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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Low-carbon hydrogen production from waste plastics via pyrolysis and in-line catalytic cracking process / Vätgasproduktion med låga kolutsläpp av plastavfall via pyrolys kombinerad med katalytisk reformering

Jin, Yanghao January 2022 (has links)
This study develops a novel pyrolysis process combined with in-line catalytic reforming toproduce high purity hydrogen and carbon products from waste plastics. The input resource is waste plastic material in the form of discarded Covid masks. Results show that for the optimized pyrolysis followed by in-line biochar-based catalytic reforming process, the hydrogen yield is 98.2 mg/g-mask (up to 87% purity), and the carbonyield is 642.4 mg/g-mask, with over 70% of the waste plastic being completely cracked to elemental carbon and hydrogen. The overall process has virtually no CO2 emissions. The use of biomass char catalysts has been studied to contribute to increased hydrogen yield. This is because the unique porous structure of the biochar catalyst increases the residence time of the pyrolysis vapor in the catalytic layer, allowing sufficient cracking of the macromolecular vapor, therefore, increasing the hydrogen yield. The process is also facilitated by the cracking temperature, which increases the cracking of the pyrolysis vapor, resulting in an increase in char yield. However, high temperatures may breakdown the structure of the biomass char catalyst, causing more of the pyrolysis vapor to be converted to CH4, reducing the hydrogen yield. The optimum hydrogen yield was obtained at process parameters of a Biochar catalyst-to-Maskratio (C/M ratio) of 2 and a cracking temperature of 900 oC. / Detta examensarbete utvecklar en ny pyrolysprocess kombinerad med en katalytisk reformeringsprocess i följd för att producera högrenade väte- och kolprodukter från plastavfall. Resursen till processen består av avfallsprodukter i form av kasserade munskydd. Resultaten visar att för den optimerade pyrolys- och biokol-katalytiska reformeringsprocessen är vätgasavkastningen 98,2 mg/g plastavfall (upp till 87 % renhet) och kolavkastningen 642,4 mg/g plastavfall, med över 70 % av plastavfallet fullständigt knäckt till enkla kol- och vätemolekyler. Den genomgripande processen har praktiskt taget inga koldioxidutsläpp. Användningen av biokol-katalysatorer av biomassa har studerats för att bidra till ett ökat vätgasutbyte. Detta beror på att biokolkatalysatorns unika porösa struktur ökar uppehållstiden för pyrolysångorna i det katalytiska skiktet, vilket möjliggör tillräcklig krackning av de makromolekylära ångorna och därmed ökar vätgasutbytet. Processen underlättas också av krackningstemperaturen, som ökar krackningen av pyrolysångorna, vilket leder till ökad kolavkastning. Höga temperaturer kan dock bryta ned strukturen hos katalysatorn för biomassakol, vilket gör att en större del av pyrolysångorna omvandlas till CH4, vilket minskar vätgasutbytet. Det optimala vätgasutbytet uppnåddes vid C/M-parameter (katalysator-till-munskydd förhållande) = 2och en krackningstemperatur på 900 0C.
252

Pyrolysis of Municipal Sewage Sludge to get a phosphorus rich char residue for soil improvement / Pyrolys av kommunalt avloppsslam för att framställa ett fosforrikt kol för jordförbättring

Shamim, Shahin January 2023 (has links)
Sewage sludge is a byproduct of wastewater treatment plants. It is a kind of waste. however, it contains several valuable nutrients like phosphorous and nitrogen that are used to rich the soil as a fertilizer compound. On the other hand, it contains some harmful and toxic compounds such as pathogens, pharmaceuticals, Polychlorinated biphenyl (PCBs), Polycyclic aromatic hydrocarbons (PAHs), endocrine-disruption, hormones, and heavy metals which are contaminants and pollutants in the environment. Pyrolysis is a way to treat these contaminants and reduces the quantity of heavy metals and removes pathogens. This project derives to pyrolysis the sewage sludge at three different temperatures 500°C,700°C, and 900°C, and evaluates the result according to the remained quantities of heavy metals and phosphorous. Each experiment was repeated three times. Then, the samples weighted and analyzed by bomb calorimeter, microwave digestion, and MP-AES. Bomb calorimetry was used for measuring the heating value to compare the remaining heating value in the samples to the raw sewage sludge. The microwave digestion system was used for chemical processing of the samples in order to break down the samples to liquid form and then the concentration of elements such as Cd, Co, Cr, Cu, Ni, Mn, Zn, Pb, and P were measured by MP-AES. The results were gathered and compared with the Regulation by European, Union, (DirectiveE86/278/EEC), and Regulation by Swedish law, (Regulation1998:994). The raw sewage sludge was delivered from Borås wastewater treatment unit after digestion in an anaerobic fermentation process. It contained about 74% water which was dried in an oven at 105°C. The results show that Cd and Co were removed from the sewage sludge and the most amount of phosphorus remained in the resulting char. The results show that the quantity of phosphorus was almost the same between 500°C-700°C. The data shows that the amount of Pb was reduced by increasing the temperature of the pyrolysis reaction. The heating value in the char was extremely close to each other in the different range of reaction temperatures between 500°C to 900°C.
253

Carbon Negative Heat and Power with Biochar Production : An Economic Analysis of a Combined Pyrolysis and CHP plant / Kolnegativ kraft och värme med biokolsproduktion : En ekonomisk analys av ett kombinerat pyrolys- och kraftvärmeverk

Bydén, William, Fridlund, David January 2020 (has links)
On the fourth of November 2016, The Paris Agreement entered into force, stating that nations worldwide should pursue efforts to limit the global temperature increase to 1,5 °C. Since then, the Intergovernmental Panel on Climate Change has specified that carbon dioxide removal, such as biochar sequestration, is necessary to achieve this goal. Biochar is a solid and porous material, rich in carbon, produced when biomass undergoes a process called pyrolysis and can, if buried in soil, sequester carbon for hundreds or even thousands of years while at the same time acting as a soil amendment. When biomass is pyrolyzed to produce biochar, a pyrolysis gas is also produced, which can be used to generate both heat and electricity. This thesis investigates if constructing and operating a plant, called a combined pyrolysis and CHP plant, which combines biochar production with heat and electricity generation, could be economically feasible and thus be an effective method for carbon dioxide removal. The findings show that constructing and operating a combined pyrolysis and CHP plant can be economically feasible. However, the economic feasibility is greatly affected by the price of biochar as a soil amendment product. The biochar market is also an undeveloped market, making price estimates of biochar far from accurate. Another factor that could significantly affect the economic feasibility of the plant is the fraction of carbon in biochar, which can be accounted for as sequestered. A higher fraction means that significantly more governmental support can be given to provide financing of the plant as well as potential revenue from carbon credits could increase. The capital cost of constructing the plant is also a factor with high uncertainty, which has a substantial effect on the economic feasibility. From this thesis, it is concluded that more research regarding the biochar market, as well as the capital costs of constructing the plant, is needed. More research could further ascertain whether or not the plant could be economically feasible and thus, an effective method for carbon dioxide removal. / Den fjärde november 2016 trädde Parisavtalet i kraft vilket uppgav att länder över hela världen ska sträva efter att begränsa den globala temperaturökningen till 1,5 grader Celsius. I enlighet med detta mål har FN:s mellanstatliga klimatpanel, IPCC, specificerat att koldioxidavlägsnande åtgärder, såsom kolinlagring genom produktion av biokol, är nödvändigt. Biokol är ett fast och poröst material, rikt på kol, som produceras när biomassa genomgår en process som kallas pyrolys. Om biokol blandas ner i jord kan det binda kol i hundratals eller tusentals år samtidigt som det fungerar som jordförbättrare. När biomassa pyrolyseras produceras också en pyrolysgas som kan användas för att generera värme och elektricitet. Det här examensarbetet undersöker om det kan vara ekonomiskt genomförbart att bygga och driva en anläggning, benämnd en kombinerad pyrolys- och kraftvärmeanläggning, som kombinerar biokolsproduktion med värme- och elproduktion för att avlägsna koldioxid från atmosfären. Resultaten från arbetet visar att det kan vara ekonomiskt genomförbart att bygga och driva en kombinerad pyrolys- och kraftvärmeanläggning. Den ekonomiska genomförbarheten påverkas dock i hög grad av priset på biokol som jordförbättringsprodukt. Marknaden för biokol är dessutom outvecklad vilket gör att priset för biokol osäkert. En annan faktor som i hög grad skulle kunna påverka den ekonomiska genomförbarheten för anläggningen är andelen kol i biokol som kan anses vara lagrad. En högre andel innebär att betydligt mer statligt stöd kan ges för att finansiera anläggningen samt att potentiella intäkter från kolkrediter kan öka. Kapitalkostnaderna för att bygga anläggningen är också en faktor med hög osäkerhet som har stor effekt på den ekonomiska genomförbarheten. Från detta examensarbete dras slutsatsen att mer forskning kring biokolsmarknaden samt kring kapitalkostnaderna för att bygga anläggningen behövs. Detta behövs för att ytterligare fastställa den ekonomiska genomförbarheten hos en sådan anläggning för att avlägsna koldioxid från atmosfären.
254

Hållbar masshantering – riskbedömning, klimat- och kostnadskalkyl / Sustainable management of contaminated soil masses – risk assessment, climate impact and cost

Bergkvist, Maria January 2024 (has links)
Ett stort antal förorenade områden finns idag i Sverige och tillämpning av riskreducerande åtgärder som till exempel schakt och deponi är vanligt förekommande. De möjliga hanteringsvägarna för uppschaktade massor är många, men en stor andel av massorna hamnar på deponier runt om i landet. Tidigare studier har visat att en ökad återanvändning av massor kan innebära både klimat- och resursbesparingar. Syftet med denna studie var att undersöka detta vidare och att studera både riskbedömningens och åtgärdsvalets effekt på klimatpåverkan och kostnaden för åtgärderna. En hypotetisk platsspecifik riskbedömning genomfördes för PAH, bly, koppar och zink och dess effekter på massklassning och möjlig återanvändning, och i sin tur effekt på klimatpåverkan studerades. Utöver det studerades även ökad återanvändning av schaktmassor i form av återanvändning inom projektområdet efter behandling med biokol. Två olika beräkningsverktyg användes vid klimatberäkningarna, Trafikverkets Klimatkalkyl och SGF:s verktyg Carbon footprint från efterbehandling och andra markarbeten. Beräkningarna i verktygen kompletterades med egen datainventering och beräkningar i de fall verktygen inte omfattade nödvändiga moment. Resultatet i studien visade att om platsspecifik biotillgänglighet beaktades i riskbedömningen, kunde riktvärdena höjas och en ökad återanvändning möjliggöras. Klimatpåverkan vid en högre grad av återanvändning, antingen utan vidare behandling eller efter behandling med biokol, var lägre än då masshantering baserades på Naturvårdsverkets generella riktvärden. Lägst klimatpåverkan kunde tillhandahållas då massor återanvändes efter behandling med biokol, där åtgärden i ett scenario resulterade i negativa växthusgasutsläpp. Samtliga scenarier som innebar ökad återanvändning av massor, resulterade även i en lägre kostnad. / A large number of contaminated areas exist in Sweden and risk-reducing measures such as dig and dump are often applied. Excavated masses can be managed in many different ways and there are several routes for which the masses can follow, but a large share of the masses often ends up on landfills all around Sweden. Previous studies have shown that an increase in reuse of masses could lead to both climate and resource savings. The aim of this study was to investigate this matter further and to study the effect on the climate impact of both risk assessment approaches and the choice of remediation method. A hypothetical risk assessment was performed for PAH, lead, copper and zinc and its effects on the mass classification and the possible reuse, and in turn its effect on the climate impact was studied. Furthermore, the increase in reuse of excavated masses within the project was studied, when using biochar as a treatment method. Two different calculation tools were used to calculate the climate impact, i.e. Trafikverkets “Klimatkalkyl” and SGF:s tool “Carbon footprint från efterbehandling och andra markarbeten”. The calculations in the tools were supplemented with data inventory and calculations, in cases where the tools did not cover the needed processes. The results showed that site specific risk assessment, where site specific bioavailability was included, could lead to higher risk limits. Higher risk limits enable increased reuse. The climate impact was lower as a result of a higher degree of reuse of masses. This applied for both scenarios when the masses were reused without any further treatment and when the masses were treated with biochar and then reused on site. The lowest climate impact was found when masses were treated with biochar, where this measure in one scenario implied negative greenhouse gas emissions. In all scenarios, an increase in reuse of masses also resulted in a lower cost.
255

Assemblages végétaux pour phytomanager des sols contaminés en métaux (Cu et Zn/Pb/Cd), rhizofiltrer de l’eau contaminée en Cu et fournir des biomasses à la bioéconomie / Plant assemblages to phytomanage metal (Cu and Zn/Pb/Cd)-contaminated soils, rhizofiltrate Cu-contaminated water, and deliver usable biomass for the bioeconomy

Oustrière, Nadège 05 December 2016 (has links)
Le phytomanagement de matrices contaminées en métaux couple leur réhabilitation écologique avec la production de biomasses végétales pour la bioéconomie. Un front de science est d’identifier des assemblages végétaux et d’optimiser leur production, aidée ou non par l’ajout d’amendements. Le phytomanagement de deux sols, l’un contaminé en Cu, l’autre en Cd, Pb et Zn, a été testé en conditions contrôlées. L’emploi conjoint de biochar et de grenaille d’acier diminue la phytotoxicité des 2 sols. En pots, sur 2 ans, cette combinaison d’amendements séquestre du carbone, diminue la phytotoxicité du sol contaminé en Cu et produit une biomasse d’Arundo donax L. et de Populus nigra L. non contaminée, utilisable par le secteur de l’énergie. Ces modalités de culture et d’amendement ont été installées pour un suivi à long terme sur le site contaminé en Cu. Parallèlement, en microcosmes, parmi 4 macrophytes utilisées en zone humide construite (CW) pour décontaminer des matrices aqueuses (i.e. Arundo donax L., Cyperus eragrostis Lam., Iris pseudacorus L. et Phalaris arundinacea L.), A. donax est la mieux adaptée pour fournir des racines à forte concentration en Cu utilisables pour produire un écocatalyseur riche en Cu. Le phytomanagement d’un effluent de bouillie bordelaise (EB, 69 μM Cu) par A. donax a été testé en CW pilote. Il est décontaminé en 48h, sa concentration en Cu respectant la réglementation du rejet d’effluent en réseau d'assainissement. Cependant, après un cycle de circulation, la concentration en Cu des racines d’A. donax (623 ± 140 mg Cu kg-1) est inférieure aux besoins de l’éco-catalyse, et le cycle serait à répéter pour atteindre les 1000 mg Cu kg-1 requis. / The phytomanagement of metal-contaminated matrices (soils and water) combines their ecological remediation and the production of non-food crops for the bioeconomy. One science frontier is to identify plant assemblage and to optimize their biomass production, aided or not by amendment addition and cultural practices. A Cu-contaminated soil and a Cd/Pb/Zn-contaminated one were phytomanaged in controlled conditions. The combination of biochar and iron grit reduced the phytotoxicity in both soils. In a 2-year pot experiment, this amendment combination decreased the phytotoxicity of the Cu-contaminated soil, enhanced soil C sequestration and produced an uncontaminated biomass of Arundo donax L. and Populus nigra L. adapted for bioenergy production. These combinations of culture and amendment are tested in field trial at the Cu-contaminated site. In parallel, in microcosm experiment, out of 4 macrophytes commonly used in constructed wetlands (CW) to clean up aqueous matrices (i.e. Arundo donax L., Cyperus eragrostis Lam., Iris pseudacorus L. and Phalaris arundinacea L.), A. donax was the best adapted to produce a high Cu-rich root mat potentially usable as Cu-ecocatalyst. Clean up of a Bordeaux mixture effluent (BME, 69 μM Cu) by A. donax was tested in a pilot-scale CW. The BME was decontaminated in 48 hours, its Cu concentration being in compliance for indirect discharge of chemical industry effluents. However, after one BME circulation cycle, root Cu concentration of A. donax roots (623 ± 140 mg kg-1) was lower than threshold value for Cu-ecocatalysts (1000 mg kg-1) and successive treatments must be repeated to achieve required Cu concentration.
256

Wirkungen von Biokohlen im System Boden-Pflanze

Reibe, Katharina 06 July 2015 (has links)
Die Anwendung von Biokohlen in der Landwirtschaft gewinnt durch die positiven Aspekte der Kohlenstoffsequestrierung, Bodenverbesserung und eines erhöhten Pflanzenwachstums in den letzten Jahren an Bedeutung. Deshalb geht die vorliegende Arbeit den Fragen nach, welche Wirkungen unterschiedliche Biokohlen in Kombination mit oder ohne Gärrest und / oder Stickstoffdünger auf die Bodenchemie, Bodenbiologie und Wachstum, Entwicklung, Ertrag, Ertragsstruktur, Nährstoffe sowie Qualität von Nutzpflanzen haben. Außerdem wurden die Effekte unterschiedlicher Biokohlen auf die Wurzelmorphologie von Sommerweizen quantifiziert. Eine weitere Frage war, inwiefern Biokohlen Stickstoffquellen sorbieren. Es wurden ein Feldversuch und mehrere Gefäßversuche durchgeführt, um die Änderungen der Bodenchemie, den Einfluss auf die Bodenbiologie am Beispiel von Collembolen und die Pflanzenparameter zu bestimmen. Für die Wurzeluntersuchungen wurden Rhizoboxversuche durchgeführt und zur Quantifizierung der Stickstoffsorption ein in vitro Versuch angelegt. Die Ergebnisse der Feld- und Gefäßuntersuchungen zeigten, dass die Biokohlen die Bodeneigenschaften positiv beeinflussten. Die Biokohlen nahmen keinen konsistenten Einfluss auf die Erträge von Kulturpflanzen. Die Nährstoffgehalte der Kulturpflanzen konnten zum Teil positiv beeinflusst werden. Die Collembolenabundanzen zeigten sowohl in der Feldstudie als auch im Gefäßversuch keine signifikanten Unterschiede zwischen den getesteten Biokohlen. Hohe Mengen der fermentierten HTC-Biokohle führten zu negativen Wirkungen auf die Collembolenabundanz im Gefäßversuch. Die Rhizoboxversuche zeigten einen positiven Einfluss der Pyro-Biokohle auf die oberirdische und unterirdische Trockenmasse sowie die Wurzelmorphologie von Sommerweizen. Unterschiedliche Stickstoffquellen wurden von der HTC-Biokohle stärker sorbiert als von der Pyro-Biokohle. Generell lässt sich aus den differenzierten Wirkungen der Biokohlen weitere Forschung mit dem Fokus Boden ableiten. / Over the past few years the use of biochars in agriculture has gained more importance due to positive effects on carbon sequestration, soil improvement and increased plant growth. Therefore, the present work pursues the question which effects different biochars have in combination with or without digestate and / or nitrogen fertilizer on soil chemistry, soil biology and growth, development, yield, yield components, nutrients and quality of crops. In addition, the effects of different biochars on root morphology of spring wheat were quantified. Further to elucidate potential mechanisms underlying biochar effects on crops it was studied how biochars sorb various nitrogen sources. A field test and several pot experiments were conducted to determine the changes in soil chemistry, the impact on soil-dwelling Collembola and plant parameters. For the root studies rhizobox experiments were performed. To quantify the nitrogen sorption of biochars an in vitro experiment was conducted. The results of the field test and pot experiments showed that biochars positively affected soil chemical characteristics. However, yields of crops were not consistently affected by biochars. The nutrient content of crops were positively influenced to some extent. The abundance of Collembola was not significantly influenced by the biochars tested in the field study and in the pot experiment. High amounts of fermented HTC-biochar had negative effects on the abundance of Collembola in the pot experiment. Rhizobox experiments showed a positive influence of Pyro-biochar on the aboveground dry matter, belowground dry matter and root morphology (e.g. root length) of spring wheat. Amount and reversibility of nitrogen sorption was dependent on the type of biochar with HTC-biochar sorbing more nitrogen than Pyro- biochar. Generally it can be concluded that because of the different effects of biochars further research with a focus on soil is needed.
257

Evaluating the rates of nitrate removal for a nitrate containing, low organic carbon wastewater interacting with carbon-containing solid substrates

Hart, Jeffrey L. (Jeffrey Le) 16 March 2012 (has links)
The primary objective of this study was to evaluate the rates of nitrate removal for a nitrate containing, low organic carbon wastewater interacting with four different carbon-containing solid substrates (alder woodchips, corn silage, manure and woodchip biochar). Batch systems were tested for nitrate removal, and systems with a combination of three carbon substrates (75% woodchips, 12.5% silage, and 12.5% manure or woodchip biochar by mass) produced average nitrate removal rates of 571 and 275 mg-N L⁻¹ D⁻¹, and systems containing the carbon substrates individually produced rates between 11.4 - 3.3 mg-N L⁻¹ D⁻¹. Silage proved to be the dominant carbon substrate providing high quantities of organic carbon to fuel denitrification. With the introduction of semi-continuous flow, all systems had nitrate removal rates that converged to 13.3 – 6.4 mg-N L⁻¹ D⁻¹, which is approximately two orders of magnitude smaller than the rates of the mixture systems in the batch experiment. Silage appeared to be removed from of the systems with liquid exchange potentially causing the rate decreases. Columns filled with various volume fractions of woodchips (100%, 25%, 12.5%, and 0%) produced nitrate removal rates between 30.8 – 2.4 mg-N L⁻¹ D⁻¹ at a 24 hour and 12 hour hydraulic residence time (HRT). Greater nitrate removal was achieved with higher HRTs and larger fractions of woodchips (the 100% woodchip system at a 24 hour HRT produced the fastest nitrate removal rate of 30.8 mg-N L⁻¹ D⁻¹). When rates were normalized to the amount of woodchips in each column, higher efficiency was found in lower woodchip fraction systems (the 12.5% woodchip column produced the highest normalized nitrate removal rate of 56 mg-N L⁻¹ D⁻¹ L[subscript woodchips]⁻¹). Woodchips proved to be best suited as a long term carbon substrate for nitrate removal in a system containing a nitrate concentrated, low organic carbon wastewater. However, large amounts of woodchips were necessary to achieve nitrate removal greater than 50%. A 41 acre hypothetical wetland with a 3.3 day HRT and a nitrate influent concentration of 45 mg-N L⁻¹ would require 30,000 yd³ of woodchips to achieve 68% nitrate removal based on the values obtained in the bench scale column experiment. / Graduation date: 2012
258

Termovalorização da biomassa de aguapé (Eichhornia crassipes) através de pirólise em reator forno rotativo / Thermovalorisation of water hyacinth (Eicchornia crassipes) biomass through pyrolysis in rotary kiln reactor

Carregosa, Ingred Suellen Carvalho 27 July 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Lignocellulosic biomass use for obtaining biofuels has been showing itself with much more evidence during these past years through cellulosic ethanol and biooils, biogases and biochars. Aquatic plants of lignocellulosic basis, Eichhornia crassipes species, commonly known by water hyacinth, represent a major environmental problem due to their invasive nature and their high proliferation rate. In this work we evaluated the possibility of use this biomass source from pyrolysis in a rotary kilns reactor in three different temperatures. The results evidence that the major yield of the liquid fraction (bio-oil + acid extract) was obtained at 500 ºC (42.11%). For 400 ºC and 600 ºC, the biochar and biogas had major production, 37.78% and 42.36%, respectively. Bio-oils characterization by GC/MS produced in microscale allowed an investigation upon the scale-up phenomenon under the bio-oils composition. The results show that, in qualitative terms, the chemical composition of bio-oils was not changed, however, at semiquantitative aspect, show they are produced in distinguish relative percentages. The mainly chemical classes identified in biooils were: acids, alcohols, phenols and sugar derivatives. Bio-oils showed in average, 68% of calorific power of the fuels derived from petroleum, glimpsing enforcement on the energetic area. In the produced biochars, with yields between 37% and 26%, the increase on pyrolysis temperature has provided an increase upon carbon concentration, and a decreasing upon the hydrogen and oxygen concentrations, reflecting in high aromaticity of the materials. These materials ware tested in some aspects about the soils management, nutritional function and water retention. In view of this, the water hyacinth pyrolysis has associated sustainability concepts and green chemistry, putting concepts of renewable energetic sources together and glimpsing an environmental problems inhibition, to offer an alternative to the 2nd generation of bio-fuels production. / O uso de biomassas lignocelulósicas para a obtenção de biocombustíveis apresenta-se com muito mais evidência nos últimos anos através do etanol celulósico e de bio-óleos, biogás e biocarvão. As plantas aquáticas de base lignocelulósica da espécie Eichhornia crassipes, popularmente conhecida por aguapé, representam um grande problema ambiental devido ao seu caráter invasor e sua alta taxa de proliferação. Neste trabalho avaliou-se a possibilidade de aproveitamento dessa fonte de biomassa a partir do processo de pirólise em um reator cilindro rotativo em três diferentes temperaturas. Os resultados demonstraram que o maior rendimento da fração líquida (bio-óleo + extrato ácido) foi obtido a 500 ºC (42,11%). Para as temperaturas de 400 e 600 ºC, o biocarvão e o biogás tiveram maior produção, 37,78% e 42,36%, respectivamente. A caracterização por CG/EM dos bio-óleos produzidos em microescala permitiram investigar o efeito de scale-up sob a composição dos bio-óleos. Os resultados mostraram que em termos qualitativos, a composição química dos bio-óleos não foi alterada, no entanto, no aspecto semiquantitativo mostraram que são produzidos em percentuais relativos distintos. As principais classes químicas identificadas nos bio-óleos foram: ácidos, álcoois, fenóis e derivados de açúcares. Os bio-óleos apresentaram em média 68% do poder calorífico do combustível derivado de petróleo, vislumbrando uma aplicação na área energética. Nos biocarvões produzidos, com rendimento variando de 37% a 26%, o aumento da temperatura de pirólise proporcionou um aumento na concentração de C, e uma diminuição nas concentrações de H e O, refletindo em maior aromaticidade dos materiais. Estes materiais foram testados sob alguns aspectos quanto ao manejo de solos, função nutricional e retenção de água. À vista disto, a pirólise de aguapé relacionou conceitos de sustentabilidade e química verde, unindo o conceito de fontes de energias renováveis com a inibição de problemas de cunho ambientais, ao oferecer uma biomassa alternativa para a produção de biocombustíveis de 2ª geração.
259

Desenvolvimento de método para determinação de agrotóxicos (perturbadores endócrinos) em água / Development of method for determination of pesticides (endocrine disruptive) in water

Santos, Ruyanne Andreza Camilo 26 February 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The water pollution causes changes in physical, chemical and biological water, which interfere with their quality, preventing its use for human consumption. Most chemical contaminants in surface water are related to industrial and agricultural sources. Since, with farming the Brazil pollute existing water resources making use of pesticides and fertilizers. This study aims to develop a fast and efficient method based on extraction techniques in solid phase (SPE) and high-performance liquid chromatography with UV detection in the ultraviolet and visible with diode array (HPLC UV-Vis / DAD) for the determination of pesticides, endocrine disruptors, epoxiconazole, fenarimol, fenbuconazole, flusilazole, flutriafol, and vinclozolin in water using biocarvões produced from agro-industry waste as an alternative sorbent for SPE. Tests with the analytes allowed the adjustment of the chromatographic conditions for simultaneous analysis of five selected pesticides. The optimal condition for the extraction of analytes was performed using 0.5 g of adsorbent to 50 mL of ultrapure water and eluted with 5 mL of acetonitrile. The biochar produced from coconut waste was tested as an adsorbent for the extraction by SPE and showed good recovery results between 75% ± 9 - 119 ± 12% for the concentration levels of 0.5 to 1 ug mL-1. The parameters studied to validate the method were: linearity and sensitivity, obtaining a good sensitivity and linear response with 0.9998 coefficients in the range of 0.01 to 10 ug mL-1; precision based on the precision of measurements (Intra) and intermediate precision (interday), obtaining results of 0.1-1%, 0.6-1%, respectively; accuracy with recovery values of 60 ± 37% - 117 ± 3% to the concentration levels of from 0.025 to 0.1 mg L-1 and 75 ± 9% - 119 ± 12% for levels 0.5 to 1 ug mL- 1 related to the biochar and C18, respectively. The LD 0.01 to 0.025 in range and LQ from 0.025 to 0.5 ug mL-1. The method developed was adequate for the determination of pesticides in water samples. / A poluição aquática provoca mudanças nas características físicas, químicas e biológicas das águas, as quais interferem na sua qualidade, impossibilitando o seu uso para o consumo humano. A maioria dos contaminantes químicos presentes em águas superficiais estão relacionados às fontes industriais e agrícolas. Uma vez que, com a atividade agrícola o Brasil polui os recursos hídricos existentes fazendo uso de agrotóxicos e fertilizantes. O presente trabalho tem como objetivo desenvolver um método rápido e eficiente baseado nas técnicas de extração em fase sólida (SPE) e cromatografia líquida de alta eficiência com detector espectrofotométrico na região do ultravioleta e visível com arranjo de diodos (HPLC UV-Vis/DAD) para a determinação dos agrotóxicos, perturbadores endócrinos, epoxiconazol, fenarimol, fenbuconazol, flusilazol, flutriafol, e vinclozolina, em água, utilizando biocarvões produzidos a partir de rejeitos de agroindústria, como adsorvente alternativo para a SPE. Testes realizados com os analitos permitiram o ajuste das condições cromatográficas para análise simultânea de cinco agrotóxicos selecionados. A condição ótima de extração dos analítos consistiu em utilizar 0,5 g do adsorvente para 50 mL de água ultrapurificada e eluição com 5 mL de acetonitrila. O biocarvão produzido a partir de rejeitos de coco foi testado como adsorvente para a extração por SPE e apresentou resultados satisfatórios de recuperação entre 75 ± 9% – 119 ± 12% para os níveis de concentração 0,5 a 1 μg mL-1. Os parâmetros estudados para a validação do método foram: linearidade e sensibilidade, obtendo-se uma boa sensibilidade e resposta linear com coeficientes de 0,9998 no intervalo de 0,01 a 10 μg mL-1; precisão com base nos estudos de repetibilidade (intradia) e precisão intermediária (interdia), obtendo-se resultados de 0,1–1%, 0,6–1%, respectivamente; exatidão com valores de recuperação entre 60 ± 37% – 117 ± 3%, para os níveis de concentração 0,025 a 0,1 μg mL-1 e 75 ± 9% – 119 ± 12% para os níveis 0,5 a 1 μg mL-1, com relação ao C18 e o biocarvão, respectivamente. O LD no intervalo de 0,01–0,025 e LQ 0,025-0,5 μg mL-1. O método desenvolvido se mostrou adequado para determinação de agrotóxicos em amostras de água.
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En studie av egenskaperna hos biokol som adsorberande agent i o‐DGTanordningar / A study of the performance of biochar as adsorbing agent in o‐DGT devices

Eliasson, Anna January 2017 (has links)
En ny komplex aspekt i frågan om vattenkvalité är ackumuleringen av organiska föroreningar.Den begränsade utbredningen av vattenrening i Brasilien såväl som i andra utvecklingsländervisar på ett tydligt behov av utveckling av billiga och effektiva metoder för provtagning ivatten. Bristen på den här typen av metoder försvårar idag möjligheterna att kontrolleravattenkvalitén och på så vis även arbetet med att säkerställa de sanitära förhållandena ivattentillgångar. Det här examensarbetet innehåller en sammanfattande genomgång avprinciperna för den passiva provtagningsmetoden med namnet ”Diffusive Gradients in Thin‐Films (DGT)”, som direktöversatt får det svenska namnet ”Diffusiva gradienter i tunnfilmer”.När metoden används för provtagning för att upptäcka olika organiska ämnen i vattnetbenämns den som o‐DGT.Målet med detta arbete är att ta fram en metod med målet att specifikt upptäcka olika typerav nya framväxande organiska föroreningar som i de flesta fall förekommer bara i väldigt lågakoncentrationer i vår miljö. Grundliga undersökningar genomfördes för att få svar på huruvidabiokol kan fungera som den bindande agenten i DGT apparatur och verka för att kunnaupptäcka och identifiera dessa ämnen på ett effektivt sätt.Resultaten från de undersökningar som genomförts hittills visar på att biokol har godpotential att tillämpas som bindande agent i filter för bruk i o‐DGT apparatur. De organiskaföreningarna av intresse i denna studie kunde alla detekteras, kvantifieras och identifieras.För optimering av provtagningsmetoden bör vidare studier vid varierande förhållanden medhänsyn till pH, temperatur och jonkoncentration genomföras, såväl som studier av detbindande lagrets egenskaper i förhållande till koncentration av biokol och lagrets tjocklek.Detta för att kunna optimera tekniken, och förhoppningsvis bidra till ett konventionelltanvändande av biokol på adsorberande agent i o‐DGT anordningar i framtiden. / A new complex aspect in the matter of water quality is the occurrence of emerging organicpollutants and contaminants in waste water. The currently low extent to which treatment ofwaste water is performed in Brazil, and in the world as a whole, there is a considerable needfor development of cheap and accurate in‐situ sampling methods for far‐reaching studies ofsurface water quality. The lack of such methods today makes the maintenance andestablishing of sanitary safety difficult. This diploma work gives a brief introduction to thebasic principles of the passive sampling method known as Diffusive Gradient in Thin‐films(DGT). A method that could be useful for such monitoring of quality in water bodies worldwide.The aim of this study is to develop a method, for the detection of organic emerging pollutantsand contaminants – i.e. compounds, which usually are present at very low concentrationswhen found in the environment as a result of human activity. More specifically, this workinvestigates the potential and usefulness of the application of DGT devices in detection oforganic compounds that can affect human health and ecosystems, even at lowconcentrations, however, their effects still are in need of further investigations.This study focuses on both purely technical as well as practical points of views. The efficiencyof organic DGT (o‐DGT) with biochar as the adsorbing agent is examined targeting thedetection of organic pollutants and contaminants in surface water. In this sense, the specificaim of the work is to evaluate the performance of biochar as adsorbing agent. This workshowed that the performance of biochar as the adsorbing agent in binding layers in o‐DGTsample devices can be considered as satisfactory since all compounds of interest in this studywas successfully detected, quantified an identified. Further investigations in the future areneeded to determine the effects of varying pH, temperature and ion concentration in thedeployment media, as well as the properties of the binding layer in relation to concentrationof biochar and the thickness of the layer. These in order to optimize the method for in‐situwater sampling, aiming conventional use of biochar as the adsorbing agent in the future.

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