Via mixed-culture fermentation, the MixAlcoTM produces carboxylic acids, which are chemically converted into industrial chemicals and hydrocarbon fuels. Using pilot fermentation data, The Continuum Particle Distribution Model (CPDM) overestimated acid concentration (30–90% error) but more closely estimated conversion (<15% error). Incorporating the effect of air into the model reduced the absolute error of all predictions by >50%. To analyze fermentation data with semi-continuous streams, the Slope method calculates the average flowrate of material from the slope of the moving cumulative sum with respect to time. Although the Slope method does not significantly improve accuracy, it dramatically reduces error compared to traditional techniques (>40% vs. <2%). Nutrients are essential for microbial growth and metabolism. For a four-bottle fermentation train, five nutrient contacting patterns (single-point nutrient addition to Fermentors F1, F2, F3, F4, and multi-point parallel addition) were investigated. Compared to the traditional nutrient contacting method (all nutrients fed to F1), the near-optimal feeding strategies improved exit yield, culture yield, process yield, exit acetate-equivalent yield, conversion, and total acid productivity by approximately 31%, 39%, 46%, 31%, 100%, and 19%, respectively. To estimate nitrogen concentration profiles, a segregated-nitrogen model uses separate mass balances for solid- and liquid-phase nitrogen; the nitrogen reaction flux between phases is assumed to be zero. Using five fermentation trains, each with a different nutrient contacting pattern, the model predictions capture basic behavior; therefore, it is a reasonable tool for estimating and controlling nitrogen profiles. To determine the optimal scenario for mixed-acid fermentations, an array of batch fermentations was performed that independently varied the C/N ratio and the blend of carbohydrate (office paper) and nutrient (wet chicken manure (CM)). Reactant was defined as non-acid volatile solids (NAVS). C/N ratios were based on non-acid carbon (CNA). A blend of 93% paper and 7% wet CM (dry basis) with a C/N ratio of 37 g CNA/g N had the highest culture yield (0.21 g acidproduced/g NAVSinitial), total acid productivity (0.84 g acidproduced/(Lliq·d)), and conversion (0.43 g NAVSconsumed/g NAVSinitial).

The main contents of campus sewage are BOD and inorganic nutrients. Conventional secondary treatment processes can remove BOD efficiently, whereas the inorganic nutrients remain mostly left. Therefore, the effluents may cause eutrophication to the receiving water bodies. Using constructed wetland treatment system to reduce nutrients become more and more popular recently. Vertical flow type subsurface process is particularly efficient in nitrogen transformations. In this research we studied the nitrogen transformation dynamics by using different types vertical flow constructed wetland system with various natural materials as the media to treat the secondary effluents from a campus sewage treatment plant. Six self designed experiment columns with broken concrete blocks, oyster shells, different sizes of marble granules, and river sands were used for this study as vertical flow constructed wetland systems. The methods of operation included batch type, continuous flow with filled water and trickling filter type, which were tested by controlling the influent flows into those six test columns. The efficiencies of various combinations in treatments and their mechanisms were discussed in the study. The experimental results showed that the best ammonium nitrogen removal efficiency was measured equal to 46.6% in batch type operations, while the continuous flow with filled water type operation showed the best performance by using concrete blocks as the media (42.8%). However, the best ammonium nitrogen removal rate in the trickling operation was found in the column with media of 3 mm marble granules (91.1%). The medium of river sand obtained the best phosphorous removal rate by using a batch flow operation. Vegetating presented only minor contributions in the column with medium of smaller grain size materials. The optimum C/N ratios for denitification tests are 3.5 and 3 by using the media of concrete and oyster, respectively.

No description available.

Activated sludge microorganisms can remove many hazardous substances from wastewater by adsorbing and concentrating them on their surfaces. Biosorption of these substances onto activated sludge surfaces are influenced by the chemical properties of the substance in question as well as the surface properties of the microorganisms. The purpose of this study is to identify the biosorption mechanisms of heavy metals and the effect of extracellular polymer (ECP) composition of activated sludge on the biosorption of Pb(II), Cd(II), Cu(II), Zn(II) and Ni(II). Microorganisms cultured under different growth conditions are expected to have different compositions of ECPs and hence, different biosorption capacities. For this purpose, three sets of reactors with C/N ratios of 9, representing a carbonlimited case / 21, representing conventional municipal wastewater treatment plant activated sludge and 43, representing nitrogen-limited condition, were set up. The semi continuous reactors were fed synthetically and operated at a sludge age of 8 days. Isotherm and kinetic experiments that were held with three different C/N ratios was indicated that the biosorptive capacity of activated sludge was highly dependent on metal species and the C/N ratio. Although, the dependence of biosorptive capacity on C/N ratio was different for each metal, biosorption properties of activated sludge were found to be directly related with ECP composition. Among the heavy metals tested, Pb(II) was the one that was adsorbed at the highest capacity at all C/N ratios. Also, with the purpose of understanding the mechanism of the process, Ca(II) and Mg(II) ions and carbohydrates released into the solution were also monitored and it was indicated that an ion exchange process is involved in the biosorption of heavy metals especially at high metal concentrations but the whole metal removal can not be explained by ion exchange.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-22T12:58:30Z No. of bitstreams: 2 christiano_conceicao_matos.pdf: 1168384 bytes, checksum: e9f190696619331c30543818c50f9de2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-22T13:13:55Z (GMT) No. of bitstreams: 2 christiano_conceicao_matos.pdf: 1168384 bytes, checksum: e9f190696619331c30543818c50f9de2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-22T13:13:53Z (GMT) No. of bitstreams: 2 christiano_conceicao_matos.pdf: 1168384 bytes, checksum: e9f190696619331c30543818c50f9de2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-22T13:14:43Z (GMT) No. of bitstreams: 2 christiano_conceicao_matos.pdf: 1168384 bytes, checksum: e9f190696619331c30543818c50f9de2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2014-12-22T13:14:43Z (GMT). No. of bitstreams: 2 christiano_conceicao_matos.pdf: 1168384 bytes, checksum: e9f190696619331c30543818c50f9de2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2013 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordenadoria de Aperfei?oamento do Pessoal de N?vel Superior (CAPES) / A Nicandra physaloides (L) Gaertn. ? uma planta daninha que infesta ?reas agr?colas brasileiras. O conhecimento do comportamento das plantas, frente aos recursos do meio, como a luz, ?gua e principalmente a disponibilidade de nutrientes no solo, torna-se fundamental para adotar t?ticas de manejo das mesmas nos agroecossistemas. Observa??es de campo sugerem a esp?cie como planta daninha de ciclo r?pido, que adapta-se bem a solos de alta fertilidade e com grande capacidade em acumular mat?ria seca, cujo material vegetal ? rapidamente decomposto no solo. O objetivo deste estudo foi avaliar o efeito do aumento de doses de nitrog?nio, f?sforo e pot?ssio no crescimento de Nicandra physaloides, bem como, os teores de nutrientes, as caracter?sticas bromatol?gicas e a rela??o C/N presentes na mat?ria seca dessa planta daninha. No primeiro experimento foi avaliada a influ?ncia das doses de nutrientes no ac?mulo e parti??o de mat?ria seca, na altura e nas taxas de crescimento de N. physaloides. No segundo experimento foram avaliados os efeitos das doses de N, P e K nos teores e ac?mulo de nutrientes, nas caracter?sticas bromatol?gicas e na rela??o C/N, presentes na mat?ria seca das plantas. Observou-se que a esp?cie ? altamente responsiva ? aduba??o. No entanto, o padr?o de distribui??o de biomassa n?o foi alterado pela aduba??o. Ao ser cultivada em solo de baixa fertilidade, N. physaloides apresentou baixas taxas de crescimento. Maiores teores de N, P e K foram encontrados em plantas submetidas aos maiores n?veis de nutrientes. O aumento nos n?veis de N, P e K no solo proporcionou maior ac?mulo total desses macronutrientes. Os tratamentos n?o influenciaram a composi??o bromatol?gica (FDN e FDA) e a rela??o C/N da planta. N. physaloides apresentou baixa rela??o C/N durante todo o per?odo de avalia??o, o que aliado aos baixos teores de FDN e FDA e ao bom ac?mulo de nutrientes, sugere que o material vegetal proveniente dessa planta seja rapidamente decomposto, proporcionando uma ciclagem r?pida de nutrientes no solo. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT Nicandra physaloides (L) Gaertn. is a weed that infests Brazilian agricultural areas. Knowledge the behavior of plants against environmental resources, such as light, water and mainly the availability of nutrients in the soil, being essential to management in agroecosystems. Field reports suggest the weed species of fast cycle has the characteristics following: well adapted to soils of high fertility and high capacity to accumulate dry matter; which plant matter is quickly decomposed in soil. The objective of this study was to evaluate the effect of increasing of N, P and K doses on growth of Nicandra physaloides as well as the nutrients content, chemical characteristics and C/N ratio of the weed. In the first experiment was evaluated the influence of nutrient levels in accumulation and partitioning of dry matter, height and growth rates of N. physaloides. In the second experiment evaluated the effects of N, P and K doses on content and accumulation of nutrients, chemical characteristics and the C/N ratio of the weed. The specie was highly responsive to fertilization. However, biomass partitioning was not altered by fertilization. When grown on low soils fertility levels, N. physaloides showed low growth rates on low nutrients level. Higher N, P and K contents were observed in plants grown on higher levels of fertilizer. The increasing of N, P and K levels of soil resulted in greater total accumulation of these macronutrients. The treatments did not affect the chemical composition (NDF and ADF) and the C/N ratio of plant. N. physaloides showed lower C/N ratio during experimental period, which combined to low levels of NDF and ADF and great nutrient accumulation, suggests that this plant matter is quickly decomposed, providing a rapid cycling of nutrients.

The aim of this diploma thesis has been to establish and to verify functionality of a model biofloc system for Nile tilapia (Oreochromis niloticus) farming. The main criteria to be observed during the experiment were chemical characteristcs of the water, development of the biofloc microflora and the reaction of the system to technological interventions. The experiment has consisted of two phases. The first phase monitored an insufficiently functioning system. Due to unsatisfactory assurance of the oxygen concentration as well as the water column stirring, 4 different types of air-sourcing devices have been used in the experiment. For assuring of the perfect stirring and of the sufficient oxygen concentration ( 6 mg×l-1) an airlift fulfilling both the criteria has been constructed. The impact of the carbohydrates application on the decrease of the amonia nitrogen has been sucessfully verified during the experiment. The average value of the C/N ratio of 14 has been reached thanks to the quantity of flour being added as the carbohydrate source into the system. When the recommended amount of TSS (200 ml×l-1) with the corresponding biofloc microflora that has been transforming all the nitrogen in the experiment tank into the microbial protein, the system was evaluated as fully functional. During the biofloc analysis, the presence of N-substances at the amount of 223.6 g at all of the experiment tank (1300 l) has been detected. In the comparison with the applied feed material at the amount of 300 g containing 39% of the N-substances, only 67.1 g of the N-substances has been added into the system. The biofloc (bacterial flakes) serves as food for the tilapia during the entire period of the functional system.

Submitted by Everaldo Pereira (pereira.evera@gmail.com) on 2017-10-10T00:38:13Z No. of bitstreams: 1 Tese - Ivan Cardoso Lemos Junior.pdf: 9961355 bytes, checksum: 8fa866ee287fa3e558713d742221a5a4 (MD5) / Made available in DSpace on 2017-10-10T00:38:13Z (GMT). No. of bitstreams: 1 Tese - Ivan Cardoso Lemos Junior.pdf: 9961355 bytes, checksum: 8fa866ee287fa3e558713d742221a5a4 (MD5) / Cânions submarinos são os principais condutos para o transporte e acumulação de sedimentos e detritos orgânicos em mar profundo via fluxos gravitacionais. Desde o início da transgressão Holocênica, o regime sedimentar em margens continentais se deslocou de um regime dominado por correntes de turbidez para outro, dominado por sedimentação hemipelágica. No entanto, é sabido que cânions submarinos ainda continuam sendo condutos preferenciais para a transferência de sedimentos modernos, principalmente aqueles próximos a fontes fluviais. Na margem continental nordeste do Brasil, o mais importante cânion submarino está associado ao delta do rio São Francisco. Na plataforma continental confrontante à desembocadura fluvial predominam sedimentos lamosos que constituem a clinoforma deltaica. Devido à pequena largura da plataforma continental e ao fato da clinoforma alcançar a cabeceira do cânion, tem sido sugerido uma conectividade entre a zona costeira e o talude. Foraminíferos são muito utilizados como proxies ecológicos para ambientes marinhos. Em mar profundo, a distribuição espacial e temporal de foraminíferos bentônicos é limitada por diversos parâmetros físico-químicos e mudanças ambientais podem ser registradas via modificações na estrutura de suas assembleias, o que faz desses organismos ótimas ferramentas para observações oceanográficas e interpretações ambientais e paleoambientais. Razões C/N e isotópicas de carbono (δ13C) e nitrogênio (δ15N) têm sido amplamente utilizadas para esclarecer as fontes e o destino da matéria orgânica no ambiente marinho, como também para indicar dinâmica sedimentar, padrão de circulação oceânica, condição paleoclimática e paleoprodutividade. O uso desses marcadores baseia-se na existência de diferenças entre suas abundâncias naturais na matéria orgânica proveniente do continente e do ambiente marinho. O objetivo deste trabalho é, com base nos foraminíferos e nas relações C/N e isotópicas (δ13C e δ15N) da matéria orgânica, descrever a dinâmica sedimentar holocênica do cânion submarino do São Francisco, relacionando-a as variações do nível do mar. Para tal, analisou-se 3,38 m de coluna de sedimento proveniente de um piston-core (SFC-1). Dados granulométricos, datações C14, teor de CaCO3 e composição do sedimento também foram utilizados. Características visuais e sedimentares do testemunho permitiram a identificação de seis fácies sedimentares que datam de ~12.000 anos cal. AP até o presente, caracterizada por cinco assembleias de foraminíferos significativamente diferentes (p<0,05). As composições elementar (Corg, Nt e C/Norg) e isotópica (δ13C e δ15N) da matéria orgânica apontam uma forte influência de fontes terrígenas para a sedimentação holocênica da matéria orgânica, mesmo em períodos de nível de mar alto, e as relações C/N x δ13C e δ15N x δ13C, associadas a fontes locais, demosntraram que a matéria orgânica depositada no interior do cânion submarino do São Francisco durante o período pós-glacial é dominada por fontes terrestres derivadas do rio São Francisco. A distibuição das especiés de foraminíferos e as razões C/N org indicam uma maior influência fluvial na deposição sedimentar até aproximadamente 8.500 anos AP, associados aos depósitos turbidíticos, e que após este período, os principais mecanismos de transporte de material continental para o interior do cânion são os movimentos de massa e o retrabalhamento dos sedimentos terrígenos depositados sobre a plataforma continental que formam a clinoforma deltaica. / Abstract Submarine canyons are the main conduits for the transport and accumulation of sediments and organic debris in deep sea via gravitational flows. From the beginning of the Holocene transgression, the sedimentary regime in continental margins moved from a regime dominated by turbidity currents to another, dominated by hemipelagic sedimentation. However, it is known that submarine canyons still remain preferential conduits for the transfer of modern sediments, especially those near river sources. At Brazil’s northeastern continental margin, the most important submarine canyon is associated with the delta of the São Francisco river. Muddy sediments are predominant in the continental shelf confronting the fluvial outlet and constitute the deltaic clinoform. Due to the small width of the continental shelf and the fact that the clinoform reaches the head of the canyon, a connectivity has been suggested between the coastal zone and the continental slope. In marine environments, foraminifera are widely used as ecological proxies. In deep sea, temporal and spatial distribution of benthic foraminifera are limited by several physical and chemical parameters and environmental changes can be registered through modifications in the structure of their assemblages, which makes these organisms great tools for oceanographic observations and environmental and paleoenvironmental interpretations. C / N and isotopic ratios of carbon (δ13C) and nitrogen (δ15N) have been widely used to clarify the sources and destination of organic matter in the marine environment, as well as to indicate sedimentary dynamics, ocean circulation pattern, paleoclimatic condition and paleoproductivity. The use of these markers is based on the existence of differences between their natural abundances in organic matter from the continent and the marine environment. The objective of the present study is, based on the foraminifera and the C / N and isotopic (δ13C and δ15N) ratios of organic matter, to describe the holocene sedimentary dynamics of the São Francisco submarine canyon, relating it to variations in sea level. For this, 3.38 m of sediment column from a piston core (SFC-1) was analyzed. Granulometric data, C14 dating, amont of CaCO3 and sediment composition were also used. Visual and sedimentary characteristics of the testimony allowed the identification of six sedimentary facies dating to ~ 12,000 years cal. AP to the present, characterized by five foraminifera assemblages significantly different (p <0.05). The organic matter elemental compositions (Corg, Nt and C / Norg) and isotopic (δ13C and δ15N) indicate a strong influence of terrigenous sources for the holocene sedimentation of organic matter, even in periods of high sea level, and the C / N x δ13C and δ15N x δ13C relations associated with local sources have shown that the organic matter deposited within the San Francisco submarine canyon during the postglacial period is dominated by terrestrial sources derived from the São Francisco River. The foraminifera species distribution and the C / Norg ratios indicate a greater fluvial influence in sedimentary deposition up to about 8,500 years AP, the main turbiditic deposits, and that after this period, the main transport mechanisms of continental material to the interior of the Canyon are the mass movements and the reworking of terrigenous sediments deposited on a continental shelf that form a deltaic clinoform.

I detta examensarbete har biogasproduktion med olika typer av gödsel som substrat, med fokus på hönsgödsel, undersökts genom satsvisa utrötningsförsök, BMP. I försöken undersöktes hur biogasutvecklingen såg ut över tid, den totala biogas- respektive metanpotentialen samt hur denna påverkas av tillsats av glycerol. Undersökningen visade att substratblandningar har större biogas- och metanpotential än enskilda substrat samt att tillsats av glycerol inte gynnar biogasproduktionen men kan gynna metanproduktionen. Undersökningen visade också att hönsgödsel har större biogaspotential, och högre metanhalt i den bildade biogasen, än nöt- och svinflytgödsel. / Superbiogödsel för ekologisk spannmålsproduktion

Global warming and air pollution are the major problems facing the world today. Therefore strict environmental legislation on the emission of harmful gases from motor vehicles has forced the automobile industry to search for alternative materials or new materials for exhaust systems. In order to produce cleaner exhaust gases, the exhaust temperature needs to be increased to approximately 900oC. Therefore, exhaust manifolds are exposed repeatedly to hot gases as they are nearest to the engine requiring good oxidation resistance, thermal fatigue properties, cold workability and weldability. One such material to meet the above characteristics is AISI 441 ferritic stainless steel, a dual stabilised Ti and Nb ferritic stainless steel. Ti and Nb are added to stainless steel to stabilise C and N due to their high tendency to form carbonitrides (Ti,Nb)(C,N) and laves phase (Fe2Nb) and Fe3Nb3C. With 18% Cr content, this steel has a good corrosion resistance at elevated temperatures. Included in many applications of this steel are those requiring deep drawing and related forming operations. However, the drawability and stretchability of ferritic stainless steels is inferior to that of the more expensive austenitic stainless steels. For instance, Columbus Stainless has experienced ridging/roping problems at times during the manufacturing process of type AISI 441 ferritic stainless steel. It is believed that this problem is related to crystallographic texture of materials which have effect on formability. The R-value in FSS can be improved through optimisation of chemical composition, which includes reducing the carbon content, and processing conditions such as reducing the slab reheating temperature, increasing annealing temperature and refining the hot band grain size. Therefore the aim of this research project was firstly to investigate effect of amount of cold reduction and annealing temperature on texture evolution and its influence on formability. The as received 4.5 mm hot band steel was cold rolled by 62, 78 and 82% reductions respectively followed by isothermal annealing of each at 900oC, 950oC and 1025oC for 3 minutes. Orientation distribution function (ODF) through X-ray diffractometer (XRD) measurement was used to characterise the crystallographic texture formed in the steel using PANanalytical X’Pert PRO diffractrometer with X’celerator detector and variable divergence. Microstructures were characterised using optical microscopy and scanning electron microscope (SEM). The results show that steels that received 78% cold reduction and annealed at 1025oC recorded the highest Rm-value and lowest ΔR-value which enhances its deep drawing capability. In addition, this steel showed the highest intensity of shifted γ-fibre, notably {554}<225> and {334}<483>. It can therefore be concluded that the γ-fibre which favours deep drawing, is optimal after 78% cold reduction and annealing at 1025oC. The second objective was to investigate the effect of (Nb+Ti) content on the crystallographic texture and the subsequent formability and ridging severity. AISI 441 ferritic stainless steel with different amount of (Nb+Ti) content was used i.e. Steel A (0.26Nb+0.2Ti), Steel B (0.44Nb+0.15Ti) and steel C (0.7Nb+0.32Ti). After a strain of 10%, steels A exhibited the least resistance against surface ridging with average roughness Ra of 1.5 μm followed by steels B with an average roughness Ra of 1.1μm. Steel C showed the highest resistance to ridging with an average roughness Ra of 0.64 μm. This was attributed to the increase in carbonitrites (NbTi)(C,N) due to increased (Nb+Ti) content which acted as nucleation sites for γ-fibre. / Dissertation (MEng)--University of Pretoria, 2013. / gm2014 / Materials Science and Metallurgical Engineering / unrestricted

Zooplankton were sampled on a monthly basis at the Bermuda Atlantic Time-series Study (BATS) site from January 1995 to December 1999. Samples were collected using a 1-m², 200 µm mesh net. The net sampled the water column in an oblique manner from the surface to a mean depth of 200 m. One day and one night tow from each cruise was examined microscopically to determine the community structure of the non-calanoid copepods. In addition, a three year set of nighttime samples were examined taken by 0.5-m², 20 and 35 µm mesh nets (1995-1996 and 1997, respectively) towed obliquely to 150 m. The dominant orders in terms of overall abundance were the Cyclopoida and Poecilostomatoida. The cyclopoid genus, Oithona, was most abundant followed by the Poecilostomatoid family, Oncaeidae, and the genera Farranula and Corycaeus. Harpacticoids, although common, were about an order of magnitude less abundant and were dominated by Macrosetella gracilis. Representatives of the Mormonilloida and Siphonostomatoida also were frequently encountered, although in much lower numbers. Overall, pronounced seasonal signals were noted; highest abundances occurred during spring and lowest during winter. However, abundance of some groups peaked either in the fall or winter, with lowest abundance in spring or summer. Miraciid copepods are estimated to consume an overall average of 359 µg C m-2 d-1 and regenerate 55 µg N m-2 d-1 derived from Trichodesmium at BATS. Highest grazing and regeneration rates were found in late summer through fall and early winter and lowest in spring and early summer. The ecological consequences of miraciid copepod feeding on Trichodesmium are discussed. The 20-35 µm net samples revealed an astonishing abundance of non-copepod species, some totally missed and others woefully under-sampled by the 200 µm net. At least four species of oncaeid copepods and the harpacticoid copepod Microsetella norvegica were found in abundances that were more than an order of magnitude higher than the corresponding numbers of non-calanoid copepods sampled by the 200 µm net. The role of all non-calanoid copepods, from both net systems, in C and N dynamics at BATS is analyzed and discussed along with the sex-ratios of most identified species.