Master of Science / Department of Civil Engineering / Alok Bhandari / In the upper Midwest, subsurface tile drainage water is a major contributor of nitrate (NO[subscript]3–N) coming from fertilizers and animal manure. Movement of NO[subscript]3-N through tile drainage into streams is a major concern as it can cause eutrophication and hypoxia conditions, as in the Gulf of Mexico. Denitrifying bioreactors is one of the pollution control strategies to treat contaminated tile drainage water. These bioreactors require four conditions which are: 1) organic carbon source, 2) anaerobic conditions, 3) denitrifying bacteria and 4) influent NO[subscript]3-N. This research focuses on investigating fate of veterinary antibiotics in woodchips commonly used in in-situ reactors. Tylosin (TYL) and sulfamethazine (SMZ) are two veterinary antibiotics which are most commonly used in the United States and can be found in tile water after manure is land applied. Partition coefficients of TYL and SMZ on wood were determined by sorption experiments using fresh woodchips and woodchips from an in situ reactor. It was concluded that the woodchips were an effective means to sorb the veterinary antibiotics leached into the tile water after application of animal manure. Linear partition coefficients were calculated and phase distribution relationships were established for both the chemicals. The fresh woodchips gave inconclusive data but predictions could be made by the information determined in the experiments using woodchips from a ten year old woodchip bioreactor. Desorption was also studied and the likelihood of desorption was predicted using the Apparent Hysteresis Index. Overall, it was found that the old woodchips allowed for quick sorption of both antibiotics. It was also found that SMZ had reversible sorption on old woodchips. Thus, it was concluded that the woodchip bioreactor would not be effective for removal of veterinary antibiotics from tile drainage. More research is required for the fate of TYL and to confirm the conclusion.

Als Totalanalysesysteme (TAS) werden Geräte bezeichnet, welche komplette chemische Analysen eigenständig ausführen. Die Einführung solcher Systeme ermöglicht einen effizienteren Arbeitsablauf in Analyselaboren, da beispielsweise die Probenmanipulation, Aufreinigung und die physikalisch-/chemische Analyse automatisiert in einem Arbeitsgang durchgeführt werden können. Die speziellen Mikrototalanalysesysteme benötigen geringere Probemengen im $\mu$L- Bereich. Durch Kontamination, Agglomeration oder einem Verschluss etwaiger Kanäle in mikrofluidischen Totalanalysesystemen kann es zu einem kompletten Systemausfall kommen. Eine Alternative bildet die akustische Levitation, um derartige Störfälle durch gänzlichen Verzicht auf Gefäße und Wandkontakte gezielt zu reduzieren. Damit die akustische Levitation erfolgreich in Mikrototalanalysesystemen Anwendung finden kann, bedarf es der technischen Weiterentwicklung von Analysemethoden und Kopplungstechniken. In der vorliegenden Arbeit wird das Hauptaugenmerk auf die Kopplung von Levitationstechnik und Massenspektrometrie gelegt. Darüber hinaus wurden spektroskopische Experimente durchgeführt, welche auf Totalreflektionen innerhalb der Tropfen beruhen. Die besonders gute Reflektion hängt damit zusammen, dass sich die Phasengrenze zwischen Luft und Flüssigkeit im Schwebezustand durch molekulare Wechselwirkungen ständig erneuert und keine produktionsbedingte raue Oberfläche aufweist. Die Kombination aus automatischer Tropfengenerierung, Spektroskopie sowie der entwickelten Methode zur Ionenerzeugung aus dem Probevolumen und der massenspektrometrischen Analyse bilden die Grundlage eines neuartigen Mikrototalanalysesystems für geringe Probemengen. / As a total analysis system (TAS) an instrument is called which carries out complete chemical analysis procedures independently. The introduction of such systems offers a more efficient workflow in analytical laboratories because the sample manipulation, purification and the actual automated analysis can be carried out in one single operation. Specialized and already existing micro total analysis systems require currently a small amount of sample in the $\mu$L range. Owing to contamination, agglomeration and thus cross-secion reduction of incorporated channels in micro fluidics total analysis systems it can lead to a complete system interruption. Hence, the implementation of acoustic levitation in these systems is interessting alternative in order to avoid such kind of problems by abandoning vessels and wall contacts completely. To ensure acoustic levitation in micro total analysis systems can be successfully applied, technical development of analytical methods and coupling techniques is required. In the present work, the coupling of levitation technology and mass spectrometry is the prioritized topic but, in addition, spectroscopic experiments based on total reflections within the levitated droplet are as well realized in order to gain process insights. The particularly good reflection at the freely levitated droplet's circumference is due to the fact that the phase boundary between air and liquid is renewed by molecular interactions constantly and has no production-related rough surface. The combination of automated droplet generation, spectroscopy as well as the developed method for ion generation from the sample volume and mass spectrometry forms the basis of a novel micro total analysis system for small sample quantities.

A introdução de metais pesados no solo pode ser efetuada através de diferentes meios, sendo muito estudadas as aplicações de lodo e de resíduos industriais. Entretanto, práticas agrícolas tradicionais também podem contribuir para levar metais ao solo, através do uso de fertilizantes minerais, defensivos e mesmo adubos orgânicos. Os objetivos desse trabalho foram considerar a relação entre concentrações de Cu em solução e na fase sólida de alguns solos do município de Louveira, SP, cultivados com figo e uva, contaminados com cobre devido à aplicação de calda bordalesa e também de dois Latossolos contaminados com cobre devido à aplicação de lodo de esgoto. Para tanto, determinou-se a capacidade adsortiva e dessortiva desses solos através de isotermas de adsorção; os valores de energia livre (∆Go) e do coeficiente de distribuição Kd das reações de adsorção de cobre. Verificou-se ainda o ajuste dos modelos de Langmuir e Freundlich aos valores experimentais obtidos no estudo de adsorção. Amostras de terra foram agitadas em duplicata por 24h com solução 0,01 mol L-1 de Ca(NO3)2 (relação 1:10) contendo: 0; 2; 5; 10; 15; 30; 50; 75 e 100 mg L-1 Cu. As concentrações do cobre em solução foram então determinadas por espectrofotometria de absorção atômica. A quantidade de metal adsorvida foi estimada pela diferença entre a concentração inicial e a concentração de equilíbrio. Para determinar a quantidade de Cu dessorvido, as amostras de terra do estudo de adsorção foram agitadas por 2h por três vezes consecutivas, com 20 ml de solução de Ca(NO3)2 0,01 mol L-1. A quantidade de cobre dessorvida foi calculada a partir das concentrações de cobre determinadas nas três etapas citadas. As isotermas de Freundlich e Langmuir mostraram-se igualmente capazes de descrever a adsorção de Cu em todos os solos estudados. Solos com maiores teores de matéria orgânica e pH em geral adsorveram maiores quantidades de cobre e apresentaram maiores coeficientes de distribuição (Kd). Nos solos sob aplicação de lodo de esgoto as quantidades de cobre dessorvido foram muito baixas. Para todos os solos o fenômeno da histerese foi expressivo. Apesar dos altos teores de Cu resultantes da aplicação de lodo e calda bordalesa, os solos evidenciaram ainda uma grande capacidade de adsorver mais metal adicionado Tais resultados reforçam a importância da matéria orgânica no manejo correto de solos contaminados com cobre proveniente da adição de lodo de esgoto e calda bordalesa. / The introduction of heavy metals in soil could be effectuated in differents ways, being the applications of sewage-sludge and industrial residues the most studied of them. However, traditional agricultural practices can contribute to take metals to the soil as well, through the use of mineral fertilizers, pesticides and also organic manure.The objectives of this research were to consider the relationship between copper concentrations in soil solution and in its solid phase on soils of orchards in Louveira region of São Paulo State, Brazil, which had been previously contaminated by copper due the application of the Bordeaux mixture; and also another two soils contaminated by copper due to the application of sewage-sludge. This study included the determination of the adsorption and desorption capacity of these soils through adsorption isotherms; the values of free energy (∆Go) and the distribution coefficient Kd. The Langmuir and Freundlich models were fitted to experimental data. Soil samples were stirred during 24 hours in duplicate with 20 mL of 0.01 mol L-1 Ca(NO3)2 solution (relation 1:10) containing: 0; 2; 5; 10; 15; 30; 50; 75 and 100 mg L-1 Cu. The metal concentrations in the equilibrium solution were determined by atomic absorption spectrophotometry. The adsorbed metal amounts were calculated with basis on the difference between the initial amount and the metal remaining content at the end of the reaction period. To determine the desorbed metal amount, the soil samples previously submitted to the adsorption trial were stirred for 2 hours, three consecutive times, with 20 ml of solution of Ca(NO3)2 0.01 mol L-1 in duplicate. The cumulative desorbed copper amount was calculated by the sum of the copper extracted in each step. The Freundlich and Langmuir isotherms presented themselves as equally capable of describing the Cu adsorption in all the studied soils. Generally, soils containing the greater organic matter content and pH, adsorbed higher amounts of copper, and presented greater distribution coefficients (Kd). In the soils submitted to sludge application copper desorption was very low. For all the studied soils samples the hysteresis phenomenon was expressive. In all soils the copper adsorption reaction was thermodynamically exothermic and spontaneous. Despite the high copper content in soils treated with sludge and the Bordeaux mixture application, a great adsorption capacity of the added copper was detected. Such results strengthen the importance of the organic matter in the correct soil management of copper contaminated soils due to the addition of sewage-sludge and Bordeaux mixture.

A introdução de metais pesados no solo pode ser efetuada através de diferentes meios, sendo muito estudadas as aplicações de lodo e de resíduos industriais. Entretanto, práticas agrícolas tradicionais também podem contribuir para levar metais ao solo, através do uso de fertilizantes minerais, defensivos e mesmo adubos orgânicos. Os objetivos desse trabalho foram considerar a relação entre concentrações de Cu em solução e na fase sólida de alguns solos do município de Louveira, SP, cultivados com figo e uva, contaminados com cobre devido à aplicação de calda bordalesa e também de dois Latossolos contaminados com cobre devido à aplicação de lodo de esgoto. Para tanto, determinou-se a capacidade adsortiva e dessortiva desses solos através de isotermas de adsorção; os valores de energia livre (∆Go) e do coeficiente de distribuição Kd das reações de adsorção de cobre. Verificou-se ainda o ajuste dos modelos de Langmuir e Freundlich aos valores experimentais obtidos no estudo de adsorção. Amostras de terra foram agitadas em duplicata por 24h com solução 0,01 mol L-1 de Ca(NO3)2 (relação 1:10) contendo: 0; 2; 5; 10; 15; 30; 50; 75 e 100 mg L-1 Cu. As concentrações do cobre em solução foram então determinadas por espectrofotometria de absorção atômica. A quantidade de metal adsorvida foi estimada pela diferença entre a concentração inicial e a concentração de equilíbrio. Para determinar a quantidade de Cu dessorvido, as amostras de terra do estudo de adsorção foram agitadas por 2h por três vezes consecutivas, com 20 ml de solução de Ca(NO3)2 0,01 mol L-1. A quantidade de cobre dessorvida foi calculada a partir das concentrações de cobre determinadas nas três etapas citadas. As isotermas de Freundlich e Langmuir mostraram-se igualmente capazes de descrever a adsorção de Cu em todos os solos estudados. Solos com maiores teores de matéria orgânica e pH em geral adsorveram maiores quantidades de cobre e apresentaram maiores coeficientes de distribuição (Kd). Nos solos sob aplicação de lodo de esgoto as quantidades de cobre dessorvido foram muito baixas. Para todos os solos o fenômeno da histerese foi expressivo. Apesar dos altos teores de Cu resultantes da aplicação de lodo e calda bordalesa, os solos evidenciaram ainda uma grande capacidade de adsorver mais metal adicionado Tais resultados reforçam a importância da matéria orgânica no manejo correto de solos contaminados com cobre proveniente da adição de lodo de esgoto e calda bordalesa. / The introduction of heavy metals in soil could be effectuated in differents ways, being the applications of sewage-sludge and industrial residues the most studied of them. However, traditional agricultural practices can contribute to take metals to the soil as well, through the use of mineral fertilizers, pesticides and also organic manure.The objectives of this research were to consider the relationship between copper concentrations in soil solution and in its solid phase on soils of orchards in Louveira region of São Paulo State, Brazil, which had been previously contaminated by copper due the application of the Bordeaux mixture; and also another two soils contaminated by copper due to the application of sewage-sludge. This study included the determination of the adsorption and desorption capacity of these soils through adsorption isotherms; the values of free energy (∆Go) and the distribution coefficient Kd. The Langmuir and Freundlich models were fitted to experimental data. Soil samples were stirred during 24 hours in duplicate with 20 mL of 0.01 mol L-1 Ca(NO3)2 solution (relation 1:10) containing: 0; 2; 5; 10; 15; 30; 50; 75 and 100 mg L-1 Cu. The metal concentrations in the equilibrium solution were determined by atomic absorption spectrophotometry. The adsorbed metal amounts were calculated with basis on the difference between the initial amount and the metal remaining content at the end of the reaction period. To determine the desorbed metal amount, the soil samples previously submitted to the adsorption trial were stirred for 2 hours, three consecutive times, with 20 ml of solution of Ca(NO3)2 0.01 mol L-1 in duplicate. The cumulative desorbed copper amount was calculated by the sum of the copper extracted in each step. The Freundlich and Langmuir isotherms presented themselves as equally capable of describing the Cu adsorption in all the studied soils. Generally, soils containing the greater organic matter content and pH, adsorbed higher amounts of copper, and presented greater distribution coefficients (Kd). In the soils submitted to sludge application copper desorption was very low. For all the studied soils samples the hysteresis phenomenon was expressive. In all soils the copper adsorption reaction was thermodynamically exothermic and spontaneous. Despite the high copper content in soils treated with sludge and the Bordeaux mixture application, a great adsorption capacity of the added copper was detected. Such results strengthen the importance of the organic matter in the correct soil management of copper contaminated soils due to the addition of sewage-sludge and Bordeaux mixture.

The field of ambient desorption/ionization mass spectrometry (ADI-MS) has existed for over a decade. ADI-MS is a technique that offers benefits including fast analysis time, simple ionization sources that are easily constructed, and little to no required sample preparation. The research presented here describes efforts to better understand plasma-based ADI-MS sources and to explore the use of hydrogen-doped plasma gases with these sources. The use of hydrogen-doped argon (H2/Ar) and hydrogen-doped helium (H2/He) as plasma gases for a dielectric barrier discharge (DBD) and an AC glow discharge is presented first. When using the DBD, the intensity of the signal obtained when analyzing organic molecules in positive ion mode was increased by factors up to 37 times. In negative ion mode, only H2/Ar was shown to enhance the signal of an organic analyte. The limits of detection for caffeine when using hydrogen-doped plasma gases were found to decrease by factors of 78 and 1.9 for H2/Ar and H2/He respectively. The same phenomenon was observed when using H2/Ar with the AC discharge, but no signal enhancement was observed when using hydrogen-doped helium with the AC discharge. Similarly, if the DBD was allowed to ground through a wire rather than through the air, no signal enhancement was observed for H2/He. Using H2/Ar with metal samples is presented second. By using the metal sample as the grounded electrode for the AC glow discharge, many different metals could be detected directly with a time-of-flight mass spectrometer (TOF-MS) in the form of atomic ions both on their own and in combination with water and ammonia from the discharge. Any refractory metals tested did not yield signal. In addition to direct analysis with a TOF-MS, the AC discharge was used as a sampling method for an inductively coupled plasma mass spectrometer (ICP-MS). When coupled with an ICP-MS, the AC glow discharge was found capable of sampling even refractory elements, though the power of the ICP was required for ionization and detection. Scanning electron microscope (SEM) images of a copper surface exposed to the plasma discharge showed signs of melting when using the H2/Ar. Finally, a computer simulation of the chemistry and flow dynamics of a DC glow discharge generated in helium is presented. The simulation explores many of the fundamental processes at work and how they depend on the composition of the plasma gas. The generation of important species in the plasma was found to depend more on the amount of N2 and H2O impurities in the plasma gas rather than on the humidity or air pressure.

[pt] O presente trabalho avaliou a eficácia da dessorção térmica in situ em remediar materiais contaminados por hidrocarbonetos de petróleo em refinarias. Paralelamente, foi projetado e construído um novo sistema modular para ser empregado sob dutovias para remediação de britas contaminadas. Os resultados do programa experimental revelaram ser possível a remediação de pavimentos de concreto contaminados por óleo combustível. A aplicação de calor na superfície do pavimento reduziu em até 65 por cento a sua resistência, porém propiciou a restauração de sua cor original. Verificou-se que os resíduos do processo, após análises mineralógicas por difração de raios X e químicas por espectroscopia de fluorescência, apresentavam uma composição muito semelhante ao solo empregado como material de construção dos aterros da refinaria, sugerindo que o resíduo possa ser advindo de transporte eólico. O sistema desenvolvido no presente trabalho apresentou um desempenho satisfatório. Verificou-se a necessidade de aeração do material remediado para eliminar a produção de coque. Adicionalmente, observou-se a importância de um bom isolamento térmico para minimizar o consumo energético e impedir a propagação de calor e das emissões para a atmosfera. As emissões geradas pelo aquecimento consistiam de olefinas e parafinas que podem ser devidamente tratadas pelo oxidador térmico. / [en] This dissertation assessed the adequacy of in situ thermal desorption (istd) in cleaning oil contaminated debris from Refineries. A new modulated istd system was designed and built in order to remediate oiled cobbles under pipeways. The experimental results revealed the possibility of cleaning concrete pavements contaminated by heavy oil. The thermal desorption process restored their original color but reduced their resistance up to 65 percent. It was observed that the resulting debris, after mineralogical analyses by X-ray diffraction and chemical analysis by X-Ray fluorescence, have a similar composition to the soil employed in the fills throughout the Refinery, indicating that the debris could well have been transported by the wind. The system devised here had a satisfactory performance. It was observed the necessity of aeration during the treatment in order to avoid the production of coke. Additionally, it was also observed the importance of a good thermal insulation in order to minimize power consumption and the propagation of heat and gas emissions to the atmosphere. The gases emissions consisted mainly of olefins and paraffins that had been reasonably been treated by the thermal oxidizer devised herein.

Although the metallurgical industry has made great strides in the reduction of unwanted emissions to the atmosphere as a result of production processes, significant challenges still exist. From a global perspective, even large reductions in emissions per produced ton become immaterial when considering that the total world production of metals continues to increase. Two such particularly hazardous emissions are sulfur dioxide, primarily from copper ore roasting, and mercury, which has had increasing emissions from the steel industry in recent years. Both pollutants have severe consequences for the environment and also for human health. The primary motivations of this work have hence been: (1). to study sulfate formation on soot from sulfur dioxide emissions reacting with ozone and H2O in the vapor phase and (2). to study factors involving the behavior of mercury adsorption on metal surfaces involved in steelmaking, in order to further the understanding of select emissions from scrap-based steelmaking. Gas phase experiments were conducted to examine the heterogeneous oxidation of sulfur dioxide on soot in the presence of ozone and water vapor. The sulfur dioxide oxidation into sulfate was quantified using a particle-into-liquid sampler coupled with ion chromatography to measure the sulfate formation at atmospheric pressure. Water vapor, ozone and sulfur dioxide concentrations were controlled. Due to the ozone oxidation, multilayer adsorption of sulfur dioxide on soot, as well as sulfate formation and physisorption on secondary surface layer sites were observed. The exposure also caused the soot to become hydrophilic, due to the sulfur dioxide adsorption and also likely the formation of carboxyl groups on the surface. No significant increase in sulfate formation was observed at ozone concentrations above 1000 ppm. The effects of common surface contaminants such as oxygen and chlorine were examined on the metal surfaces, as well as the impact of changes in temperature, with controlled conditions using thermal desorption auger electron spectroscopy. It was established that low temperatures (82 K through 111 K) were conducive to mercury adsorption, wherein physisorption and subsequent lateral mercury interactions in mercury adlayers occurred. Chlorine appeared to favor mercury uptake, as determined by the increased mercury coverage at low temperatures on polycrystalline iron, copper and zinc. Oxygen, however, was found to be an inhibitor of mercury, most notably at room temperature. It was surprising to establish that no mercury adsorbed on zinc surfaces at room temperature and only on polycrystalline samples at low temperature. The mercury signal intensity increased up to the limit of the melting temperature for iron systems, on the oxidized copper surface and the polycrystalline zinc surfaces, prior to desorption from the surfaces. It is suggested that this is due to a rearrangement of mercury atoms on the surface at increasing temperatures, whereas at 85 K, mercury adhered to its initial adsorption position. In other words, mercury wet these surfaces on annealing, transitioning from an islanded surface at low temperature to a smooth layer before desorption. Based on these results, it was concluded that the mercury bond to the oxidized surface was weakened compared to clean copper. Furthermore, it is proposed that a surface phase transition occurred on polycrystalline zinc prior to desorption. No such transition was observed on iron. Activation energies of desorption were calculated for the relevant metal surfaces. It was established that clean iron had the highest activation energy of desorption. The large bond strength between mercury and iron may account for the highest desorption temperature of the iron systems. Zinc and copper had similar activation energies and desorption temperatures, which were respectively lower than that of iron. X-Ray Photoelectron and Auger Electron Spectroscopy were used to ascertain common surface contamination, i.e. chlorine, oxygen and sulfur, which affected mercury adsorption. Laser Ablation Inductively Coupled Plasma Time of Flight Mass Spectrometry was used to determine the depth of mercury adsorption on the samples. The technique also showed that the samples contained mercury in the surface layers. Accompanied by the rising demand for metals is the increase in emissions from metals manufacturing. Moreover, it is critical to minimize sulfur dioxide emissions as particulates from soot continue to be released in the atmosphere. For scrap-based steelmaking, monolayer mercury adsorption on clean iron and copper at room temperature are significant results. With the rising use of electronic devices in vehicles, the sorting of scrap becomes increasingly important. Mercury not adsorbing on zinc at room temperature is also of relevance as it disproves the theory of increased mercury adsorption with the increased use of galvanized scrap in summer conditions. However, the low temperature studies showed multilayer adsorption of mercury on iron, zinc and copper, which has relevance for the reported temporal variations of mercury deposition in arctic regions. Keywords: mercury, iron, zinc, sulfur dioxide, adsorption, pollution, thermal desorption, polycrystalline, surfaces, spectroscopy / QC 20120326

Demands for zero greenhouse-gas emission vehicles have sharpened with today’s increased focus on global warming. Hydrogen storage is a key technology for the implementation of hydrogen powered vehicles. Metal hydrides can claim higher energy densities than alternative hydrogen storage materials, but a remaining challenge is to find a metal hydride which satisfies all current demands on practical usability. Several metals store large amounts of hydrogen by forming a metal hydride, e.g., Mg, Ti and Al. The main problems are the weight of the material and the reaction energy between the metal and hydrogen. Magnesium has a high storage capacity (7.6 wt.% hydrogen) in forming MgH2; this is a slow reaction, but can be accelerated either by minimizing the diffusion length within the hydride or by changing the diffusion properties. Light-metal hydrides have been studied in this thesis with the goal of finding new hydrogen storage compounds and of gaining a better understanding of the parameters which determine their storage properties. Various magnesium-containing compounds have been investigated. These systems represent different ways to address the problems which arise in exploiting magnesium based materials. The compounds were synthesized in sealed tantalum tubes, and investigated by in situ synchrotron radiation X-ray powder diffraction, neutron powder diffraction, isothermal measurements, thermal desorption spectroscopy and electron microscopy. It is demonstrated that hydrogen storage properties can be improved by alloying magnesium with yttrium or scandium. Mg-Y-compounds decompose in hydrogen to form MgH2 nano-structures. Hydrogen desorption kinetics are improved compared to pure MgH2. The influence of adding a third element, gallium or zinc has also been studied; it is shown that gallium improves hydrogen desorption from YH2. ScAl1-xMgx is presented here for the first time as a hydrogen storage material. It absorbs hydrogen by forming ScH2 and Al(Mg) in a fully reversible reaction. It is shown that the hydrogen desorption temperature of ScH2 is reduced by more than 400 °C by alloying with aluminium and magnesium.

Lignocellulosic biomass (e.g., non food-based agricultural resides and forestry wastes) has recently been promoted for use as a source of bioethanol instead of food-based materials (e.g., corn and sugar cane), however to fully realize these benefits an improved understanding of lignocellulosic recalcitrance must be developed. The primary goal of this thesis is to gain fundamental knowledge about the surface of the plant cell wall, which is to be integrated into understanding biomass recalcitrance. Imaging mass spectrometry by TOF-SIMS and MALDI-IMS is applied to understand detailed spatial and lateral changes of major components in the surface of biomass under submicron scale. Using TOF-SIMS analysis, we have demonstrated a dilute acid pretreated poplar stem represented chemical differences between surface and bulk compositions. Especially, abundance of xylan was observed on the surface while sugar profile data showed most xylan (ca. 90%) removed from the bulk composition. Water only flowthrough pretreated poplar also represented difference chemistry between surface and bulk, which more cellulose revealed on the surface compared to bulk composition. In order to gain the spatial chemical distribution of biomass, 3-dimensional (3D) analysis of biomass using TOF-SIMS has been firstly introduced in the specific application of understanding recalcitrance. MALDI-IMS was also applied to visualize different molecular weight (e.g., DP) of cellulose oligomers on the surface of biomass.

No description available.