Dissertations / Theses on the topic 'Gases from plants Measurement'

Thesis (Ph. D. in Climate Physics and Chemistry)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 161-167).
Methane (CH 4 ), nitrous oxide (N20) and sulfur hexafluoride (SF6) are powerful greenhouse gases with global budgets that are well-known but regional distributions that are not adequately constrained for the purposes of mitigation and policy initiatives. Quantifying emissions using inverse approaches at the national scale requires measurements that specifically target the region of interest. Primarily due to the lack of atmospheric measurements from the region, emissions estimates of these greenhouse gases from India have largely been missing. New in situ measurements of atmospheric mole fractions from a Himalayan station in Darjeeling, India (27.03'N, 88.26'E, 2200 meters above sea level) have been collected from December 2011 for CH4 and March 2012 for N20 and SF6 to February 2013 using high-precision instrumentation that is linked to the Advanced Global Atmospheric Gases Experiment (AGAGE). These measurements comprise the first high-frequency dataset of these gases collected in India and are used for measurement-based assessment of emissions. Several features are identified. In SF6 , the signal associated with Northern Hemispheric background is typically present. CH4 and N20 mole fractions are almost always enhanced over the background, suggesting strong regional sources. Additionally, a diurnal signal resulting from thermally driven winds is seasonally present. A particle dispersion model is used to track 'air histories' of measurements, quantifying the sensitivity of concentrations at Darjeeling to surface emissions. The effect of topography on the derived air histories is investigated to test the robustness of the model in simulating transport in this complex environment. The newly acquired data set is used to investigate the ability of the model to reproduce signals that stem from the mesoscale diurnal winds. The sensitivities of meteorological resolution and particle release height are investigated to better quantify some of the uncertainties associated with this chemical transport model. A Quasi-Newton inverse method is used to estimate emissions at monthly resolution. CH4 , N20 and SF6 emissions from India are found to be 44.3% Tg yr- 1, 825 1045/707 GgN yr- 1 and 221 241/205 kton yr-', respectively. Significant uncertainty reduction is seen on emissions from India during the summer when the monsoon results in high sensitivity over the subcontinent.
by Anita Lakshmi Ganesan.
Ph.D.in Climate Physics and Chemistry

Doctor of Philosophy
Department of Biological and Agricultural Engineering
Ronaldo Maghirang
Emission of greenhouse gases (GHGs), including nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2), from open beef cattle feedlots is becoming an environmental concern; however, scientific information on emissions and abatement measures for feedlots is limited. This research was conducted to quantify GHG emissions from feedlots and evaluate abatement measures for mitigating emissions. Specific objectives were to: (1) measure N2O emissions from the pens in a commercial cattle feedlot; (2) evaluate the effectiveness of surface amendments in mitigating GHG emissions from feedlot manure; (3) evaluate the effects of water application on GHG emissions from feedlot manure; and (4) compare the photo-acoustic infrared multi-gas analyzer (PIMA) and gas chromatograph (GC) in measuring concentrations of N2O and CO2 emitted from feedlot manure. Field measurements on a commercial beef cattle feedlot using static flux chambers combined with GC indicated that N2O emission fluxes varied significantly with pen surface condition. The moist/muddy surface had the largest median emission flux; the dry and compacted, dry and loose, and flooded surfaces had significantly lower median emission fluxes. Pen surface amendments (i.e., organic residues, biochar, and activated carbon) were applied on feedlot manure samples in glass containers and evaluated for their effectiveness in mitigating GHG emissions. Emission fluxes were measured with the PIMA. For dry manure, all amendments showed significant reduction in N2O and CO2 emission fluxes compared with the control (i.e., no amendment). For moist manure, biochar significantly reduced GHG emissions at days 10 and 15 after application; the other amendments had limited effects on GHG emissions. The effect of water application on GHG emissions from feedlot manure was evaluated. Manure samples (with and without water application) were placed in glass containers and analyzed for GHG emission using a PIMA. For the dry manure, GHG emissions were negligible. Application of water on the manure samples resulted in short-term peaks of GHG emissions a few minutes after water application. Comparison of the GC and PIMA showed that they were significantly correlated but differed in measured concentrations of N2O and CO2. The PIMA showed generally lower N2O concentrations and higher CO2 concentrations than the GC.

The document reviews the current and projected electricity demand until the year 2030 along with the fuel mix. Several projections based on different agencies were studied in order to understand the trend of fuel mix projected to be used. Clearly, the fuel mix being used or projected is unsustainable. Depletion of fossil fuels, increasing demand and environmental impacts are some of the factors that emphasize the use of Alternative Sources of Electricity. Three of the upcoming Alternative Sources - Solar, Wind and Landfill Gases - are discussed and compared in the document. Based on the comparison, Landfill Gas projects seem to be very favorable, despite the higher costs related with such projects, several advantages over the other two Alternative Sources are discussed in the document. The several advantages of Landfill Gas projects, such as emissions reduction, better power quality, reduction in transmission losses, and several others are discussed in the document

Thesis (MSc (Conservation Ecology and Entomology)--University of Stellenbosch, 2006.
A pilot study was conducted at the Namakwa Sands Mineral Separation Plant, to investigate the effects of acidic gaseous emissions from the Mineral Separation Plant on the adjacent Succulent Karoo vegetation. Sulphuric acid fumes, a major gaseous emission of the mineral processing, was the subject of investigation of the present study, due to the potential high negative impact of elevated concentrations thereof on vegetation in the ecosystem. Permanent sample plots along three transects radiating from the Mineral Separation Plant were laid out in the eastern, south-eastern and southern directions following the prevailing wind directions and practical consideration of land accessibility. The ecological components assessed as indicators of possible pollution levels in the environment included percentage plant mortality, foliar sulphur content of selected plant species, chemical composition of solubles in mist and dust samples, and soil pH. In addition, the vegetation was screened for plant species suitable to be used as potential bioindicators. Potential bioindicator plant species were selected on the basis of their relatively wide distribution in the study area and apparent sensitivity to the ambient air pollutants. The percentage of dead plants of each species that occurred on the sample plots was used as a criterion of the possible sensitivity of the plant species towards air pollution. The bioindicator plant species selected for potential monitoring purposes were: Galenia fruticosa, Lampranthus suavissimus, Lycium ferocissimum and a Ruschia sp. (SP 9). Plant mortality was greater nearer the emission source, with 28 + 5 % dead plants at 400 m, 19 + 6 % at 800 m and only 10 + 4 % at 1,200 m from the Mineral Separation Plant. Data summed for all species recorded and pooled for all three transects per sampling distance. With the methods used in this study, in the case of all sample plots on the three transects, no significant difference was found between the mean pH values of soil samples collected from open spaces without plant cover (8.01 + 0.46) and those collected underneath shrubs (8.91 + 0.96). Subsequently only the pH values of soil samples collected on open spaces were used to investigate the variation in soil acidity with distance and direction from the emission source. The means represent total number of samples from open space versus those collected from underneath shrubs. The pH of soil samples increased with distance from the emission source along the transects to the south and south-east of the emission source. Eastward of the emission source, soil pH values remained relatively low at all sample distances. This pilot study could not determine whether the continuous acidity of the soil along the eastern transect in the direction of the prevailing wind, was caused by increased deposition of gaseous emissions on the higher lying hilly terrain in this area, or by the underlying geology. Ion chromatographic analysis of mist and dust samples collected on each sample plot indicated the presence of several chemicals that had probably originated from the gaseous emissions from the Mineral Separation Plant as well as wind blown constituents from the adjacent surroundings of the sample plots. Of these chemicals, only the sulphate concentrations of the mist and dust samples were further evaluated, since that could be related to the emission of sulphuric acid fumes by the Mineral Separation Plant. Results indicated that the mean sulphate concentration of mist and dust samples collected from sample plots relatively close to the Mineral Separation Plant, 118.8 + 31.6 mg/litre (400 m), were higher than further afield, decreasing to 57 + 30.1 mg/litre at 800 m and 43.1 + 19.6 mg/litre at 1,200 m. These values, representing the mean sulphate concentrations of mist and dust samples at each sampling distance (data of the three transects pooled), differ significantly at the 85 % confidence level. Statistical evaluation of the data of the mist and dust pH measurements, pooled for the three transects on the basis of distance, indicated a gradual increase of the mean values from 400 m (7.3 + 0.26), through 800 m (7.7 + 0.34), to 1,200 m (8.2 + 0.83), although these values were not significantly different. A decreasing trend in accordance with that in the case of the sulphate concentrations of mist and dust samples with distance from the mineral processing plant, was also observed in the sulphur content of the leaves of selected plant species, with mean sulphur content higher at 400 m sampling distance (0.29 + 0.091 %) than at 800 m (0.264 + 0.086 %) and a further decline at 1,200 m (0.232 + 0.079 %), data of the three transects pooled. However, these values were also not significantly different. Although not significantly so, the decreasing trend in the results of the sulphate concentration of mist and dust samples, the sulphur content of plant leaf samples as well as plant mortality observed, and increasing soil pH values with distance from the Mineral Separation Plant, suggest that the gaseous emissions from the Mineral Separation Plant could probably have had a detrimental effect on the adjacent Succulent Karoo vegetation. A more detailed study is necessary to confirm this trend. In addition it is recommended that in order to clarify the soil pH measurements outcome along the eastern transect that were contradicted by the results of the mist and dust pH measurements, a more intensive survey over a greater distance (at least further than 1.2 km from the Mineral Separation Plant), be conducted to quantify vegetation damage and acid deposition to the east of the emission source.

Methane is the most abundant organic chemical in the earth's atmosphere. Its abundance in the atmosphere is increasing with time and has reached levels not seen in recent geological history. The methane is produced both naturally, and anthropogenically. One of the sources of anthropogenic methane is manure from domesticated animals. Casada and Safley (1990) estimated the amount of methane generated from this source. This was done by estimating the Methane Conversion Factor (MCF) typically achieved by various waste management systems. This study was done to evaluate those estimates of the MCF. The MCF's for the most dominant of disposal methods, rangeland/pasture disposal, were much lower than the earlier estimates. Other waste management systems, such as solid storage and liquid slurry storage had much higher MCF's, at 20° and 30° C. However, these waste management methods are more prevalent in parts of the world where the average annual temperature is closer to 10° C. At that temperature, the MCF is negligible in all waste management systems. This study showed that the previously reported estimates of MCF for some waste management systems were higher than what was actually the case. Consequently earlier estimates of the amount of methane generated from manures were higher than what this study found.
Graduation date: 1994

abstract: Constructed treatment wetlands (CTW) have been a cost-efficient technological solution to treat different types of wastewater but may also be sources of emitters of methane (CH4) and nitrous oxide (N2O). Thus, my objective for this dissertation was to investigate CH4 and N2O fluxes via multiple pathways from the Tres Rios CTW located in Phoenix, AZ, USA. I measured gas fluxes from the CTW along a whole-system gradient (from inflow to outflow) and a within-marsh gradient (shoreline, middle, and open water sites). I found higher diffusive CH4 release in the summer compared to spring and winter seasons. Along the whole-system gradient, I found greater CH4 and N2O emission fluxes near the inflow compared to near the outflow. Within the vegetated marsh, I found greater CH4 emission fluxes at the vegetated marsh subsites compared to the open water. In contrast, N2O emissions were greater at the marsh-open water locations compared to interior marsh. To study the plant-mediated pathway, I constructed small gas chambers fitted to Typha spp. leaves. I found plant-mediated CH4 fluxes were greater near the outflow than near the inflow and that CH4 fluxes were higher from lower sections of plants compared to higher sections. Overall, Typha spp. emitted a mean annual daily flux rate of 358.23 mg CH4 m-2 d-1. Third, using a 30-day mesocosm experiment I studied the effects of three different drydown treatments (2, 7, 14 days) on the fluxes of CH4 and N2O from flooded CTW soils. I found that CH4 fluxes were not significantly affected by soil drydown events. Soils that were dry for 7 days shifted from being N2O sources to sinks upon inundation. As a result, the 7-day drydown soils were sinks while the 14-day drydown soils showed significant N2O release. My results emphasize the importance of studying ecological processes in CTWs to improve their design and management strategies so we can better mitigate their greenhouse gas emissions.
Dissertation/Thesis
Doctoral Dissertation Biology 2017

碩士
國立陽明大學
環境衛生研究所
93
With the rising economy and the growing population in Taiwan, amounts of waste are increasing rapidly. Large proportions of waste are food wastes which can be composted to be new resources, but follow after will have odor problems. Currently, the measurement for odors is using olfactometry or precision instruments, such as GC. The former one is based on subjective determining, and the latter one is not appropriate enough to represent the humans’ olfactory feelings. In a previous study, gas detect tubes and GC/MS were used to identify more than 20 chemicals in the odors from Taiwan’s food waste composting plants. In this study, we used SnO2 gas sensor and olfactometry to measure field samples from food waste composting plants, the six criticalchemicals of odors, including ammonia, acetic acid, trimethylamine, ethylbenzene, dimethylsulphide, and p-cymene that are all over human detect threshold in food waste composting plant gas. The feasibility of SnO2 gas sensor to measure odors was conducted and assessed the human thresholds of six odorants respectively for Taiwanese by using olfactometry. Results show there are good correlations between the results of SnO2 gas sensor and olfactometry (R=0.6583 for ammonia, R=0.9342 for acetic acid, R=0.9582 for trimethylamine, R＝0.8311 for ethylbenzene, R＝0.9829 for dimethylsulphide and R＝0.9331 for p-cymene, respectively）when six odorants in higher concentrations（ammonia: 5-100 ppm, acetic acid: 0.1-100 ppm, trimethylamine, ethylbenzene, dimethylsulphide and p-cymene: 0.25-100 ppm）. And there is a high correlation between the results of field samples from food waste composting plant measuring by SnO2 gas sensor and olfactometry. The human odor detection thresholds of ammonia, acetic acid, ethylbenzene, dimethylsulphide, trimethylamine, and p-cycmene for Taiwanese are 1.0258 ppm, 0.0546 ppm, 0.0849 ppm, 0.0088 ppm, 0.0003 ppm, and 0.0284 ppm, respectively. The study reveals that SnO2 gas sensor could be a convenient and quicker equipment to measure odors by assisting or replacing with olfactometry for emitted odors of food waste compsdting plant.

Due to the spread of urbanisation and increased environmental awareness, odour has become a major problem in communities surrounding landfills. The aim of this research was to investigate odour emissions from landfills and develop a management tool that operators could use to assist in minimising the impacts of odour. The management tool would be in the form of real-time predictions of odour concentrations in the vicinity of a source. The Bisasar Road landfill in Springfield, Durban was a case study site for the research. The methodologies used in this project can be divided into three broad categories. Firstly, flow visualisation experiments were conducted on the case study site to investigate the effects of complex terrain and the results compared to predictions from a dispersion model. Secondly, source characterisation was done on-site. Sources of odour were identified using a portable odour monitor (Electronic nose). Sources of odour were then sampled using sorbent tubes and analysis done using Gas Chromatography - Mass Spectrometry. Thirdly, numerical dispersion modelling was done. Five available dispersion models were assessed and compared against one another in order to select the most suitable model for this application. A software management tool or 'Odour Management System' (OMS), was designed and implemented on a computer at the Bisasar Road landfill. Qualitative results of the flow visualisation experiments show that terrain does have an effect on a dispersing plume path for short-range predictions. Comparisons between the flow experiments and model predictions are qualitatively consistent. Quantitative results were not obtained for the emission flow rate and emission concentration of landfill gas. The chemical composition of the fresh waste gas was determined. ADMSTM(Advanced Dispersion Modelling System) was found to be the most suitable dispersion model for this application. The OMS has been installed on-site to produce odour concentration graphics every ten minutes. A fence line odour control misting system has been installed along approximately 600 metres of the landfill border based on work done as part of this project. Weather conditions and information provided by the OMS, assist in running the odour control system economically.
Thesis (M.Sc.Eng.)-University of Natal,Durban, 2002.

The thesis presents observations on the CO2 mixing ratio and the carbon isotopic ratio (13C/12C i.e. δ13) of atmospheric CO2 from the Indian region, for the period 2008 - 2011. An experimental system was established at the Centre for Earth Sciences, Indian Institute of Science, Bangalore. The experimental protocol involves collection of air samples, extraction of CO2 from the air samples collected, and finally the measurement of the CO2 mixing ratio and isotopic ratios of the extracted CO2 using pressure gauge readings and the dual inlet peripheral of the isotope ratio mass spectrometer, IRMS MAT 253. The isotopic ratios measured are scaled to VPDB and corrected for their N2O contribution. The experimental set up is calibrated with primary carbonate standards (NBS19) and an air CO2 reference mixture. The analytical precision (reproducibility of paired samples) obtained for the atmospheric CO2 measurement is ±7 µ mol.mol-1, ±0.05‰ and ±0.17‰ for the mixing ratio, δ 13C and δ 18Oof atmospheric CO2 respectively. The present study lays emphasis on the CO2 mixing ratio and the δ 13C of atmospheric CO2. There are very few atmospheric CO2 monitoring stations in India. There exists only one long-term monitoring station, Cabo de Rama, on the west coast of India. Of late, a few new stations for measuring atmospheric trace gases have been in operation, with the major focus being on remote locations. Urban stations in India have never been monitored before for both the mixing ratio and the δ13C of atmospheric CO2 together. Monitoring urban stations in India is crucial today as they have become prime emitters of CO2 due to industrial activity. The emission from the sources varies seasonally and is influenced by factors like the Indian monsoon. The Indian subcontinent is surrounded by the Arabian Sea, the Indian Ocean and the Bay of Bengal which act differentially in terms of CO2 uptake or release. There is also a differential transport of CO2 to and from the open ocean. Thus, understanding the spatial pattern of CO2 in the marine region close to the Indian subcontinent is essential to understand the oceanic uptake/release of CO2. As part of this thesis, an urban area was monitored during 2008 - 2011 and the marine region was observed during the southwest monsoon of 2009. The temporal variation of the CO2 mixing ratio and δ13C of atmospheric CO2 was observed over an urban station, Bangalore (12° 58′ N, 77° 38′ E, masl= 920 m), India. Since Bangalore is one of the developing urban cities in India, it is interesting to monitor Bangalore air to understand the impact of anthropogenic emissions on atmospheric CO2 variability. The region has four distinct seasons, dry summer (March – May), southwest monsoon (June – September), post monsoon (October – November) and winter (December – February). Thus, it is also an ideal location to identify the effect of different seasons on the contribution of CO2 from various sources. Air samples were collected from the Indian Institute of Science campus, Bangalore, during 2008 - 2011. Both the diurnal and seasonal variations of the mixing ratio and δ13C of CO2 were observed in Bangalore. On the diurnal scale, a higher mixing ratio with lighter carbon isotopes (negative value) of δ13C of CO2 was recorded in the air-CO2 analyzed during the early morning compared to the late afternoon samples. The observations suggest that coal combustion, biomass burning and car exhausts are possible sources for CO2 identified based on the Keeling plot method. The nocturnal boundary layer (NBL) is found to influence the buildup of CO2 concentration in the early morning. The presence of the NBL in the early morning prevents the mixing of locally produced air with the CO2 from the free atmosphere above. Thus, the free air contribution of CO2 is reduced during the early morning rather than in the afternoon. The effect of seasonal variability in the height of the NBL on the air CO2 mixing ratio and the 13C of atmospheric CO2 were documented in the present study. On a seasonal scale, the free air contribution of CO2 was found to be higher during the southwest monsoon and winter compared to the dry hot summer and post monsoon period. On a seasonal time scale, a sinusoidal pattern in both the mixing ratio and δ13C has been recorded in the observations. While compared with nearby CO2 monitoring stations like the coastal station, Cabo de Rama, and the Open Ocean station, Seychelles, maintained by CSIRO Australia and NOAA-CMDL respectively, Bangalore recorded higher amplitudes of seasonal variation. Seasonal scale variations have revealed an additional source i.e. emission from the cement industry along with other sources identified from diurnal variations. The emission of CO2 from these different sources is not constant; rather it was found to vary with different seasons. The enhanced biomass burning during the dry season drives the δ13C of atmospheric CO2 towards more negative values, while during the southwest monsoon; the increased biosphere cover pushes the δ13C value of atmospheric CO2 towards positive values. The effect of La Nina in 2011 is also prominent in the observation. The study also intends to identify the spatial variability of both the mixing ratio and δ 13C air-CO2 close to the urban station, Bangalore based on the simultaneous sampling of air from three locations, Bangalore and two coastal stations, Mangalore and Chennai, which are equidistant from Bangalore. Samples were collected during the southwest monsoon and winter of 2010 - 2011. The observations documented a similar source of CO2 for all the three stations irrespective of the season. The factor responsible for the variability in the mixing ratio and the δ 13C of air CO2 among these stations is the differential transport of air from the marine region and its mixing with locally produced air. To identify the variability of atmospheric CO2 over the marine region, the atmosphere over the Bay of Bengal was monitored during the southwest monsoon of 2009 as part of the Continental Tropical Convergence Zone (CTCZ) Cruise expedition. The ocean surface water was also monitored simultaneously for the δ18O of water and the δ13C of dissolved inorganic carbon measurement. The combined observations of both air and water have shown the transport of continental air to the marine region and its uptake by the ocean during the period. The variability of atmospheric-CO2 is also observed during special events like the solar eclipse. During the annular solar eclipse of 15th January, 2010 an unusually depleted source value was identified for Bangalore air. The role of the boundary layer and a change in photosynthesis were identified as possible factors affecting air CO2 composition. In conclusion, the thesis has provided the first observations on air CO2 variability from an urban station in India. The observations have identified the possible sources of CO2 and have demonstrated the role of climatic phenomena like the Atmospheric Boundary Layer, Indian Monsoon, and La Nina in controlling the behaviour of sources and sinks and thus affecting the air CO2 variability over land and ocean. The seasonal scale variation based on day-to-day variability in the afternoon samples has revealed the important contribution of emissions from the cement industry whose contribution was absent in the diurnal variability. Thus, it is evident from this study that the timing of air sampling is crucial while identifying the sources. The per capita emission of individual urban stations in India is different; thus, it is essential to monitor more urban stations to identify sources and their different contributions. In future, the simultaneous monitoring of both continental and marine air over both the Arabian Sea and the Bay of Bengal will enable us to understand the long range transport of atmospheric CO2. The long term monitoring of CO2 from the Indian region can give us a better perspective on the effect of the Indian monsoon on air CO2 variability and vice versa.