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- All Subjects: Environmental engineering
- Creators: Herckes, Pierre
- Creators: Delgado, Anca G
Description
Titanium dioxide (TiO2) nanomaterial use is becoming more prevalent as is the likelihood of human exposure and environmental release. The goal of this thesis is to develop analytical techniques to quantify the level of TiO2 in complex matrices to support environmental, health, and safety research of TiO2 nanomaterials. A pharmacokinetic model showed that the inhalation of TiO2 nanomaterials caused the highest amount to be absorbed and distributed throughout the body. Smaller nanomaterials (< 5nm) accumulated in the kidneys before clearance. Nanoparticles of 25 nm diameter accumulated in the liver and spleen and were cleared from the body slower than smaller nanomaterials. A digestion method using nitric acid, hydrofluoric acid, and hydrogen peroxide was found to digest organic materials and TiO2 with a recovery of >80%. The samples were measured by inductively coupled plasma-mass spectrometry (ICP-MS) and the method detection limit was 600 ng of Ti. An intratracheal instillation study of TiO2 nanomaterials in rats found anatase TiO2 nanoparticles in the caudal lung lobe of rats 1 day post instillation at a concentration of 1.2 ug/mg dry tissue, the highest deposition rate of any TiO2 nanomaterial. For all TiO2 nanomaterial morphologies the concentrations in the caudal lobes were significantly higher than those in the cranial lobes. In a study of TiO2 concentration in food products, white colored foods or foods with a hard outer shell had higher concentrations of TiO2. Hostess Powdered Donettes were found to have the highest Ti mass per serving with 200 mg Ti. As much as 3.8% of the total TiO2 mass was able to pass through a 0.45 um indicating that some of the TiO2 is likely nanosized. In a study of TiO2 concentrations in personal care products and paints, the concentration of TiO2 was as high as 117 ug/mg in Benjamin Moore white paint and 70 ug/mg in a Neutrogena sunscreen. Greater than 6% of Ti in one sunscreen was able to pass through a 0.45 um filter. The nanosized TiO2 in food products and personal care products may release as much as 16 mg of nanosized TiO2 per individual per day to wastewater.
ContributorsWeir, Alex Alan (Author) / Westerhoff, Paul K (Thesis advisor) / Hristovski, Kiril (Committee member) / Herckes, Pierre (Committee member) / Arizona State University (Publisher)
Created2011
Description
Contaminants of emerging concern (CECs) present in wastewater effluent can threat its safe discharge or reuse. Additional barriers of protection can be provided using advanced or natural treatment processes. This dissertation evaluated ozonation and constructed wetlands to remove CECs from wastewater effluent. Organic CECs can be removed by hydroxyl radical formed during ozonation, however estimating the ozone demand of wastewater effluent is complicated due to the presence of reduced inorganic species. A method was developed to estimate ozone consumption only by dissolved organic compounds and predict trace organic oxidation across multiple wastewater sources. Organic and engineered nanomaterial (ENM) CEC removal in constructed wetlands was investigated using batch experiments and continuous-flow microcosms containing decaying wetland plants. CEC removal varied depending on their physico-chemical properties, hydraulic residence time (HRT) and relative quantities of plant materials in the microcosms. At comparable HRTs, ENM removal improved with higher quantity of plant materials due to enhanced sorption which was verified in batch-scale studies with plant materials. A fate-predictive model was developed to evaluate the role of design loading rates on organic CEC removal. Areal removal rates increased with hydraulic loading rates (HLRs) and carbon loading rates (CLRs) unless photolysis was the dominant removal mechanism (e.g. atrazine). To optimize CEC removal, wetlands with different CLRs can be used in combination without lowering the net HLR. Organic CEC removal in denitrifying conditions of constructed wetlands was investigated and selected CECs (e.g. estradiol) were found to biotransform while denitrification occurred. Although level of denitrification was affected by HRT, similar impact on estradiol was not observed due to a dominant effect from plant biomass quantity. Overall, both modeling and experimental findings suggest considering CLR as an equally important factor with HRT or HLR to design constructed wetlands for CEC removal. This dissertation provided directions to select design parameters for ozonation (ozone dose) and constructed wetlands (design loading rates) to meet organic CEC removal goals. Future research is needed to understand fate of ENMs during ozonation and quantify the contributions from different transformation mechanisms occurring in the wetlands to incorporate in a model and evaluate the effect of wetland design.
ContributorsSharif, Fariya (Author) / Westerhoff, Paul (Thesis advisor) / Halden, Rolf (Committee member) / Fox, Peter (Committee member) / Herckes, Pierre (Committee member) / Arizona State University (Publisher)
Created2013
Description
Trichloroethene (TCE) and hexavalent chromium (Cr (VI)) are ubiquitous subsurface contaminants affecting the water quality and threatening human health. Microorganisms capable of TCE and Cr (VI) reductions can be explored for bioremediation at contaminated sites. The goal of my dissertation research was to address challenges that decrease the efficiency of bioremediation in the subsurface. Specifically, I investigated strategies to (i) promote improve microbial reductive dechlorination extent through the addition of Fe0 and (ii) Cr (VI) bio-reduction through enrichment of specialized microbial consortia. Fe0 can enhance microbial TCE reduction by inducing anoxic conditions and generating H2 (electron donor). I first evaluated the effect of Fe0 on microbial reduction of TCE (with ClO4– as co-contaminant) using semi-batch soil microcosms. Results showed that high concentration of Fe0 expected during in situ remediation inhibited microbial TCE and ClO4– reduction when added together with Dehalococcoides mccartyi-containing cultures. A low concentration of aged Fe0 enhanced microbial TCE dechlorination to ethene and supported complete microbial ClO4– reduction. I then evaluated a decoupled Fe0 and biostimulation/bioaugmentation treatment approach using soil packed columns with continuous flow of groundwater. I demonstrated that microbial TCE reductive dechlorination to ethene can be benefitted by Fe0 abiotic reactions, when biostimulation and bioaugmentation are performed downstream of Fe0 addition. Furthermore, I showed that ethene production can be sustained in the presence of aerobic groundwater (after Fe0 exhaustion) by the addition of organic substrates. I hypothesized that some lessons learned from TCE Bioremediation can be applied also for other pollutants that can benefit from anaerobic reductions, like Cr (VI). Bioremediation of Cr (VI) has historically relied on biostimulation of native microbial communities, partially due to the lack of knowledge of the benefits of adding enriched consortia of specialized microorganisms (bioaugmentation). To determine the merits of a specialized consortium on bio-reduction of Cr (VI), I first enriched a culture on lactate and Cr (VI). The culture had high abundance of putative Morganella species and showed rapid and sustained Cr (VI) bio-reduction compared to a subculture grown with lactate only (without Morganella). Overall, this dissertation work documents possible strategies for synergistic abiotic and biotic chlorinated ethenes reduction, and highlights that specialized consortia may benefit Cr (VI) bio-reduction.
ContributorsMohana Rangan, Srivatsan (Author) / Krajmalnik-Brown, Rosa (Thesis advisor) / Delgado, Anca G (Thesis advisor) / Torres, César I (Committee member) / van Paassen, Leon (Committee member) / Arizona State University (Publisher)
Created2022
Description
The world currently faces hundreds of millions of cubic meters of soil contaminated with petroleum crude oil residuals. The application of ozone gas (O3) to contaminated soil is an effective means to oxidize petrogenic compounds and, when used with bioremediation, remove the oxidized byproducts. The overarching goal of this dissertation was to evaluate two areas of potential concern to large-scale O3 deployment: the capacity of O3-treated petroleum contaminated soils to support seed germination before bioremediation and the transport characteristics of O3 in soil columns. A matched study comparing the germination outcomes of radish (Raphanus sativus L.), grass (Lagurus ovatus), and lettuce (Lactuca sativa) in soils contaminated with three crude oils at various O3 total-dose levels showed that radish germination was sensitive to the soluble byproducts of oxidized petroleum (assayed as dissolved organic carbon [DOC]), but not sensitive to the unreacted petroleum (total petroleum hydrocarbon [TPH]). A multivariable logistic regression model based on the radish results showed that adverse germination outcomes varied with the DOC concentration and that DOC ecotoxicity decreased with increasing O3 dose-level and background organic material. The model was used to create a risk management map of conditions that created 10%, 25%, and 50% extra risks of adverse radish germination. Thus, while O3 effectively lowered TPH in soils, the byproducts exhibited ecotoxicity that inhibited radish germination. On the other hand, the sensitivity of radish germination to oxidized petroleum byproducts could be utilized to assess ecological risk. The feasibility of gas transport in the soil matrix is also of paramount concern to field-scale utilization of O3. A matched study comparing TPH removal at three field-relevant loading rates (4, 12, or 36 mgozone/ gsoil/ hr) and various total dose-levels showed an anisotropic pattern along the axial distance favoring the column inlet end. The asymmetry decreased as loading rate decreased and with concurrent improvements in O3-transport distance, O3 utilization, and heat balance. Overall, a low O3 loading rate significantly improved O3 transport and utilization efficiency, while also better distributing reaction-generated heat along the gas flow path for a depth typically utilized in bioremediation field settings.
ContributorsYavuz, Burcu Manolya (Author) / Rittmann, Bruce E (Thesis advisor) / Delgado, Anca G (Committee member) / Westerhoff, Paul (Committee member) / Arizona State University (Publisher)
Created2022
Description
Mining-influenced water (MIW) is an acidic stream containing a typically acidic pH (e.g., 2.5), sulfate, and dissolved metal(loid)s. MIW has the potential to affect freshwater ecosystems and thus MIW requires strategies put in place for containment and treatment. Lignocellulosic sulfate-reducing biochemical reactors (SRBRs) are considered a cost-effective passive treatment for MIW and have been documented to continuously treat MIW at the field-scale. However, long-term operation (> 1 year) and reliable MIW treatment by SRBRs at mining sites is challenged by the decline in sulfate-reduction, the key treatment mechanism for metal(loid) immobilization. This dissertation addresses operational designs and materials suited to promote sulfate reduction in lignocellulosic SRBRs treating MIW. In this dissertation I demonstrated that lignocellulosic SRBRs containing spent brewing grains and/or sugarcane bagasse can be acclimated in continuous mode at hydraulic retention times (HRTs) of 7-12 d while simultaneously removing 80 ± 20% – 91 ± 3% sulfate and > 98% metal(loid)s. Additionally, I showed that decreasing the HRT to 3 d further yields high metal(loid) removal (97.5 ± 1.3% – 98.8 ± 0.9%). Next, I verified the utility of basic oxygen furnace slag to increase MIW pH in a two-stage treatment involving a slag stage and an SRBR stage containing spent brewing grains or sugarcane bagasse. The slag reactor from the two-stage treatment increased MIW pH from 2.6 ± 0.2 to 12 ± 0.3 requiring its re-combination with fresh MIW to reduce pH to 5.0 ± 1.0 prior to entering the lignocellulosic SRBRs. The lignocellulosic SRBRs from the two-stage treatment successfully continued to remove metal(loid)s, most notably cadmium, copper, and zinc at ≥ 96%. In additions to these outcomes, I performed a metadata analysis of 27 SRBRs employing brewers spent grains, sugarcane bagasse, rice husks and rice bran, or a mixture of walnut shells, woodchips, and alfalfa. I found that sugarcane bagasse SRBRs can remove between 94 and 168 mg metal(loid) kg–1 lignocellulose d–1. In addition, Bacteroidia relative abundances showed a positive correlation with increasing sulfate removal across all 27 SRBRs and are likely essential for the degradation of lignocellulose providing electron donors for sulfate reduction. Clostridia and Gammaproteobacteria were negatively correlated with sulfate reduction in the 27 SRBRs, however SRBRs that received alkalinized MIW had lower relative abundances of Clostridia, Gammaproteobacteria, and methanogenic archaea (known competitors for sulfate-reducing bacteria). Overall, my dissertation provides insight into lignocellulosic materials and operational designs to promote long-term sulfate-reduction in lignocellulosic SRBRs treating MIW.
ContributorsMiranda, Evelyn Monica (Author) / Delgado, Anca G (Thesis advisor) / Santisteban, Leonard (Committee member) / Hamdan, Nasser (Committee member) / Rittmann, Bruce (Committee member) / Arizona State University (Publisher)
Created2023
Description
Halogens in drinking water sources, such as bromine (Br) and iodine (I) pose no direct health risk, but are critical precursors in formation of cyto- and genotoxic brominated and iodinated (Br-/I-) DBPs. However, few spatial or historic datasets exist for bromine and iodine species in drinking water sources. This dissertation aims to quantify and understand the occurrence and speciation of Br and I in groundwater and surface water serving as source waters for drinking water treatment plants (DWTPs). Aggregation of data from >9000 non-drinking water sampling locations in USA collected from 1930-2017 on halides (bromide (Br-) and iodide (I-)) determined that Br- concentrations were 50 μg/L and 100 μg/L; and I- concentrations were 12 μg/L and 13 μg/L in surface and groundwater respectively. Although, these locations were not drinking water sources, this first of its kind analysis provides potential bounds for Br- and I-. To focus specifically on DWTP sources, a nationwide survey of >250 drinking water sources was conducted between 2018-2020. Br- ion is the only bromine specie, whereas both inorganic (iodide and iodate ions) and organic iodine occur. I- concentrations ranged from 1-250 μg/L and are 4 to 100 times lower than Br- concentrations (10-7800 μg/L, median=80 μg/L). No strong correlation exists between bromide and iodide occurrence (R<0.5, p<0.005). I- was detected in 50% of the samples (75th percentile=5 μg/L) and IO3- was detected in 40% (75th percentile=3 μg/L) of all the samples. To quantify iodine species, tandem ion chromatography and inductively coupled plasma mass spectrometry was applied for the first time in drinking water sources. I- and IO3- peaks were well resolved and have minimum detection limit of 0.4 μg/L and 0.7 μg/L respectively. Organic iodine (Org-I) peaks in select drinking water samples from the nationwide survey were partically resolved ranging from <5 to 40 μg/L. This dissertation provides updated nationwide Br- survey and first ever national I species survey. The data generated through this dissertation will be useful to further Br-/I-DBP formation and toxicity research by providing relevant drinking water sources information. Future research targeting Br- and I- removal is advocated for managing Br-/I-DBPs in watersheds.
ContributorsSharma, Naushita (Author) / Westerhoff, Paul (Thesis advisor) / Karanfil, Tanju (Committee member) / Herckes, Pierre (Committee member) / Lackner, Klaus (Committee member) / Arizona State University (Publisher)
Created2021
Description
Trichloroethene (TCE) is a ubiquitous soil and groundwater contaminant. The most common bioremediation approach for TCE relies on the process of reductive dechlorination by Dehalococcoides mccartyi. D. mccartyi use TCE, dichloroethene, and vinyl chloride as electron acceptors and hydrogen as an electron donor. At contaminated sites, reductive dechlorination is typically promoted by adding a fermentable substrate, which is broken down to short chain fatty acids, simple alcohols, and hydrogen. This study explored microbial chain elongation (MCE), instead of fermentation, to promote TCE reductive dechlorination. In MCE, microbes use simple substrates (e.g., acetate, ethanol) to build medium chain fatty acids and also produce hydrogen during this process. Soil microcosm using TCE and acetate and ethanol as MCE substrates were established under anaerobic conditions. In soil microcosms with synthetic groundwater and natural groundwater, ethene was the main product from TCE reductive dechlorination and butyrate and hydrogen were the main products from MCE. Transfer microcosms using TCE and either acetate and ethanol, ethanol, or acetate were also established. The transfers with TCE and ethanol showed the faster rates of reductive dechlorination and produced more elongated products (i.e., hexanoate). The microbial groups enriched in the soil microcosms likely responsible for chain elongation were most similar to Clostridium genus. These investigations showed the potential for synergistic microbial chain elongation and reductive dechlorination of chlorinated ethenes.
ContributorsRobles, Aide (Author) / Delgado, Anca G. (Thesis advisor) / Torres, Cesar I. (Committee member) / van Paassen, Leon (Committee member) / Arizona State University (Publisher)
Created2019
Description
Petroleum contamination is ubiquitous during extraction, transportation, refining, and storage. Contamination damages the soil’s ecosystem function, reduces its aesthetics, and poses a potential threat to human beings. The overall goals of this dissertation are to advance understanding of the mechanisms behind ozonation of petroleum-contaminated soil and to configure an effective integrated bioremediation + ozonation remedial strategy to remove the overall organic carbon. Using a soil column, I conducted batch ozonation experiments for different soils and at different moisture levels. I measured multiple parameters: e.g., total petroleum hydrocarbons (TPH) and dissolved organic carbon (DOC), to build a full understanding of the data that led to the solid conclusions. I first demonstrated the feasibility of using ozone to attack heavy petroleum hydrocarbons in soil settings. I identified the physical and chemical hurdles (e.g., moisture, mass transfer, pH) needed to be overcome to make the integration of chemical oxidation and biodegradation more efficient and defines the mechanisms behind the experimental observations. Next, I completed a total carbon balance, which revealed that multiple components, including soil organic matter (SOM) and non-TPH petroleum, competed for ozone, although TPH was relatively more reactive. Further experiments showed that poor soil mixing and high soil-moisture content hindered mass transfer of ozone to react with the TPH. Finally, I pursued the theme of optimizing the integration of ozonation and biodegradation through a multi-stage strategy. I conducted multi-stages of ozonation and bioremediation for two benchmark soils with distinctly different oils to test if and how much ozonation enhanced biodegradation and vice versa. With pH and moisture optimized for each step, pre-ozonation versus post-ozonation was assessed for TPH removal and mineralization. Multi-cycle treatment was able to achieve the TPH regulatory standard when biodegradation alone could not. Ozonation did not directly enhance the biodegradation rate of TPH; instead, ozone converted TPH into DOC that was biodegraded and mineralized. The major take-home lesson from my studies is that multi-stage ozonation + biodegradation is a useful remediation tool for petroleum contamination in soil.
ContributorsChen, Tengfei (Author) / Rittmann, Bruce E. (Thesis advisor) / Westerhoff, Paul (Committee member) / Krajmalnik-Brown, Rosa (Committee member) / Delgado, Anca G (Committee member) / Arizona State University (Publisher)
Created2018
Description
Electrospinning is a means of fabricating micron-scale diameter fiber networks with enmeshed nanomaterials. Polymeric nanocomposites for water treatment require the manipulation of fiber morphology to expose nanomaterial surface area while anchoring the nanomaterials and maintaining fiber integrity; that is the overarching goal of this dissertation. The first investigation studied the effect of metal oxide nanomaterial loadings on electrospinning process parameters such as critical voltage, viscosity, fiber diameter, and nanomaterial distribution. Increases in nanomaterial loading below 5% (w/v) were not found to affect critical voltage or fiber diameter. Nanomaterial dispersion was conserved throughout the process. Arsenic adsorption tests determined that the fibers were non-porous. Next, the morphologies of fibers made with carbonaceous materials and the effect of final fiber assembly on adsorption kinetics of a model organic contaminant (phenanthrene, PNT) was investigated. Superfine powdered activated carbon (SPAC), C60 fullerenes, multi-walled carbon nanotubes, and graphene platelets were added to PS and electrospun. SPAC maintained its internal pore structure and created porous fibers which had 30% greater PNT sorption than PS alone and a sevenfold increase in surface area. Carbon-based nanomaterial-PS fibers were thicker but less capacious than neat polystyrene electrospun fibers. The surface areas of the carbonaceous nanomaterial-polystyrene composites decreased compared to neat PS, and PNT adsorption experiments yielded decreased capacity for two out of three carbonaceous nanomaterials. Finally, the morphology and arsenic adsorption capacity of a porous TiO2-PS porous fiber was investigated. Porous fiber was made using polyvinylpyrrolidone (PVP) as a porogen. PVP, PS, and TiO2 were co-spun and the PVP was subsequently eliminated, leaving behind a porous fiber morphology which increased the surface area of the fiber sevenfold and exposed the nanoscale TiO2 enmeshed inside the PS. TiO2-PS fibers had comparable arsenic adsorption performance to non-embedded TiO2 despite containing less TiO2 mass. The use of a sacrificial polymer as a porogen facilitates the creation of a fiber morphology which provides access points between the target pollutant in an aqueous matrix and the sorptive nanomaterials enmeshed inside the fiber while anchoring the nanomaterials, thus preventing release.
ContributorsHoogesteijn von Reitzenstein, Natalia Virginia (Author) / Westerhoff, Paul (Thesis advisor) / Hristovski, Kiril (Committee member) / Perreault, Francois (Committee member) / Herckes, Pierre (Committee member) / Arizona State University (Publisher)
Created2018
Description
Engineered nanoparticles (NPs) pose risk potentials, if they exist in water systems at significant concentrations and if they remain reactive to cause toxicity. Three goals guided this study: (1) establishing NP detecting methods with high sensitivity to tackle low concentration and small sizes, (2) achieving assays capable of measuring NP surface reactivity and identifying surface reaction mechanisms, and (3) understanding the impact of surface adsorption of ions on surface reactivity of NPs in water.
The size detection limit of single particle inductively coupled plasma spectrometry (spICP-MS) was determined for 40 elements, demonstrating the feasibility of spICP-MS to different NP species in water. The K-means Clustering Algorithm was used to process the spICP-MS signals, and achieved precise particle-noise differentiation and quantitative particle size resolution. A dry powder assay based on NP-catalyzed methylene blue (MB) reduction was developed to rapidly and sensitively detect metallic NPs in water by measuring their catalytic reactivity.
Four different wet-chemical-based NP surface reactivity assays were demonstrated: “borohydride reducing methylene blue (BHMB)”, “ferric reducing ability of nanoparticles (FRAN)”, “electron paramagnetic resonance detection of hydroxyl radical (EPR)”, and “UV-illuminated methylene blue degradation (UVMB)”. They gave different reactivity ranking among five NP species, because they targeted for different surface reactivity types (catalytic, redox and photo reactivity) via different reaction mechanisms. Kinetic modeling frameworks on the assay outcomes revealed two surface electron transfer schemes, namely the “sacrificial reducing” and the “electrode discharging”, and separated interfering side reactions from the intended surface reaction.
The application of NPs in chemical mechanical polishing (CMP) was investigated as an industrial case to understand NP surface transformation via adsorbing ions in water. Simulation of wastewater treatment showed CMP NPs were effectively removed (>90%) by lime softening at high pH and high calcium dosage, but 20-40% of them remained in water after biomass adsorption process. III/V ions (InIII, GaIII, and AsIII/V) derived from semiconductor materials showed adsorption potentials to common CMP NPs (SiO2, CeO2 and Al2O3), and a surface complexation model was developed to determine their intrinsic complexation constants for different NP species. The adsorption of AsIII and AsV ions onto CeO2 NPs mitigated the surface reactivity of CeO2 NPs suggested by the FRAN and EPR assays. The impact of the ion adsorption on the surface reactivity of CeO2 NPs was related to the redox state of Ce and As on the surface, but varied with ion species and surface reaction mechanisms.
The size detection limit of single particle inductively coupled plasma spectrometry (spICP-MS) was determined for 40 elements, demonstrating the feasibility of spICP-MS to different NP species in water. The K-means Clustering Algorithm was used to process the spICP-MS signals, and achieved precise particle-noise differentiation and quantitative particle size resolution. A dry powder assay based on NP-catalyzed methylene blue (MB) reduction was developed to rapidly and sensitively detect metallic NPs in water by measuring their catalytic reactivity.
Four different wet-chemical-based NP surface reactivity assays were demonstrated: “borohydride reducing methylene blue (BHMB)”, “ferric reducing ability of nanoparticles (FRAN)”, “electron paramagnetic resonance detection of hydroxyl radical (EPR)”, and “UV-illuminated methylene blue degradation (UVMB)”. They gave different reactivity ranking among five NP species, because they targeted for different surface reactivity types (catalytic, redox and photo reactivity) via different reaction mechanisms. Kinetic modeling frameworks on the assay outcomes revealed two surface electron transfer schemes, namely the “sacrificial reducing” and the “electrode discharging”, and separated interfering side reactions from the intended surface reaction.
The application of NPs in chemical mechanical polishing (CMP) was investigated as an industrial case to understand NP surface transformation via adsorbing ions in water. Simulation of wastewater treatment showed CMP NPs were effectively removed (>90%) by lime softening at high pH and high calcium dosage, but 20-40% of them remained in water after biomass adsorption process. III/V ions (InIII, GaIII, and AsIII/V) derived from semiconductor materials showed adsorption potentials to common CMP NPs (SiO2, CeO2 and Al2O3), and a surface complexation model was developed to determine their intrinsic complexation constants for different NP species. The adsorption of AsIII and AsV ions onto CeO2 NPs mitigated the surface reactivity of CeO2 NPs suggested by the FRAN and EPR assays. The impact of the ion adsorption on the surface reactivity of CeO2 NPs was related to the redox state of Ce and As on the surface, but varied with ion species and surface reaction mechanisms.
ContributorsBi, Xiangyu (Author) / Westerhoff, Paul K (Thesis advisor) / Rittmann, Bruce E. (Committee member) / Herckes, Pierre (Committee member) / Richert, Ranko (Committee member) / Arizona State University (Publisher)
Created2018