Phosphorus (P) pollution of waterbodies is a global issue with detrimental environmental, social and economic impacts. Low-cost and sustainable P removal technologies are therefore required to tackle P pollution, whilst also offering a technique for reclaiming P. Ochre, a waste product from minewater treatment plants (MWTPs), has been proposed as a suitable material for the removal of P from enriched waters due to a high content of Fe, Al, Ca and Mg, which have high affinities for P removal. Whilst a range of studies have been conducted investigating ochre as a P adsorbent, most of these are large-scale field experiments and lack understanding of the underlying processes of P removal by ochre. There have also been very few detailed comparisons of different ochre types. The primary focus of this thesis is thus to provide a process-based understanding of P removal by various ochres, in order to investigate the optimal conditions for the use of ochres in the treatment of aquatic P pollution. Seven ochres from six MWTPs in the UK and Ireland were investigated, one of which was in a pelleted form. The ochres were largely comprised of Al, Ca, Fe and Mg (42-68 % by dry weight), had a high B.E.T. surface area, 56-243 m2 g-1, and contained mineral surfaces with a high affinity for P adsorption, such as goethite and calcite. A novel batch experiment methodology was utilised to calculate the adsorption characteristics of ochre at discrete pH conditions. The variation of these characteristics with pH indicates the importance and requirement for such a method to study adsorption by materials at the expected pH conditions of application. At the pH conditions of wastewater streams (~pH 7), the P adsorption capacities of the ochres, determined from fitting adsorption isotherms, was 11.8–43.1 mg P g-1. Results of P adsorption batch experiments were modelled in ORCHESTRA, wherein P removal by the ochres was described well by adsorption onto hydrous ferric oxides. Three of the ochres contain relatively high calcite contents and due to a poor fit of the model to the observed datasets at high pH conditions, with equilibrium P concentrations lower in the batch experiments than the modelled result, adsorption onto calcite is suggested as a P removal mechanism for these ochres at pH > 7. Environmental application of ochre filters will require P removal under flow-through transport conditions. Column experiments were therefore conducted using two ochres, coarse-grained Polkemmet ochre and Acomb pellets (column volume 1055 cm3, pore space 490-661 cm3, typical pore volumes of experiments: 220-400). P removal efficiency increased with contact time, and the presence of competing ions had only marginal effects on P removal. Resting the column substrate for 48 hours between P applications greatly increased the P removal efficiency of a packed column of Polkemmet ochre, resulting in 81 % of influent P removed over 1000 pore volumes of operation (7.68 mg P g-1). Acomb pellets had a lower P removal efficiency than Polkemmet ochre. It is suggested that the high calcium content of the pellets, as a result of the pelletisation process, has created a substrate where the dominant P removal mechanism at neutral pH conditions is adsorption to calcite, which has slower reaction kinetics than adsorption onto goethite. Therefore, this pelleted ochre requires a higher contact time for adsorption reactions to occur. It is suggested that ochre filters are most suitable for application in situations where flow rate is constant or can be controlled e.g. septic tank effluent. Ochres which dry to a coarse particle size are preferred for use as a substrate as pelletisation requires capital, expertise and can produce substrates with slower P sorption kinetics. Resting the filter substrate between P application regenerates surface sites for adsorption, and filters should be run in parallel to maximise P removal efficiency. Acomb pellets, which are a mix of iron hydroxides and alkaline materials, may have potential application as a permeable reactive barrier substrate to treat P enriched ground waters. Further research utilising fine-grained ochres as an additive to P rich fertilisers or for use in continuously stirred tank reactors is recommended.

The quality of worlds’ water resources is facing new challenges, for instance detectable concentration of various trace contaminants under the term micropollutants is discharging into water bodies from both municipal wastewater treatment plants and from on-site wastewater facilities. A project called RedMic aim at identifying and quantifying emissions of micropollutants from on-site wastewater treatments as a basis for providing innovative treatment technologies to reduce potential risks for groundwater and surface water contamination. This thesis work deals with two of the work packages in the RedMic project: a column experiment to test the capability of 10 adsorbents to remove micropollutants and a multi-criteria analysis is conducted to evaluate if a filter composed of granulated activated carbon (GAC) or ozonation can be used for on-site wastewater treatment facilities. Based on the removal efficiency of dissolved organic carbon (DOC) of selected adsorbents, two types of activated carbon reduced up to 90% DOC concentration in the effluents. Moreover, six other adsorbents also showed good removal efficiency with around 60% in the second sampling. However, the data used in this thesis was only from the initial part of the experiment that continued and the final results will be published elsewhere. Two system solutions were evaluated with multi-criteria analysis: sandbed filter with either GAC filtration (1) or with ozonation (2) System solution 1 was found to have advantage compared to system 2.

Tetrachloroethylene and its daughter-products represent a group of contaminations which are frequently found at sites with industrial activities, such as metal processing, electrotechnical and pharmaceutical industries as well as dry cleaning of clothing and the production of colours, paints and laquers. Due to their toxicity and persistence under natural conditions "denser-than-water" non aqueous phase liquids are substantial threats to the subsurface environment as well as the surface ecosystems including human beings. During the last two decades a number of technical solutions has been presented to enhance the situation of contaminated areas. One of the more recently established concepts are permeable reactive barriers. Permeable reactive barriers are passive in situ treatment zones containing a reactive material suitable to remove the contamination from the groundwater. They are installed downgradient from the pollution source perpendicular to the groundwater flow direction to immobilise or degrade the dissolved pollutants in the groundwater as it flows through. This project was organised in two main parts. The first part assessed seven different iron powders in batch experiments to determine the most efficient powder in terms of degradation velocity. The second part of the study employed this powder in a column experiment using different mixing ratios with sand to evaluate its performance under simulated subsurface conditions in a permeable reactive barrier. The aim of this experiment was to obtain a more detailed description of the behaviour and performance of the selected material. In the batch experiment the most promissing iron powder produced a half-life of tetrachloroethylene of 2.36 h. The column study demonstrated that cis-dichloroethylene has the longest half-life compared to tetrachlorethylene and trichloroethylene with 1.65 h. Having the longest half-life of all chloroethylenes included in this investigation the cis-dichloroethylene concentration will determine the dimensioning of a permeable barrier for remediation purposes.

Los modelos numéricos son herramientas fundamentales para realizar predicciones de muchos problemas enfrentados por ingenieros geotécnicos y geoambientales. Sin embargo, para que estos modelos puedan realizar predicciones confiables, los parámetros de entrada del modelo deben ser estimados considerando el efecto escala. En este contexto, esta tesis se concentra en las reglas del cambio de escala de los parámetros de flujo y transporte de masa en un suelo tropical a través de estudios numéricos, de laboratorio y de campo. Esta está organizada en cuatro partes. Primero, la heterogeneidad, correlación y correlación cruzada entre los parámetros de transporte de solutos (dispersividad, ¿, y coeficiente de partición, Kd) y las propiedades del suelo fueron estudiadas en detalle. En esta parte fue verificado que la conductividad hidráulica (K) y los parámetros de transporte de solutos son altamente heterogéneos, mientras que las propiedades del suelo no lo son. La correlación espacial de ¿ y K con variables estadísticamente significativas fue estudiada. Este resultado probablemente podrá mejorar la estimación en casos de estudios de pequeña escala debido a que solo fue observada correlaciones de hasta 2,5 m. Este estudio fue un primer intento de evaluar la variación espacial en el coeficiente de correlación de los parámetros de transporte de un soluto reactivo y de un no reactivo, indicando las variables más relevantes y aquella que debería ser incluida en estudios futuros. En la segunda parte, el efecto escala en K, dispersividad y coeficiente de partición de potasio y clorito fue estudiado experimentalmente a través de experimentos de laboratorio y de campo. El objetivo de esta parte fue contribuir a la discusión sobre el efecto escala en K, ¿ y Kd, y entender como estos parámetros se comportan con el cambio de escala de medición. La dispersividad tiende a aumentar con la altura de la muestra de manera exponencial. El coeficiente de partición tiende a aumentar con la altura, el diámetro y el volumen de la muestra. Estas diferencias encontradas en los parámetros de acuerdo con la escala de medición deben ser considerados cuando estos valores sean usados posteriormente como datos de entrada de modelos numéricos; de otra manera, las respuestas pueden ser malinterpretadas. Tercero, análisis estocásticos tridimensionales de cambio de escala de la conductividad hidráulica fueron realizados usando los métodos de promedios simples y de Laplace con piel para una variedad de tamaños de bloques usando mediciones reales de K. En esta parte son demostrados los errores que pueden ser introducidos al usar métodos determinísticos de cambio de escala usando promedios simples de las mediciones de K sin llevar en consideración la correlación espacial. La aplicación muestra que la heterogeneidad de K puede ser incorporada en la práctica diaria del modelador geotécnico. Los aspectos que considerar durante un proceso de cambio de escala también son discutidos. Finalmente, la dependencia del exponente de la norma-p como función del tamaño del bloque fue analizada. En la última parte, una aplicación de cambio de escala estocástico del coeficiente de dispersión hidrodinámica D y del factor de retardo R fue realizada usando datos reales con el objetivo de reducir la falta de casos de investigación experimental de cambio de escala de parámetros de transporte de solutos reactivos. El cambio de escala de D fue realizado usando el método de macrodispersión. El método de promedio simple de norma-p fue usado para realizar el cambio de escala de R. Una buena propagación de incertidumbres fue alcanzada. Métodos simples de cambio de escala pueden ser introducidos en la práctica del modelaje usando programas comerciales de transporte y conseguir reproducir el transporte en escala gruesa, pero puede requerir correcciones con el objetivo de reducir el efecto de suavizado de la heterogeneidad causado por el / Numerical models are becoming fundamental tools to predict a range of complex problems faced by geotechnical and geo-environmental engineers. However, to render the model reliable for future predictions, the model input parameters must be determined with consideration of the scale effects. In this context, this thesis focuses on upscaling of water flow and mass transport in a tropical soil by means of numerical, laboratory and field studies. This thesis is organized in four parts. First, the heterogeneity, correlation and cross-correlation between solute transport parameters (dispersivity, ¿, and partition coefficient, Kd) and soil properties were studied in detail. In this part, it was verified that the hydraulic conductivity (K) and solute transport parameters are highly heterogeneous, while soil properties not. Spatial correlation of ¿, K, and statistically significant variables were studied, and it would probably improve the estimation only in a small-scale study, since the spatial correlation were only observed up to 2.5 m. This study was a first attempt to evaluate the spatial variation in the correlation coefficient of transport parameters of a reactive and a nonreactive solute, indicating the more relevant variables and the one that should be included in future studies. In the second part, scale effect on K, dispersivity and partition coefficient of potassium and chloride is studied experimentally by means of laboratory and field experiments. The purpose of was to contribute to the discussion about scale effects on K, ¿ and Kd and understanding how these parameters behave with the change in the scale of measurement. Results shows that K increases with scale, regardless of the method of measurement. Dispersivity trends to increases exponentially with the sample height. Partition coefficient, tend to increase with sample length, diameter and volume. These differences in the parameters according to the scale of measurement must be considered when these observations are later used as input to numerical models, otherwise the responses can be misrepresented. Third, stochastic analysis of three-dimensional hydraulic conductivity upscaling was performed using a simple average and the Laplacian-with-skin methods for a variety of block sizes using real K measurements. In this part it was demonstrated the errors that can be introduced by using a deterministic upscaling using simple averages of the measured K without accounting for the spatial correlation. The application shows that K heterogeneity can be incorporated in the daily practice of the geotechnical modeler. The aspects to consider when performing the upscaling were also discussed. Finally, the dependence of the exponent of the p-norm as a function of the block size was analyzed. In the last part, an application of stochastic upscaling of hydrodynamic dispersion coefficient (D) and retardation factor (R) was performed using real data aiming to reduce the lack in experimental upscaling of reactive solute transport research. Upscaling of D was done using macrodispersion method. Simple average method based on p-norm was used to perform R upscaling. A good propagation of the uncertainties was achieved. Simple upscaling methods can be incorporated to the modeling practice using commercial transport codes and properly reproduce de transport at coarse scale but may require corrections to reduce smoothing of the heterogeneity caused by the upscaling procedure. / Els models numèrics s'estan constituint en eines fonamentals per a realitzar prediccions d'una àmplia gamma de problemes enfrontats per enginyers geotècnics i geoambientales. No obstant açò, perquè aquests models puguen realitzar prediccions fiables, els paràmetres d'entrada del model han de considerar l'efecte escala. En aquest context, aquesta tesi es concentra en les regles del canvi d'escala dels paràmetres de flux i transport de massa en un sòl tropical a través d'estudis numèrics, de laboratori i de camp. Aquesta tesi està organitzada en quatre parts. Primer, l'heterogeneïtat, correlació i correlació creuada entre els paràmetres de transport de soluts (dispersivitat, ¿, i coeficient de partició, Kd) i les propietats del sòl van ser estudiades detalladament. En aquesta part va ser verificat que la conductivitat hidràulica (K) i els paràmetres de transport de soluts són altament heterogenis, mentre que les propietats del sòl no ho són. La correlació espacial de ¿ i K amb variables estadísticament significatives va ser estudiada. Aquest resultat probablement podrà millorar l'estimació en casos d'estudis de xicoteta escala a causa que solament va ser observada correlacions de fins a 2,5 m. Aquest estudi va ser un primer intent d'avaluar la variació espacial en el coeficient de correlació dels paràmetres de transport d'un solut reactiu i d'un no reactiu, indicant les variables més rellevants i aquelles que haurien de ser inclosas en estudis futurs. En la segona part, l'efecte escala en K, dispersivitat i coeficient de partició de potassi i clorito va ser estudiat experimentalment a través d'experiments de laboratori i de camp. L'objectiu d'aquesta part va ser contribuir a la discussió sobre l'efecte escala en K, ¿ i Kd, i entendre com aquests paràmetres es comporten amb el canvi d'escala de mesurament. La dispersivitat tendeix a augmentar amb l'altura de la mostra, és a dir, amb la longitud del transport, de manera exponencial. El coeficient de partició tendeix a augmentar amb l'altura, el diàmetre i el volum de la mostra. Aquestes diferències en els paràmetres d'acord amb l'escala de mesurament han de ser considerats quan aquests valors siguen usats posteriorment com a dades d'entrada de models numèrics; d'una altra manera, les respostes poden ser malament interpretades. Tercer, anàlisis estocàstiques tridimensionals de canvi d'escala de la conductivitat hidràulica van ser realitzats usant els mètodes de mitjanes simples i de Laplace amb pell per a una varietat de grandàries de blocs usant mesuraments reals de K. En aquesta part són demostrats els errors que poden ser introduïts en usar mètodes determinístics de canvi d'escala usant mitjanes simples dels mesuraments de K sense tindre en consideració la correlació espacial. L'aplicació mostra que l'heterogeneïtat de K pot ser incorporada en la pràctica diària del modelador geotècnic. Els aspectes a considerar durant un procés de canvi d'escala també són discutits. Finalment, la dependència de l'exponent de la norma-p com a funció de la grandària del bloc va ser analitzada. En l'última part, una aplicació de canvi d'escala estocàstic del coeficient de dispersió hidrodinámica D i del factor de retard R va ser realitzada usant dades reals amb l'objectiu de reduir la falta de casos de recerca experimental de canvi d'escala de paràmetres de transport de soluts reactius. El canvi d'escala de D va ser realitzat usant el mètode de macrodispersió. El mètode de mitjana simple de norma-p va ser usat per a realitzar el canvi d'escala de R. Una bona propagació d'incerteses va ser aconseguida. Mètodes simples de canvi d'escala poden ser introduïts en la pràctica de la modelació usant programes comercials de transport i aconseguir reproduir el transport en escala gruixuda, però pot requerir correccions amb l'objectiu de reduir l'efecte de suavitzat de l'heterogeneïtat causat pel procés de canvi d'escala. / Almeida De Godoy, V. (2018). Upscaling of water flow and mass transport in a tropical soil: numerical, laboratory and field studies [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/102405

Eutrophication has long been an environmental problem and the effects from fertilizingarable land is a known source. The degree of phosphorus saturation (DPS)and easily soluble phosphorus (P) are different variables used in different countriesto try to predict the leaching of P from soils. The purpose of this master thesiswas to investigate what variable can be used as a predictor for leached P from soilsand to investigate what extent P leaching from the topsoil can be readsorbed inthe subsoil. The extraction method used for DPS was the Swedish standard lactateextraction and for easily soluble P were distilled water, CaCl2-solution and artificialrainwater with recipe from SMHI used. Three different soils in Sweden were used,two arable soils with different chemical properties and one forest soil. The soilswere filtered (2 mm) and put into columns since the texture was of interest ratherthan the structure. CaCl2-solution was used to saturate the samples and artificialrainwater was used for irrigation. The results showed that easily soluble P is areasonable indicator for leached P and that the subsoil affects the total leachingof P. However, no significant correlation was found between DPS and leached P,indicating that it may not be a suitable indicator of leaching. On the other hand,DPS can be seen as a reasonable indicator for easily soluble P since the correlationtest showed almost significant correlation. The results also showed that the electricconductivity in the leachate correlates to the leached P for the arable soils. For amore reliable result, more soils should be analyzed during more days.

Orientador: José Ricardo Sturaro / Banca: Paulo Milton Barbosa Landim / Banca: Adriana Cavalieri Sais / Resumo: A contaminação de solos por metais pesados constitui-se em um problema ambiental que, geralmente, produz riscos permanentes à saúde humana e aos sistemas ecológicos, portanto com freqüente necessidade de intervenção por meio de tecnologias de remediação. Uma de tecnologias alternativas para a remediação de solos contaminados com metais pesados é a lavagem de solos in situ, cujo processo de remoção de contaminantes do solo envolve a percolação de uma solução extratora. Este trabalho propõe o emprego da metodologia de superfície de resposta para ajustar um modelo que aponte combinações entre os parâmetros da solução extratora - concentração de etileno diaminotetraacético dissódico (Na2EDTA), volume e pH da solução extratora - que possibilitem reduzir a concentração de cobre de um solo arenoso, a níveis de risco inferiores aos valores de intervenção para os cenários de exposição adotados pela Companhia Ambiental do Estado de São Paulo. Para tanto, realizou-se uma série de ensaios de lixiviação em coluna utilizando-se um Neossolo Flúvico artificialmente contaminado (1257,3 mg kg-1). Os ensaios foram conduzidos em triplicata e configuraram um arranjo experimental do tipo planejamento composto central rotacional, composto por 15 diferentes combinações dos parâmetros da solução extratora e de uma replicata no ponto central. Os resultados obtidos mostraram que a metodologia de superfície de resposta possibilitou o ajuste de um modelo, que aponta combinações de concentração de Na2EDTA, volume e pH da solução extratora que permitem reduzir a concentração de cobre de um determinado Neossolo Flúvico a valores inferiores aos dispostos pela Companhia Ambiental do Estado de São Paulo, para os cenários de exposição industrial, residencial, agrícola ou de proteção máxima. / Abstract: The soil contamination by heavy metals is an environmental problem that usually produces permanent risk to human health and ecological systems that often need the intervention through remediation technologies. An alternative remediation technology for soils contaminated with heavy metals is the soil flushing, which the contaminant removing process involves the percolation of an extraction solution. This work proposes the use of response surface methodology to adjust a model that points out combinations among the parameters of the extraction solution -ethylenediaminetetraacetic disodium (Na2EDTA) concentration, volume e pH of extraction solution -to reduce the concentration of copper in a sandy soil to risk levels lower than the intervention levels for exposure scenarios adopted by Environmental Company of Sao Paulo State. Thus, a series of tests in leaching column was carried out using a Fluvisol artificially contaminated (1257,3 mg kg-1). The tests were conducted in triplicate and setup an experimental array of type central composite rotatable design, composed of 15 different combinations of the parameters of the extraction solution and one replicate in the center point. The results showed that the response surface methodology allowed the fit of a model that identifies combinations of Na2EDTA concentration, volume and pH of the extraction solution to reduce the concentration of copper in a Fluvisol to values lower than those adopted by Environmental Company of Sao Paulo State for the exposure scenarios, namely industrial, residential, agricultural or maximum protection. / Mestre

Phosphorous and nitrogen are vital elements for the well-being of biological life. Industrial discharges, waste water infiltration systems, conventional waste water collection and treatment systems, agricultural runoffs and landfill leachates had been emitting significant quantity of these nutrients into water bodies. These induced negative consequences to the environment including eutrophication of aquatic water bodies, toxicity to marine life and depletion of phosphate resources. Reactive filter technology is developed based on the need to remove and retain nutrients from waste water while improving the quality of effluents from emission sources. Reactive filter materials are used to build filter bed systems that treats domestic waste water, storm water, landfill leachates and contaminated subsurface water to the desired quality. In the past natural minerals such as zeolites and industrially produced polonite had been subject to laboratory study for the sorption of ammonium, heavy metals and phosphorous. The following paper is based on the results of experiment consisting of two columns packed with mordenite and polonite reactive materials filtering in series to reduce NH4 and PO4 content of a waste water. Septic tank effluent pre filtered using 0.45 μm filter is used as influent waste water into the dual columns. The dual column filtered a total of 24.07l s (372PV) and 23.42 ls (496PV) of the waste water. Sampling of the feed water and filtrates of both columns were done every second day with measurement of pH, conductivity and temperature. Analyzed samples confirmed that the dual column filtration resulted in re-moval efficiency of 84.39 % (PO4), 67.98 % (NH4) and -37.762.8 % (NOx). Filtration in the first (mordenite) column resulted in relatively larger proportion of the influent ammonium ion exchange than sorption of phosphate while the filtration in the second (polonite) column sorbed quite high amount of phosphorous than ammonium from effluent of the first column. Saturation of mordenite occurred faster even though there was sorption potential for few more of influent ammonium. All PO4 removal in mordenite column occurred above breakthrough condition. Polonite packed column was in a condition of a third of it’s saturation potential for PO4 removal at the end of the experiment. pH of samples was the parameter which is correlated significantly with filtration in polonite column than temperature and electrical conductivity. The performance of polonite was higher at higher pH than at lower pH. The mean concentrations of the dual column effluent were 0.77 mg-PO4/l and 11.13 mg-NH4/l. This is acceptable by the standards of environmental laws. The result of the experiment is valuable in prediction of performance and designing of real time filter bed.

Eutrophication due to excess loading of phosphorus (P) is a leading cause of water quality degradation within the United States. The aim of this study was to investigate P removal and recovery with 12 materials (four calcite varieties, wollastonite, dolomite, hydroxylapatite, eggshells, coral sands, biochar, and activated carbon. This was accomplished through a series of batch experiments with synthetic wastewater solutions ranging from 10-100 mg PO₄-P/ L. The results of this study were used to establish large-scale, calcite-based column filter experiments located in the Rubenstein School of Environment and Natural Resources' Eco-Machine. Influent and effluent wastewater samples were routinely collected for 64 days. Measures of filter performance included changes in pH, percent reduction and mass adsorbed of P. After the columns reached saturation, filter media was analyzed for the mineralogical content by X-ray powder diffraction (XRD). In the batch experiments, P removal and recovery varied among the media and across treatments. The best performing minerals were calcite, wollastonite, and hydroxylapatite. Eggshells, activated carbon, and coral sands also reduced and adsorbed P. The remaining materials had the lowest reductions and adsorption of P. Results from batch experiments informed the design of large column filters within the Rubenstein School of the Environment and Natural Resources' Eco-Machine. Removal and adsorption rates of P by the three column filters were similar. The columns achieved an average P reduction of 12.53% (se = 0.98) and an average P adsorption of 0.649 mg PO₄-P/ kg media (se = 0.03) over a 4-h hydraulic retention time. Paired T-tests showed that P reductions were statistically significant (p-value < 0.05) on the majority of sampling dates until the columns reached saturation. Saturation was reached after 31 days for two of the columns and 36 days for the third column. The filter media consistently buffered the pH of the wastewater to approximately 6.0-7.0 with no indication of diminishing buffer capacity after saturation. XRD analysis was not able to detect any P species within the crystalline structure of the filter media. This research contributes to the understanding of how the selected media perform during P removal and recovery programs, while providing information on the performance of large column filters operating within advanced, ecologically engineered wastewater treatment systems.

Made available in DSpace on 2014-06-11T19:26:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-09Bitstream added on 2014-06-13T19:13:05Z : No. of bitstreams: 1 goncalves_rh_me_rcla.pdf: 965679 bytes, checksum: c05e92494197dce7544dd639d4fa9e8c (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A contaminação de solos por metais pesados constitui-se em um problema ambiental que, geralmente, produz riscos permanentes à saúde humana e aos sistemas ecológicos, portanto com freqüente necessidade de intervenção por meio de tecnologias de remediação. Uma de tecnologias alternativas para a remediação de solos contaminados com metais pesados é a lavagem de solos in situ, cujo processo de remoção de contaminantes do solo envolve a percolação de uma solução extratora. Este trabalho propõe o emprego da metodologia de superfície de resposta para ajustar um modelo que aponte combinações entre os parâmetros da solução extratora – concentração de etileno diaminotetraacético dissódico (Na2EDTA), volume e pH da solução extratora – que possibilitem reduzir a concentração de cobre de um solo arenoso, a níveis de risco inferiores aos valores de intervenção para os cenários de exposição adotados pela Companhia Ambiental do Estado de São Paulo. Para tanto, realizou-se uma série de ensaios de lixiviação em coluna utilizando-se um Neossolo Flúvico artificialmente contaminado (1257,3 mg kg-1). Os ensaios foram conduzidos em triplicata e configuraram um arranjo experimental do tipo planejamento composto central rotacional, composto por 15 diferentes combinações dos parâmetros da solução extratora e de uma replicata no ponto central. Os resultados obtidos mostraram que a metodologia de superfície de resposta possibilitou o ajuste de um modelo, que aponta combinações de concentração de Na2EDTA, volume e pH da solução extratora que permitem reduzir a concentração de cobre de um determinado Neossolo Flúvico a valores inferiores aos dispostos pela Companhia Ambiental do Estado de São Paulo, para os cenários de exposição industrial, residencial, agrícola ou de proteção máxima. / The soil contamination by heavy metals is an environmental problem that usually produces permanent risk to human health and ecological systems that often need the intervention through remediation technologies. An alternative remediation technology for soils contaminated with heavy metals is the soil flushing, which the contaminant removing process involves the percolation of an extraction solution. This work proposes the use of response surface methodology to adjust a model that points out combinations among the parameters of the extraction solution –ethylenediaminetetraacetic disodium (Na2EDTA) concentration, volume e pH of extraction solution –to reduce the concentration of copper in a sandy soil to risk levels lower than the intervention levels for exposure scenarios adopted by Environmental Company of Sao Paulo State. Thus, a series of tests in leaching column was carried out using a Fluvisol artificially contaminated (1257,3 mg kg-1). The tests were conducted in triplicate and setup an experimental array of type central composite rotatable design, composed of 15 different combinations of the parameters of the extraction solution and one replicate in the center point. The results showed that the response surface methodology allowed the fit of a model that identifies combinations of Na2EDTA concentration, volume and pH of the extraction solution to reduce the concentration of copper in a Fluvisol to values lower than those adopted by Environmental Company of Sao Paulo State for the exposure scenarios, namely industrial, residential, agricultural or maximum protection.

The agricultural sector is one of the largest consumers of fresh water. With the ever-increasing problem of water scarcity, urbanization, over-population, and climate change, fresh water resources used by agriculture could be put to better use by redirecting it for drinking water purposes. In this context, many countries reuse treated urban waste water for irrigation, to overcome this problem. While this is a sustainable practice, the reuse of urban wastewater could facilitate the spread of pathogenic bacteria (or antibiotic resistant bacteria) in the subsoil region and consequently the groundwater. Since groundwater is one of the main sources of drinking water, the contaminants could pose a risk to human health. Furthermore, obtaining scientific data for emerging contaminants during water reuse is the need of the hour. The objective of this work is to build a mechanistic model that can aid in the development of large-scale risk assessment models; thus facilitating the setup of water reuse regulations for the relevant pathogenic organisms. In the present study, process based models were developed and evaluated using lab scale results. Then, the relative time scales of the processes are compared, and the relative importance of the various process studies are assessed. When assessing time scales of the processes, it is kept in mind that processes with relatively fast time scales can be approximated using equilibrium models, relatively slow processes can be neglected, and only the rate limiting processes can neither be neglected or further simplified in further model development. Therefore, an idea of the rate limiting processes assessed in lab scale can serve as important tools facilitating model simplification when evaluating larger scale models. A combined experimental and modelling approach has been used to study relevant transport and reactive processes during bacteria transport through sandy sediments. The mechanistic model contained transport processes which were implemented using the advective dispersive equation. An additional straining process was added using non-linear rate law. The biological processes of decay, respiration, attachment, and growth were expressed using linear rate laws. This mechanistic model was verified using data from fully water saturated, sediment packed lab-scale column experiments. Continuous injection of tracer, microspheres, and Enterococci (in water environments with and without dissolved oxygen and nutrients) was performed. The experiment was verified for three flow velocities (0.13, 0.08 and 0.02 cm/min), and the parameter values were compared for these flow velocities using dimensionless numbers. The linear rate coefficients were converted to a dimensionless form (Peclet and Damkoehler numbers respectively) to facilitate the comparison of processes across the various flow velocities. The results indicate that the processes of attachment and growth are flow dependent. Furthermore, in the presence of dissolved oxygen, attachment of bacteria to sediment was the most influential process. Sensitivity analysis showed that the parameters representing growth and respiration were influential, and care must be taken when using the results for field-scale experiments or models. These processes and parameters add new knowledge on the impact of urban wastewater reuse on the spread of pathogenic bacteria (especially resilient species like Enterococci), and emphasizes the importance of research in this area. Future work could focus on obtaining data from culture independent methods and extension of the model framework, and include (where necessary) non-linear rate laws. This will provide a critical pathway to developing a decision support framework for use by regulatory frameworks, policy makers, stakeholders, local and global environmental agencies, World Health Organization, or the United Nations.:List of Figures vii List of Tables xi List of Abbreviations xiii List of Symbols xv Summary xvii Zussamenfassung xix 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Broad Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Hypotheses and Research objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Outline of the work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Concepts, terminologies, and methodology 7 2.1 Concepts and terminologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.2 The vadose zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1.3 Porosity and pore models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1.4 Darcy’s law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Bacteria strain used and Processes Studied . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.1 Enterococcus faecalis JH2-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.2 Advection and Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2.3 Straining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2.4 Microbial Decay and Respiration . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2.5 Microbial Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.2.6 Microbial Growth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2.7 Dimensionless numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.3 Experimental design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.4 Model setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3 Reactive-transport modelling of Enterococcus faecalis JH2-2 passage through water saturated sediment columns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.2 Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.1 Experimental study. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.2 Modeling and data analysis procedure. . . . . . . . . . . . . . . . . . . . . . . . 40 3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.1 Determination of hydraulic and non-reactive transport parameters (experiments E1 and E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.2 Determination of parameters related to the bacteria transport (E3 series) . . . 45 3.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.1 Physical processes (E1 and E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.2 Biological Processes (E3 series) . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.5 Conclusions and Outlook. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 3.6 Supplementary material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 4 Determining the impact of flow velocities on reactive processes associated with Enterococcus faecalis JH2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 4.2 Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.2.1 Experimental setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.2.2 Model Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 4.3 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 4.3.1 Tracer and microsphere experiments. . . . . . . . . . . . . . . . . . . . . . . . . 74 4.3.2 Bacteria experiments - comparison of processes. . . . . . . . . . . . . . . . . . . 75 4.4 Conclusions and Future work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 4.5 Supplementary material 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 4.6 Supplementary Material 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 5 Synthesis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.1 Discussion and conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.2 Critical review, pathways towards future work . . . . . . . . . . . . . . . . . . . . . . . 91 Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Note on the commencement of the doctoral procedure. . . . . . . . . . . . . . . . . . . . 107 Übereinstimmungserklärung. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 List of Publications and conference presentations. . . . . . . . . . . . . . . . . . . . . . . . 111 Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 / Der Agrarsektor ist einer der größten Verbraucher von Süßwasser. Angesichts der zunehmenden Wasserknappheit, der Verstädterung, der Überbevölkerung und des Klimawandels könnten die von der Landwirtschaft genutzten Süßwasserressourcen besser genutzt werden, indem sie für Trinkwasserzwecke umgewidmet werden. In diesem Zusammenhang verwenden viele Länder aufbereitetes kommunales Abwasser für die Bewässerung, um dieses Problem zu lösen. Dies ist zwar eine nachhaltige Praxis, aber die Wiederverwendung von kommunalem Abwasser könnte die Ausbreitung pathogener Bakterien (oder antibiotikaresistenter Bakterien) im Untergrund und damit im Grundwasser fördern. Da das Grundwasser eine der Hauptquellen für Trinkwasser ist, könnten diese Schadstoffe eine Gefahr für die menschliche Gesundheit darstellen. Darüber hinaus ist es ein Gebot der Stunde, wissenschaftliche Daten über neu auftretende Verunreinigungen bei der Wasserwiederverwendung zu gewinnen. Ziel dieser Arbeit ist es, ein mechanistisches Modell zu erstellen, das bei der Entwicklung groß angelegter Risikobewertungsmodelle behilflich sein kann und somit die Aufstellung von Vorschriften für die Wiederverwendung von Wasser für die relevanten pathogenen Organismen erleichtert. In der vorliegenden Studie wurden prozessbasierte Modelle entwickelt und anhand von Ergebnissen im Labormaßstab bewertet. Anschließend werden die relativen Zeitskalen der Prozesse verglichen und die relative Bedeutung der verschiedenen Prozessstudien bewertet. Bei der Bewertung der Zeitskalen der Prozesse wird berücksichtigt, dass Prozesse mit relativ schnellen Zeitskalen durch Gleichgewichtsmodelle angenähert werden können, relativ langsame Prozesse können vernachlässigt werden, und nur die ratenbegrenzenden Prozesse dürfen in der weiteren Modellentwicklung weder vernachlässigt noch vereinfacht werden. Daher kann eine Vorstellung von den ratenbegrenzenden Prozessen, die im Labormaßstab bewertet werden, als wichtiges Instrument zur Vereinfachung des Modells bei der Bewertung von Modellen in größerem Maßstab dienen. Ein kombinierter experimenteller und modellierender Ansatz wurde verwendet, um relevante Transport- und reaktive Prozesse während des Bakterientransports durch sandige Sedimente zu untersuchen. Das mechanistische Modell enthielt Transportprozesse, die mit Hilfe der Advektions-Dispersions-Gleichung implementiert wurden. Ein zusätzlicher Filtrationsprozess ('straining') wurde mit Hilfe nichtlinearer Ratengesetze hinzugefügt. Die biologischen Prozesse des Zerfalls, der Atmung, der Anhaftung und des Wachstums wurden durch lineare Ratengesetze ausgedrückt. Dieses mechanistische Modell wurde anhand von Daten aus vollständig wassergesättigten, sedimentgefüllten Säulenexperimenten im Labormaßstab verifiziert. Kontinuierliche Injektion von Tracer, Mikrosphären und Enterokokken (in Wasserumgebungen mit und ohne gelösten Sauerstoff und Nährstoffe) wurde durchgeführt. Das Experiment wurde für drei Strömungsgeschwindigkeiten (0,13, 0,08 und 0,02 cm/min) verifiziert, und die Parameterwerte wurden für diese Strömungsgeschwindigkeiten anhand dimensionsloser Zahlen verglichen. Die linearen Ratengesetze wurden in eine dimensionslose Form umgewandelt (Peclet- bzw. Damköhler-Zahlen), um den Vergleich der Prozesse bei den verschiedenen Strömungsgeschwindigkeiten zu erleichtern. Die Konzentrationen wurden in regelmäßigen Abständen sowohl am Einlass als auch am Auslass der Kolonnen gemessen. Die überprüften Prozesse waren Advektion, Dispersion, Filtration, Zerfall, Atmung, Wachstum und Anhaftung. Der Versuch wurde für drei Strömungsgeschwindigkeiten (0,13, 0,08 und 0,02 cm/min) wiederholt, und die verifizierten Parameterwerte wurden für diese Strömungsgeschwindigkeiten verglichen. Die Ergebnisse zeigen, dass die Prozesse der Anhaftung und des Wachstums strömungsabhängig sind. Darüber hinaus war bei Vorhandensein von gelöstem Sauerstoff die Anhaftung der Bakterien an das Sediment der einflussreichste Prozess. Die Sensitivitätsanalyse zeigte, dass die Parameter, die das Wachstum und die Atmung repräsentieren, einflussreich sind, so dass bei der Verwendung der Ergebnisse für Experimente oder Modelle im Feldmaßstab Vorsicht geboten ist. Diese Prozesse und Parameter liefern neue Erkenntnisse über die Auswirkungen der Wiederverwendung von kommunalem Abwasser auf die Ausbreitung pathogener Bakterien (insbesondere widerstandsfähiger Arten wie Enterokokken) und unterstreichen die Bedeutung der Forschung in diesem Bereich. Zukünftige Arbeiten könnten sich auf die Gewinnung von Daten aus kulturunabhängigen Methoden und die Erweiterung des Modellrahmens konzentrieren und (wo nötig) nichtlineare Parameter einbeziehen. Dies wird einen entscheidenden Weg zur Entwicklung eines Rahmens für die Entscheidungsfindung darstellen, der von Regulierungsbehörden, politischen Entscheidungsträgern, Interessengruppen sowie lokalen und globalen Umweltbehörden, der Weltgesundheitsorganisation oder den Vereinten Nationen genutzt werden kann.:List of Figures vii List of Tables xi List of Abbreviations xiii List of Symbols xv Summary xvii Zussamenfassung xix 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Broad Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Hypotheses and Research objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Outline of the work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Concepts, terminologies, and methodology 7 2.1 Concepts and terminologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.2 The vadose zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1.3 Porosity and pore models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1.4 Darcy’s law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Bacteria strain used and Processes Studied . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.1 Enterococcus faecalis JH2-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.2 Advection and Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2.3 Straining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2.4 Microbial Decay and Respiration . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2.5 Microbial Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.2.6 Microbial Growth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2.7 Dimensionless numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.3 Experimental design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.4 Model setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3 Reactive-transport modelling of Enterococcus faecalis JH2-2 passage through water saturated sediment columns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.2 Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.1 Experimental study. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.2 Modeling and data analysis procedure. . . . . . . . . . . . . . . . . . . . . . . . 40 3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.1 Determination of hydraulic and non-reactive transport parameters (experiments E1 and E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.2 Determination of parameters related to the bacteria transport (E3 series) . . . 45 3.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.1 Physical processes (E1 and E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.2 Biological Processes (E3 series) . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.5 Conclusions and Outlook. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 3.6 Supplementary material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 4 Determining the impact of flow velocities on reactive processes associated with Enterococcus faecalis JH2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 4.2 Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.2.1 Experimental setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.2.2 Model Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 4.3 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 4.3.1 Tracer and microsphere experiments. . . . . . . . . . . . . . . . . . . . . . . . . 74 4.3.2 Bacteria experiments - comparison of processes. . . . . . . . . . . . . . . . . . . 75 4.4 Conclusions and Future work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 4.5 Supplementary material 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 4.6 Supplementary Material 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 5 Synthesis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.1 Discussion and conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.2 Critical review, pathways towards future work . . . . . . . . . . . . . . . . . . . . . . . 91 Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Note on the commencement of the doctoral procedure. . . . . . . . . . . . . . . . . . . . 107 Übereinstimmungserklärung. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 List of Publications and conference presentations. . . . . . . . . . . . . . . . . . . . . . . . 111 Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115