R-3 Repository :: Browsing by Author "Tomson, Mason B."

Browsing by Author "Tomson, Mason B."

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A New Assay Method for Scale Inhibitor Detection at Low Concentrations
(2014-04-23) Liu, Ya; Tomson, Mason B.; Bedient, Philip B.; Li, Qilin
Accurate detection of scale inhibitors has always been crucial to scale control in industry. However, analyzing scale inhibitors at low concentrations, especially with polymeric scale inhibitors, remains an ongoing challenge. This paper presents an assay method designed to detect all types of scale inhibitors, especially at low concentrations, and an expert program developed to guide the method. The program guides the preparation of a field brine barite solution at a fixed barite super-saturation. Scale inhibitor concentration is then measured via the method of standard additions, assuming a linear relationship between the scale inhibitor concentration and the logarithm of barite induction time. Seven different scale inhibitors, including phosphonates, carboxylates and sulfonates, were detected in two typical synthetic brines at low concentrations. In addition, this assay method has also been applied to scale inhibitor detection in actual field brines. In general, this easily-implemented method can directly detect the residual level of any scale inhibitors in field brine about 0.1 mg/L active. Emphasis in this paper is on low concentrations. Measurement of low concentration scale inhibitors not only helps to monitor scaling tendency but also effectively prevents overuse of scale inhibitors and thereby protects the environment and saves money. This is one of the few methods that can detect most scale inhibitors at such low concentrations. Field applications, strengths, and interferences are discussed using laboratory and field examples.
A numerical model of processes governing groundwater contaminant transport
(1983) Springer, Nina K.; Bedient, Philip B.; Wheeler, Mary F.; Tomson, Mason B.
The purpose of this research was to develop a numerical model to simulate transport of solutes in groundwater which could be used to 1) predict existing or potential groundwater contamination and 2) aid determination of governing transport mechanisms in the field. The numerical model developed successfully uses a Laplace Modified Alternating Direction Implicit solution scheme to solve, for the first time in this application, a finite-difference expression for the governing transport equations. The model incorporates transport processes of advection, dilution, physical dispersion, reaction, and adsorption. The major advantages of the model are its non-iterative solution scheme which allows quick solutions, its non-time-dependent stability, and its wide and flexible range of transport process simulation capabilities. The transport model was linked to an existing groundwater flow model, GWSIM-II. This model, a modification of the Prickett-Lonnquist model used by the Texas Department of Water Resources, calculates groundwater heads over time by solving a finite difference form of the unsteady state pressure equation. The resulting combined model was called MPACTS; a model of physical and chemical transport in the subsurface. The accuracy of the model was verified by comparing MPACTS solutions and analytical solutions to simple problems. The model solutions to these problems are quite accurate when reasonable model parameters are used. In order to demonstrate application of the model to field data, MPACTS was used to simulate groundwater contamination at a rapid soil infiltration sewage treatment facility at Fort Devens, Massachusetts. Contamination by chlorides and a trace level organic, tetrachloroethylene, was modeled. The site was fairly well documented with respect to groundwater heads and chloride concentration in the immediate vicinity of the basins, but was not defined elsewhere. The lack of good definition over the whole modeled area, typical of field studies, was reflected in inaccuracies in simulated contaminant concentrations. However, the simulations were sufficiently accurate to be used for estimation of contaminant contours at the site.
A rapid, simple method to measure the desorption-resistant fraction of sediment sorbed contaminants
(2003) Cong, Lili; Tomson, Mason B.
Resistant desorption has been widely observed for hydrophobic organic contaminants. It is an important process that impacts sediment quality and contaminated sediment management. Conventional approaches to measure the desorption resistant fraction of sorbed contaminants are by conducting repetitive water desorption, in which the desorption resistant fraction is determined by measuring the solid phase concentration after extended desorption times. This method is time-consuming and impractical for widespread applications. In addition, the final measurement of the solid phase concentration is subject to considerable error, because there is always a fraction of water associated with the solid due to the incomplete separation of the liquid phase from the solid. In this research, a new experimental protocol was developed to rapidly and accurately measure the desorption resistant fraction based on the study of desorption of phenanthrene from Utica sediment.
A Study of Surface Treatments on Carbonate Core Material for Application to Mineral Precipitation and Dissolution during Geologic Carbon Storage
(2013-06-05) Work, Sarah; Tomson, Mason B.; Bedient, Philip B.; Ward, C. H.; Hirasaki, George J.
Underground injection of acid gas has been studied for several decades for oil field applications, such as enhanced oil recovery (EOR), but is now being studied as a solution to climate change. This research aims to simulate underground conditions at injection sites, such as the pilot scale injection site located near the site of a coal fired power facility in the Black Warrior Basin of Alabama. This proposed carbon capture and sequestration (CCS) location would involve injection of liquid CO2 into a carbonaceous saline aquifer. The objective of this study was to investigate carbonate surface treatments that alter the kinetics and mechanism of mineral dissolution resulting from the injection of an acid gas (CO2) into a geologic formation. A variety of mineral coatings were tested in an attempt to preserve mineral integrity under acidic conditions. Surface active chemicals were first tested, including scale inhibitors, followed by a novel acid induced surface treatment that precipitates an inorganic layer on the calcite to preserve the acid soluble mineral. These experiments are the first to investigate the use of scale inhibitors for mineral preservation, although were found ultimately to have little impact on dissolution kinetics. However, anions of moderate to strong acids induced surface coatings that were determined to effectively inhibit dissolution. Additionally, a novel, high pressure flow-through experimental apparatus was developed to simulate pressure and temperature conditions relevant to injection sites. Similar mineralogical studies in the literature have used pressurized, unstirred, batch systems to simulate mineral interactions. Solids with an acid induced surface coating were tested in the high pressure column and no calcium was found to leave the column.
Alkalinity and phosphonate studies for scale prediction and prevention
(1993) Hunter, Margaret Ann; Tomson, Mason B.
Scale formation is a problem in many processes that handle large volumes of water. The retention and release of phosphonates, as relates to their use in the squeeze procedure for the petroleum industry, were studied. A new method for measuring bicarbonate alkalinity in the presence of carboxylic acids was developed using a CO$\sb2$ evolution technique. Solubility and core flow-through experiments were used for phosphonate studies. Dissociation constants and solubility products for the aminomethyl and methyl phosphonic acids were determined at 70$\sp\circ$C. The effects of one, three and five phosphonate functional group(s) on the retention and the release of diethylenetriaminepenta(methylene phosphonic acid), aminotri(methylene phosphonic acid), aminomethylphosphonic acid, and methylphosphonic acid were examined. Amine functional group(s) have an effect on retention and release of the phosphonates. The retention of the amine phosphonates under acidic conditions is directly dependent on the number of phosphonate functional groups.
An analysis of sorption in the field and the implications for transport and risk
(2000) Moore, Ellen Marie; Tomson, Mason B.
There is often a fraction of contaminants in the subsurface which is observed to persist for long periods of time and resist removal. The phenomenon of incomplete or slow desorption has been shown in the laboratory for many different soil and sediment types and chemicals and a model was developed known as irreversible sorption. Hydrocarbon data from several field sites are compared to the linear and irreversible sorption isotherms and it appears that field data are described by a combination of the linear and irreversible models. A one-dimensional transport model which includes a linear or irreversible term for sorption generally predicts significantly lower concentrations with the linear term than the irreversible term. However, estimates of risk through groundwater and air exposure pathways decrease when sorption is described by the irreversible model. The combination of these factors with the uncertainties that remain presents a complicated problem for site management.
An assessment of point and nonpoint pollution loads into Lake Houston
(1981) Newell, Charles J.; Bedient, Philip B.; Rowe, Peter G.; Tomson, Mason B.
The urbanization process has affected the characteristics of pollutant loads from both stormwater runoff (or nonpoint sources) and from sewage treatment plants (or point sources) in the tributaties of the 2828 mi lake Houston watershed. Land use projections indicate the urban development, which has caused water quality deterioration in seme tributaties, will continue at nearly the same overall rate in the 198 to 199 period as in the 197 to 198 period. The patterns of growth, however, will shift from development concentrated in the Cypress Creek and Lake Environs areas to several of the previously undeveloped watersheds; this will impact on water quality of the streams in these areas. A detailed point source analysis indicated that most of the larger sewage treatment plants acconmodating the increases in population in the Cypress Creek watershed had difficulty in providing accepted levels of treatment. All violated State of Texas standards for effluent quality to some degree, and treatment process upsets greatly increased effluent loads for sane parameters. The fate of the plant's nutrient loads at low flow was also examined: almost all of the nutrients were carried to the lake by the Cypress Creek low flow transport process. During these low flow periods, critical for lake water quality, point sources accounted for 25% of the nitrate-nitrogen (NOg) and 75% of the total phosphorus (TP) loads to Lake Houston. The nonpoint source analysis showed that urban development has increased total suspended solids (TSS) loads to lake Efouston. The rapidly urbanizing watershed, Cypress Creek, contributes 27-35% of the annual TSS load to the lake although it accounts for only 11% of the entire basin's area. The load analysis provided the following yearly pollutant loads to the lake (for an average year's flow under present development conditions): 159 • 16Kg TSS/y ear,31.8 * 1° Kg N^NO^/year, and 1.4 • 1 Kg TP/year. Because of continuing development in the entire basin, lake TSS loads are expected to rise to 194 • 1 Kg TSS/year in 199, a 22% increase. Two different basin-wide management policies were examined and results indicated that although stormwater detention sedimentation ponds were an effective measure to prevent this increase in TSS loads, they probably could not be applied to reduce TSS loads much below present levels. The instantaneous load-runoff methodology using periodic grab sample data, used to calculate nonpoint pollutant loads, seemed to work well for TSS loads in general and for nutrient loads in the undeveloped watersheds. The method seemed to underestimate nonpoint nutient loads from developing watersheds, probably because of the high variability of stormwater runoff concentrations in these areas. An intensive storm sampling program on two storms, used in the management policy analysis, was also applied to the load-runoff methodology. This analysis indicated that future studies designing monitoring programs to calculate annual pollutant budgets to Lake Kbuston should employ intensive storm sampling techniques rather than the sampling at regular intervals performed by earlier studies.
Application of nanoparticles in downhole detection
(2014-12-11) Wang, Lu; Tomson, Mason B.; Bedient, Philip B.; Tour, James M.
The revolution of nanotechnology leads to the increasing application of nanoparticles in many industry fields. Nanoparticles, due to the small size, are supposed to transport through subsurface formation without breaking rock structure and thus have received tremendous attention1-12. Nanoparticles also have many unique physical, chemical and optical properties, which are not found in bulk samples with the same chemical composition. Such nanoparticles, therefore, may be attractive as candidates to detect the chemical and physical properties underground, by directly interact with the important targets. Because of the increasing energy demands, it becomes more desirable to develop new technology to detect the downhole conditions. In this paper, nanoparticles possessing functionalized carbon black cores and treated polyvinyl alcohol addends was designed as carrier to deliver probe molecules into the reservoir. When applied in the aqueous environment, nanoparticles tend to interact with the rock surface, which may affect the mobility and stability of the nanoparticles. Deposition of nanoparticles will remove the nanoparticles from the aqueous environment, and therefore understanding the fate and transport of nanoparticles is vitally important for determination of further application strategy. The stability and transport behavior were tested under high temperature, high salinity conditions through a variety of rock formations. A non-radioactive probe molecule, which can be easily detected by mass spectrometry, triphenolamine (TPA), was attached to the nanoparticles surface. When the nanoparticles passed through columns packing with different oil saturation ground rocks, the probe molecules, THA, was selectively released from nanoparticles. This study simulates detection and quantitative analysis of the hydrocarbon content in downhole rock formations, which is vitally needed for oilfield. This technology also shows the potential to be used for DNAPL detection in ground water remediation field. Crude oil is classified as “sour” when it contains total sulfur content greater than 0.5%. Among these sulfur species, H2S is the one of main impurities in sour crude. The sour crude is toxic and corrosive to the materials of construction in pipelines and other holding and transportation vessels. Since the sulfur amount in a sample of crude depends on where it was found, if the concentration of the sulfur species in the subsurface could be accurately monitored, then geologists might be able to evaluate the quality of the crude before large scale extraction ensues. A H2S-sensitive molecule was selected to be attached to nanoparticles surface and the detection ability of H2S concentration was tested. The experimental results show that the fluorescent enhancement of the H2S-sensitive addends correlates to the H2S content.
Arsenic Adsorption to N anoparticulate Magnetite in Natural Waters: Batch versus Column-Specific Effects
(2011) Farrell, Jesse Walter; Tomson, Mason B.
Increasingly, cities in Latin America recognize the importance of drinking water quality on public health. A water assessment of Guanajuato, Mexico, and surrounding areas found arsenic in wells above the Mexican drinking water standard (251lg/1). A collaborative effort was initiated to develop and field test a new arsenic removal method using high surface area sorbents. Nanoscale magnetite, previously shown to effectively adsorb arsenic in batch systems, was packed in sand columns to create a continuous treatment process. Design and operating conditions were assessed in bench-scale columns, and subsequently, a pilot column with 456 g ($2.50 US) of commercially available, food-grade magnetite demonstrated removal of the equivalent arsenic contained in 1,360 liters of Guanajuato groundwater. However, strong interferences were present in natural waters as breakthrough of arsenic in laboratory columns was delayed> 1 Ox with a synthetic feed solution as compared to groundwater at the same pH. Adsorption isotherms conducted with pretreated Guanajuato groundwater helped deduce the species of utmost interference: silica. By the removal or addition of silica, adsorption isotherms confirmed silica's strong effect. Low-level geothermal waters with high silica concentrations are common throughout central Mexico and other parts of the world presenting a major challenge for arsenic adsorbents. Arsenic adsorption improved through pH reduction in batch; however, pilot-scale column experiments showed no improvement with the same treatment. Silica preloading, deep-bed redox processes, and influent water impurities provided plausible explanation for the column observations. Breakthrough was monitored closely in columns sampled from 4 locations along their length. Synthetic solution with silica, in contrast to a baseline without silica, showed decreasing arsenic adsorption with distance through the column, characteristic of pre1oading, and a regression in breakthrough suggested oxidation at the magnetite surface. Calcium has been shown in batch systems to improve arsenic adsorption kinetics but not equilibrium partitioning in the presence of silica. In column experiments, the addition of calcium substantially increased arsenic adsorption in the presence of silica beyond batch model predictions confirming column-specific enhancements. The column-specific effects of silica, calcium, and redox would not be observable from adsorption isotherms but have critical importance to arsenic treatment by nanomagnetite columns.
Arsenic removal using iron oxides: Application of magnetite nanoparticles and iron salts
(2008) Yean, Su Jin; Tomson, Mason B.
Elevated levels of arsenic in groundwater have generated great attention worldwide because of its wide occurrences throughout the world and toxicity at low concentration. This work introduces a possible application at household levels to provide arsenic-safe water using nanoscale iron oxide (i.e., magnetite nanoparticles) and iron salts (i.e., ferric nitrate and ferric chloride) as adsorbents and coagulants, respectively. Recent publications illustrate that more than 70 million people are chronically exposed to arsenic-contaminated groundwater and suffer from skin lesions and cancers worldwide. A number of technologies (for example, ion exchange and membrane methods) are currently available to remove arsenic; however, each technique has drawbacks to be applicable in the developing countries. Therefore, it is crucial to develop a technology to treat arsenic-contaminated groundwater. Our results show an immediate reduction of arsenic concentration in solution to meet the maximum contaminant level of arsenic (10 microg L-1) in drinking water. Also, iron concentrations in solution are below the World Health Organization guideline value of 300 microg L-1. Contrary to previous results reported by other researchers, arsenic(III), known as more problematic in natural water, is also removed as effectively as arsenic(V) by using our method. When citrate, one of most common organic ligands in environments, is initially added to arsenic-containing solutions, the formation of iron oxides from iron salts is completely inhibited and resulting arsenic concentration remains the same as the initial arsenic concentration, indicating that arsenic removal does not occur. However, other common carboxylic acids such as tartarate, succinate, malate, formate, and tricarballylate, have a negligible impact on preventing the formation of iron hydroxides and resulting arsenic removal from solution. This work shows the efficient method to reduce high arsenic concentrations in groundwaters and better understanding of arsenic removal mechanisms using iron salts and iron oxides.
Asphaltene Behavior in Crude Oil Systems
(2013-10-31) Panuganti, Sai; Chapman, Walter G.; Vargas, Francisco M; Hirasaki, George J.; Tomson, Mason B.
Asphaltene, the heaviest and most polarizable fraction of crude oil, has a potential to precipitate, deposit and plug pipelines, causing considerable production costs. The main objective of this study is to contribute to the thermodynamic and transport modeling of asphaltene in order to predict its precipitation, segregation and deposition. Potential calculation of some thermophysical properties of asphaltene is also explored. Predicting the flow assurance issues caused by asphaltene requires the ability to model the phase behavior of asphaltene as a function of pressure, temperature and composition. It has been previously demonstrated that the Perturbed Chain form of Statistical Association Fluid Theory (PC-SAFT) equation of state can accurately predict the phase behavior of high molecular weight compounds including that of asphaltene. Thus, a PC-SAFT crude oil characterization methodology is proposed to examine the asphaltene phase behavior under different operating conditions. With the fluid being well characterized at a particular reservoir depth, a compositional grading algorithm can be used to analyze the compositional grading related to asphaltene using PC-SAFT equation of state. The asphaltene compositional grading that can lead in some cases to the formation of a tar mat is studied using the same thermodynamic model. Quartz crystal microbalance experiments are performed to study the depositional tendency of asphaltene in different depositing environments. The possibility of simulating asphaltene deposition in a well bore is discussed by modeling the capillary data, which simultaneously accounts for asphaltene precipitation, aggregation and deposition. The work presented is expected to contribute to the calculation of thermophysical properties of hydrocarbons and in particular of asphaltene, characterization of crude oils, improve tools to model asphaltene phase behavior, check the quality of fluid samples collected and the accuracy of (pressure, volume and temperature) PVT tests, reduce the uncertainties related to reservoir compartmentalization, optimize the logging during data acquisition, prediction of tar mat occurrence depths, improved understanding of the asphaltene deposition process, and finally optimize the wellbore operating conditions to reduce the asphaltene deposit.
Battery metal recycling by flash Joule heating
(AAAS, 2023) Chen, Weiyin; Chen, Jinhang; Bets, Ksenia V.; Salvatierra, Rodrigo V.; Wyss, Kevin M.; Gao, Guanhui; Choi, Chi Hun; Deng, Bing; Wang, Xin; Li, John Tianci; Kittrell, Carter; La, Nghi; Eddy, Lucas; Scotland, Phelecia; Cheng, Yi; Xu, Shichen; Li, Bowen; Tomson, Mason B.; Han, Yimo; Yakobson, Boris I.; Tour, James M.; Welch Institute for Advanced Materials; NanoCarbon Center; Applied Physics Program; Smalley-Curl Institute
The staggering accumulation of end-of-life lithium-ion batteries (LIBs) and the growing scarcity of battery metal sources have triggered an urgent call for an effective recycling strategy. However, it is challenging to reclaim these metals with both high efficiency and low environmental footprint. We use here a pulsed dc flash Joule heating (FJH) strategy that heats the black mass, the combined anode and cathode, to >2100 kelvin within seconds, leading to ~1000-fold increase in subsequent leaching kinetics. There are high recovery yields of all the battery metals, regardless of their chemistries, using even diluted acids like 0.01 M HCl, thereby lessening the secondary waste stream. The ultrafast high temperature achieves thermal decomposition of the passivated solid electrolyte interphase and valence state reduction of the hard-to-dissolve metal compounds while mitigating diffusional loss of volatile metals. Life cycle analysis versus present recycling methods shows that FJH significantly reduces the environmental footprint of spent LIB processing while turning it into an economically attractive process.
Broadening theories of soils genesis: Insights from Tanzania and simple models
(2007) Little, Mark Gabriel; Lee, Cin-Ty A.; Luttge, Andreas; Tomson, Mason B.; Anderson, John B.; Ewing, Maurice W.; Masiello, Caroline A.
Three basic assumptions of soil formation are challenged herein: the degree of chemical weathering decreases with depth; increased physical weathering due to high topographical gradients causes an increase in chemical weathering; and the mineral soil derives from the transformation of in situ parent material. The first part presents an investigation into the degree and nature of chemical weathering during soil formation on a volcanic substrate on Mt. Kilimanjaro in northern Tanzania. The degree of weathering was found to increase with depth in the soil profile. Observations show that the upper and lower layers of the weathering profile have undergone different weathering histories. The presence of a buried paleosol or enhanced weathering due to lateral subsurface water flow may explain the observations, the latter having novel implications for the transport of dissolved cations to the ocean. The second part presents a model to test the link between chemical weathering associated with soil formation and erosion associated with mass wasting. The predicted ratios suspended/dissolved ratios, however, are all higher than observed in rivers, the discrepancy worsening with increasing topographic relief. This discrepancy arises from the fact that in regions of high relief, mass wasting are so high that soil mantles do not reside on hillslopes long enough to allow for significant chemical weathering. The discrepancy between the model and observations can be explained by: over-estimate of predicted suspended load; absence of chemical weathering of deltaic/alluvial sediments from the model; or chemical weathering associated with groundwater weathering. The third part presents data from a sequential extraction on a basaltic soil from Mt. Meru in Northern Tanzania. The behavior of relatively immobile elements is consistent with soil formation being accompanied by mass loss due to chemical weathering. However, superimposed on this mass loss appears to be enrichment of most elements measured. These data suggest that the surface of the Meru soil columns may have experienced "re-fertilization" by the deposition of volcanic ash.
Carbon Nanomaterials for Detection, Assessment and Purification of Oil and Natural Gas
(2014-04-21) Hwang, Chih-Chau; Tour, James M.; Barron, Andrew R.; Tomson, Mason B.
This thesis studies several carbon nanomaterials. Their synthesis and characterization are studied as well as their potential applications to the oil industry. The carbon nanomaterials studied here include mesoporous carbon (CMK-3), sulfur- or nitrogen-doped porous carbon (SPC or NPC), and commercial carbon black (CB). Through appropriate functionalization, these carbon nanomaterials exhibit unique properties and their performances in detection, assessment as well as purification of oil and natural gas are studied and demonstrated. First, it was shown that amine-modified CMK-3 composites, polyethylenimine-CMK-3 (PEI-CMK-3) and polyvinylamine-CMK-3 (PVA-CMK-3) can be synthesized through in situ polymerization of amine species within the channels of the CMK-3. The synthesis process results in the entrapped amine polymers interpenetrating the composite frameworks of the CMK-3, improving the CO2 capture performance and recycle stability. CO2 uptake by the synthesized composites was determined using a gravimetric method at 30 °C and 1 atm; the 39% PEI-CMK-3 composite had ~12 wt% (3.1 mmol/g) CO2 uptake capacity and the 37% PVA-CMK-3 composite had ~13 wt% (3.5 mmol/g) CO2 uptake capacity. A desorption temperature of 75 °C was sufficient for regeneration. The CO2 uptake was the same when using 10% CO2 in a 90% CH4, C2H6 and C3H8 mixture, underscoring this composite’s efficacy for CO2 sequestration from natural gas. Secondly, nucleophilic porous carbons (SPC and NPC) were synthesized from simple and inexpensive carbon-sulfur and carbon-nitrogen precursors. A strong sorbate-sorbent interaction between CO2 and nucleophilic centers in the porous carbon was established using spectroscopic and heat of sorption data. Raman spectroscopy supports the assertion that the nucleophilic centers react with the CO2 to produce carbonate anions that further cause polymerization in the porous carbon channels to form poly(CO2) under much lower pressure than previously reported for such polymer formation. Once returned to ambient conditions, the poly(CO2) depolymerizes during the pressure swing, leading to a sorbent that can be easily regenerated without the thermal energy input that is required for traditional liquid phase sorbents. The synergy between the nucleophilic centers and the high surface area porous carbon produces a sorbent with high CO2 capacity, selectivity, and volumetric efficiency, so that the materials have potential to be used for CO2 removal from natural gas streams. As energy demand continues to increase, it is desirable to produce as much oil as possible from existing oil wells. Tracers have long been used to map entry/exit well correlations in the oil-field, but they do not provide any information about the environment between the entry and exit locations. Hence, the third part of this thesis will show that nanoparticles possessing functionalized carbon black (fCB) cores and sulfated polyvinyl alcohol (sPVA) addends can be designed to transport hydrocarbon detection molecules through subsurface rock formations. The sPVA-fCBs are stable under high-temperature and salinity conditions and are transported through a variety of oilfield rock types. A non-radioactive probe molecule that is easily detectable by mass spectrometry, triheptylamine (THA), was adsorbed onto the sPVA-fCBs. The THA was selectively released when the nanoparticles were passed through a column of isooctane-containing crushed rock, providing a path to both entry and exit correlations and a measure of oil content. This study simulates detection and quantitative analysis of the hydrocarbon content in downhole rock formations, which is a critically needed assessment in older oilfields. Crude oil is classified as “sour” when it contains a total sulfur content greater than 0.5%. Among these sulfur species, H2S is the one of main impurities in sour crude. The sour crude is toxic and corrosive to the materials of construction in pipelines and other holding and transportation vessels. Since the sulfur amount in a sample of crude depends on where it was found, if the concentration of the sulfur species in the subsurface could be accurately monitored, then geologists might be able to evaluate the quality of the crude before large scale extraction ensues. The last part of the thesis covers polyvinyl alcohol functionalized carbon black (PVA-CB). The particles have high stability under high temperature and salinity conditions, and they acts as a carrier to transport molecular cargo efficiently through simulated oilfield formations. After being functionalized with H2S-sensitive moieties, the functionalized PVA-CB can be pumped through H2S-containing oil and water in porous rock and the H2S content can be determined based on the fluorescent enhancement of the H2S-sensitive addends.
Carbon-60 nanoparticles: Adsorption and desorption of organic contaminants, and transport in soil
(2006) Cheng, Xuekun; Tomson, Mason B.
C 60 is a new form of carbon with unique properties due to its small size. Since it has been predicted that C 60 will be manufactured by tons, there is no doubt that it will ultimately find their way to the environment. Because of the insolubility of C 60 in water, one might expect that it would not enter groundwater in great quantities. However, "nC 60 " (water-stable C 60 aggregates) can be formed in water by exchange of solvents, or simply by stirring, indicating that C 60 might be readily available in groundwater. Therefore it is necessary to investigate the transport of C 60 particles and their interactions with other environmental contaminants. The adsorption and desorption of naphthalene and 1,2-dichlorobenzene, two common organic contaminants, with nC 60 in water was investigated and sorption hysteresis was observed. Naphthalene adsorption-desorption with activated carbon particles and soil organic carbon was also conducted. Similar sorption hysteresis was observed. Experimental data were fitted with different sorption models. The Dual-Equilibrium desorption model fits experimental data well. Each DED model fitting parameter has similar values for all three forms of carbon, indicating the possibility to predict the carbonaceous nanomaterial-contaminant interactions from well known carbon materials. The transport of nC 60 through a soil column was characterized by flow-through apparatus. It was observed in the transport study that nC 60 have limited mobility in the soil column at typical groundwater velocity, but they were more mobile at higher velocities. The effect of adsorbed nC 60 on naphthalene is similar to that of soil organic carbon. This study provides useful information for the environmental risk assessment of C 60 fullerene.
Characterization of Friction Reducer Properties in Oil-Field Operations
(2015-01-15) Bolanos Ellis, Valerie; Tomson, Mason B.; Alvarez, Pedro; Bedient, Philip; Tomson , Ross
Friction reducers are essential additives used to economically achieve the high pumping rates required for slickwater fracturing. Decreased friction reducer performance in high-TDS brines has been a major challenge for reusing produced water in hydraulic fracturing. Little work has been done to identify the specific parameters that affect polymeric friction reduction. This research uses friction flow loop experiments to characterize the performance of partially hydrolyzed polyacrylamide friction reducers in conditions relevant to the oil field. Polymer concentration and degree of hydrolysis effects on friction reduction are evaluated in the ranges of 0.25-2 gpt and 0-30%, respectively. The decrease in friction reducer performance is measured in brines up to 120,000 mg/L TDS with varying multivalent cation concentrations. The friction reducer interactions with Na+, Ca2+, Mg2+, Fe3+, and Al 3+ ions are individually assessed. The results are compared to experiments with a commercial friction reducer, and used to propose an empirical model to predict friction reducer performance based on water composition.
Critical Uncertainties and Gaps in the Environmental- and Social-Impact Assessment of the Proposed Interoceanic Canal through Nicaragua
(Oxford University Press, 2016) Huete-Pérez, Jorge A.; Ortega-Hegg, Manuel; Urquhart, Gerald R.; Covich, Alan P.; Vammen, Katherine; Rittmann, Bruce E.; Miranda, Julio C.; Espinoza-Corriols, Sergio; Acevedo, Adolfo; Acosta, María L.; Gómez, Juan P.; Brett, Michael T.; Hanemann, Michael; Härer, Andreas; Incer-Barquero, Jaime; Joyce, Frank J.; Lauer, J. Wesley; Maes, Jean Michel; Tomson, Mason B.; Meyer, Axel; Montenegro-Guillén, Salvador; Whitlow, W. Lindsay; Schnoor, Jerald L.; Alvarez, Pedro J.J.
The proposed interoceanic canal will connect the Caribbean Sea with the Pacific Ocean, traversing Lake Nicaragua, the major freshwater reservoir in Central America. If completed, the canal would be the largest infrastructure-related excavation project on Earth. In November 2015, the Nicaraguan government approved an environmental and social impact assessment (ESIA) for the canal. A group of international experts participated in a workshop organized by the Academy of Sciences of Nicaragua to review this ESIA. The group concluded that the ESIA does not meet international standards; essential information is lacking regarding the potential impacts on the lake, freshwater and marine environments, and biodiversity. The ESIA presents an inadequate assessment of natural hazards and socioeconomic disruptions. The panel recommends that work on the canal project be suspended until an appropriate ESIA is completed. The project should be resumed only if it is demonstrated to be economically feasible, environmentally acceptable, and socially beneficial.
Dispersion and retardation of contaminants in a high pressure liquid chromatography soil column system
(1984) Waggett, Gordon Gray; Tomson, Mason B.; Bedient, Philip B.; Ward, C. H.
The development of a high-pressure/high-flow rate soil chromatography system as a protocol method for the rapid screening of chemicals in natural, undisturbed aquifer samples is proposed. A mathematical advective-dispersive transport model was applied which evaluated the soil column and apparatus as a two-layered system. Results pertaining to the dispersion and retardation of six neutral-organic contaminants in one aquifer sample indicated that useful information could be obtained for other soil samples and transport processes as well. Close agreement was reached between experimental and theoretical breakthrough curves. Correlations between dispersion, seepage velocity and retardation were addressed. The transport model assumed equilibrium adsorption mechanisms. Kinetic- equilibrium adsorption terms may be necessary to model the retardation mechanisms at high flow rates.
Dynamic optimization of detention storage in urbanizing areas
(1982) Flores, Alejandro C.; Bedient, Philip B.; Tomson, Mason B.; Rowe, Peter G.
Rapid urban development in many areas has increased stormwater runoff and outdated traditional open channel drainage systems. Stormwater management alternatives such as channel enlargement are often difficult to implement in developing urban areas due to downstream land use restrictions. Detention storage in upper watershed areas is an effective stormwater control, but random or unplanned placement can significantly reduce its effectiveness and in some cases aggravate potential flood hazards. Earlier approaches to size and locate detention storage in a watershed have generally relied on trial-and-error methods. The purpose of this research is to develop a method to optimize the size and location of detention storage in a watershed. Hydrologic models were used in the method including two existing models, HEC-1 a flood hydrograph package and STOREME a single reservoir routing. DBOPTE, a multiple detention basin and channel network routing especially developed for this research, was used to optimize the size and location of detention storage. The method was applied to a one and a ten square mile hypothetical watershed with typical rainfall, physiography, soils, drainage patterns and land use data for the Houston area. The general methodology developed can he applied to any watershed where local data are available for runoff hydrograph prediction. Results for the one square mile watershed showed that the 25 year detention storage design is very effective in the peak runoff reduction for any flood frequency. For the ten square mile watershed, several physiography shapes were studied and results showed a higher peak runoff response for concentrated shapes than for elongated under developed conditions. Detention storage is more effective when located in the upper portion (67-8%) of the watershed rather than the downstream portion. For the 1 year flood frequency, detention storage volumes were .5 Acre-ft per acre of development and land requirements for a 5 ft basin depth were less than 1% of the watershed area. Land use distribution affects the detention storage volumes; for example, developing areas from downstream to upstream can require 28% more detention storage volumes than developing in both directions with undeveloped land in the middle.
Dynamics and control of temperature in the aerobic digestion of waste activated sludge
(1984) Sparks, John P.; Andrews, John F.; Bedient, Philip B.; Tomson, Mason B.
Pilot plant data and computer simulation show significant process benefits from the separation of aeration and mixing in open tank aerobic digestion. Open tank operation results in surface heat losses which cancel the heat gain of the exothermic organism decay reaction and drive digestion temperatures toward ambient atmospheric conditions. Diffused aeration produces a further evaporative heat loss through vapor enrichment of the diffused air. Mechanical mixers, however, elevate digestion temperatures through heat input from mixing and lower required air flow rates. Solids destruction rates are increased by higher digestion temperatures and increased oxygen transfer efficiency. For this reason, mechanical mixers should be included in the design of aerobic digesters and may relieve overload conditions at existing wastewater facilities. Also, the correlation between temperature history and solids destruction indicates that time-temperature data may be a valid indicator of sludge stability.

Browsing by Author "Tomson, Mason B."

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