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Assimilation of Organic Carbon by Aquatic ActinomycetesShao, Yi-min 08 1900 (has links)
There were two purposes of this investigation: the first was to develop a method for studying spore germination, hyphal growth and mycelial development of the aquatic actinomycetes under the microscope so that the life cycle of this organism could be continuously followed. The second purpose was to determine the rate of carbon utilization from various types of nutritional sources, and to correlate this with the colony development and spore formation.
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Organic geochemistry of the Neogene sediments from the Pattani Basin, Gulf of Thailand, palaeodepositional environments and hydrocarbon source potentialJankaew, Kruawun January 2002 (has links)
The Neogene sediment from the Pattani Basin, Gulf of Thailand, were subjected to detailed organic geochemical study. The results suggest that the Neogene source rocks have potential for hydrocarbon generation (as shown by high TOC content). Sequences 2, 3 and part of Sequence 4 are mature and capable of producing hydrocarbons, while those from Sequence 5 are immature. The top of the oil window estimated from biomarker maturity parameters (i.e. CPI and homohopane ratios) is at approximately 6000 feet. SCI data also support this proposal. The biomarker composition and distributions of the bitumen extracts reflect the abundance of higher plant contributions with varying amount of bacterial input, in oxic to sub-oxic conditions during deposition of the sediments. A strong contribution of terrestrially derived organic matter (higher plants) is indicated by the bimodal distribution of <i>n</i>-alkanes, OEP distribution of the <i>n</i>-alkanes in the range C<sub>23</sub>-C<sub>33</sub>, high Pr/Ph ratios, low S%, the occurrence and abundance of several biological markers, including oleanenes, oleanane, bicadinanes, tricyclic terpanes, abnormally high C<sub>31</sub> homohopane R epimer, and high C<sub>29</sub> steranes. Abundant coals in Sequences 5 and 4 contain higher plant material, interpreted as deposited in deltaic swamp environments. Kerogen typing shows that vitrinite (Type III kerogen) is the dominant organic matter in the samples from the Pattani Basin, suggesting potential to generate gas and condensate. The other organic macerals found include cutinite and spore/pollen (Type II kerogen), amorphous (Type I/II/III kerogen) and inertinite (Type IV). In general, molecular and microscopic examination of the Neogene succession of the Pattani Basin suggests a fluvio-deltaic environment, with peat swamps in Sequence 5 and the upper part of Sequence 4. This interpretation is confirmed by pollen analysis data. The age diagnostic pollen found in a few samples from Sequence 5 suggest the time of deposition as Middle Miocene to Pliocene.
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Removal of organic carbon by using a membrane bioreactorLin, Yu-Ting 27 July 2009 (has links)
The drinking water treated by water treatment plant (WTP) usually has an
excess of assimilable organic carbon (AOC) in distribution systems in south Taiwan.
They will cause the growth of heterotrophic plate count (HPC) and deterioration of
water quality in pipeline of distribution systems. Recently, part of traditional
purification processes were changed into advanced processes in WTP. The past
researches showed the combined advanced processes ultrafitration (UF) / reverse
osmosis (RO) in south WTP in Taiwan has the removal problems of AOC in above
UF / RO processes because the organic compounds in raw water caused a fouling
layer which was formed on the membranes surface. These problems made the
back-wash frequency increasing, short membrane life and raising cost.
The study combines activated carbon and membrane bioreactor (MBR) to
explore the removal efficiency of drinking water in laboratory. The system showed
the removal efficiencies of dissolved organic carbon (DOC) and AOC were 57%
and 36%, respectively in average. More, the system showed the removal
efficiencies of DOC and AOC were 81% and 66%.
The results of this research showed good removal efficiency was found in
AOC and DOC. Good quality of biological stability, removal of organic compounds,
low cost in building and maintaining were reached.
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Karola TothKarola, Toth 12 1900 (has links)
ABSTRACT
The effects of restoration on dissolved organic carbon (DOC) dynamics
were examined at the Boi~-des-Bel peatland. This study included both laboratory
measurements of DOC production by different peatland vegetative components
and field measurements of DOC dynamics within a recently restored, a cutover
and a natural peatland.
Shrub and herbaceous plant material were found to be the most significant
producers of DOC in the short term. Moss, peat and straw samples had a high
potential to release DOC ;;ontinuously under warm, moist and aerobic conditions.
On a short timescale, all components have the potential to release the three
dissolved organic matter (DOM) fractions examined with humic acid (HA) most
prominently being produced by shrubs and herbaceous plants and hydrophilic
(HPI) and hydrophobic (HPO) fractions by mosses, peat and straw.
Comparison of growing season results over three study years at the
restored and cutover site indicated that DOC concentrations increased after
restoration while DOC export decreased due to lowered runoff caused by the
blockage of drainage ditches. Compared to the natural peatland, both the restored
and the cutover site had a more humic DOM character. No difference could be
found between the character of DOM released from the restored and cutover sites.
The most active layer of DOM production was the top 75 em where the water
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table fluctuated during the season. Water storage units such as pools and ditches
also play an important role in DOM export from the site.
Spring snowmelt was found to be the most significant DOC export event
of the study season in 2001, when export values were significantly larger than
those measured during the growing season. Solubility of the different DOM
fractions was the main controlling factor on the DOM character seen at the
outflows. Storm events contributed significantly to the summer DOC output.
DOC dynamics were affected by antecedent moisture conditions and differences
emerged between the restored and cutover site during this period.
The results of this study emphasize the importance of managing water
table fluctuations and the restoration (reestablishment) of Sphagnum species in
order to improve the retention of DOM within cutover peatlands. / Thesis / Master of Science (MS)
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Quantification of soil organic carbon using mid- and near- DRIFT spectroscopyKang, Misun 30 September 2004 (has links)
New, rapid techniques to quantify the different pools of soil organic matter (SOM) are needed to improve our understanding of the dynamics and spatio-temporal variability of SOM in terrestrial ecosystems. In this study, total organic carbon (TOC) and oxidizable organic carbon (OCWB) fraction were calibrated and predicted by mid- and near-DRIFT spectroscopy in combination with partial least squares (PLS) regression method. PLS regression is a multivariate calibration method that can decompose spectral data (X) and soil property data (Y) into a new smaller set of latent variables and their scores that best describe all the variance in the data. Oxidizable organic carbon content was measured by a modified Walkley-Black method, and total organic carbon was measured by the carbon analyzer.
The floodplain and Blackland Prairie soils in Texas were used for prediction of TOC and OCWB using mid- and near-DRIFT spectroscopy. Floodplain soil is mainly composed of quartz and kaolinite, whereas Blackland Prairie soils contain high concentrations of smectitic clays and low to high concentrations of carbonate minerals. The total organic carbon of 68 soil samples from two Texas sites varied between 0.19 and 4.36 wt.% C, and the oxidizable organic carbon of 26 samples from floodplain soils was in the range of 0.05 to 1.33 wt.% C.
TOC and OCWB of soil were successfully calibrated and predicted by the PLS regression method using mid- and near-DRIFT spectroscopy. The correlation using mid-IR spectra for TOC (r = 0.96, RMSEV = 0.32 for calibration; r = 0.93, RMSEP = 0.44 for prediction) was about the same as the near-IR result (r = 0.95, RMSEV = 0.37; r = 0.93, RMSEP = 0.42). Therefore, we can also use mid-infrared region for quantification of total organic carbon in soils. The PLS1 regression model (r = 0.92) for prediction of OCWB using mid-IR spectra was more accurate than the PLS2 regression model (r = 0.90). PLS models showed better correlation with spectral data than the univariate least square regression method(r = 0.83) with TOC measured by the carbon analyzer.
This study shows that the partial least squares (PLS1) method using mid-and near-IR spectra of neat soil samples can be used to predict both total organic carbon and oxidizable carbon fraction as a fast and routine quantitative method.
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Carbon kinetic isotope effects in the gas-phase reactions of nonmethane hydrocarbons with hydroxyl radicals and chlorine atoms /Anderson, Rebecca S. January 2005 (has links)
Thesis (Ph.D.)--York University, 2005. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 178-194). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR11544
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Dissolved organic carbon dynamics in tallgrass prairie streamsHiggs, Sophie Alexandra January 1900 (has links)
Master of Science / Division of Biology / Walter K. Dodds / Contrary to the previous notion that a stream acts primarily as the transporter of materials from land to oceans, research has shown that in-stream processing of organic matter and nutrients is significant and relevant at a global scale. Dissolved organic carbon (DOC) is the most abundant form of organic carbon in streams and has been demonstrated as an important source of energy supporting stream food webs. Understanding the dynamics of DOC in streams is, therefore, important in determining the contribution of flowing waters to global carbon storage and release. However, DOC exists as many different compounds, varying in source, composition, and quality. The composition of DOC that ends up in streams is partly controlled by the surrounding watershed, and landscape effects on DOC quality and quantity in streams have been observed. In the North American Tallgrass prairie, woody encroachment has led to changes in riparian vegetation, potentially altering the DOC received by the stream, and making it important to understand rates of DOC transformation as landscape alterations continue. The heterogeneity of the DOC pool makes it difficult to fully describe its components and to measure transformation rates. DOC uptake, or biological use, has been estimated through several methods including in-stream additions of various DOC sources and bottle incubations of stream water and sediments. One problem with addition methods for calculating uptake is that the DOC pool is difficult to replicate and additions of simple compounds or organic leachates do not represent total dissolved organic carbon (TDOC) dynamics. Another potential issue is that additions of a labile compound could potentially alter microbial activity through a priming effect and therefore distort ambient DOC uptake estimates. Finally, uptake parameters are mostly calculated assuming benthic uptake while recent studies have shown that planktonic uptake of DOC can also be significant. We conducted this study with these three considerations in mind.
In the first chapter, we describe our use of in situ additions of glucose and bur oak leaf leachate in prairie stream reaches and concentrations of specific components to determine uptake dynamics of various specific DOC components, from a simple sugar to more complex plant compounds. We calculated uptake parameters of glucose and two different oak leaf components. We found that using glucose concentrations rather than TDOC concentrations, as has been done in previous studies, to measure uptake parameters resulted in higher uptake rates, indicating the importance of measuring the specific component added. Through leaf leachate additions, we found that an amino acid like component was consistently taken up faster than a humic-like component. The second chapter addresses the questions of uptake location and priming through a series of recirculating chamber incubations. We found that benthic uptake of leaf leachate was more important than that in the water column. Finally, elevated uptake of one leaf leachate component in the presence of glucose indicated a priming effect on microbial DOC uptake.
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Evaluation of Anaerobic Biodegradation of Organic Carbon Extracted from Aquifer SedimentKelly, Catherine Aileen 20 November 2006 (has links)
In conjunction with ongoing studies to develop a method for quantifying potentially biodegradable organic carbon (Rectanus et al 2005), this research was conducted to evaluate the extent to which organic carbon extracted using this method will biodegrade in anaerobic environments. The ultimate goal is to use this method for the evaluation of chloroethene contaminated sites in order to estimate the long-term sustainability of monitored natural attenuation (MNA) as a remediation strategy. Although relatively recalcitrant under aerobic conditions, the breakdown of chlorinated solvents primarily occurs through the anaerobic process of reductive dechlorination. The biodegradation of organic carbon in these anaerobic environments drives the system to reducing conditions conducive for reductive dechlorination. The extraction procedure developed by Rectanus et al. (2005) has been tested in several series of aerobic bioassays to determine the biodegradable fraction of carbon extracted. This study seeks to show that the carbon removed from the sediment by this extraction process will also degrade in anaerobic environments.
Three aquifer sediment samples characterized by low, medium, and high carbon concentrations were taken from Naval Submarine Base Kings Bay, Georgia. Two sites were also sampled from Naval Amphibious Base Little Creek, Virginia. MLS20 is a site located inside of a chloroethene plume, and MLS10 is located outside of the plume. For approximately 12 weeks aqueous total organic carbon (TOC), headspace carbon dioxide (CO2), volatile fatty acids (VFAs), and headspace hydrogen concentrations were monitored for evidence of the biodegradation of organic carbon.
Although few VFAs were observed throughout the experiments, their presence as early as 8 days after inoculation indicated that the bioassays were anaerobic. The fewest VFAs were seen in the MLS20 bioassays, while the most VFAs were observed in the MLS10 bioassays. MLS20 exhibited low levels of TOC loss and the low VFA levels indicate that complex organic matter was not highly degraded in these bioassays. The higher level of VFAs observed in MLS10 bioassays corresponded with little TOC degradation, indicating that although more complex organics were being broken down, conditions were not reduced enough to further oxidize the organic carbon. As much as 50% TOC loss was observed in the Kings Bay bioassays with few VFAs detected.
Loss of TOC was accompanied by CO₂ generation which provides supporting evidence that organic carbon was being oxidized. Hydrogen was observed in the bioassays, suggesting that VFAs resulting from organic carbon breakdown were being oxidized. This indicates that organic carbon removed from sediment using the extraction process is biodegraded anaerobically and could lead to conditions capable of sustaining reductive dechlorination. / Master of Science
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Modeling variation of pollutants in advanced and conventional water treatment processChang, Ting-Wei 16 August 2011 (has links)
According to the literature, the deterioration of water quality in pipeline networks of water distribution is not solely due to the deterioration of raw water quality outlet from water treatment plants, but primarily due to the multiplication of microorganisms in water distribution pipelines, a phenomenon known as after-growth or re-growth. Presently, the most effective method of a biological stability in treated water for controlling microbial re-growth is by limiting nutrients, including nitrogen, phosphorus, and organic carbon. The content of assimilable organic carbon (AOC) within organic carbon is considered to be the most main factor for controlling the growth of microorganisms in the water distribution systems.
The objects of this work were to study the Cheng Ching Lake Water Treatment Plant (CCLWTP) in Kaohsiung and the Gong Yuan Water Treatment Plant (GYWTP) in Chiayi. Water samples were collected once a month from December 2008 to November 2009. The major difference between the study objects was that front one is an advanced water treatment plant, and the other a traditional one. In order to understand the difference in biological stability between these two water treatment plants, AOC meaurement was conducted. The goals of this study were: (1) to understand the water purification process of advanced and traditional water treatment plants, and to understand the concentration in AOC fluctuation in their water distribution networks; (2) to learn about differences in how the two water treatment plants remove AOC, and to know where is improvement ; (3) to use program analysis to produce a simple formula and AOC-related water quality parameters for the two water treatment plants, providing AOC control and management strategies in the future.
The results concluded that the raw water of the two water treatment plants was primarily a hybrid of hydrophobic and hydrophilic molecules, and the highest values of AOC were found in winter. The CCLWTP had an overall removal rate of 54 %, and the GYWTP had an overall removal rate of 36 %. The CCLWTP conformed to the additions of an advanced water purification unit, but the water treatment process was relatively complex. Its AOC concentration varied considerably during the course of the water treatment process, while that of the GYWTP showed more stable measurements. The CCLWTP used coagulation precipitation, rapid filtration, and biological activated carbon filtration to effectively remove the AOC. The coagulation precipitation unit used by the GYWTP was most effective process in the removal of AOC and rapid filtering was less effective one.
The treated water of CCLWTP maintained an AOC concentration under 51 £gg acetate-C/L in its water distribution network, while the treated water of GYWTP mostly kept a concentration of AOC lower than 71 £gg acetate-C/L. Although the CCLWTP water pipe network had lower AOC values, it demonstrated unstable changes in levels of AOC concentration. This shows that oxidation and disinfectants in the water treatment process cannot successfully oxidize all organic matter into AOC. In contrast, the GYWTP showed a more stable removal in AOC content.
For the artificial neural network system simulation, the simulation values of CCLWTP water treatment process and water distribution network are correlated less closely with the measured actual value than those of the GYWTP do. This is found to be mostly due to the relatively large fluctuations in AOC in the CCLWTP. The AOC values in the CCLWTP water treatment process and water distribution network are highly correlated to TOC, TDS, and NH3-N. For the GYWTP, AOC values were mostly correlated to TOC, temperature, and NH3-N. Finally, the two common factors for water quality at both water plants were TOC and NH3-N, we recommend that these two items can be taken into consideration to control and manage AOC in water treatment.
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Fluorescence of dissolved organic matter in natural watersMcDonald, Adrian January 1998 (has links)
No description available.
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