The knowledge of the dynamics of soil water is essential in agricultural, hydrological and environmental engineering as it controls plant growth, key hydrological processes, and the contamination of surface and subsurface water. Nearby remote sensing can be used for characterizing non-destructively the hydrogeophysical properties of the subsurface. In that respect, ground penetrating radar (GPR) constitutes a promising high resolution characterization tool. However, notwithstanding considerable research has been devoted to GPR, its use for assessing quantitatively the subsurface properties is constrained by the lack of appropriate GPR systems and signal analysis methods. In this study, a new integrated approach is developed to identify from GPR measurements the soil water content and hydraulic properties governing water transfer in the subsurface. It is based on hydrodynamic and electromagnetic inverse modeling. Research on GPR has focused on GPR design, forward modeling of GPR signal, and electromagnetic inversion to estimate simultaneously the depth dependent dielectric constant and electric conductivity of the shallow subsurface, which are correlated to water content and water quality. The method relies on an ultrawide band stepped frequency continuous wave radar combined with an off-ground monostatic TEM horn antenna. This radar configuration offers possibilities for real time mapping and allows for a more realistic forward modeling of the radar-antenna-subsurface system. Forward modeling is based on the exact solution of Maxwell's equations for a stratified medium. The forward model consists in elementary linear components which are linked in series and parallel. The GPR approach is validated for simple laboratory and outdoor conditions. GPR signal inversion enables the monitoring of the soil water dynamics, which can be subsequently inverted for estimating the soil hydraulic properties. A specifically designed hydrodynamic inverse modeling procedure which requires only water content data as input is further developed and validated to obtain the soil hydraulic properties under laboratory conditions.

The S shaped log log drawdown time curve typical of pumping tests in unconfined aquifers is reinvestigated via numerical experiments. We examine the temporal and spatial evolution of the rate of change in storage in an unconfined aquifer during pumping. This evolution is related to the transition of water release mechanisms from the expansion of water and compaction of the porous medium to the drainage of water from the unsaturated zone above the initial water table and initially saturated pores as the water table falls during the pumping of the aquifer. We conclude that the transition of the water release mechanisms and vertical flow are the cause of the S shaped drawdown time. Cross-correlation analysis is then employed to examine the relationship between hydraulic properties of an unconfined aquifer and pressure observations. The analysis reveals that head observed in the saturated zone at late times along a streamline is positively correlated with the conductivity (K(s)) of the region upstream of the observation location, and negatively correlated with the K(s) of the region downstream of the observation location along the same streamline. Besides, head observations in the saturated zone at the early time are positively correlated with specific storage (S(s)) in a narrow region between the observation and pumping locations. At intermediate and late times, the head positively correlates with the heterogeneity of α (pore-size distribution parameter) in a thin disk-shaped unsaturated region above the pumping and observation locations. Saturated water content θ(s) in the vadose zone directly above the pumping and monitoring locations is found positively correlated with the head observations during the intermediate times and late times.In the end, a stochastic inverse estimation is conducted to jointly interpret a sequential pumping test in a three dimensional unconfined aquifer. K(s), S(s), θ(s) and α are estimated at the same time. The estimated results capture the pattern of the heterogeneous parameters as well as the details with a smooth distribution. The estimated heterogeneous parameter fields produce better head predictions than the traditional homogeneous method.

Forward and inverse modeling studies of the relationship between tree ring width and bivariate climate are performed using a model called VS-Lite. The monthly time-step model incorporates two simple but realistic nonlinearities in its description of the transformation of climate variability into ring width index. These features ground VS-Lite in scientific principles and make it more complex than empirically-derived statistical models commonly used to simulate tree ring width. At the same time, VS-Lite is vastly simpler and more efficient than pre-existing numerical models that simulate detailed biological aspects of tree growth. A forward modeling validation study shows that VS-Lite simulates a set of observed chronologies across the continental United States with comparable or better skill than simulations derived from a standard, linear regression based approach. This extra skill derives from VS-Lite's basis in mechanistic principles, which makes it more robust than the statistical methodology to climatic nonstationarity. A Bayesian parameterization approach is also developed that incorporates scientific information into the choice of locally optimal VS-Lite parameters. The parameters derived using the scheme are found to be interpretable in terms of the climate controls on growth, and so provide a means to guide applications of the model across varying climatologies. The first reconstructions of paleoclimate that assimilate scientific understanding of the ring width formation process are performed using VS-Lite to link the proxy data to potential climate histories. Bayesian statistical methods invert VS-Lite conditional on a given dendrochronolgy to produce probabilistic estimates of local bivariate climate. Using VS-Lite in this manner produces skillful estimates, but does not present advantages compared another set of probabilistic reconstructions that invert a simpler, linear, empirical forward model. This result suggests that future data-assimilation based reconstructions will need to integrate as many data sources as possible, both across space and proxy types, in order to benefit from information provided by mechanistic models of proxy formation.

Modelos matemáticos são comumente utilizados no estudo da dinâmica da água no solo não-saturado. A principal equação para se quantificar esta dinâmica é a equação diferencial de Richards. Sua solução direta é impossível na maioria dos casos, necessitando de métodos numéricos, dos quais se destaca a utilização das funções de condutividade e de retenção de água de Van Genuchten - Mualem para obtenção da solução numérica. Diante disto, o objetivo deste trabalho foi apresentar um novo método para a obtenção dos parâmetros de Van Genuchten - Mualem, que utiliza a modelagem inversa de dados de teores de água medidos periodicamente e obtidos por experimento de evaporação assistido por atenuação de radiação gama, para a modelagem inversa foi utilizado o software Hydrus-1D. O método foi testado em amostras com diferentes texturas, colhidas em 11 localidades na região de Piracicaba-SP. Dos conjuntos de exemplares analisados, apenas um apresentou resultado insatisfatório, concluindo que o método é válido / Mathematical models are commonly used in studies of water dynamics in unsaturated soil. The main equation to quantify water the dynamics is the differential Richards equation. Its analytical solution is impossible in almost all cases, requiring numerical methods, among which the Van Genuchten - Mualem water conductivity and water retention functions are frequently used to obtain the numerical solution. The objective of this work is to present a new method to obtain the Van Genuchten - Mualem parameters, using the inverse modeling of water content data measured periodically by gamma radiation attenuation in evaporating samples. Hydrus-1D software was used for the inverse modeling. The method was tested in samples with different textures, collected in 11 locations in the region of Piracicaba, state of São Paulo, Brazil. Of the sets of samples analyzed, only one presented an unsatisfactory result, concluding that the method is valid

Uncertainty in the emission estimates is one the main reasons for shortcomings in the Chemistry Transport Models (CTMs) which can reduce the confidence level of impact assessment of anthropogenic activities on air quality and climate. This dissertation focuses on understating the uncertainties within the CTMs and reducing these uncertainties by improving emission estimates The first part of this dissertation focuses on reducing the uncertainties around the emission estimates from oil and Natural Gas (NG) operations by using various observations and high-resolution CTMs. To achieve this goal, we used Weather Research and Forecasting with Chemistry (WRF-Chem) model in conjunction with extensive measurements from two major field campaigns in Colorado. Ethane was used as the indicator of oil and NG emissions to explore the sensitivity of ethane to different physical parametrizations and simulation set-ups in the WRF-Chem model using the U.S. EPA National Emission Inventory (NEI-2011). The sensitivity analysis shows up to 57.3% variability in the modeled ethane normalized mean bias (NMB) across the simulations, which highlights the important role of model configurations on the model performance. Comparison between airborne measurements and the sensitivity simulations shows a model-measurement bias of ethane up to -15ppb (NMB of -80%) in regions close to oil and NG activities. Under-prediction of ethane concentration in all sensitivity runs suggests an actual under-estimation of the oil and NG emissions in the NEI-2011 in Colorado. To reduce the error in the emission inventory, we developed a three-dimensional variational inversion technique. Through this method, optimal scaling factors up to 6 for ethane emission rates were calculated. Overall, the inversion method estimated between 11% to 15% higher ethane emission rates in the Denver-Julesburg basin compared to the NEI-201. This method can be extended to constrain oil and NG emissions in other regions in the US using the available measurement datasets. The second part of the dissertation discusses the University of Iowa high-resolution chemical weather forecast framework using WRF-Chem designed for the Lake Michigan Ozone Study (LMOS-2017). LMOS field campaign took place during summer 2017 to address high ozone episodes in coastal communities surrounding Lake Michigan. The model performance for clouds, on-shore flows, and surface and aircraft sampled ozone and NOx concentrations found that the model successfully captured much of the observed synoptic variability of onshore flows. Selection of High-Resolution Rapid Refresh (HRRR) model as initial and boundary condition, and the Noah land surface model, significantly improved comparison of meteorology variables to both ground-based and aircraft data. Model consistently underestimated the daily maximum concentration of ozone. Emission sensitivity analysis suggests that increase in Hydrocarbon (HC). Variational inversion method and measurements by GeoTAS and TROPOMI instruments and airborne and ground-based measurements can be used to constrain NOx emissions in the region.

Processes that take place in the Earth’s mantle are not accessible to direct observation. Natural samples of mantle material that have been transported to the surface as xenoliths provide useful information on phase relations and compositions of phases at the pressure and temperature conditions of each rock fragment. In the past, considerable effort has been devoted by petrologists to investigate upper mantle processes experimentally. Results of high temperatures, high pressure experiments have provided insight into lower crust-upper mantle phase relations as a function of temperature, pressure and composition. However, the attainment of equilibrium in these experiments, especially in complex systems, may be very difficult to test rigorously. Furthermore, experimental results may also require extrapolation to different pressures, temperatures or bulk compositions. More recently, thermodynamic modeling has proved to be a very powerful approach to this problem, allowing the deciphering the physicochemical conditions at which mantle processes occur. On the other hand, a comprehensive thermodynamic model to investigate lower crust-upper mantle phase assemblages in complex systems does not exist. ¶ In this study, a new thermodynamic model to describe phase equilibria between silicate and/or oxide crystalline phases has been derived. For every solution phase the molar Gibbs free energy is given by the sum of contributions from the energy of the end-members, ideal mixing on sites, and excess site mixing terms. It is here argued that the end-member term of the Gibbs free energy for complex solid solution phases (e.g. pyroxene, spinel) has not previously been treated in the most appropriate manner. As an example, the correct expression of this term for a pyroxene solution in a general (Na-Ca-Mg-Fe2+-Al-Cr-Fe3+-Si-Ti) system is presented and the principle underlying its formulation for any complex solution phase is elucidated.¶ Based on the thermodynamic model an algorithm to compute lower crust-upper mantle phase equilibria for subsolidus mineral assemblages as a function of composition, temperature and pressure has been developed. Included in the algorithm is a new way to represent the total Gibbs free energy for any multi-phase complex system. At any given temperature and pressure a closed multi-phase system is at its equilibrium condition when the chemical composition of the phases present in the system and the number of moles of each are such that the Gibbs free energy of the system reaches its minimum value. From a mathematical point of view, the determination of equilibrium phase assemblages can, in short, be defined as a constrained minimization problem. To solve the Gibbs free energy minimization problem a ‘Feasible Iterate Sequential Quadratic Programming’ method (FSQP) is employed. The system’s Gibbs free energy is minimized under several different linear and non-linear constraints. The algorithm, coded as a highly flexible FORTRAN computer program (named ‘Gib’), has been set up, at the moment, to perform equilibrium calculations in NaO-CaO-MgO-FeO-Al2O3-Cr2O3-Fe2O3- SiO2-TiO2 systems. However, the program is designed in a way that any other oxide component could be easily added.¶ To accurately forward model phase equilibria compositions using ‘Gib’, a precise estimation of the thermodynamic data for mineral end-members and of the solution parameters that will be adopted in the computation is needed. As a result, the value of these parameters had to be derived/refined for every solution phase in the investigated systems. A computer program (called ‘GibInv’) has been set up, and its implementation is here described in detail, that allows the simultaneous refinement of any of the end-member and mixing parameters. Derivation of internally consistent thermodynamic data is obtained by making use of the Bayesian technique. The program, after being successfully tested in a synthetic case, is initially applied to pyroxene assemblages in the system CaO-MgO-FeO-Al2O3-SiO2 (i.e. CMFAS) and in its constituent subsystems. Preliminary results are presented.¶ The new thermodynamic model is then applied to assemblages of Ca-Mg-Fe olivines and to assemblages of coexisting pyroxenes (orthopyroxene, low Ca- and high Ca clinopyroxene; two or three depending on T-P-bulk composition conditions), in CMFAS system and subsystems. Olivine and pyroxene solid solution and end-member parameters are refined, in part using ‘GibInv’ and in part on a ‘trial and error’ basis, and, when necessary, new parameters are derived. Olivine/pyroxene phase relations within such systems and their subsystems are calculated over a wide range of temperatures and pressures and compare very favorably with experimental constraints.

Natural attenuation refers to the observed reduction in contaminant concentration via natural processes as contaminants migrate from the source into environmental media. Assessment of the dimensions of contaminant plumes and prediction of their fate requires predictions of the rate of dissolution of contaminants from residual non-aqueous-phase liquids (NAPLs) into the aquifer and the rate of contaminant removal through biodegradation. The available techniques to estimate these parameters do not characterize their confidence intervals by accounting for their relationships to uncertainty in source geometry and hydraulic conductivity distribution. The central idea in this thesis is to develop a flexible modeling approach for characterization of uncertainty in residual NAPL dissolution rate and first-order biodegradation rate by tailoring the estimation of these parameters to distributions of uncertainty in source size and hydraulic conductivity field. The first development in this thesis is related to a distance function approach that characterizes the uncertainty in the areal limits of the source zones. Implementation of the approach for a given monitoring well arrangement results in a unique uncertainty band that meets the requirements of unbiasedness and fairness of the calibrated probabilities. The second development in this thesis is related to a probabilistic model for characterization of uncertainty in the 3D localized distribution of residual NAPL in a real site. A categorical variable is defined based on the available CPT-UVIF data, while secondary data based on soil texture and groundwater table elevation are also incorporated into the model. A cross-validation study shows the importance of incorporation of secondary data in improving the prediction of contaminated and uncontaminated locations. The third development in this thesis is related to the implementation of a Monte Carlo type inverse modeling to develop a screening model used to characterize the confidence intervals in the NAPL dissolution rate and first-order biodegradation rate. The development of the model is based on sequential self-calibration approach, distance-function approach and a gradient-based optimization. It is shown that tailoring the estimation of the transport parameters to joint realizations of source geometry and transmissivity field can effectively reduce the uncertainties in the predicted state variables.

Crustal deformation can be the result of volcanic and tectonic activity such as fault dislocation and magma intrusion. The crustal deformation may precede and/or succeed the earthquake occurrence and eruption. Mitigating the associated hazard, continuous monitoring of the crustal deformation accordingly has become an important task for geo-observatories and fast response systems. Due to highly non-linear behavior of the crustal deformation fields in time and space, which are not always measurable using conventional geodetic methods (e.g., Leveling), innovative techniques of monitoring and analysis are required. In this thesis I describe novel methods to improve the ability for precise and accurate mapping the spatiotemporal surface deformation field using multi acquisitions of satellite radar data. Furthermore, to better understand the source of such spatiotemporal deformation fields, I present novel static and time dependent model inversion approaches. Almost any interferograms include areas where the signal decorrelates and is distorted by atmospheric delay. In this thesis I detail new analysis methods to reduce the limitations of conventional InSAR, by combining the benefits of advanced InSAR methods such as the permanent scatterer InSAR (PSI) and the small baseline subsets (SBAS) with a wavelet based data filtering scheme. This novel InSAR time series methodology is applied, for instance, to monitor the non-linear deformation processes at Hawaii Island. The radar phase change at Hawaii is found to be due to intrusions, eruptions, earthquakes and flank movement processes and superimposed by significant environmental artifacts (e.g., atmospheric). The deformation field, I obtained using the new InSAR analysis method, is in good agreement with continuous GPS data. This provides an accurate spatiotemporal deformation field at Hawaii, which allows time dependent source modeling. Conventional source modeling methods usually deal with static deformation field, while retrieving the dynamics of the source requires more sophisticated time dependent optimization approaches. This problem I address by combining Monte Carlo based optimization approaches with a Kalman Filter, which provides the model parameters of the deformation source consistent in time. I found there are numerous deformation sources at Hawaii Island which are spatiotemporally interacting, such as volcano inflation is associated to changes in the rifting behavior, and temporally linked to silent earthquakes. I applied these new methods to other tectonic and volcanic terrains, most of which revealing the importance of associated or coupled deformation sources. The findings are 1) the relation between deep and shallow hydrothermal and magmatic sources underneath the Campi Flegrei volcano, 2) gravity-driven deformation at Damavand volcano, 3) fault interaction associated with the 2010 Haiti earthquake, 4) independent block wise flank motion at the Hilina Fault system, Kilauea, and 5) interaction between salt diapir and the 2005 Qeshm earthquake in southern Iran. This thesis, written in cumulative form including 9 manuscripts published or under review in peer reviewed journals, improves the techniques for InSAR time series analysis and source modeling and shows the mutual dependence between adjacent deformation sources. These findings allow more realistic estimation of the hazard associated with complex volcanic and tectonic systems. / Oberflächendeformationen können eine Folge von vulkanischen und tektonischen Aktivitäten sein, wie etwa Plattenverschiebungen oder Magmaintrusion. Die Deformation der Erdkruste kann einem Erdbeben oder einem Vulkanausbruch vorausgehen und/oder folgen. Um damit drohende Gefahren für den Menschen zu verringern, ist die kontinuierliche Beobachtung von Krustendeformationen eine wichtige Aufgabe für Erdobservatorien und Fast-Responce-Systems geworden. Auf Grund des starken nicht-linearen Verhaltens von Oberflächendeformationsgebiet in Zeit und Raum, die mit konventionellen Methoden nicht immer erfasst werden (z.B., Nivellements), sind innovative Beobachtungs- und Analysetechniken erforderlich. In dieser Dissertation beschreibe ich Methoden, welche durch Mehrfachbeobachtungen der Erdoberfläche nit satellitengestützem Radar eine präzise und akkurate Abbildung der raumzeitlichen Oberflächendeformationen ermöglichen. Um die Bildung und Entwicklung von solchen raumzeitlichen Deformationsgebieten besser zu verstehen, zeige ich weiterhin neuartige Ansätze zur statischen und zeitabhängigen Modellinversion. Radar-Interferogramme weisen häufig Gebiete auf, in denen das Phasensignal dekorreliert und durch atmosphärische Laufzeitverzögerung verzerrt ist. In dieser Arbeit beschreibe ich wie Probleme des konventionellen InSAR überwunden werden können, indem fortgeschrittene InSAR-Methoden, wie das Permanent Scatterer InSAR (PSI) und Small Baseline Subsets (SBAS), mit einer Wavelet-basierten Datenfilterung verknüpft werden. Diese neuartige Analyse von InSAR Zeitreihen wird angewendet, um zum Beispiel nicht-lineare Deformationsprozesse auf Hawaii zu überwachen. Radar-Phasenänderungen, gemessen auf der Pazifikinsel, beruhen auf Magmaintrusion, Vulkaneruption, Erdbeben und Flankenbewegungsprozessen, welche durch signifikante Artefakte (z.B. atmosphärische) überlagert werden. Mit Hilfe der neuen InSAR-Analyse wurde ein Deformationsgebiet ermittelt, welches eine gute Übereinstimmung mit kontinuierlich gemessenen GPS-Daten aufweist. Auf der Grundlage eines solchen, mit hoher Genauigkeit gemessenen, raumzeitlichen Deformationsgebiets wird für Hawaii eine zeitabhängige Modellierung der Deformationsquelle ermöglicht. Konventionelle Methoden zur Modellierung von Deformationsquellen arbeiten normalerweise mit statischen Daten der Deformationsgebiete. Doch um die Dynamik einer Deformationsquelle zu untersuchen, sind hoch entwickelte zeitabhängige Optimierungsansätze notwendig. Dieses Problem bin ich durch eine Kombination von Monte-Carlo-basierten Optimierungsansätzen mit Kalman-Filtern angegangen, womit zeitlich konsistente Modellparameter der Deformationquelle gefunden werden. Ich fand auf der Insel Hawaii mehrere, raumzeitlich interagierende Deformationsquellen, etwa Vulkaninflation verknüpft mit Kluftbildungen und Veränderungen in bestehenden Klüften sowie zeitliche Korrelationen mit stillen Erdbeben. Ich wendete die neuen Methoden auf weitere tektonisch und vulkanisch aktive Gebiete an, wo häufig die eine Interaktion der Deformationsquellen nachgewiesen werden konnte und ihrer bedeutung untersucht wurde. Die untersuchten Gebiete und Deformationsquellen sind 1) tiefe und oberflächliche hydrothermale und magmatische Quellen unterhalb des Campi Flegrei Vulkans, 2) gravitationsbedingte Deformationen am Damawand Vulkan, 3) Störungsdynamik in Verbindung mit dem Haiti Beben im Jahr 2010, 4) unabhängige blockweise Flankenbewegung an der Hilina Störungszone, und 5) der Einfluss eines Salzdiapirs auf das Qeshm Erdbeben im Süd-Iran im Jahr 2005. Diese Dissertation, geschrieben als kumulative Arbeit von neun Manuskripten, welche entweder veröffentlicht oder derzeit in Begutachtung bei ‘peer-review’ Zeitschriften sind, technische Verbesserungen zur Analyse von InSAR Zeitreihen vor sowie zur Modellierung von Deformationsquellen. Sie zeigt die gegenseitige Beeinflussung von benachbarten Deformationsquellen, und sie ermöglicht, realistischere Einschätzungen von Naturgefahren, die von komplexen vulkanischen und tektonischen Systemen ausgehen.

Basic oxygen furnace (BOF) slag media were studied through a series of laboratory, modeling and field studies as a potential treatment material for use in on site wastewater disposal systems. Microsphere enumeration methodology was examined in a factorial experiment to evaluate the minimum density and minimum number of microspheres that should be counted to ensure accurate and precise estimations of concentration. The results suggest that to minimize variability at least 350 microspheres should be counted and a microsphere density of 25-40 microspheres field-1 is necessary. A review of existing methodologies for high-titer bacteriophage production was conducted and an amalgamation of existing methodologies was chosen that reliably achieves elevated concentration and ensures a purified suspension. A combination of batch and column studies was conducted to evaluate the removal of the bacteriophage, PRD-1, and virus-sized fluorescent microspheres by BOF media, and to delineate the relative contributions of the two principle attenuation processes, inactivation and attachment. In the batch studies, substantial removal of PRD-1 does not occur in the pH 7.6 and 9.5 suspensions, but at pH 11.4, removal of the virus was 2.1 log C/C0 day-1 for the first two days, followed by 0.124 log C/C0 day-1 over the subsequent 10 days. Two column studies were conducted after 60 and 300 days of saturation with artificial groundwater at a flow rate of 1 pore volume day-1 using two BOF mixtures. After 300 days of column saturation, microsphere concentrations approached input levels, indicating a removal of 0.1-0.2 log C/C0 and suggesting attachment processes were negligible. PRD-1 removal was more pronounced (1.0-1.5 log C/C0). The reduction of PRD-1 is likely the result of a combination of virus inactivation at elevated pH (10.6-11.4), and attachment processes. Geochemical factors controlling microsphere attachment were compared between the two sets of experiments after 60 and 300 days of column saturation. Differences in attachment efficiency may be due to higher influent DOC concentration in the second experiment, conversion of amorphous iron phases to more crystalline forms over time, reductive dissolution of preferable attachment sites on iron phases, or precipitation of calcite. Hydrus-1D, a one-dimensional numerical model, was used to quantify transport processes, inactivation and attachment/detachment, occurring in the column experiments by model inversion. Fitted microsphere breakthrough closely matched observed data, whereas PRD-1 breakthrough with realistic parameter values does not closely match the peaked nature of the observed curves. The model achieved improved fits for microsphere and PRD-1 breakthrough when both strongly- and weakly-binding sites are represented. A unique set of parameter estimates could not be determined because of overparameterization of the inverse modeling for the experimental systems. An alternative latrine incorporating BOF slag media was constructed in a periurban community located near São Paulo, Brazil. Pathogen indicator removal is approximately 4-5 orders of magnitude in less than one meter of vertical transport through the BOF slag media. In a control latrine, constructed with similar hydraulic characteristics and inert materials, comparable reductions in pathogenic indicators were observed over three meters of vertical transport.

Basic oxygen furnace (BOF) slag media were studied through a series of laboratory, modeling and field studies as a potential treatment material for use in on site wastewater disposal systems. Microsphere enumeration methodology was examined in a factorial experiment to evaluate the minimum density and minimum number of microspheres that should be counted to ensure accurate and precise estimations of concentration. The results suggest that to minimize variability at least 350 microspheres should be counted and a microsphere density of 25-40 microspheres field-1 is necessary. A review of existing methodologies for high-titer bacteriophage production was conducted and an amalgamation of existing methodologies was chosen that reliably achieves elevated concentration and ensures a purified suspension. A combination of batch and column studies was conducted to evaluate the removal of the bacteriophage, PRD-1, and virus-sized fluorescent microspheres by BOF media, and to delineate the relative contributions of the two principle attenuation processes, inactivation and attachment. In the batch studies, substantial removal of PRD-1 does not occur in the pH 7.6 and 9.5 suspensions, but at pH 11.4, removal of the virus was 2.1 log C/C0 day-1 for the first two days, followed by 0.124 log C/C0 day-1 over the subsequent 10 days. Two column studies were conducted after 60 and 300 days of saturation with artificial groundwater at a flow rate of 1 pore volume day-1 using two BOF mixtures. After 300 days of column saturation, microsphere concentrations approached input levels, indicating a removal of 0.1-0.2 log C/C0 and suggesting attachment processes were negligible. PRD-1 removal was more pronounced (1.0-1.5 log C/C0). The reduction of PRD-1 is likely the result of a combination of virus inactivation at elevated pH (10.6-11.4), and attachment processes. Geochemical factors controlling microsphere attachment were compared between the two sets of experiments after 60 and 300 days of column saturation. Differences in attachment efficiency may be due to higher influent DOC concentration in the second experiment, conversion of amorphous iron phases to more crystalline forms over time, reductive dissolution of preferable attachment sites on iron phases, or precipitation of calcite. Hydrus-1D, a one-dimensional numerical model, was used to quantify transport processes, inactivation and attachment/detachment, occurring in the column experiments by model inversion. Fitted microsphere breakthrough closely matched observed data, whereas PRD-1 breakthrough with realistic parameter values does not closely match the peaked nature of the observed curves. The model achieved improved fits for microsphere and PRD-1 breakthrough when both strongly- and weakly-binding sites are represented. A unique set of parameter estimates could not be determined because of overparameterization of the inverse modeling for the experimental systems. An alternative latrine incorporating BOF slag media was constructed in a periurban community located near São Paulo, Brazil. Pathogen indicator removal is approximately 4-5 orders of magnitude in less than one meter of vertical transport through the BOF slag media. In a control latrine, constructed with similar hydraulic characteristics and inert materials, comparable reductions in pathogenic indicators were observed over three meters of vertical transport.