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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.
41

[en] APPRECIATION OF THE POTENCIAL OF HUMIC ACID EXTRACTION FROM DIFFERENT CARBON BEARING MATERIALS / [pt] AVALIAÇÃO SOBRE O POTENCIAL DE EXTRAÇÃO DE ÁCIDOS HÚMICOS A PARTIR DE DIFERENTES PRECURSORES CARBONÁCEOS

03 November 2021 (has links)
[pt] O Ácido Húmico (AH) é uma fração orgânica obtida em solos, corpos hídricos bem como em matrizes carbonáceas. Nos últimos anos o interesse associado a esta substância vem crescendo progressivamente à medida que novas aplicações são descobertas, tais como: fertilizantes, recuperação de áreas degradadas e tratamento de efluentes contaminados com metais. As principais características dos AH são dependentes do método de extração e da matriz escolhida, posto que se pode extraí-lo de uma ampla gama de matérias primas, assim como por meio de diferentes métodos. Dentro deste contexto, o objetivo principal do presente trabalho pretende avaliar o potencial de extração de ácido húmico a partir de diferentes precursores carbonáceos. Foram utilizadas três matrizes carbonáceas distintas: rejeito de carvão mineral (RCM), coque mineral (CM) e coque verde de petróleo (CVP). Além deste estudo experimental foram apresentados alguns resultados de estudo semelhante disponível na literatura. O método de extração utilizado foi adaptado de Trompowski et al (2005), e a caracterização foi feita utilizando-se técnicas de ICP-OES, CNHS, MEV/EDS, FTIR e Difração de Raio-X. A eficiência da extração, em termos de recuperação em massa, variou, significativamente, em função do método adotado, sendo os melhores resultados associados ao rejeito de carvão mineral (17,0 porcento), ao passo que a menor eficiência está relacionada ao coque verde de petróleo, após destilação (0,2 porcento). A extração a partir do coque verde de petróleo, como recebido, é inviável em função da sua imiscibilidade com a solução de ácido nítrico. Os resultados obtidos a partir do FTIR foram satisfatórios para todos os AH analisados, apresentando bandas características de AH e compatíveis com o indicado na literatura. Os resultados da análise de ICP-OES apresentaram baixa presença de metais e elementos traços para o AH oriundo do coque mineral. No que diz respeito ao ácido húmico extraído do rejeito de carvão mineral, que apresentou a maior concentração inicial de metais, principalmente ferro, foi implementado, com sucesso, uma purificação utilizando ácido nítrico. Com base nos resultados obtidos é possível afirmar que a utilização de diferente precursores carbonosos permitiu a extração de AH com características semelhantes aqueles citados na literatura e extraídos de outras fontes. / [en] The humic acid (HA) is an organic fraction that can be found in soil and watercourses as well as in carbonaceous matrices. In recent years the interest associated with this substance has been growing steadily as new applications are discovered, such as fertilizers, remediation of degraded areas and treatment of wastewater contaminated with metals. The main features of HA are dependent on the method of extraction and the chosen matrix, since it can be extract from a wide range of raw materials, as well as by different methods. Within this context, the main objective of this work is related to an assessment of the potential of extracting humic acid from different carbonaceous precursors. three different carbonaceous matrices were used: coal tailings (RCM), coke (CM) and green petroleum coke (CVP). Besides this experimental study some results of a similar study available in the literature were presented. The extraction method used was adapted from Trompowski et al, and the characterization was done using ICP- OES techniques, CNHS, MEV / EDS and FTIR. The extraction efficiency, in terms of mass recovery, significantly varied depending on the method used, the best results being associated with coal tailings (17.0 percent), while lower efficiency relates to the calcinated petrocoke after distillation (0.2 percent). The extraction from green petroleum coke, as received, is unfeasible due to its immiscibility with the nitric acid solution. The results obtained from FTIR were satisfactory for all the HA analyzed, displaying bands consistent with those from HA and compatible with bands shown in the literature. The results of the analysis of ICP-OES showed a low presence of metals and trace elements coming from the HA for coke. With respect to the extracted humic acid from coal tailings, which showed the highest initial concentration of metals, particularly iron, was successfully implemented, a purification with nitric acid. Based on the results obtained it can be stated that the use of different carbonaceous precursors allowed the extraction of humic acid with similar characteristics as cited in the literature and those obtained from other sources.
42

Identification of extraction methods for the production of humic acids from black liquor

Mema, Vusumzi (Vusie) 12 1900 (has links)
Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2006. / South Africa has a variety of sources for humic substances that may be utilised for the large-scale production of specialised fertilizers. Humic substances are dark coloured fully decomposed remains of plant and animal organic matter. Amongst the sources that were investigated in this study, a 5-weeks old compost (C5W), a 6-weeks old compost (C6W), a compost prepared by Medallion Mushroom farm for the production of mushrooms (CB1), a compost produced as waste material after mushroom production (CB2), recycled water used in compost (i.e. CB1) preparation for mushroom production (“Goodie water,” GW) and black liquor from pulp industry (BL), black liquor showed the best potential for the large scale production of humic acids in South Africa. The quantity and quality of humic acids in these materials were determined by using the basic acid-precipitation method and E6/E6 ratio analyses of the products. Extracting humic acids from black liquor was optimised by comparing three possible variations to the standard humic acid-precipitation method (HAp), namely, lignin extraction/humic acid precipitation method (LHAp), humic acid precipitation/acid treatment method (HApA) and lignin extraction/humic acid precipitation/acid treatment method (LHApA). The method of extraction had a substantial impact on the quantity and quality of humic acids produced. Humic acid precipitation method followed by humic acid precipitation/acid treatment method (HApA) demonstrated high quantities of humic acids compared to lignin extraction/humic acid precipitation method (LHAp) and lignin extraction/humic acid precipitation/acid treatment method (LHApA). Analyses such as Fourier Transform Infrared (FTIR) spectroscopy, Ultraviolet Visible Spectroscopy (UV-VIS), High Performance Liquid Chromatography (HPLC) and Elemental Analysis demonstrated that the quality of humic acids produced from black liquor was similar to those reported previously. The type of material (e.g. softwood, hardwood and bagasse) used for black liquor production significantly affected the elemental and molecular composition of humic acids produced. The quality of humic acids produced was affected by both lignin extraction and acid treatment. However, chemical analyses indicated that the features of the humic acids extracted from black liquor correlated with their lignin origin. Humic acids from hardwood and softwood black liquor had a low nitrogen and high sulphur content compared to those extracted from black liquor produced from bagasse material. Although chemical and instrumental analysis of humic acids was quite reasonable for all humic acids produced, LHAp method was favoured for the extraction of humic acids from pine liquor due to the high quantity of humic acids produced (low S and ash contents). The humic acids extracted by means of HAp method and HApA had a positive effect on plant growth, when extracted from bagasse and Eucalyptus black liquors. Humic acids extracted by HAp from pine liquor had an inhibitory effect on plant growth. A possible process flow for the large-scale production of humic acids from black liquor was formulated. The possible process flow indicated that with the amounts of black liquor produced from pulp industry production of humic acids in South Africa is a possibility. Nevertheless, there is still more that needs to be done to investigate the cost effectiveness of this production prior its implementation. HAp method was most suitable for the production of humic acids from Eucalyptus and bagasse liquors in terms of quantity and plant response but LHAp method was more suitable for the production of humic acids from pine liquor in terms of both quantity and quality.
43

Sorption organischer Chemikalien an Huminstoff-Komponenten – Experimentelle Analyse, pH-Abhängigkeit und Modellierung

Hammer, Heiko 09 February 2016 (has links) (PDF)
Das Verfahren zur Bestimmung von Koc-Werten nach OECD Richtlinie 121 ist zur Abschätzung der Sorptionskoeffizienten einzelner Stoffklassen gut geeignet. Die komplexen Wechselwirkungen eines Stoffes mit einer Matrix bei dem Sorptionsprozess konnten durch die Erweiterung des Kalibrierdatensatzes und den zusätzlichen stationären Phasen besser dargestellt werden. Die empirische Annahme der Kapazitätsfaktorensumme aus Cyano-Phase, Diol-Phase und Amino-Phase berücksichtigt die Wechselwirkungen von polaren Stoffen mit polaren Phasen und kann zur Bestimmung des Sorptionskoeffizienten weiterer Stoffklassen (z.B.: Amine, Alkohole) unter OECD-Bedingungen angewendet werden. Der Vorteil dieser Bestimmungsmethode ist, dass der Sorptionskoeffizient Koc unter umweltrelevanten Versuchsbedingungen ermittelt wurde und weitere Parameter wie zum Beispiel die pH-Wert-Abhängigkeit untersucht werden können. Auch eine hohe Reproduzierbarkeit des Verfahrens ist gewährleistet, da die verschiedenen HPLC-Säulen kommerziell erhältlich sind. Ein großer Nachteil der Bestimmungsmethode ist die einfache Struktur der Sorbensmatrizes, welche die Komplexität der Umwelt- bzw. Bodenmatrix nur bedingt wiedergeben können. Weiterhin ist die Bestimmung des Sorptionskoeffizienten mittels der drei unterschiedlichen HPLC-Säulen zeitaufwendiger als Sorptionsversuche mit einem Sorbensmaterial. Aus diesem Grund wurde in weiteren Sorptionsversuchen ein Sorbens gesucht, welches die natürlichen Sorptionsprozesse besser abbildet. Für das Beurteilen des Sorptionsverhaltens von organischen Verbindungen an natürlichen Sorbentien wurden in Batchversuchen die Sorptionskoeffizienten bestimmt. Mit dem Festlegen der Sorptionsparameter (z.B.: Sorptionskinetik, Sorbensmenge, Extraktionszeit) liegt ein valides Verfahren zur Aufnahme von Sorptionsisothermen vor. Von den verschiedenen Sorptionsmatrizes bilden die Huminsäuren den Sorptionsprozess von organischen Stoffen an natürlichen Böden am besten ab. Die Aldrich-Huminsäure wurde als Sorbens für die Durchführung von Säulenversuchen ausgewählt, da für diese Sorptionsmatrix die Sorptionskoeffizienten mit Literaturdaten am besten übereinstimmen. Für die Anwendung eines weiteren Analysenverfahrens wurde die Säulenmethode mit einer immobilisierten Aldrich-Huminsäure-Silikagel-HPLC-Säule durchgeführt. Die Aldrich-Huminsäure-immobilisierte-stationäre-Phase wurde durch eine mehrstufige organische Synthese unter inerten Bedingungen hergestellt. Zur Verifizierung der eingesetzten Huminsäure-Säule wurden die Stabilität der Matrix mit der theoretischen Bodenzahl N, des Säulendrucks und der Kapazitätsfaktor eines Kontrollstoffes erfolgreich überprüft. Die Porösität der Säulenmatrix, der organische Anteil des Sorbens und die Leitfähigkeit der mobilen Phase wurden als weitere Versuchsparameter überprüft, und es wurde darauf geachtet, dass umweltrelevante Bedingungen bei den Sorptionsversuchen vorliegen. Das HPLC-Verfahren wurde durch die hohe Übereinstimmung zwischen experimentellen Koc-Werten der Aldrich-Huminsäure und den Koc-Literaturwerten aus Batchversuchen mit Böden für neutrale organische Stoffe verifiziert. Auch beim Vergleich der Sorptionsergebnisse von verschiedenen Huminstoff-Matrizes besitzt die Aldrich-Huminsäure die Koc-Werte mit der größten Übereinstimmung mit Literaturdaten. Zur Beurteilung des Sorptionsverhaltens eines Stoffes in der Umwelt wurde die Einteilung von Höltig erweitert. Zum Treffen einer Aussage über das Sorptionsverhaltens eines Stoffes wurde neben dem log Kow auch der log Koc verwendet und für ionische Stoffe in Sorptionsklassen eingeteilt. Für 30 umweltrelevante und toxische Stoffe ohne Sorptionskoeffizient wurde ein Koc-Wert ermittelt und das Sorptionsverhalten nach dem erweiterten Hölting-Modell abgeschätzt. Dabei zeigten 2,6-Di-t-butyl-p-benzochinon, Epoxiconazol und Chalconepoxid nach dem Modell ein relevantes Sorptionsverhalten (log Koc= 2,39 bis 3,18). Für einen Koc-Datensatz von 85 Stoffen wurde mit dem Aldrich-Huminsäure-Säulenverfahrens ein Abraham-Modell aufgestellt. Das Modell liefert die signifikanten Phasenparameter e, s, b, v und und hohe Regressionskoeffizienten (r2=0,91, q2cv= 0,89). Demnach ist das aufgestellte Abraham-Modell für 16 Stoffklassen sehr gut geeignet, die Sorptionskoeffizienten vorherzusagen. Auch der Vergleich mit dem Abraham-Modell von Nyguyen (2005) zeigt, dass die Aldrich-Huminsäure die Sorptionseigenschaften von Böden sehr gut abbilden kann. Für eine Vielzahl an Stoffen lagen keine Literaturwerte vor, so dass mit Hilfe der HPLC-Säulenmethode zeitnah weitere Stoffklassen in das Abraham-Modell implementiert werden können. Für 40 organische Basen mit einem pKs-Bereich von 0,50 bis 10,69 und einem logKow- Bereich von -0,02 bis 5,51 wurde der Sorptionskoeffizient bei 3 pH-Werten ermittelt. Für 9 organische Basen, welche im untersuchten pH-Wertbereich ausschließlich neutral vorliegen, wurde kein signifikanter Einfluss des pH-Werts auf den Sorptionskoeffizienten ermittelt. Für kationisch vorliegende organische Basen wurde mit steigendem pH-Wert ein zunehmender Sorptionskoeffizient bestimmt. Eine Erhöhung des Sorptionskoeffizienten bei pH 5 und pH 7 beruht auf zusätzlichen ionischen Molekül-Matrix-Wechselwirkungen zwischen organischen Basen und Sorbens. Auch für die organischen Basen, welche im pH-Bereich von 3 bis 7 mit beiden Spezies vorliegen, konnte bei dem pH-Wert 5 oder pH-Wert 7 die größten Sorptionskoeffizienten ermittelt werden. Die starke Zunahme der Sorptionskoeffizienten kann neben hydrophoben Wechselwirkungen auf dem Maximum an ionischen Bindungen bei pH 5 oder pH 7 zwischen der kationischen Spezies der Base und den anionischen Carboxyl-Gruppen der Aldrich-Huminsäure basieren. Für 16 organische Basen, welche im pH-Wertbereich bei pH 7 neutral und bei pH 3 ionisch vorliegen, wurde ein linearer Zusammenhang zwischen log Koc.n und log Koc.ion aufgestellt. Für die Annahme, das für einen Stoff der Sorptionskoeffizient einer Spezies ermittelt wurde, gilt die Näherung dass mindestens 90 Prozent der Spezies vorliegen müssen. Das Modell zur Berechnung des pH-abhängigen Sorptionskoeffizienten beruht auf 55 log Koc(pH)-Werten von organischen Basen. Für die Anwendung des Modells muss eine organische Base im untersuchten pH-Wertbereich als neutrale Spezies vorliegen. Bei einem Vergleich der experimentellen Sorptionskoeffizienten mit den berechneten Werten von Franco stellte sich heraus, dass das Literaturmodell zur Vorhersage des Koc(pH) nur bedingt geeignet ist. In zukünftigen Arbeiten kann das erstellte Abraham-Modell für eine noch bessere praxisbezogene Anwendung auf weitere umweltrelevante Stoffklassen erweitert werden. Zur Erstellung eines Gesamtmodells für ionisch und neutral vorliegende organische Basen müssen pH-abhängige Sorptionskoeffizienten weiterer Basen ermittelt werden.
44

\"Técnicas espectroscópicas aplicadas à análise da matéria orgânica do solo em pomares de citros sob adição de lodo de esgoto\" / \"Spectroscopic techniques applied to the soil organic matter determination in citrus cultivations under sewage sludge application\"

Narimoto, Kelly Mayumi 27 October 2006 (has links)
A produção de lodo de esgoto vem aumentando a cada dia nas estações de tratamento, e a sua disposição final é um problema a ser resolvido. Uma das alternativas encontradas para a disposição final desses resíduos com benefícios ambientais e principalmente econômicos é a reciclagem agrícola, devido a sua composição em termos de matéria orgânica e nutrientes para as plantas. O objetivo deste trabalho foi avaliar os efeitos da adição do lodo de esgoto na matéria orgânica do solo, em um experimento de curto período de duração. As amostras utilizadas neste experimento foram coletadas na Fazenda Retiro, município de Monte Azul Paulista/SP, em áreas com cultivo de citros. O experimento foi composto de 5 tratamentos, uma testemunha e 4 doses de logo de esgoto. Além dos 5 tratamentos também foram amostrados o solo de mata (referência) e lodo de esgoto. Dessas amostras foram extraídos os ácidos húmicos (AH). Foram avaliadas as alterações ocorridas nas estruturas dos AH quanto aos teores de carbono, composição de grupos funcionais, número de radicais livres do tipo semiquinona e grau de humificação. O solo in natura também foi avaliado quanto aos teores de carbono e grau de humificação da matéria orgânica (MO). Para isso, foram utilizadas técnicas como análise elementar, TOC e espectroscopia de EPR, 13C RMN, FTIR, UV-Vis, Fluorescência e FIL. Através dos resultados de análise elementar, foi possível notar que não houve alterações na estrutura dos AH após a adição de lodo de esgoto, podendo ser comprovado através dos espectros de FTIR e 13C RMN, onde não foram observadas diferenças significativas para os diferentes tratamentos. A adição de lodo de esgoto em solos sob cultivo agrícola, entretanto, incorporou MO fresca, pois quando se compara o solo testemunha e o solo que recebeu a dose mais alta de lodo observa-se um aumento de 75% no carbono orgânico do solo. O AH do lodo de esgoto possui um caráter bastante alifático e em sua estrutura uma considerável quantidade de radicais livres do tipo semiquinona. Ao ser adicionado ao solo, observa-se que modifica a concentração do número de radicais livres do tipo semiquinona sem alterar os grupos funcionais do AH do solo. Portanto, no sistema estudado, a adição de lodo de esgoto mostra que o número de radicais livres do tipo semiquinona presentes no solo não é proporcional ao grau de humificação da MO do solo. Os resultados demonstraram que a espectroscopia de fluorescência tanto em solução como a Induzida por Laser forneceu dados coerentes à cerca do grau de humificação da MO. Foi possível observar uma diminuição no grau de humificação no solos submetidos à adição de lodo de esgoto, aproximando-se do solo de mata utilizado como referência. A concentração de carbono no solo aumentou, mesmo depois de ter sido interrompida a aplicação por 2 anos, e o grau de humificação da MO diminuiu, sendo menor ainda do que o solo de mata utilizado com referência. Portanto, podemos considerar este tipo de manejo onde se utiliza lodo de esgoto para condicionamento do solo apropriado tanto do ponto de vista ambiental quanto do ponto de vista agronômico. / The production of sewage sludge increases daily in treatment stations and definitive disposal is a problem to be resolved. One of the alternatives found to dispose such residues, with environmental and economic benefits, is agricultural recycling, owing to its organic composition and plant nutrients. The objective of the present work was to asses the effects of waste sludge addition to soil organic matter in an experiment of short duration. The samples used in this experiment were collected from Fazenda Retiro, a municipality of Monte Azul Paulista/SP, in an area that has citrus plantations. The experiment was composed of 5 treatments, reference soil and 4 sewage sludge doses. In addition to the 5 treatments, the forest soil (reference) and sewage sludge were also sampled. From these samples humic acids (HA) were extracted. The alterations that occurred in the HA structures were assessed regarding ratios of carbon, composition of functional groups, number of semiquinone-type free radicals and rate of humification. In natura soil was also assessed regarding carbon ratio and rate of humification of organic material (OM). Thus, techniques as elementary analysis, TOC and EPR spectroscopy, 13C RMN, FTIR, UV-Vis, Fluorescence and FIL were used. By means of elementary analysis results, it was possible to notice that there was no alteration in the HA structure after addition of sewage sludge, therefore, verifying through FTIR and 13C RMN spectra no significant differences observed for the different treatments. However, addition of sewage sludge in agricultural cultivated soils incorporated fresh OM, since when comparing the reference soil and the soil that received the highest dose of sludge, an increase of 75% is observed in the organic carbon of the soil. The HA of the sewage sludge has a very aliphatic characteristic and in its structure, a considerable quantity of semiquinone-type free radicals. It is observed that when added to the soil, it modifies the concentration of the number of semiquinone-type free radicals, without altering the HA functional groups of the soil. Therefore, in the studied system, addition of sewage sludge demonstrates that the number of semiquinone-type free radicals found in the soil is not proportional to the rate of OM humification of the soil. The results demonstrated that fluorescence spectroscopy in solution, as well as Laser-Induced fluorescence of whole soil, provided coherent data concerning the rate of OM humification. It was possible to observe reduction in the rate of humification in soils submitted to sewage sludge, in close approximation to the forest soil used as reference. The carbon concentration in the soil increased, even after interrupting application for 2 years, and humification degree of OM diminished, proving to be less than the forest soil used as reference. Thus, we can consider this type of management, when sewage sludge is used to condition soil, as appropriate from an environmental point of view, as well as from an agronomical one.
45

Compostos orgânicos de origem agroindustrial e urbana aplicados à produção vegetal e fertilidade do solo / Organic compounds from urban and agricultural residues applied to vegetal production and soil fertility

Pigatin, Lívia Botacini Favoretto 15 February 2011 (has links)
A definição mais amplamente aceita estabelece que compostagem é a decomposição controlada, exotérmica e bioxidativa de materiais de origem orgânica por microorganismos autóctones, num ambiente úmido, aquecido e aeróbio, com produção de dióxido de carbono, água, minerais e uma matéria orgânica estabilizada, definida como composto. Em função do potencial inerente aos compostos orgânicos tem-se observado sua crescente utilização na agricultura, tomando lugar dos fertilizantes minerais. Devido à disponibilidade e baixo custo na região de São Carlos-SP, os compostos a serem utilizados foram provenientes de resíduos de poda de árvores, bagaço de laranja, torta de filtro e esterco bovino. A humanidade produz uma grande quantidade de tipos de resíduos, os quais podem ser utilizados como matéria-prima no processo de compostagem. A poda de árvores é um resíduo facilmente encontrado tanto na zona rural como nas cidades, sendo geralmente descartada. Nas cidades este descarte pode se tornar um problema, na medida em que aumenta o volume de lixo produzido, sobrecarregando os depósitos ou aterros sanitários. O bagaço de laranja é o principal subproduto da indústria de processamento de citrus, correspondendo a cerca de 45% da massa total da fruta e pode se tornar um grande problema para indústria, pois se deteriora muito rápido durante a estocagem. A torta de filtro é um resíduo proveniente da indústria sucroalcooleira e é obtido do processo de clarificação do caldo de cana. O esterco bovino é um resíduo amplamente usado in natura como adubo orgânico, porém, o processo de compostagem torna-o mais estável e otimiza suas propriedades fertilizantes. De maneira geral, a influência dos compostos orgânicos na produção vegetal e na fertilidade do solo requer mais estudos devido à complexidade dos agroecossistemas. O objetivo desse trabalho foi avaliar a influência de diferentes compostos orgânicos nas doses selecionadas, na produção da planta medicinal Ocimum selloi Benth em um solo tropical arenoso (Latossolo Vermelho-Amarelo distrófico, coletado na Fazenda Canchin, na região de São Carlos-SP), em comparação com fertilizante mineral. Para observar os efeitos da adubação orgânica ou mineral foram analisados os ácidos húmicos extraídos dos solos utilizando espectroscopia na região do infravermelho próximo com transformada de Fourier, fluorescência e análise elementar. Para a análise do solo intacto utilizou-se a fluorescência induzida por laser e espectrsocopia na região do infravermelho médio. Também foram realizadas análises de fertilidade do solo e do tecido vegetal, bem como analíses para avaliação do desenvolvimento vegetal. A análise estatística dos dados (Análise de Componetes Principais) de fertilidade do tecido vegetal e do solo, e dos dados de NIRS, mostraram uma separação dos tratamentos em dois grupos. Foi possível verificar que o tratamento L2 foi o mais próximo do tratamento com adubação mineral, enquanto que os tratamentos L1, L3 e L4 ficaram mais próximos ao tratamento referência (sem adubação). Esses resultados são condizentes com o diagnóstico nutricional das plantas pelo método visual, além de serem similares com as análises químicas e espectroscópicas feitas por Fialho et al. (2010). Experimentos de infravermelho com transformada de Fourier forneceram espectros com bandas características de grupos alifáticos para o ácido húmico extraído do lodo, comprovando seu alto grau de alifaticidade. Dados de fluorescência utilizando diferentes metodologias e fluorescência induzida por laser, de amostras de solo intacto, apresentaram comportamento similar. É importante salientar, que de maneira geral, o tratamento L2 (adubação com composto que possue como material de partida esterco bovino e poda de árvores) é o mais similar ao fertilizante mineral, podendo trazer maiores benefícios quando aplicados ao solo em questão. De modo geral constata-se a viabilidade do uso de compostos orgânicos como alternativa ao uso de fertilizantes minerais, contudo o manejo e as implicações na nutrição de plantas e a plena produtividade das culturas ainda representa desafio importante para as pesquisas. / The most widely accepted definition about composting is that it is a controlled exothermic and bioxidative decomposition of organic materials by autochthonous microorganisms, resulting in a wet, warm and aerobic environment, with production of carbon dioxide, water, minerals and, a stabilized organic matter, defined as compost. Due to the availability and low cost in the region of São Carlos-SP, the organic composts used came from waste of tree pruning, orange bagasse, filter cake and manure. The humanity produces a lot of kinds of residues which can be use as raw material in composting production. Pruning trees is a waste easily found in both rural and urban areas, and they are generally discarded. In the cities, this disposal may become a problem, because it increases the volume of produced waste, overloading quickly deposits or landfills. The orange peel is the main by-product of citrus industry, representing about 45% of the total weight of the fruit and it can becomes a major problem for industry, because it deteriorates very rapidly during storage. The filter cake is a residue from the ethanol industry and is obtained from the solid precipitate from the sugarcane juice clarification (to produce sugar or ethanol) and, the boiler ash. The bovine manure is a waste widely used in natura as organic fertilizer however; the composting process makes it more stable and enhances its fertilizing properties. In general, the influence of organic composts in plant production and soil fertility requires more studies due to the complexity of agroecosystems. The objective of this work was to evaluate the influence of different composts and selected doses, on the production of the medicine plant Ocimum selloi Benth in a tropical sandy soil (colleted at Canchin Farm in the region of the city of São Carlos, São Paulo state), in comparison to mineral fertilizer. The studies showed differences between composts applied in the soil. Non-additional application of mineral fertilizers was done. The results were compared with the former ones observed by Fialho et al. (2010), using chemical and spectroscopic methods to evaluate the compost humification. Analysis of fertility of the soils under organic composts application or not, analysis of fertility of plant tissues (leaves) and analysis for evaluation of plant development were done to evaluate the performance of the tested treatments (L1, L2, L3 and L4). In order to observe the effects of the composts addition, the humic acids extracted from soils were analyzed by Fourier transform infrared spectroscopy (FTIR), fluorescence spectroscopy and elementar analysis. To analyse the intact soil laser induced fluorescence (LIF) and near-infrared reflectance spectroscopy (NIRS) was used. The results obtained with Principal Component Analysis (PCA) of fertility analysis of plant tissues and soils and NIRS, showed the treatments were separated into two main clusters. It was possible to verify the treatment called L2 and were nearest to commercial treatment (mineral fertilizer) and in the L1, L3 and L4 were nearest to the reference samples. These results are consistent with the nutritional diagnosis of plants by the visual method, and are similar to the chemical and spectroscopic analysis made by Fialho et al. (2010).The results obtained by Fourier transformed infrared showed spectra with characteristic bands from aliphaticity groups for humic acid from organic composts, confirming their high aliphacitity degree. Data from fluorescence utilizing different methodologies and laser induced fluorescence, from intact soil, showed similar results. Importantly, that in general, treatment L2 is most similar to mineral fertilizer, and can bring greater benefits when applied to the soil in question. Overall it appears the feasibility of using organic composts as an alternative to the use of mineral fertilizers, but management and the implications for plant nutrition and optimum crop yield still represents an important challenge for research.
46

Estudo da humificação da matéria orgânica de um cambissolo em diferentes sistemas de manejo por meio de técnicas espectroscópicas

Bonometo, Vanessa Elvira 22 June 2010 (has links)
Made available in DSpace on 2017-07-21T19:25:59Z (GMT). No. of bitstreams: 1 Vanessa Elvira Bonometo.pdf: 1928189 bytes, checksum: 6d3aff421841c38eb85f9fcb925b0243 (MD5) Previous issue date: 2010-06-22 / Stocks and stability of soil organic matter (SOM), even accounting approximately 5% of soil total, are indicators of quality and sustainability of the management system to which the soil is submitted, it has influence on nutrient availability for plants, assists in erosion retention, increases aggregates stability and assists in carbon sequestration. As labile SOM becomes stable through the humification process, affected by climate, soil type and management systems, the molecular structures gain complexity resulting in the formation of groups such as fluorescent aromatic rings and quinines, which can be evaluated by spectroscopy techniques. The purpose of this research was to use spectroscopic techniques to measure the humification of organic matter in a Cambisol, which comes from Irati – PR, submitted to two management systems: conventional tillage and no-tillage (six years and nine years). The forest was used as comparison. Analysis were performed using laser induced fluorescence (LIF) in whole soil (no chemical or physical treatment), and fractions obtained by physical fractionation by granulometry: (clay), (silt) e (fine sand) e (sand). The samples were also analyzed for fluorescence of humic acids, obtained by chemical fractionation of soil and absorption spectroscopy, UV-Visible ( ratio). The results of these tests show no difference in the degree of humification of SOM between management systems. / Os estoques e a estabilidade da matéria orgânica do solo (MOS), mesmo representando cerca de 5% do total do solo, são indicadores da qualidade e da sustentabilidade do sistema de manejo ao qual o solo está submetido, pois tem influência na disponibilidade de nutrientes para as plantas, auxilia na retenção de processos erosivos, aumenta a estabilidade de agregados e auxilia no sequestro de carbono. À medida que a MOS lábil torna-se estável por meio do processo de humificação, afetado pelo clima, tipo de solo e sistemas de manejo, as estruturas moleculares ganham complexidade, resultando na formação de grupos fluorescentes como anéis aromáticos e quinonas, que podem ser avaliados por técnicas espectroscópicas. O objetivo desta pesquisa foi utilizar técnicas espectroscópicas para medir a humificação da matéria orgânica de um Cambissolo Háplico, proveniente do município de Irati – PR, submetidos a dois sistemas de manejo: plantio convencional e plantio direto (de seis e de nove anos). Foi utilizada a mata para comparação. Foram realizadas análises de fluorescência induzida a laser (FIL) nas amostras de solo inteiro (sem nenhum tratamento físico ou químico) e das suas fracões obtidas através de fracionamento físico granulométrico: (argila), (silte) e (areia fina) e (areia grossa). Também foram realizadas análises de fluorescência dos ácidos húmicos, obtidos por meio de fracionamento químico do solo, e espectroscopia de absorção de UV-Visível (razão ). Os resultados desta análise mostram que não houve diferença no grau de humificação da MOS entre os sistemas de manejo.
47

Análises espectroscópicas da matéria orgânica de solos sob aplicação de águas residuárias / Spectroscopic analyses of soil organic matter under irrigation with trated wastewater

Santos, Cleber Hilario dos 16 October 2008 (has links)
Em todo o mundo existe uma crescente competição pelo uso de água entre diversos setores da sociedade. O consumo de água na agricultura é grande em relação a outros tipos de uso, podendo afetar a disponibilidade deste recurso para a população urbana se este não for bem administrado. No Brasil, a agricultura consome cerca de 61% da água doce total. Entre as diferentes alternativas utilizadas pelas sociedades contemporâneas para solucionar ou minimizar este problema, visando à utilização racional e eficiente desse precioso recurso natural, o reuso de águas residuárias (efluentes) é uma opção viável econômica e ambientalmente correta. O objetivo desse trabalho foi estudar as alterações na matéria orgânica de um Argissolo Vermelho Distrófico Latossólico cultivado com capim-Bermuda Tifton 85 submetidos à adição de efluentes gerados na estação de tratamento de esgoto. As amostras utilizadas foram coletadas no município de Lins/SP em experimento já em andamento. O delineamento experimental empregado foi o de blocos completos casualizados com seis tratamentos e três repetições. Os seis tratamentos estudados foram: (1) SI - sem irrigação e sem fertilização nitrogenada mineral (FNM) - (branco); (2) E100 - irrigação com efluente e 100% (520 Kg ha-1 ano-1) da dose recomendada de FNM para o capim Tifton - 85; (3) E66 - irrigação com efluente e 66% (343,2 Kg ha-1 ano-1) da FNM; (4) E33 - irrigação com efluente e 33% (171,6 Kg ha-1 ano-1) da FNM; (5) E0 - irrigação com efluente e 0% (0 Kg ha-1 ano-1) da FNM; (6) W100 - irrigação com água de consumo e 100% (520 Kg ha-1 ano-1) da FNM. Dessas amostras foram extraídos os ácidos húmicos (AH) para observar os efeitos da adição do efluente de esgoto tratado (EET) utilizando ressonância magnética nuclear de 13C (13C RMN), infravermelho com transformada de Fourier (FTIR), fluorescência de luz uv-visível, ressonância paramagnética eletrônica (RPE) e análise elementar (C, H, N, S). Para análise do solo intacto utilizou-se a fluorescência induzida por laser e os teores de carbono foram determinados pelo carbono orgânico total (COT). Através dos resultados obtidos pela análise elementar, FTIR e 13C RMN não foi possível obter informações a respeito das alterações na composição dos AH após a adição do EET, pois estas técnicas não foram sensíveis às mudanças da MO. Tanto os experimentos de FTIR como o de 13C RMN forneceu espectros com bandas características de grupos alifáticos, comprovando seu alto grau de alifaticidade. Os resultados da espectroscopia de fluorescência em solução demonstraram que a irrigação com EET aumenta tanto a concentração de estruturas complexas quanto o grau de humificação dos AH. Os resultados de FIL para solos inteiros, entretanto, não mostraram alteração significativa com a irrigação com EET (exceto o tratamento E33), indicando que as alterações das substâncias húmicas no solo analisado ocorreram preferencialmente nos AH e afetando muito pouco da humina, que representa mais de 80% das SH do solo. Os resultados obtidos por RPE demonstraram que os tratamentos irrigados com EET apresentaram um aumento na concentração de radicais livres do tipo semiquinona, com o aumento da adubação, exceto o tratamento E33. Sendo assim, em relação a MOS, a irrigação com EET por um período de quatro não causa mudanças significativas, e neste aspecto pode ser indicada como alternativa de irrigação não impactando significativamente a matéria orgânica e proporcionando benefícios econômicos, ambientais e sociais. / Around the world there is a growing competition for the use of water among several sectors of society. Water consumption in agriculture is large when compared to other types of use and can affect the availability of water for the urban population unless it is well administered. In Brazil, agriculture consumes about 61% of the total freshwater. Among the different ways tried by contemporary societies to solve or minimize this problem, aiming to use rationally and efficiently this precious natural resource, reuse of wastewater (effluents) is an economically viable and environmentally correct option. The aim of this work was to study the changes in organic matter in a Typic Hapludults cultivated with Tifton 85 Bermudagrass submitted to addition of effluent generated by sewage treatment. The utilized samples were collected at Lins / SP, being part of a previously started experiment. The experimental design employed was the randomized complete blocks, with six treatments and three replications. The analyzed six treatments were: (1) WI - without irrigation and without nitrogen as mineral fertilizer (NMF) - (white), (2)E100 - irrigation with effluent and 100% (520 kg ha-1 year-1) of the recommended dose of NMF for the Bermudagrass Tifton - 85, (3) E66 - irrigation with eflluent and 66% (343.2 kg ha-1 year-1) of the NMF, (4)E33 - irrigation with effluent and 33% (171.6 Kg ha-1 year-1) of the NMF,(5) E0 - irrigation with effluent and 0% (0 kg ha-1 year-1) of the NMF,(6) W100 - irrigation with water for consumption and 100% (520 Kg ha-1 year-1) of the NMF. Humic acids (HA) were extracted from these samples in order to observe the effects of adding treated sewage effluent (TSE) using nuclear magnetic resonance of 13C (13C NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, UVvisible and fluorescence spectroscopy, electronic paramagnetic resonance (EPR) spectroscopy and elementary analysis (C, H, N, S). In order to analyze the whole soil, laser induced fluorescence (LIF) was utilized, and the carbon levels were determined through total organic carbon (TOC). Through the results obtained by elementary analysis, FTIR and 13C NMR, it was not possible to obtain information about changes in the composition of HA after adding the TSE, because these techniques were not sensitive to changes in OM. Both 13C NMR and FTIR provided spectra with bands typical of aliphatic groups, showing their high degree of aliphaticity. The fluorescence spectroscopy results for samples in solution demonstrated that the irrigation with TSE increases both the concentration of complex structures and the humification degree of HA. The results of LIF for the whole soil, however, showed no significant change with irrigation with TSE (except for the treatment E33), indicating that changes of humic substances in the analyzed soil occurred mainly in HA, and affecting very little on humin, which represents more than 80% of the soil HS. The results obtained by EPR demonstrated that the treatments irrigated with TSE showed an increase in the concentration of semiquinone-type free radicals, with increasing fertilization, except for the treatment E33. Therefore, regarding SOM, irrigation with TSE along a four years period did not cause significant changes, and, under this viewpoint, it can be indicated as an alternative irrigation not significantly impacting the organic matter and providing economic, environmental and social benefits.
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Effect of peat components on microorganisms, with special reference to humic acids /

Muthukumarasamy, Sivagurunathan, January 1900 (has links)
Thesis (M.Sc.), Memorial University of Newfoundland, 2000. / Bibliography: leaves 133-144.
49

A predictive model for chloroform formation from humic substances

Engerholm, Bruce Alison January 1981 (has links)
No description available.
50

Characterization and Modeling of Macromolecules on Nanoparticles and Their Effects on Nanoparticle Aggregation

Louie, Stacey Marie 01 July 2014 (has links)
The increasing production and usage of engineered nanoparticles has raised concerns about potential ecological and human exposures and the risks these novel materials may pose. Nanoparticles are often manufactured with an organic macromolecular coating, and they will attain further coatings of adsorbed natural organic matter (NOM) in the environment. The overall objective of this thesis is to improve our ability to quantify the effects of adsorbed coatings on nanoparticle fate in the environment. The physicochemical properties of the coating or the adsorbing macromolecule are expected to strongly mediate the surface interactions, and hence the environmental fate, of coated nanoparticles. To this end, this research focuses on assessing a coating characterization method and applying extensive characterization of NOM coatings to enable the development of correlations to predict nanoparticle deposition onto model environmental surfaces and aggregation. The first objective is to assess the applicability of a soft particle electrokinetic modeling approach to characterize adsorbed layer thickness, which contributes to repulsive steric forces that will affect nanoparticle deposition. A statistical analysis determined that high uncertainty in fitted layer thicknesses will limit this approach to thin, low-charged coatings (for which it may be advantageous to typical sizing methods such as dynamic light scattering). Application of this method in experimental studies further confirmed the model limitations in estimating layer thicknesses and the inability of this measurement (and other commonly measured properties) to fully explain nanoparticle deposition behavior. These results demonstrated the need for improved detail and accuracy in coating characterization. The second objective is to correlate the properties of NOM to its effects on gold nanoparticle aggregation, with particular focus on the role of heterogeneity or polydispersity of the NOM molecular weight. Multiple types of NOM collected from representative water bodies and soils were used, both in whole and separated into molecular weight (MW) fractions, and characterized for chemical composition and MW distribution. While average MW of the NOM provided good correlation with aggregation rate, the highest MW components were found to contribute disproportionately in stabilizing nanoparticles against aggregation, highlighting the importance of measuring and accounting for high MW components to explain nanoparticle aggregation. However, an outlier from the MW trend was identified, emphasizing the need for additional characterization (e.g. of reduced sulfur content or the conformation of the adsorbed NOM) to fully explain the effects of NOM on nanoparticle aggregation. Altogether, this research provides novel knowledge that will guide future application of characterization methods to predict attachment processes for coated nanoparticles in the environment.

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