Filter Cake, which contains leachable nickel and vanadium above the criteria in the Alberta Waste Control Regulation, is produced at an oil sands facility operated by Nexen Inc. and is currently being disposed in a landfill. Bench scale and field tests were performed with stabilization/solidification (S/S) treatment reagents such as Portland cement, fly ash, elemental sulphur, and CETCO Oilfield Service’s proprietary reagents to assess their efficacy at reducing leachable metals in Filter Cake. The CETCO reagents were the most effective treatment for reducing leachable nickel and vanadium in Filter Cake. Treatments with Portland cement were successful in bench scale tests, but inconsistent in field tests. The inconsistent results obtained for Portland cement may have been due to interferences of the cement reactions from factors such as fine particulates. S/S treatments of Filter Cake present a viable waste management option. However, the associated reduced cost and environmental impacts were not substantial.

No description available.

O processo de reaproveitamento dos Resíduos de Construção e Demolição (RCD) na cidade de Londrina, Estado do Paraná, foi pesquisado. O objeto da investigação foi analisar a política sobre a reciclagem dos resíduos da construção na cidade. Constatou-se que o município tem observado as legislações atuais e que tem organizado e disciplinado a atuação dos grandes e pequenos gerdores. Também foram analisados os procedimentos adotados por uma empresa ambientalmente licenciada, identificando seu processo de produção do material reciclado e caracterizando o produto a ser reutilizado. O material reciclado é o resultado da rebritagem do resíduo da construção, que se transforma em pedras e areia resultantes da trituração de concreto puro ou da trituração conjunta de concreto, argamassa, pisos, revestimentos e tijolos cerâmicos. Foi analisado esse processo para verificar a existência de procedimentos de identificação de contaminação na empresa para a utilização dos resíduos na reciclagem e, principalmente, verificar a existência de contaminação no produto. Nos agregados produzidos foram identificados alumínio e cádmio em excesso e, para que possam ser utilizados livres destes contaminantes, foi proposta a técnica de estabilização por solidificação. No entanto, os resultados não foram os esperados, uma vez que observou-se aumento dos teores destes contaminantes após o encapsulamento usando a técnica à base de cimento Portland. Concluiu-se que, provavelmente, como já foi observado em pesquisas anteriores, a causa principal desse aumento é a contaminação do cimento, único material adicionado aos resíduos para a fabricação dos corpos de prova. Uma proposta de protocolo para a reutilização de resíduos de construção e demolição com resíduos industriais incorporados foi também apresentada, bem como recomendações para a produção e utilização de agregados reciclados. Como a contaminação do cimento parece ser recorrente, sugere-se que estudos sobre as possíveis causas da contaminação e desvios das normas técnicas sejam mais profundamente pesquisados. / The recycling process of construction and demolition residues (RCD) in the city of Londrina, Parana State, was searched. The object of the research was to analyze the policy on recycling of construction residues in the city. It was found that the city has noted the current legislation and has organized and disciplined the performance of large and small generators. Were also analyzed the procedures adopted by an environmentally licensed company, identifying its production process of recycled material and featuring the product to be reused. The recycled material is the result of rebritagem the residue of the construction, which turns into gravels and sand resulting from pure concrete grinding or joint grinding of concrete, mortar, floors, tiles and bricks. This process was analyzed to check for contamination identification procedures in the company for the use of residue recycling and especially check for contamination in the product. In produced clusters identified excess aluminum and cadmium, that can be used free of such contaminants, it has been proposed for stabilization/solidification technique. However, the results were not expected given that there was increase in levels of these contaminants after encapsulation technique using Portland cement-based. It was concluded that, probably, as has been observed in previous research, the main cause of this increase is contamination of the cement, only material added to the residue for the manufacture of test specimens. A proposed protocol for the reuse of construction and demolition residue with embedded industrial residue was also presented, as well as recommendations for the production and use of recycled aggregates. As cement contamination seems to be recurring, it is suggested that studies on the possible causes of contamination and technical norms deviations are more thoroughly researched.

Muddringsprojekt är en global företeelse och görs av flera olika anledningar, till exempel för miljömässiga aspekter och för breddning av farleder. För att få en hållbar utveckling är det viktigt att finna bra lösningar på frågan hur förorenade sediment skall hanteras . I Mälaren kommer olika muddringsprojekt att genomföras för att bredda farleden från slussen i Södertälje till hamnarna i Köping och Västerås. Muddringsprojekten skall genomföras av Sjöfartsverket, Köpings kommun och Västerås stad. En metod för att omhänderta muddermassorna är att stabilisera/solidifiera dem genom att blanda i ett bindemedel bestående av en blandning av cement, masugnsslagg och aktivt kol och låta dem härda. Detta görs för att förbättra materialets geotekniska egenskaper samt för att immobilisera föroreningar. Syftet med detta examensarbete var att undersöka om det går att använda krossade stabiliserade/solidifierade muddermassor ovan vattenytan till exempel i vägkonstruktioner alternativt som fyllnadsmaterial. Möjligheten för användandet av de stabiliserade/solidifierade materialet utvärderades genom att materialets geotekniska och miljömässiga egenskaper undersöktes. Den miljöpåverkan som de stabiliserade/solidifierade materialet skulle kunna ha på den omgivning där de används har undersökts genom analyser av totala föroreningshalter samtkoncentrationer vid lakning. Detta gjordes dels genom egna skakförsök och dels genom utvärdering av resultat från undersökningar som Statens geotekniska instituts (SGI)miljölaboratorium gjort. När det gäller materialets geotekniska egenskaper utvärderades resultat från undersökningar genomförda av SGIs geotekniska laboratorium. Stabiliseringen/solidifiering gjorde att de undersökta metallerna som förekommer som katjoner immobiliserades, vilket ledde till att lakningen minskade. Däremot fungerade imobiliseringen inte för anjoner; om det skulle ha förekommit höga halter av toxiska anjoner som till exemple arsenik, vanadin och molybden skulle dessa ha lakats ut. Ur ett miljömässigt perspektiv skulle det gå bra att använda det undersökta materialet då koncentrationen i lakvätskan låg under de båda gränsvärden som används; gränsvärden för inert avfall och gränsvärden för mindre än ringa risk vid användning av avfall för anläggningsändamål. När det gäller hållfasthet uppfyllde materialet efter 28 dagars härdning inte kraven som ställs för användning i vägkonstruktion. Däremot hade materialets geotekniska egenskaper förbättrats jämfört med de obehandlade sedimenten. / Dredging is a global phenomenon carried out for several different reasons, e.g. environmental remediation and expansion of shipping lanes. A sustainable solution to the problem of how contaminated sediment should be handled is thus important to achieve a more sustainable development. Several dredging projects will be implemented in the lake Mälaren to widen the shipping lane from the lock in Södertälje to the ports of Köping and Västerås. The dredging will be carried out as a joint effort by the Swedish Maritime Administration, the City of Västerås and Köping municipality. One method used for treating dredged sediments is stabilization/solidification. This is carried out to improve the geotechnical properties of the material and to immobilize contaminants. The method works as follows: Sediments are dragged form the lake, mixed with a binding agent consisting of cement, granulated blastfurnace slag and active carbon and then left to harden. The objective of this master thesis was to investigate the feasibility of using the stabilized/solidified material on land above the water surface. Examples of applications for the crushed material are in road construction or as fillers for vegetation surfaces. The stabilized/solidified material was evaluated with respect to environmental factors and geotechnical properties to determine if it was appropriate to use for these applications. To investigate the potential impact of the stabilized/solidified material on the surrounding environment, analysis of total contamination content and leaching tests were evaluated. In this thesis, batch-leaching tests for metals were performed as well as evaluation of lab results from surveys conducted in the environmental laboratory at the Swedish Geotechnical Institute. The geotechnical properties of the material were evaluated based on results from experimentsconducted by the geotechnical laboratory at the Swedish Geotechnical Institute. The results from the treatment with stabilization/solidification showed that most of the studied metals were immobilized, and the leaching of these metals decreased. From an environmental perspective it would be feasible to use the material, as the results of the leaching test were below the limit values used in the assessment; limits for inert waste and limits for less than small risk (‘mindre än ringa risk’) in use of waste for construction purposes. In terms of the geotechnical features, after 28 days of hardening the material did not meet the requirements for use in road construction. However, the material's geotechnical properties such as strength had improved compared to the untreated sediments.

O processo de reaproveitamento dos Resíduos de Construção e Demolição (RCD) na cidade de Londrina, Estado do Paraná, foi pesquisado. O objeto da investigação foi analisar a política sobre a reciclagem dos resíduos da construção na cidade. Constatou-se que o município tem observado as legislações atuais e que tem organizado e disciplinado a atuação dos grandes e pequenos gerdores. Também foram analisados os procedimentos adotados por uma empresa ambientalmente licenciada, identificando seu processo de produção do material reciclado e caracterizando o produto a ser reutilizado. O material reciclado é o resultado da rebritagem do resíduo da construção, que se transforma em pedras e areia resultantes da trituração de concreto puro ou da trituração conjunta de concreto, argamassa, pisos, revestimentos e tijolos cerâmicos. Foi analisado esse processo para verificar a existência de procedimentos de identificação de contaminação na empresa para a utilização dos resíduos na reciclagem e, principalmente, verificar a existência de contaminação no produto. Nos agregados produzidos foram identificados alumínio e cádmio em excesso e, para que possam ser utilizados livres destes contaminantes, foi proposta a técnica de estabilização por solidificação. No entanto, os resultados não foram os esperados, uma vez que observou-se aumento dos teores destes contaminantes após o encapsulamento usando a técnica à base de cimento Portland. Concluiu-se que, provavelmente, como já foi observado em pesquisas anteriores, a causa principal desse aumento é a contaminação do cimento, único material adicionado aos resíduos para a fabricação dos corpos de prova. Uma proposta de protocolo para a reutilização de resíduos de construção e demolição com resíduos industriais incorporados foi também apresentada, bem como recomendações para a produção e utilização de agregados reciclados. Como a contaminação do cimento parece ser recorrente, sugere-se que estudos sobre as possíveis causas da contaminação e desvios das normas técnicas sejam mais profundamente pesquisados. / The recycling process of construction and demolition residues (RCD) in the city of Londrina, Parana State, was searched. The object of the research was to analyze the policy on recycling of construction residues in the city. It was found that the city has noted the current legislation and has organized and disciplined the performance of large and small generators. Were also analyzed the procedures adopted by an environmentally licensed company, identifying its production process of recycled material and featuring the product to be reused. The recycled material is the result of rebritagem the residue of the construction, which turns into gravels and sand resulting from pure concrete grinding or joint grinding of concrete, mortar, floors, tiles and bricks. This process was analyzed to check for contamination identification procedures in the company for the use of residue recycling and especially check for contamination in the product. In produced clusters identified excess aluminum and cadmium, that can be used free of such contaminants, it has been proposed for stabilization/solidification technique. However, the results were not expected given that there was increase in levels of these contaminants after encapsulation technique using Portland cement-based. It was concluded that, probably, as has been observed in previous research, the main cause of this increase is contamination of the cement, only material added to the residue for the manufacture of test specimens. A proposed protocol for the reuse of construction and demolition residue with embedded industrial residue was also presented, as well as recommendations for the production and use of recycled aggregates. As cement contamination seems to be recurring, it is suggested that studies on the possible causes of contamination and technical norms deviations are more thoroughly researched.

Depuis la fin du 20ème siècle, notre société a pris conscience que la protection de l’environnement et le développement durable sont nécessaires à notre épanouissement futur. Des directives ont contraint les pouvoirs publics, les collectivités, ainsi que les industriels à réagir notamment en s’impliquant dans la recherche. Les cimentiers sont aussi concernés. La fabrication du ciment nécessite énormément de matières premières.L’objectif principal de cette thèse est donc de valoriser les sous-produits industriels en matériaux cimentaires. Le contexte et la problématique des déchets sont abordés, ainsi que la possibilité de valorisation par les ciments. La méthodologie mise en place et son originalité sont expliqués. Dans un premier temps, le protocole de caractérisation des déchets minéraux a été développé et les résultats en laboratoire sont prometteurs pour le remplacement du calcaire et de l’argile dans le cru d’un ciment. Les cuissons en laboratoire ont permis d’obtenir un ciment comportant les 4 phases d’un Portland. La synthèse en plus grande quantité d’une formulation en laboratoire a mis en évidence de bonnes performances mécaniques sur mortiers au jeune âge. Dans un deuxième temps, les meilleures formulations ont été testées à l’échelle industrielle, dans le four de ARF. Le cru, malaxé par trémies agitatrices, a été une réussite. Enfin, l’immobilisation des polluants dans une matrice cimentaire des résidus de combustion, provenant des combustibles secondaires de ARF a permis de déclasser le déchet stabilisé/solidifié par réduction granulométrique du matériau avant tabilisation/solidification. / Since 20th century’s end, our society started to take conscience of environmental protection and sustainable development are required to our future blooming. Directives have obliged public authorities, communities, such as industry to be reacted particularly while being implied in research. The cement-manufacturers are also concerned. The process cement-manufacturer requires large quantities of raw materials. The main objective of the thesis is to value industrial by-products by cementitious materials. Context and problem of wastes were discussed, as well as the possibility of valorization such as the cements. The methodology set up for the thesis and its originality are explained. First, the protocol of characterization of mineral wastes was developed. The results in laboratory are promising for the replacement of limestone and clay in the cement’s raw meal and different formulations. The cookings in laboratory allowed obtaining a cement containing 4 phases of Portland. The synthesis in bigger quantity of a formulation in laboratory highlighted good mechanical performances on mortars at the young age. In a second stage, the best formulations were tested on an industrial scale in the ARF’s kiln. The raw meal, mixed by hoppers agitators, was a success. Finally, immobilization of pollutants in a cement matrix of the residues after combustion, resulting from secondary fuels of ARF, was studied to be able to downgrade the waste stabilized/solidified by grading reduction of the material before stabilization/solidification.

Heavy-metal contamination in soils has become a serious environmental problem. Among all metals, excessive amount of zinc was released to soils over the years. Zinc is not only toxic to human being, but also to plants. High concentration of zinc is extremely phytotoxic. Currently, the most popular method to remediate heavy-metal contaminated soils is stabilization/solidification (S/S) technique as it is cheaper, faster and more effective to remediate heavy metals than other remediation methods. Portland cement is the most-used binder in S/S technique. However, the production of Portland cement has released a significant amount of carbon dioxide, which strongly contributes to global warming. In addition, zinc retards the setting and hydration of Portland cement, which would require more Portland cement to remediate zinc-contaminated sites. Therefore, researchers are looking for new materials to improve the performance of Portland cement in zinc-contaminated soils. In recent years, the application of graphene-based materials in concrete had proved to be effective. Due to relative cost-effectiveness and comparable properties, multi-layer graphene, known as graphene nanoplatelets, may show a promising potential in construction. Moreover, research has reported that graphene nanoplatelets can be exfoliated from graphite and potentially scaled up for full-scale applications. At present, there is no application of graphene nanoplatelets in the S/S of contaminated soils and the roles of graphene nanoplatelets in cement-stabilized zinc-contaminated clay remained unknown. In this research, graphene nanoplatelets were dispersed in solution with a high-shear mixing apparatus. Dispersed graphene nanoplatelets solution was then applied to zinc-contaminated soil along with cement. To evaluate the efficacy of this S/S method, various influencing factors such as mixing sequence, graphene nanoplatelets content, zinc content, cement content, and curing time were studied. An optimum graphene nanoplatelets content was determined through the unconfined compressive strength (UCS) of the stabilized/solidified samples. It was found that at the optimum content, the unconfined compressive strength of cement-stabilized zinc-contaminated clay was improved by 22.3% with the addition of graphene nanoplatelets. Also, graphene nanoplatelets were effective at moderate zinc content and low cement content. Graphene nanoplatelets accelerated cement hydration effectively at early ages. Microstructural analyses indicated that more hydration products were developed in samples with graphene nanoplatelets. At current stage, it is still expensive to apply graphene nanoplatelets in S/S technique; however, it is possible to exfoliate graphite into graphene nanoplatelets in future research. / Graduate / 2022-05-12

<p>Predmet izučavanja ove disertacije obuhvatio je ispitivanje uticaja starenja stabilizovanog/solidifikovanog&nbsp; (S/S)&nbsp; sedimenta&nbsp; zagađenog te&scaron;kim metalima i arsenom, i efikasnost primenjenih imobilizacionih agenasa (Portland cement, kreč, leteći pepeo, zeolit, montmorilonit i kaolinit) nakon dugogodi&scaron;njeg starenja S/S sme&scaron;a. Shodno tome ispitana je dugoročna stabilnost i postojanost dobijenih S/S sme&scaron;a sa aspekta izluživanja pomenutih metala, promene u minerolo&scaron;kim i strukturnim karakteristikama, kao i uticaj su&scaron;enja i zrenja materijala na pomenute parametre. Istraživanja u disertaciji obuhvatila su dve faze. Prva faza imala je za cilj procenu rizika i&nbsp; početnu karakterizaciju netretiranog sedimenta primenom analize pseudo-ukupnog sadržaja metala kojom je utvrđen sadržaj metala u početnom uzorku sedimenta. Druga faza uključivala je primenu tretmana stabilizacije i solidifikacije na kontaminirani sediment dodavanjem različitih imobilizacionih agenasa. Analize su se vr&scaron;ile nakon 7 i 28 dana od primenjenog S/S tretmana, kao i nakon 7 godina sa ciljem da se utvrdi uticaj vi&scaron;egodi&scaron;njeg starenja i zrenja monolitnih sme&scaron;a na mobilnost metala i strukturne karakteristike sme&scaron;a. U&nbsp; okviru&nbsp; druge faze istraživanja ispitana je toksičnost S/S sme&scaron;a primenom DIN i TCLP testova izluživanja, dok je test toksičnosti primenom bakterija Vibrio Fischeri&nbsp; doprineo u&nbsp; sagledavanju&nbsp; procene rizika S/S sme&scaron;a po organizme. Nakon 28 dana i 7 godina kori&scaron;ćena je sekvencijalna ekstrakcija za&nbsp; određivanje mobilnost i biodostupnost metala u monolitnim matriksima. U cilju&nbsp; utvrđivanja mikrostukturnih karakteristika sedimenta primenjena je rendgenska difrakciona analiza (XRD) za ispitivanje kristalnih struktura&nbsp; S/S sme&scaron;a i detekciju mineralnog sastava. Pomoću elektronskog mikroskopa i energodisperzivnog detektora&nbsp; sa X-zrakom (SEM/EDS) određena je kvalitativna i kvantitativna distribucija metala i&nbsp; drugih elemenata od interesa, dok se za identifikaciju formiranih funkcionalnih grupa u monolitnim sme&scaron;ama primenio spektrometar sa infracrvenom Furijeovom transformacijom (FTIR). Na osnovu dobijenih rezultata zaključeno je da se mobilnost te&scaron;kih metala i arsena značajno smanjila nakon 7 godina za sme&scaron;e tretirane cementom (C5), krečom (L10), letećim pepelom (F30) i kaolinitom&nbsp; (K20), a efekat stabilizacije je pokazan transformacijom metala iz direktne toksične frakcije u&nbsp; stabilnije oblike. Sme&scaron;e C5 i K20 ispoljavaju&nbsp; najmanje toksične efekate od svih sme&scaron;a, jer je procenat inhibicije&nbsp; na&nbsp; bioluminiscentnim&nbsp; bakterijama manji od 13%, dok je u pogledu izdržljivosti monolitna sme&scaron;a C5 pokazala najveću pritisnu čvrstoću od svih sme&scaron;a. Dobijeni podaci su neprocenjivi za dobijanje stvarnog uvida u dugoročnu efikasnost&nbsp; primenjenog&nbsp; tretmana i mogućnost bezbedne upotrebe ili odlaganja dobijenih S/S sme&scaron;a sa aspekta za&scaron;tite životne sredine, kao i ekonomski i ekolo&scaron;ki prihvatljivog upravljanja opasnim otpadom.</p> / <p>The subject of study in this dissertation included to investigate the&nbsp; effect&nbsp; of&nbsp; aging&nbsp; of&nbsp; stabilized/solidified&nbsp; (S/S)&nbsp; sediment&nbsp; contaminated with&nbsp; heavy&nbsp; metals&nbsp; and&nbsp; arsenic,&nbsp; and&nbsp; the&nbsp; efficacy&nbsp; of&nbsp; the&nbsp; applied immobilization&nbsp; agent&nbsp; (Portland&nbsp; cement,&nbsp; lime,&nbsp; fly&nbsp; ash,&nbsp; zeolite, montmorillonite and kaolinite) after long-term aging of S/S mixtures. The<br />long&nbsp; -&nbsp; term stability and stability of the obtained S/S mixtures from the aspect of leaching of the mentioned metals, changes in mineralogical and structural characteristics,&nbsp; as&nbsp; well&nbsp; as&nbsp; the&nbsp; influence&nbsp; of&nbsp; drying&nbsp; and maturation of the material on the mentioned parameters were examined. The&nbsp; research&nbsp; in&nbsp; the&nbsp; dissertation&nbsp; included&nbsp; two&nbsp; phases.&nbsp; The&nbsp; first&nbsp; phase aimed&nbsp; at&nbsp; risk&nbsp; assessment&nbsp; and&nbsp; initial characterization&nbsp; of&nbsp; untreated sediment using pseudo-total metal content analysis which determined the<br />metal content in the initial sediment sample.&nbsp; The second phase involved applying&nbsp; stabilization&nbsp; and&nbsp; solidification&nbsp; treatments&nbsp; to&nbsp; the&nbsp; contaminated sediment&nbsp; by&nbsp; adding&nbsp; various&nbsp; immobilizing&nbsp; agents.&nbsp; The&nbsp; analyzes&nbsp; were performed after 7 and 28&nbsp; days from the applied S/S treatment, as well as after 7 years in order to determine the influence of perennial aging and maturation&nbsp; of&nbsp; monolithic&nbsp; mixtures&nbsp; on&nbsp; metal&nbsp; mobility&nbsp; and&nbsp; structural characteristics&nbsp; of&nbsp; the&nbsp; mixtures.&nbsp; In&nbsp; the&nbsp; second&nbsp; phase&nbsp; of&nbsp; the&nbsp; study,&nbsp; the toxicity&nbsp; of&nbsp; S/S&nbsp; mixtures&nbsp; using&nbsp; DIN&nbsp; and&nbsp; TCLP&nbsp; leaching&nbsp; tests&nbsp; was examined, while&nbsp; the&nbsp; toxicity&nbsp; test&nbsp; using&nbsp; bacteria&nbsp; Vibrio&nbsp; Fischeri contributed&nbsp; to&nbsp; the assessment&nbsp; of&nbsp; the&nbsp; risk&nbsp; of&nbsp; S/S&nbsp; mixtures&nbsp; to&nbsp; organisms. After&nbsp; 28 days&nbsp; and&nbsp; 7 years,&nbsp; sequential extraction was&nbsp; used to&nbsp; determine the mobility and bioavailability of metals in monolithic matrices. In order to&nbsp; determine&nbsp; the&nbsp; microstructural&nbsp; characteristics&nbsp; of&nbsp; the&nbsp; sediment,&nbsp; x-ray diffraction analysis (XRD) was used to examine the crystal structures of&nbsp; S/S mixtures and&nbsp; to detect the mineral composition.&nbsp; The qualitative and quantitative&nbsp; distribution&nbsp; of&nbsp; metals&nbsp; and&nbsp; other&nbsp; elements&nbsp; of&nbsp; interest&nbsp; was determined using an electron microscope and an energy-dispersive X-ray detector&nbsp; (SEM&nbsp; /&nbsp; EDS),&nbsp; while&nbsp; an&nbsp; infrared&nbsp; Fourier&nbsp; transform spectrometer(FTIR) was used to identify the formed functional groups in monolithic mixtures. Based on the obtained results, it was concluded that the mobility of heavy metals and arsenic decreased significantly after 7 years&nbsp; for&nbsp; mixtures&nbsp; treated&nbsp; with&nbsp; cement&nbsp; (C5),&nbsp; lime&nbsp; (L10),&nbsp; fly ash&nbsp; (F30) and&nbsp; kaolinite&nbsp; (K20),&nbsp; and&nbsp; the&nbsp; stabilization&nbsp; effect&nbsp; was&nbsp; shown&nbsp; by transformation&nbsp; of&nbsp; metals&nbsp; from&nbsp; direct&nbsp; toxic&nbsp; fractions&nbsp; into&nbsp; more&nbsp; stable forms. Mixtures&nbsp; C5&nbsp; and&nbsp; K20&nbsp; exhibit&nbsp; the&nbsp; least&nbsp; toxic&nbsp; effects&nbsp; of&nbsp; all mixtures, because the percentage of inhibition on bioluminescent bacteria is less than 13%, while in terms of durability, the monolithic mixture C5 showed&nbsp; the&nbsp; highest&nbsp; compressive&nbsp; strength&nbsp; of&nbsp; all&nbsp; mixtures.&nbsp; The&nbsp; obtained data are invaluable for gaining real insight into the long-term efficiency of the applied treatment and the possibility of safe use&nbsp; or disposal of the obtained&nbsp; S/S&nbsp; mixtures&nbsp; from&nbsp; the&nbsp; aspect&nbsp; of&nbsp; environmental&nbsp; protection,&nbsp; as well&nbsp; as&nbsp; economically&nbsp; and&nbsp; ecologically&nbsp; acceptable&nbsp; hazardous&nbsp; waste management.</p>

Submitted by Maicon Juliano Schmidt (maicons) on 2015-07-06T13:37:21Z No. of bitstreams: 1 Joice Brochier Schneider.pdf: 4213539 bytes, checksum: 49fa8f402cb598050e77b581c7d7d449 (MD5) / Made available in DSpace on 2015-07-06T13:37:21Z (GMT). No. of bitstreams: 1 Joice Brochier Schneider.pdf: 4213539 bytes, checksum: 49fa8f402cb598050e77b581c7d7d449 (MD5) Previous issue date: 2012-08-21 / FAPERGS - Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul / Projeconsult Engenharia Ltda. / A ideia de se transformar resíduos em matéria prima tem produzido esforços no sentido de estudá-los e qualificá-los, já que o aproveitamento integral de resíduos é uma necessidade cada vez maior na indústria moderna, principalmente pela crescente escassez de recursos naturais não renováveis e a necessidade de preservação e recuperação do meio ambiente. O resíduo cinza de casca de arroz (CCA), resultante da queima da casca de arroz para geração de energia, vem sendo utilizado em diversos ramos industriais. Destaca-se sua aplicação na construção civil e também como material adsorvente. A CCA utilizada neste trabalho está misturada com carvão ativado (CA). Esta mistura é proveniente de filtros de adsorção de sistemas de remediação de áreas degradadas com hidrocarbonetos de petróleo. Com isto, o objetivo deste trabalho foi avaliar a solidificação/estabilização de hidrocarbonetos de petróleo, em especial, benzeno, tolueno, etilbenzeno e xileno (BTEX), contidos no adsorvente composto por CCA e CA, em matriz de cimento Portland. Para tal, foram confeccionadas argamassas com substituição do agregado natural, em volume, pelos seguintes materiais: resíduo, nos teores de 10% e 30%, adsorvente CCA/CA in natura no teor de 30% e adsorvente CA in natura, também no teor de 30%. Essas argamassas foram caracterizadas ambientalmente, através dos ensaios descritos nas Normas Brasileiras. Analisou-se também a influência dessa substituição, através da determinação de propriedades no estado fresco (evolução da temperatura semi-adiabática de hidratação, penetração de cone e tempo de pega), de propriedades mecânicas (resistência à tração na flexão e à compressão) e caracterização dos produtos de hidratação através das técnicas de difração de Raio-X e espectroscopia de infravermelho. A argamassa RESÍDUO 10% atingiu a maior temperatura e menor tempo entre o início e fim da evolução da temperatura devido à hidratação. Já a argamassa RESÍDUO 30%, ao contrário, apresentou o maior tempo, fato justificado pela ação do óleo, presente no resíduo incorporado, que impediu, em parte, a passagem da água, retardando o processo de hidratação. Todas as argamassas, em relação a REFERÊNCIA, apresentaram menor consistência, na penetração de cone, e menor tempo de início e fim de pega. Resultados estes que corroboram, para as argamassas RESÍDUO 10%, CCA/CA 30% e CA 30% com a evolução da temperatura semi-adiabática da temperatura. A incorporação do resíduo não interferiu na formação dos compostos de hidratação do cimento, porém, a hidratação, conforme os resultados obtidos na evolução da temperatura semi-adiabática, ocorreu mais lentamente com a substituição de 30% da areia natural pelo resíduo. Os resultados da espectroscopia de infravermelho sugerem a presença BTEX nas argamassas RESÍDUO 30% e RESÍDUO 10%. Carbonatos e silicatos também foram identificados em todas as argamassas. Quanto aos resultados de resistência mecânica, observou-se, na resistência à tração na flexão, que a diferença entre o maior e menor desempenho, entre as argamassas REFERÊNCIA, RESÍDUO 10% e RESÍDUO 30%, foi de 8,9% e 5,6% para 7 e 21 dias, respectivamente. Já na resistência à compressão, aos 7 dias, os resultados obtidos das argamassas RESÍDUO 10% e RESÍDUO 30% foram superiores ao de REFERÊNCIA. Aos 21 dias, a REFERÊNCIA apresentou o melhor desempenho, 31,7% e 52,5% superior à argamassa RESÍDUO 30% e RESÍDUO 10%, respectivamente. Com os resultados de resistência mecânica obtidos, não foi possível avaliar a melhoria de desempenho com relação à idade. Porém, observou-se que a contaminação presente contribuiu para a resistência das argamassas, quando comparadas a CCA/CA 30%. Logo, sugere-se que a presença do contaminante possivelmente contribuiu quanto à aderência entre as partículas da mistura. Na caracterização ambiental, as argamassas confeccionadas foram classificadas como Classe II A, resíduo não perigoso, não inerte. A análise do extrato lixiviado e solubilizado das argamassas RESÍDUO 30% e RESÍDUO 10% não identificou a presença de hidrocarbonetos de petróleo. Estes resultados, associados à espectroscopia de infravermelho, às propriedades mecânicas bem como ao odor característico dos corpos de prova, confirmam a s/s do contaminante na matriz de cimento Portland. Este resultado positivo representa um avanço na busca da viabilidade de se empregar o resíduo CCA/CA contaminado com hidrocarbonetos de petróleo, direta ou indiretamente, para algum fim comercial. / The idea of turning waste into raw material has made efforts to study them and qualify them as the full utilization of waste is an increasing need in modern industry, mainly by increasing scarcity of non-renewable natural resources and need for preservation and restoration of the environment. The residue of rice husk ash (RHA), resulting from the burning of rice husk for power generation, has been used in various industries. We highlight its application in construction and as adsorbent material. The CCA used in this work is mixed with activated carbon (AC). This mixture is from adsorption filter remediation systems of degraded with petroleum hydrocarbons. With this, the objective of this study was to evaluate the solidification / stabilization of petroleum hydrocarbons, in particular benzene, toluene, ethylbenzene and xylene (BTEX), composed of adsorbent contained in CCA and CA, in Portland cement matrix. To this end, mortars were prepared with substitution of natural aggregate, by volume, of the following materials: residue, content of 10% and 30%, adsorbent CCA / CA in natura content of 30% and CA adsorbent in nature, also the content 30%. These environmentally mortars were characterized by the tests described in the Brazilian Standards. It was also analyzed the influence of substitution by determining the properties in the fresh state (temperature evolution semi-adiabatic hydration, penetration cone and setting time), mechanical properties (tensile strength in bending and compression), and characterization of the hydration products through the techniques of X-ray diffraction and infrared spectroscopy. The mortar RESIDUE 10% reached the highest temperature and shortest time between the beginning and end of the temperature due to hydration. Already 30% RESIDUE mortar, instead, showed the greatest time, which may be explained by the action of the oil present in the residue incorporated, which prevented partly the passage of water, slowing the hydration process. All mortars, for the reference, showed less consistency, cone penetration, and shorter start and end of the handle. These results corroborate that, for mortars RESIDUE 10% CCA/CA 30% CA and 30% with the temperature evolution of the semi-adiabatic temperature. The incorporation of the residue did not affect the formation of the compounds of the cement hydration, however, hydration, as the results in the evolution of semi-adiabatic temperature, was slower by replacing 30% of the natural sand residue. The results of infrared spectroscopy suggests the presence BTEX in mortars RESIDUE RESIDUE 30% and 10%. Silicates and carbonates have also been identified in all mortars. Regarding the results of mechanical strength was observed in tensile strength in bending, the difference between the highest and lowest performance among REFERENCE mortars, 10% Residue and Residue 30%, was 8.9% and 5 6% for 7 and 21 days, respectively. In the compressive strength after 7 days, the results of mortar RESIDUE RESIDUE 10% and 30% were higher than the reference. At 21 days, the REFERENCE showed the best performance, 31.7% and 52.5% higher than the mortar WASTE WASTE 30% and 10%, respectively. With the results obtained from mechanical strength, it was not possible to evaluate the performance improvement with respect to age. However, it was observed that this contributed to the contamination resistance of mortars, compared to CCA / CA 30%. Therefore, it is suggested that the presence of the contaminant as possibly contributing to adhesion between the particles of the mixture. In characterizing environmental mortars made were classified as Class II, non-hazardous waste, not inert. The analysis of the extract solubilized and leached mortar WASTE WASTE 30% and 10% failed 17 to identify the presence of petroleum hydrocarbons. These results, combined with the infrared spectroscopy, the mechanical properties and the odor of the specimens, confirm / s of the contaminant in the matrix of Portland cement. This result represents a breakthrough in the search for feasibility of employing the waste CCA/CA contaminated with petroleum hydrocarbons, directly or indirectly, for any commercial purpose.

Les ciments phosphomagnésiens sont des ciments inorganiques de la famille des ciments activés par des acides. Malgré le fait qu'ils soient connus depuis le début du XXème siècle, leur utilisation reste assez limitée dans le génie civil. Ces matériaux sont utilisés dans le cadre de réparation notamment pour des réparations routières qui nécessitent un développement rapide des résistances en compression. Plus récemment, ces ciments ont été utilisés pour des applications de stabilisation/solidification (S/S) des déchets et notamment de certains types de déchets chimiquement incompatibles avec le ciment Portland. Toutefois, les défis de mise en œuvre de ce type de ciment sont liés à la nature même de la réaction, très exothermique et très rapide. La phase liante de ces ciments, la k-struvite (MgKPO4.6H2O), est obtenue par un mélange de magnésie (MgO) et de dihydrophosphate de potassium (KH2PO4) en présence d'eau. MgO + KH2PO4 + 5H2O  MgKPO4.6H2OLes mécanismes qui régissent la prise de ce ciment sont encore mal connus et plusieurs théories, mettant en jeu ou non la formation de produits secondaires, ont été proposées. Nos travaux de recherche ont porté sur la compréhension des mécanismes de prise des ciments phosphomagnésiens ainsi que sur l'influence des paramètres de formulation sur les propriétés de ces ciments. L'étude a montré que la formation de la k-struvite passe par une réaction de précipitation-dissolution d'un produit intermédiaire, la newberyite (MgHPO4.3H2O). Les réactions de formation de ces deux produits sont contrôlées par le taux de sursaturation des espèces en solution et le pH du milieu réactionnel. L'étude met également en lumière la forte sensibilité de ces ciments à la quantité d'eau introduite. Avec un rapport E/C très faible comparativement à un ciment Portland (rapport E/C compris entre 0,1 et 0,25), une faible variation (0,02) entraine la ségrégation de la pâte de ciment et une hétérogénéité à la surface du matériau. Parmi les paramètres de formulation, le rapport molaire MgO/KH2PO4 (Mg/P) est le plus important. En effet, il influe sur la quasi-totalité des propriétés du ciment : résistance en compression, temps de prise, chaleur de réaction, fluidité de la pâte, …. L'utilisation de faibles rapports Mg/P entraine une mauvaise tenue à l'eau du ciment, la formation de cristaux à l'intérieur de la microstructure et visibles à la surface de l'échantillon (apparition d'une efflorescence) ainsi qu'un gonflement important de la pâte de ciment (pouvant aller jusqu'à la fissuration des échantillons). A l'issue de l'étude paramétrique une formulation d'une pâte a pu être définie. Des mesures de variations dimensionnelles, ainsi que des mesures de retrait chimique ont été effectuées, afin de mieux comprendre les mécanismes mis en jeu pour induire les phénomènes de gonflement. En support, des analyses de la microstructure (MEB, DRX, ATG) ainsi que des essais de lixiviation viennent compléter la campagne expérimentale. Ces résultats viennent confirmer l'influence d'un rapport Mg/P faible sur le gonflement et la tenue à l'eau du ciment phosphomagnésien. Pour finir, une étude sur l'influence des divers ajouts, dans le but d'améliorer ses performances, a montré que les fillers inertes (sable siliceux ou cendres volantes) retardent le temps de prise et réduisent la chaleur d'hydratation / Magnesium phosphate cements are the most representative cements of the activated-by-acid cements family. Despite the fact that they are known since the early 20th century, their use in civil engineering is fairly limited. These materials are used for road repairs where the fast compressive strength development is an advantage. Recently they have also been used in wastes stabilization/solidification (S/S), especially with wastes incompatible with Portland cement. The challenges of the use of these cements are related to the nature of their formation reaction: fast, very exothermic, with a very short setting time (only a few minutes).The bonding phase, k-struvite (MgKPO4.6H2O), is obtained from magnesium oxide mixed in water with monopotassium phosphate (KH2PO4).MgO + KH2PO4 + 5H2O  MgKPO4.6H2OThe setting mechanisms are still poorly known and various theories, involving or not secondary product formation, have been suggested. Our researches have aimed to understand the setting mechanisms, as well as the influence of the formulation parameters on the properties of the magnesium phosphate cement. Results show that the formation of k-struvite involved a precipitation-dissolution reaction of an intermediate product, the newberyite (MgHPO4.3H2O). Formation reactions of these two products are controlled by the supersaturation rate and the pH of the solution. The study highlights the strong effect of water on the properties of fresh cement paste. With a low mass ratio e/c in comparison of Portland cement (ratio e/c between 0,1 and 0,25), a slight modification of the ratio (0,02) leads to a segregation and a surface heterogeneity of the cement paste. Among the formulation parameters, the molar ratio MgO/KH2PO4 (Mg/P) seems the most important parameter. Indeed, it impacts most of the properties of the magnesium phosphate cement (compressive strength, setting time, reaction heat, paste fluidity …). Low Mg/P ratios lead to poor water resistance, to crystals formation inside the microstructure that can be seen on the surface of the sample (an efflorescence appearance), and to important swelling of the paste, leading to the cracking of the samples. After the parametric study, a magnesium phosphate cement paste has been defined. Dimensional changes and chemical shrinkage measurement were conducted to understand the mechanisms involved in this swelling phenomenon. In support, microstructural analyses (SEM, XRD, TGA) and leaching tests complete the experimental campaign. The results confirm the influence of a low Mg/P ratio on cement swelling and water resistance. Finally, a study on various additions to the paste has been conducted, with the purpose of improving the cement paste performances. It shows that the addition of an inert filler (siliceous sand or fly ashes) has a retarding effect and reduced the reaction heat