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You searched for +publisher:"Colorado School of Mines" +contributor:("Regnery, Julia"). Showing records 1 – 3 of 3 total matches.

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Colorado School of Mines

1. Almaraz, Nohemi. Emergence and fate of iodinated organic compounds and disinfection by-products during biological treatment of oil and gas produced water.

Degree: MS(M.S.), Civil and Environmental Engineering, 2018, Colorado School of Mines

Oil and gas (O&G) development in arid regions throughout the United States has increased water demands for development of industrial, agricultural, and residential sectors. Treating and recycling wastewater generated during O&G production for potential surface discharge and beneficial reuse can help alleviate water demands in several water-intensive sectors. Several treatment technologies to improve water quality for potential surface discharge, live-stock watering, dust suppression, and on-site water reuse can be implemented. Biological active filters (BAFs) are one treatment technology that can be effectively used as pre-treatment of O&G wastewater to remove organic matter and reduce fouling in downstream membrane treatment processes for desalination. Because O&G wastewater is halogen rich, formation and toxicity of treatment byproducts with iodide and bromide constituents is of concern when planning potential treatment management strategies for complex waste streams like O&G produced water. In this study, we investigated the occurrence of iodinated organic compounds (IOCs) in BAFs treating O&G produced water. The occurrence of three IOCs was monitored by quantifying chloroiodomethane, diiodomethane, and triiodomethane in nine BAF treatment systems operated with different granular activated carbon media and nutrient type before and after treatment. Chloroiodomethane, diiodomethane, and triiodomethane were measured by headspace solid-phase microextraction gas chromatography mass spectrometry at concentrations up to 16.6 μg/L, 442 μg/L, and 4,316 μg/L, respectively. Triiodomethane, an iodinated disinfection byproduct (I-DBP), was the IOC that was predominantly measured in treated produced water with more than 90% contribution to the total sum of three quantified IOCs in 21 samples analyzed (n=21). A moderately strong correlation (r=0.59) was established between iodide concentration and the total concentration of the three quantified IOCs (n=26). This relationship indicates the likelihood that the inorganic iodide introduced to the system in PW is converted to IOCs (organic iodine) during treatment. Additionally, organisms belonging to the iodide oxidizing bacterium (IOB) genus were also found at relatively high abundance (51.5%) in water treated through biological active filters but not produced water (0.2%). The occurrence of IOB, IOCs, and I-DBPs during biological treatment of O&G produced water has not been previously reported and can be indicative of an underestimated formation pathway of I-DBPs in complex waste streams. Advisors/Committee Members: Cath, Tzahi Y. (advisor), Higgins, Christopher P. (committee member), Regnery, Julia (committee member).

Subjects/Keywords: gas chromatography mass spectrometry; oil and gas wastewater; biological active filters; produced water; iodinated organic compounds

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Almaraz, N. (2018). Emergence and fate of iodinated organic compounds and disinfection by-products during biological treatment of oil and gas produced water. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/172333

Chicago Manual of Style (16th Edition):

Almaraz, Nohemi. “Emergence and fate of iodinated organic compounds and disinfection by-products during biological treatment of oil and gas produced water.” 2018. Masters Thesis, Colorado School of Mines. Accessed April 11, 2021. http://hdl.handle.net/11124/172333.

MLA Handbook (7th Edition):

Almaraz, Nohemi. “Emergence and fate of iodinated organic compounds and disinfection by-products during biological treatment of oil and gas produced water.” 2018. Web. 11 Apr 2021.

Vancouver:

Almaraz N. Emergence and fate of iodinated organic compounds and disinfection by-products during biological treatment of oil and gas produced water. [Internet] [Masters thesis]. Colorado School of Mines; 2018. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/11124/172333.

Council of Science Editors:

Almaraz N. Emergence and fate of iodinated organic compounds and disinfection by-products during biological treatment of oil and gas produced water. [Masters Thesis]. Colorado School of Mines; 2018. Available from: http://hdl.handle.net/11124/172333


Colorado School of Mines

2. Drumheller, Zachary W. Development of a control optimization algorithm with uncertain parameter inversion for stochastic, nonlinear systems: a proof-of-concept applied to managed aquifer recharge and recovery.

Degree: MS(M.S.), Mechanical Engineering, 2015, Colorado School of Mines

Aquifers around the world show troubling signs of irreversible depletion and seawater intrusion as climate change, population growth, and urbanization lead to reduced natural recharge rates and overuse. Scientists and engineers have begun to re-investigate the technology of managed aquifer recharge and recovery (MARR) as a means to increase the reliability of the diminishing and increasingly variable groundwater supply. Unfortunately, MARR systems remain wrought with operational challenges related to the quality and quantity of recharged and recovered water stemming from a lack of data-driven, real-time control. From a control system perspective, MARR facilities represent a difficult class of problems because they are governed by a coupled set of nonlinear, partial differential equations (e.g., unsaturated and multiphase flow) whose parameters are often uncertain and possibly time-varying. To date, engineers have developed several stochastic simulation-based control optimization methods to control similar systems; however, these methods have only been implemented in hypothetical simulations, and they often required direct access to the complex set of governing equations. This project seeks to develop and validate a more general simulation-based control optimization algorithm that can be used to ease the operational challenges of MARR facilities as a proof-of-concept. The algorithm was designed to treat the numeric model of the physical system as a black box so that various existing simulation packages for different physical systems could be used interchangeably. The SCOA-DUPI (Simulation-based Control Optimization Algorithm with Dynamic Uncertain Parameter Inversion) compensates for uncertainty in the modeling parameters by continually collecting data from a sensor network embedded within the physical system. At regular intervals the data is fed into an inversion algorithm, which calibrates the uncertain parameters and generates the initial conditions of a predictive model. The specific SCOA-DUPI prototype for MARR applications improved upon uncertain estimates of the hydraulic conductivity field using observed hydraulic head data. The calibrated model is then passed to a genetic algorithm to execute simulations and determine the best course of action, e.g., the optimal pumping policy for current aquifer management goals. The optimal controls are then autonomously applied to the system, and after a set amount of time, the process repeats. Experiments to calibrate and validate the SCOA-DUPI were conducted at the laboratory-scale in a small (18"H x 46"L) two-dimensional synthetic aquifer under both homogeneous and heterogeneous packing configurations. The synthetic aquifer used uniform, well characterized technical sands and the electrical conductivity signal of an inorganic conservative tracer as a surrogate measure for water quality. The synthetic aquifer was also outfitted with an array of various sensors and an autonomous pumping system. The results from the initial experiments validated the feasibility of the… Advisors/Committee Members: Berger, John R. (advisor), Smits, Kathleen M. (advisor), Celik, Ozkan (committee member), Illangasekare, T. H. (committee member), Regnery, Julia (committee member).

Subjects/Keywords: optimal control of stochastic; simulation-based control optimization; parameter estimation; nonlinear systems with latency; managed aquifer recharge and recovery; genetic algorithm; dynamic parameter inversion; Groundwater recharge; Aquifer storage recovery; Algorithms; Stochastic systems; Simulation methods; Control theory

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Drumheller, Z. W. (2015). Development of a control optimization algorithm with uncertain parameter inversion for stochastic, nonlinear systems: a proof-of-concept applied to managed aquifer recharge and recovery. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/17139

Chicago Manual of Style (16th Edition):

Drumheller, Zachary W. “Development of a control optimization algorithm with uncertain parameter inversion for stochastic, nonlinear systems: a proof-of-concept applied to managed aquifer recharge and recovery.” 2015. Masters Thesis, Colorado School of Mines. Accessed April 11, 2021. http://hdl.handle.net/11124/17139.

MLA Handbook (7th Edition):

Drumheller, Zachary W. “Development of a control optimization algorithm with uncertain parameter inversion for stochastic, nonlinear systems: a proof-of-concept applied to managed aquifer recharge and recovery.” 2015. Web. 11 Apr 2021.

Vancouver:

Drumheller ZW. Development of a control optimization algorithm with uncertain parameter inversion for stochastic, nonlinear systems: a proof-of-concept applied to managed aquifer recharge and recovery. [Internet] [Masters thesis]. Colorado School of Mines; 2015. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/11124/17139.

Council of Science Editors:

Drumheller ZW. Development of a control optimization algorithm with uncertain parameter inversion for stochastic, nonlinear systems: a proof-of-concept applied to managed aquifer recharge and recovery. [Masters Thesis]. Colorado School of Mines; 2015. Available from: http://hdl.handle.net/11124/17139


Colorado School of Mines

3. Wallen, Benjamin M. Heat and mass transfer through disturbed soil: multiscale experimental and modeling investigation.

Degree: PhD, Civil and Environmental Engineering, 2016, Colorado School of Mines

Landmines are one of the most prolific, human-made environmental hazards impacting the world. Although there are numerous technologies used to detect buried landmines, none enable a perfect find rate, in part, due to the heterogeneous nature of the environment in which they are buried. Variations in environmental conditions such as soil moisture and climate (e.g., temperature, diurnal fluctuations) impact detection performance. Improved understanding of the environmental conditions associated with minefield emplacement is needed to enable improvement in the algorithms used by detection technologies (e.g., infrared, ground penetrating radar), thus increasing their performance and probability of detection rates. However, there is a lack of understanding of the effect of the mine placement on the heat and mass transfer dynamics in the vicinity of the mine. More specifically, very little is known about how soil disturbance, a process that changes the soil thermal and hydraulic properties of the soil surrounding the mine, due to the placement and burial of the mine effects the soil moisture and temperature conditions in the vicinity of the mine. This is important because understanding these impacts enables increased ability to compare progressively complex models to measured aspects of interest specific to landmine emplacement conditions. The purpose of this research is to better understand the effect of soil disturbance (i.e., loosening the soil) and mixing (i.e., combining different soil types) on heat and mass transfer behavior in the vicinity of buried landmines. The aim is that this knowledge can help future research efforts to improve algorithms associated with various detection technologies. This research integrates a field experiment and numerous laboratory experiments with analytical modeling. In the first task, the thermal conductivity of mixed sands are evaluated at the small scale, providing critical knowledge of the unique behavior. Results indicate that for the test sands studied, knowledge of soil density enables identification of both saturated and dry thermal conductivity which enhances modeling of the thermal conductivity-saturation relationships. Experimental data were used to test thermal conductivity-saturation models. The analytical models varied in their ability to capture the thermal behavior, demonstrating the need for a physically based thermal conductivity-saturation model. The second task compares several approaches used to determine evaporation with several laboratory evaporation and evapotranspiration experiments in an effort to determine an appropriate method that can be applied to studies of landmine detection, specifically, disturbed soil conditions. Results demonstrate that the methods vary in their ability to capture atmospheric versus diffusion dominated evaporative stages for the test soils and boundary conditions studied. Although no one method is applicable for all boundary and initial conditions, the sensible heat balance and heat pulse method enabled the highest level of agreement… Advisors/Committee Members: Smits, Kathleen M. (advisor), Illangasekare, T. H. (committee member), Howington, Stacy (committee member), Regnery, Julia (committee member), Wu, Ning (committee member).

Subjects/Keywords: binary mixtures; disturbed soil; evaporation method comparison; field experiment; landmine detection; thermal conductivity

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wallen, B. M. (2016). Heat and mass transfer through disturbed soil: multiscale experimental and modeling investigation. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/170236

Chicago Manual of Style (16th Edition):

Wallen, Benjamin M. “Heat and mass transfer through disturbed soil: multiscale experimental and modeling investigation.” 2016. Doctoral Dissertation, Colorado School of Mines. Accessed April 11, 2021. http://hdl.handle.net/11124/170236.

MLA Handbook (7th Edition):

Wallen, Benjamin M. “Heat and mass transfer through disturbed soil: multiscale experimental and modeling investigation.” 2016. Web. 11 Apr 2021.

Vancouver:

Wallen BM. Heat and mass transfer through disturbed soil: multiscale experimental and modeling investigation. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/11124/170236.

Council of Science Editors:

Wallen BM. Heat and mass transfer through disturbed soil: multiscale experimental and modeling investigation. [Doctoral Dissertation]. Colorado School of Mines; 2016. Available from: http://hdl.handle.net/11124/170236

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