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Oleaginous yeasts posses the ability to accumulate increased amount of lipids under appropriate conditions. These microbial lipids vary in the composition of fatty acids which results in their wide application in the biotechnological industry. This master thesis focuses on the lipid production and fatty acids composition from waste substrates by the yeasts Metschnikowia depending on various cultivation conditions. The influence of temperature, the ratio of carbon and nitrogen in medium, and the concentration of different carbon sources was studied. The cheap and easy available waste substrates as glycerol and animal fat were used for the cultivation. The production characteristics of the yeasts were monitored by various technique including gas chromatography, Raman spectroscopy and fluorescence microscopy FLIM. Moreover, the partial optimalization of the pulse field gel electrophoresis was applied in order to characterize the karyotype of the yeasts Metschnikowia. All the studied strains were able to use the waste substrates and at the same time to produce lipids. The amount of lipids and mainly their compositions vary depending on the yeast strain and on the culture conditions. Nevertheless, the ability of the yeasts to produce significant amount of unsaturated fatty acids by manipulation of culture conditions was proved. The maximum lipid yield was achieved by M. pulcherrima 149 on glycerol medium and by M. andauensis 129 on medium containing waste animal fat.

Since their introduction to Lake Erie, dreissenid mussels may have reengineered the cycling of nutrients in the lake so that the nearshore benthic community intercepts, retains, and recycles greater quantities of nutrients. This study traces particulate matter on a basin scale by characterizing the chemical composition (POC and PN concentrations, POC/PN mass ratios, δ¹³C and δ¹⁵N) of suspended particulate matter in Lake Erie, three tributary inflows, and the lake outflow between May and October, 2002. The data are used to 1) determine the relative contributions of allochthonous and autochthonous sources to suspended particulate matter, 2) identify possible sources of suspended particulate matter, and 3) compare suspended particulate matter in the eastern basin of Lake Erie with that in the central and western basins. Mean POC concentrations range from 175 to 4494 ??g/L and mean PN concentrations range from 33 to 812 ??g/L in this system. Mean POC/PN mass ratios are similar across all sampling locations, ranging between 4. 5 and 6. 9, and indicate that suspended particulate matter at these sites is mainly derived from autochthonous sources, particularly plankton. The ranges of δ¹³C (-34 to -22 ?) and δ¹⁵N (1 to 12 ?) identify terrestrial plants and soil matter, aquatic macrophytes, phytoplankton, and sewage as possible sources of suspended particulate matter at all sites. Plankton is probably the dominant source of suspended particulate matter at each site, with smaller contributions from allochthonous and other autochthonous sources. Significant differences in the concentration and isotope data between inflow and lake or outflow sites indicate that tributary inflows may receive greater contributions from terrestrial plants and soils and aquatic macrophytes than the lake and outflow. δ¹⁵N signatures also identify animal manure as a possible source of suspended particulate matter at the inflows. PN concentrations and δ¹⁵N signatures suggest that the shallowest nearshore sites close to Peacock Point in the eastern basin receive PN from a source that is not present at the other eastern basin sites or at the sites in the central and western basins. This source may be related to dreissenid mussels at these nearshore sites recycling nitrogen back into the water column.

Since their introduction to Lake Erie, dreissenid mussels may have reengineered the cycling of nutrients in the lake so that the nearshore benthic community intercepts, retains, and recycles greater quantities of nutrients. This study traces particulate matter on a basin scale by characterizing the chemical composition (POC and PN concentrations, POC/PN mass ratios, δ¹³C and δ¹⁵N) of suspended particulate matter in Lake Erie, three tributary inflows, and the lake outflow between May and October, 2002. The data are used to 1) determine the relative contributions of allochthonous and autochthonous sources to suspended particulate matter, 2) identify possible sources of suspended particulate matter, and 3) compare suspended particulate matter in the eastern basin of Lake Erie with that in the central and western basins. Mean POC concentrations range from 175 to 4494 µg/L and mean PN concentrations range from 33 to 812 µg/L in this system. Mean POC/PN mass ratios are similar across all sampling locations, ranging between 4. 5 and 6. 9, and indicate that suspended particulate matter at these sites is mainly derived from autochthonous sources, particularly plankton. The ranges of δ¹³C (-34 to -22 ?) and δ¹⁵N (1 to 12 ?) identify terrestrial plants and soil matter, aquatic macrophytes, phytoplankton, and sewage as possible sources of suspended particulate matter at all sites. Plankton is probably the dominant source of suspended particulate matter at each site, with smaller contributions from allochthonous and other autochthonous sources. Significant differences in the concentration and isotope data between inflow and lake or outflow sites indicate that tributary inflows may receive greater contributions from terrestrial plants and soils and aquatic macrophytes than the lake and outflow. δ¹⁵N signatures also identify animal manure as a possible source of suspended particulate matter at the inflows. PN concentrations and δ¹⁵N signatures suggest that the shallowest nearshore sites close to Peacock Point in the eastern basin receive PN from a source that is not present at the other eastern basin sites or at the sites in the central and western basins. This source may be related to dreissenid mussels at these nearshore sites recycling nitrogen back into the water column.

This study used the sediment samples collected in May (dry season) and September (wet season) 2010 in a river delta and tidal flat complex around Jhoushuei River mouth in Central Taiwan to examine seasonal sediment transport pathways and sources. Four different approaches were used in the analysis of grain-size distribution pattern. They include (1) the McLaren-Bowles method, and (2) the transport vector technique (Gao-Collins method), and (3) a combination of `filtering' and the empirical orthogonal (eigen) function (EOF) analysis technique, and (4) C/N elemental ratios of organic sediments. The results of surface grain size distributions of sediment range from clay to medium sand towards the sea, and very fine sand deposited in the river delta. On the upper tidal flat, mud content of the wet season is higher than dry season due to higher river output of organic sediment and low-energy sediment transport. In wet season, according to the fine-grained sediment from the Jhoushuei River is therefore mainly discharged to the offshore area and little remain around the tidal flat, the influence of river on the grain-size distribution is the least. The results based on McLaren-Bowles method indicate that there were two type sediment transport pathways, (1) the river carried sediment to the coast, then alone the northeast-southwest direction by the longshore current, and (2) during the flood tide, the riverine sediment move to northeast and east through the river delta and tidal creek to the upper tidal flat, respectively. The results based on Gao-Collins method indicate that there was possible seasonal variation of sediment transport pathways on the river delta front, where the significant transport was seaward in the wet season whereas the transport was the opposite in the dry season. On the tidal flat, the model results indicate that seaward transport seems to be controlled by ebb tidal current perhaps due to the sampling at low-tide.

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.

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.

Peepoo, self-sanitising, biodegradable toilet is characterized by low carbon to nitrogen (C-N) ratio and low dry matter (DM) content. Principal nutrients (nitrogen (N), phosphorous (P) and potassium (K)) are also not in a balance as required by most crops. It was expected that the mixing of used Peepoos with other organic materials might balance its chemical characteristics. In this thesis, availability and suitability of common organic materials produced in Kenya has been investigated for mixing with used Peepoo bags to obtain a balanced fertilizer product from the crop nutrition aspect. Seven organic residues were selected from the list of 13 on the basis of their availability near the processing site in Nairobi. The selected residues were then chemically analyzed for their individual plant nutrient content. The analysis results were used subsequently to simulate the chemical composition of a wide range of Peepoo-Residue mixtures. The evaluation of the theoretical mixtures based on DM content, C-N ratio and NPK ratio showed that the majority of investigated mixtures had DM content below 60 %. Majority of the mixtures showed C-N ratio between 10-1:1. All the mixtures deviated from the common nutrient uptake ratio of crops (1:0.5:1.4). Composite mixtures with more than 2 ingredients resulted in a balanced fertilizer product. The study concludes and recommends that the composite mixtures with more than two ingredients should be considered for practical processing of Peepoos into a commercial fertilizer product.

To achieve a sustainable use of energy we must increase our use of renewable energysources, biogas if one such source. One of the greatest potentials for biogas are in theagricultural sector and the Energy Agency calculates that 25% of the available manurecan be used for biogas production. The purpose of this thesis is to contribute withknowledge of co-digestion of manure and how this affects the methane potential andhow co-digestion affects the contents of NH4 in the sludge. The report includes a literature study to understand the digestion process and its partsand allows interpretation of data. The report includes analysis of data from HalmstadUniversitys experiment of anaerobic digestion and an additional digestion. The resultsobtained in this study shows that the effect of co-digestion varies depending on manure.Horse and chicken manure and beef and pig manure gives a positive effect to the codigestion.