de panela granulada para el último año del mismo
This project aims to determine the feasibility of installing a production plant of granulated panela in the region of Lima through the development of major commercial, technological and financial aspects. A market research was developed to define the target market of the product, which is conformed by the inhabitants of Lima from 18 to 60 years of socioeconomic sector A with a sophisticated lifestyle2. Using this segmentation and surveys to measure the intent and intensity of purchase, it was determined that the demand of the project is 177 tons of granulated panela for the last year of it.
Trabajo de investigación

Granular media continue to be among the most manipulated materials found in various industries. Particle interactions in granular flow has fundamental importance in analyzing the performance of a wide range of key engineering applications such as hoppers, tumblers, and mixers etc. In spite of such ubiquitous presence, till date, our understanding of the granular flow is very limited. This restricts our ability to design efficient and optimal granular processing equipment. Additionally, the existing design abilities are also constrained by the number of particles to be analyzed, where, a typical industrial application involves millions of particles. This motivated the current research where investigations on the above limitations are pursued from three different angles: experimental, theoretical, and simulation. More specifically, this work aims to study particle-wall interaction and developing a computationally efficient cellular automata simulation framework for industrial granular applications. Towards this end, the current research is divided into two part: (I) energy dissipation during particle-wall interaction (II) cellular automata modeling. In part I, detailed experiments are performed on various sphere-thin plate combinations to measure the coefficient of restitution (COR) which is a measure of energy dissipation and it is one of the most important input parameters in any granular simulation. Alternatively, the energy dissipation measure also used to evaluate the elastic impact performance of superelastic Nitinol 60 material. Explicit finite element simulations are performed to gain detail understanding of the contact process and underlying parameters such as contact forces, stress-strain fields, and energy dissipation modes. A parametric study reveals a critical value of plate thickness above which the effect of plate thickness on the energy dissipation can be eliminated in the equipment design. It is found that the existing analytical expressions has limited applicability in predicting the above experimental and numerical results. Therefore, a new theoretical model for the coefficient of restitution is proposed which combines the effect of plastic deformation and plate thickness (i.e. flexural vibrations). In part II, in order to advance the existing granular flow modeling capabilities for the industry (dry and slurry flows) a cellular automata (CA) modeling framework is developed which can supplement the physically rigorous but computationally demanding discrete element method (DEM). These include a three-dimensional model which takes into account particle friction and spin during collision processing, which provides the ability to handle flows beyond solely the kinetic regime, and a multiphase framework which combines computational fluid dynamics (CFD) with CA to model multi-million particle count applications such as particle-laden flows and slurry flows.

Au Québec, des milliers de tonnes de résidus de béton sont issus de la démolition des infrastructures et des milliers de tonnes de verre sont récupérés annuellement. Seulement près de la moitié de ces résidus sont réutilisés. La pression pour trouver des applications potentielles permettant une réutilisation optimale de ces résidus de démolition est grandissante. Dans un contexte de développement durable, la ville de Montréal a comme défi de réutiliser tous les matériaux de démolition qu’elle génère et tout le verre qu’elle récupère. Ce projet de recherche, financé par la ville de Montréal, s’inscrit donc dans une perspective de valorisation des matériaux recyclés et de développement de matériaux innovants et durables. L’objectif de cette étude de recherche est d’étudier et d’évaluer les divers potentiels d’application des granulats de béton recyclé et des granulats de verre recyclé dans les bétons compactés au rouleau. Le programme d’essais réalisé dans le cadre de cette étude comporte quatre phases. Dans un premier temps, des essais réalisés sur les matériaux recyclés ont permis de mieux les caractériser afin de formuler des mélanges de BCR optimaux. Par la suite, les propriétés à l’état frais et les propriétés mécaniques des BCR ont été réalisées en laboratoire. L’analyse de ces propriétés a permis de déterminer un taux de remplacement optimal. Ce taux de remplacement a été utilisé afin d’évaluer l’impact sur la durabilité des mélanges. Finalement, des analyses sommaires ont été réalisées afin de démontrer l’impact économique et environnemental d’un remplacement granulaire par des MR-2 dans les BCR. Les travaux de recherches ont montré qu’un remplacement granulaire par des matériaux recyclés affecte les propriétés à l’état frais, les propriétés mécaniques et la durabilité des BCR. Il a été montré qu’un taux de remplacement de ± 40 % dans le cas des granulats de béton recyclé et de ± 25 % dans le cas des granulats de verre recyclés permet d’obtenir un BCR présentant des propriétés satisfaisantes. Finalement, des analyses sommaires démontrent que l’utilisation de matériaux recyclés dans les BCR est profitable tant en matière économique et qu’en matière environnementale.

The supply and bulk handling of raw materials is of fundamental importance in many facets of the manufacturing community, the scope of which ranges from mining to pharmaceuticals and critical aspects of steel production. This thesis is based on the development of a 3D spherical ''Discrete Element Method" (DEM) modelling code to assist in the computer simulation of granular flow through a steelworks industrial environment. Presented in this work is a thorough evaluation and review of DEM techniques, highlighting the variety of discrete elements, contact special searches and contact interaction forces. Also addressed here is a validation of the current DEM Fortran code, using the effects of frictional forces on particulate flowing behaviour, in terms of "Angles of Repose". The introduction of these forces followed a "Linear Spring Dash-pot" (LSD) method and "Soft Sphere" approach where contact penetration is small in comparison with element diameter. Both surface and boundary deformations were neglected during contact interaction and boundary conditions were implemented using a "Solid Works" 3D design package. The results of the validation and frictional inputs in this modelling case were used as a calibration to set initial parameters of the discrete elements when simulating different material size distributions, and inter-particulate bonding scenarios due to the influence of moisture. To introduce attractive force due to moisture a "Toriodal Approximation'' was used in conjunction with the "Soft Sphere" method that showed novelty in contact interactions between elements of differing radii. The model was ultimately applied to practical material flow situations that exhibit system deterioration and inter-particulate degradation leading to atmospheric dust suspension. To express quantitive information kinetic energy transfer was recorded at boundary impact scenarios to isolate regions of severe momentum change and high intensity flow rates. The resulting energy trend examinations relating to extensive theoretical application of the current model correlated strongly with actual equipment damage and material flow patterns. The acquisition of data in this format delivers a 3D insight into the internal dynamics of material flow through a domain and could be essential in developmental optimisation.

Esta tesis doctoral versa sobre la eliminación simultánea de compuestos fenólicos con reactores de biomasa granular trabajando en continuo. El estudio está dividido en dos partes principales; el primer tema trata sobre la modelización de la nitritación, mientras que el otro está dedicado al trabajo experimental sobre la nitritación y eliminación simultánea de compuestos fenólicos. En el estudio de modelización, se desarrolló un modelo matemático de biopelícula para describir la nitritación en reactores de biomasa granular aerobia operando en continuo. El modelo incorpora una estrategia de control del ratio [DO]/[TAN], para mantener un valor deseado de la relación entre las concentraciones de oxígeno disuelto (DO) en el efluente del reactor y nitrógeno amoniacal total [TAN]. El modelo se validó con un gran número de datos experimentales previamente publicados en la bibliografía, así como con datos obtenidos de reactores granulares tratando agua de rechazo a escala laboratorio y piloto. El modelo se utilizó para estudiar el efecto de: a) las consignas de DO y TAN, b) la temperatura de operación, c) las características de la biopelícula (tamaño de partícula, densidad) y d) la concentración de amonio en el afluente, sobre la consecución de la nitritación completa. Los resultados indicaron que la nitritación completa se mantuvo estable y se potenció usando la estrategia de control de la proporción [DO]/[TAN] en la operación del reactor de biomasa granular aerobia. Además, el modelo predijo que gránulos aerobios mayores a 1.5 mm y concentraciones altas de amonio en el afluente potenciaba la obtención de nitritación completa estable, mientras que la densidad de biopelículas tenía poca influencia en este estudio. Además se demostró que era posible la nitritación total a bajas temperaturas con reactores de biomasa granular. Para el trabajo experimental, se utilizó un reactor tipo airlift. Para la puesta en marcha del reactor, se utilizó como inóculo biomasa de un reactor de biomasa granular aerobia que realizaba eliminación de nutrientes. Como alimento del reactor se utilizó un agua residual sintética con un alto contenido de amonio (950 ± 25 mg N L-1). El reactor se operó hasta la obtención de nitritación parcial. Una vez obtenida la nitritación parcial, el reactor se bioaumentó con un lodo activo que contenía biomasa degradadora de p-nitrofenol (PNP) para mejorar el crecimiento de microorganismos degradadores de fenol sobre los gránulos nitrificantes. Acto seguido, mientras el reactor trataba una carga elevada de amonio, se añadieron progresivamente al afluente o-cresol (hasta 100 mg L-1) o PNP (hasta 15 mg L-1), siendo éstos alimentados al reactor con el objetivo de estudiar la nitritación parcial simultánea a la eliminación de o-cresol o de PNP. En el estudio de la nitritación parcial simultánea a la eliminación de o-cresol, se mantuvo el proceso de nitritación parcial estable durante más de 100 días de operación. Además, se obtuvo una biodegradación completa de o-cresol durante todo el periodo experimental. También se realizaron choques de carga de o-cresol, durante los cuales el proceso de nitritación parcial se mantuvo estable y sin verse afectado por esos eventos. Las cargas volumétricas obtenidas de nitrógeno (NLRV) y de o-cresol (CLRV) fueron de 1.1 g N L-1 d-1 y 0.11 g o-cresol L-1 d-1, respectivamente. El análisis de hibridación in situ de fluorescencia (FISH) indicó que en los gránulos había presencia del género Acinetobacter, de bacterias amonio-oxidantes betaproteobacteriales y de Nitrobacter sp. Posteriormente, se continuó con la operación del reactor, y se llevó a cabo un experimento relacionado con el funcionamiento del reactor bajo tres escenarios de alternancia secuencial de contaminantes (SAP). En cada uno de los escenarios SAP se añadieron 15 mg L-1 de compuestos fenólicos secundarios (i.e. PNP, fenol y 2-clorofenol (2CP)) al afluente por un periodo de tiempo corto (entre 20 y 25 años). Los resultados ilustraron que se mantuvo la nitritación parcial y la biodegradación de o-cresol sin mostrar ningún signo de inhibición por la presencia de PNP o de fenol. Sin embargo, en presencia de 2CP en el afluente, se registró durante tres días un 90% de la nitritación parcial y un 25% de la degradación de o-cresol. Estos resultados sugieren que las bacterias amonio oxidantes (AOB) son mas sensibles a la inhibición por 2CP que las heterótrofas (degradadoras de o-cresol). En el estudio de la nitritación simultánea a la eliminación de PNP, se mantuvo la nitritación durante la mayor parte del periodo operacional, obteniéndose un efluente adecuado para la desnitrificación heterotrófica. Sin embargo, durante los primeros 175 días, la biodegradación de PNP fue inestable, observándose diversos episodios de acumulación de PNP. Esta acumulación se determinó que era debida a las condiciones limitantes de DO. El incremento de la concentración de DO en el reactor de 2 a 4 mg O2 L-1 permitió obtener eliminación completa y estable de PNP hasta el fin del periodo experimental. Las NLRV y la carga de PNP obtenidas fueron de 1.0 g N L-1 d-1 y 16 mg PNP L-1 d-1, respectivamente. Además, se evaluó el funcionamiento del reactor realizando dos estudios de hambruna, i) hambruna de PNP y ii) hambruna total (parada del reactor). Los resultados mostraron que 2 días después al fin del periodo de hambruna se obtuvo una recuperación total de la degradación de PNP, mientas que la recuperación total de la nitritación simultánea a la eliminación de PNP se consiguió solo 11 después de volver a poner en marcha el reactor. En conclusión, el uso de reactores de biomasa granular aerobia para realizar nitritación simultánea a la eliminación de compuestos fenólicos es factible. Ésta podría ser considerada la mejor técnica disponible para el tratamiento aguas residuales industriales complejas con contenido de amonio en alta carga y compuestos fenólicos. Se ha probado que la biomasa granular aerobia es resistente a sobrecargas puntuales, a presencia alterna de compuestos recalcitrantes y a periodos de hambruna; estas condiciones, debido a los cambios de planificación de la producción, pueden encontrarse frecuentemente en plantas de tratamiento de aguas residuales industriales. En un futuro próximo, proponemos que la nitritación simultánea a la eliminación de compuestos fenólicos podría combinarse tanto con la desnitrificación heterotrófica o con el proceso anammox para una eliminación sostenible del nitrógeno.
The simultaneous nitritation and phenolic compounds removal using aerobic granular reactors in continuous mode were studied in this Ph.D. thesis. The study is divided into two main subjects; the first one is devoted to the modeling of nitritation while the other part is dedicated to the experimental work of simultaneous nitritation and phenolic compounds removal using granular reactors. In the modeling study, a mathematical biofilm model was developed to describe nitritation in aerobic granular reactors operating in continuous mode. The model incorporated a [DO]/[TAN] ratio control strategy to maintain the proportion between the concentrations of dissolved oxygen (DO) and total ammonia nitrogen (TAN) in the reactor effluent to a desired value. The model was validated with a large set of experimental results previously reported in the literature, as well as, data gathered from laboratory scale and pilot plant granular reactors treating reject water. The model was used to study the effect of: a) DO and TAN setpoints, b) operating temperature, c) biofilm characteristics (granules size, density) and d) ammonium concentrations in the influent on the achievement of full nitritation. The results indicated that full nitritation was stably maintained and enhanced by applying the [DO]/[TAN] ratio control strategy in the operation of aerobic granular sludge reactor. Moreover, the model predicted that aerobic granules size larger than 1.5 mm and high ammonium concentrations in the influent enhanced the achievement of stable full nitritation, while poor influence of the biofilm density was found with the simulation study. Furthermore, at low temperature, full nitritation with granular reactors was demonstrated to be possible. In the experimental work, an airlift reactor was employed. In the reactor start-up, granular sludge from a reactor performing biological nutrient removal was used as inoculum. A synthetic wastewater containing high-strength ammonium concentrations (950 ± 25 mg N L- 1) was fed into the airlift reactor. The reactor was operated until partial nitritation was obtained. Once partial nitritation was achieved, the airlift reactor was bioaugmented with pnitrophenol (PNP)-degrading activated sludge to enhance the growth of phenolic-degraders over the nitrifying granules. Immediately, o-cresol (up to 100 mg L-1) or PNP (up to 15 mg L- 1) were progressively added to the high-strength ammonium influent and fed into the reactor with the objective of studying the simultaneous partial nitritation and o-cresol removal and the simultaneous nitritation and (PNP) removal. First, in the study of simultaneous partial nitritation and o-cresol removal, a stably partial nitritation process was maintained for more than 100 days of operation. Moreover, full biodegradation of o-cresol was achieved during the whole experimental period. Also, o-cresol shock load events were applied and the partial nitritation process was kept stable and unaffected during these events. The achievable nitrogen loading rate (NLRv) and o-cresol loading rate (CLRv) were ca. 1.1 g N L-1d-1 and 0.11 g o-cresol L-1d-1, respectively. Analysis of fluorescent in-situ hybridization (FISH) indicated that Acinetobacter genus, betaproteobacterial ammonia-oxidizing bacteria and Nitrobacter sp. were present into the granules. Later, the operation of the reactor was continued, and an experiment devoted to the performance of the reactor under three sequentially alternating pollutant (SAP) scenarios was executed. In each one of the SAP scenarios, 15 mg L-1 of the secondary phenolic compounds (i.e. p-nitrophenol (PNP), phenol and 2-chlorophenol (2CP)) were added in the regular influent for a short period of time (between 20 to 25 days). The results illustrated that partial nitritation and o-cresol biodegradation were maintained without exhibiting any sign of inhibition by the presence of PNP or phenol. However, when 2CP was present in the influent, 90 % of the partial nitritation and 25 % of the o-cresol degradation was inhibited within three days. This finding suggests that the ammonia oxidizing bacteria (AOB) is more sensitive to 2CP inhibition than heterotrophs (o-cresol-degraders). Second, in the study of simultaneous nitritation and PNP removal, nitritation was maintained during most of the operation period producing an effluent suitable for heterotrophic denitrification. However, in the first 175 days, PNP biodegradation was unstable and several accumulation episodes occurred. The oxygen limiting condition was found to be the main explanation of these events. The increase of dissolved oxygen concentration (DO) in the reactor from 2 to 4 mg O2 L-1 permitted to achieve complete and stable PNP removal till the end of the experimental period. The achieved NLRv and PNP loading rate (PNP-LRv) were ca. 1.0 g N L-1d-1 and 16 mg PNP L-1d-1, respectively. Besides, the performance of the reactor was further assessed by performing two starvation studies, i) PNP starvation and ii) total starvation period (reactor shutdown). Results show that full recovery of PNP degradation was achieved within 2 days after the PNP starvation period ended, while full recovery of simultaneous nitritation and PNP removal was accomplished in just 11 days after the restart of the reactor. In conclusion, the use of continuous aerobic granular reactors for the simultaneous nitritation and phenolic compounds removal is feasible. This could be regarded as a best available technique for the treatment of complex industrial wastewaters containing high-strength ammonium concentrations and phenolic compounds. Aerobic granules are proven to be resistant and resilient to the shock loads, to the alternating presence of recalcitrant compounds and to starvation periods; conditions frequently found in industrial wastewater treatment plants due to changes on the industrial production schedules. In the near future, we propose the simultaneous nitritation and phenolic compounds removal should be combined with either heterotrophic denitrification or Anammox for sustainable nitrogen removal.

L’objectif essentiel de ce travail consiste à préparer des grains, à la fois, uniformes et consistants destinés à l’adsorption dynamique sur lit fixe de certains polluants susceptibles de polluer les eaux. Pour préparer ces grains, nous avons utilisé le procédé de la granulation humide d’une bentonite algérienne initialement traitée et modifiée par pontage à l’aide d���un mélangeur granulateur à haut taux de cisaillement. Les conditions de préparation de ces complexes organo-inorgano-argileux granulés (COIAG) sont liées au rapport massique de mouillage (L/S), à la concentration en liant (silicone) et à la vitesse de rotation du mélangeur. L’application dans l’adsorption en système monocomposé simple et/ou en mélange binaire, en réacteur discontinu, montre bien l’efficacité de cette nouvelle génération de grains adsorbants (qmax>350 mg/g à pH=6) vis-à-vis des deux colorants utilisés (Jaune Basique 28 -JB28- et Vert Malachite -VM-). Par ailleurs, les résultats de l’adsorption en mode continu (en réacteur à lit fixe ascendant) montent globalement que la durée de vie du lit de l’adsorbeur dépend essentiellement de la vitesse superficielle du flux entrant, de la concentration initiale en polluant et de la hauteur du lit d’adsorbant
The aim of the study was to prepare resistant and spherical inorgano-organo pillared clays (GIOC) granules for wastewater treatment using a new and simple method named high-shear wet granulation. To optimize the preparation method, the effects of the main process parameters, such as binder concentration, liquid to solid ratio and impeller speed on granule properties (size distribution, friability and disintegration tests) were investigated. Their use in the single-component adsorption systems and / or binary mixtures in a batch reactor, shows the effectiveness of this new generation of grain adsorbents (qmax> 350 mg/g at pH = 6) towards two basic dyes (Basic Yellow BY28 Yellow and Green Malachite G. M. ). Furthermore, the results of dynamic adsorption in fixed bed showed that the efficiency of bed is function of superficial velocity, the initial concentration of pollutant and the height of the adsorbent bed

In this chapter, the physics of wet granular matter is discussed. The practical significance of wet granular matter goes of course well beyond the construction of sand sculptures. Most industrial raw materials are solids and come in granular form, and the processes into which they feed involve their being mixed with liquids and agglomerated, conveyed, kneaded, or cast in moulds. For appropriately engineering these processes, including the minimization of energy consumption, a deep understanding of the mechanical properties of this class of materials is indispensable. Furthermore, if we want to mitigate, or even reliably predict, such devastating events as land slides or mud flows, we need to study the dynamical behaviour of wet granular matter in detail. This applies as well to other, similar systems of relevance, such as ice and snow avalanches, which can be modelled as wet granular systems as well.

Abstract This book chapter outlines the extraction and purification (i.e. determination of starch in roots, water requirements, industrial-grade tapioca starch manufacture, semi-mechanized tapioca starch manufacture, modern methods of tapioca starch manufacture), physiochemical properties (i.e. biochemical content, amylose and amylopectin content), structural properties (i.e. granular morphology, XRD and starch crystallinity, structure of amylose and amylopectin), functional properties (i.e. swelling pattern and solubility, viscosity, rheological properties, retrogradation, thermal properties, DSC, and digestibility) of cassava.

We propose a novel, high degree of freedom variable stiffness joint for use in a miniature snake-like robot for minimally invasive surgeries via granular jamming. By pulling granule filled membrane-columns under vacuum, the columns and joint stiffen as the granular matter begin to jam. In our experiments, we achieved a four-fold increase in stiffness, and the stiffness can be achieved while the columns are straight or bent. Current flexible manipulators in industrial and medical robotics have followed two dominating methods of actuation and stiffness control. The first method is the continuum manipulator, which utilizes tendons or rods to bend the manipulator in a continuous fashion. The second method is classified as the highly articulated robot, where the manipulator is comprised of multiple segments linked by motor-driven universal joints. Like the latter, our manipulator is highly articulated, however stiffness of each joint can be independently controlled by the granular jamming principle. This paper studies the effect of grain type and vacuum pressure for stiffness tuning. We found that granules with a matte surface were able to achieve higher stiffnesses, with a cube shape exhibiting the highest stiffness, but at the cost of high levels of hysteresis.

Granular flow behavior is of fundamental interest to the engineering and scientific community because of the prevalence of these flows in the pharmaceutical, agricultural, food service, and powder manufacturing industries. Granular materials exhibit very complex behavior, oftentimes acting as solids and at other times as fluids. This dual nature leads to very complex and rich behavior, which is not yet well understood. Therefore, the present investigation introduces a new technique that can potentially be used to unveil the mystery of granular flow phenomena. To this end, advanced finite element modeling and simulation techniques have been applied to the study of the complex nature of granular flow. More specifically, the explicit dynamic code LS-DYNA has been utilized to gain an understanding of the complex flow nature and collision stresses of granules in a shear cell.

The flow of solid granular material has been proposed as an alternative lubricant to conventional liquid lubricants. Since granular flows are also in numerous industrial and natural processes, they have been the subject of numerous studies. However, it has been a challenge to understand them because of their non-linear and multiphase behavior. There have been several past experiments, which have gained insight into granular flows. For example, previous work by the authors sheared grains in a two-dimensional annular shear cell by varying the velocity and roughness [1]. The present experimental work attempts to further insights from the previous work by specifically studying the interaction between rough surfaces and granular flows when the global solid fraction and grain materials are varied. A two dimensional annular (granular) shear cell, with a stationary outer ring and inner driving wheel, was used for this work. Digital particle tracking velocimetry was used to obtain local granular flow data such as velocity, local solid fraction, and granular temperature. Slip between the driving wall and first layer of granules is also extracted. This slip can be interpreted as momentum transfer or traction performance in granular systems such as wheel-terrain interaction. Parametric studies of global solid fraction and the material of the rough driving surface, attempt to show how these parameters affect the local granular flow properties.

Several processes in nature as well as many industrial applications involve static or dynamic granular materials. Granulates can adopt solid, liquid or gas like states and thereby reveal intriguing physical phenomena not observable in its versatility for any other form of matter. The frequent occurrence of phase transitions and the related characteristics thereby strongly affect their processing quality and economics. This situation demands for prediction methods for the behavior of granulates. In this context simulations provide a feasible alternative to experimental investigations. Several different simulation approaches are applicable to granular materials. The time-driven Discrete Element Method turns out to be the most complex but also as the most general method. The method has been used in a wide variety of scientific fields for more than thirty years. With the tremendous increase in available computer power, especially in the last years, the method is more and more developing to the state of the art simulation technique for granular materials. Despite of the long time of usage, model advances and theoretical and experimental studies are not harmonized in the different branches of application, providing potential for improvements. Therefore, the scope of this paper is a review of methods and models based on theoretical considerations and experimental data from literature. Through model advances it is intended to contribute to a general enhancement of techniques, which are then directly available for simulations.

Hexanitrostilbene (HNS) is a secondary, granular explosive with a wide usage in commercial and governmental sectors. For example, HNS is used in the aerospace industry as boosters in rockets, in the oil and gas industry in linear shaped charge designs in wellbore perforating guns, and in a number of applications in the US Department of Energy (DOE) and Department of Defense (DoD). In many of these applications, neat granules of HNS are pressed without binder and device performance is achieved with shock initiation of the powdered bed. Previous studies have demonstrated that powdered explosives do not transmit sharp shocks, but produce dispersive compaction waves. These compaction waves can induce combustion in the material, leading to a phenomenon termed Deflagration-to-Detonation Transition (DDT). The Baer-Nunziato (B-N) multiphase model was developed to predict compressive reaction in granular energetic materials due to shock and non-shock inputs using non-equilibrium multiphase mixture theory. The B-N model was fit to historical data of HNS, and this model was used to predict recent impact experiments where samples pressed to approximately 60% of theoretical maximum density (TMD) were shock loaded by high-velocity flyers [1]. Shock wave computations were performed using CTH, an Eulerian, multimaterial, multidimensional, finite-volume shock physics code developed at Sandia National Laboratories [2]. Predicted interface velocities using the B-N model were shown to be in good agreement with the measurements. Furthermore, an uncertainty quantification study was performed and the computational results are presented with best estimates of uncertainty.

Granular flow behavior is of fundamental interest to the engineering and scientific community because of the prevalence of these flows in the pharmaceutical, agricultural, food service, and powder manufacturing industries. When granular media come under external load, inter-particle forces in the granular media form an inhomogeneous distribution. In this study, a simulation of the contact forces in granular media was carried out using an explicit finite element method on a biaxial cell of approximately 2500 particles. Some of the key results included the capturing of normal force and tangential force distributions within a granular shear cell.

The influence of processing the serpentinite quarry from the Caucasian mountains at the foot of the Mount Elbrus crushed waste on soil agrochemical properties, phytotoxicity of spring barley, influence on barley plant biomass and its chemical composition were investigated. Ground and granular serpentinite had a different effect on soil and plants. Application of serpentinite fertilizers significantly increased the content of calcium, iron, 227.95-376.75 and 5.05-9.62 mg kg-1, total and plant-derived magnesium 0.34-0.52 and 1.19-2.16 mg kg-1, lead and nickel, while the amount of copper dropped substantially; the soil was becoming more alkaline. Application of ground serpentinite lead to alkalizing of the soil much more compared to the granular, with a significant increase in plant-derived magnesium. The influence of serpentinite increased the yield of spring barley plants in green and dry mass by 0.049-0.256 and 0.011-0.046 g or 0.65-3.41 and 1.19-2.59% out of the growing vessel, and dry matter increased by 0.12-0.26 % units, the yield of spring barley green and dry mass under the influence of ground serpentinite was higher than of granular serpentinite fertilizer, and the dry matter was found to be significantly higher than that of unfertilized spring barley plants. Ground and granular serpentinite was not phytotoxic to spring barley. An application of ground serpentinite increased an amount of calcium, potassium and magnesium in the barley dry matter compared to the granular serpentinite. Ground and granular serpentinite reduced the amount of trace elements copper and manganese in the dry mass of the plant, and the amount of zinc decreased only after fertilization with granular serpentinite. An application of serpentinite significantly decreased content of lead, chrome and cadmium while nickel content significantly increased in the dry matter of barley plants.

Abstract Granular material is ubiquitous in nature and plays a significant role in industry. Researchers have paid a lot of attention to density and velocity distributions of dense granular flows. However, the motion of individual particle is hard to capture because visualizing individual particles in a dense granular flow, especially in 3D, is very difficult and could be expansive. Here we use the magnetic particle tracking (MPT) technique to capture the motion of a single particle in a sheared dense granular flow. The accuracy of MPT is quantified using experimental results. The sheared granular flow is generated in a Couette cell by rotating a plate at the bottom of a cylinder container. It is able to generate different shear stresses by controlling the speed of the plate. By tracking the magnetic particle in the cylinder, we can capture the velocity of an individual particle at different locations in the granular flow.