Le non traitement et/ou le traitement inadéquat des eaux usées constitue l’une des causes principales de la pollution des ressources en eau. Pour y remédier il importe de mettre en place des infrastructures d’assainissement fonctionnelles et d’optimiser leur performance. Améliorer les stratégies de contrôle est l’action principale de cette optimisation, et la modélisation en est l’un des défis à relever. Pour ce faire, les présents travaux visent à fournir des connaissances spécifiques sur la variabilité des eaux usées urbaines de Cotonou et du Grand-Nancy et de disposer de données expérimentales qui serviront à court ou moyen termes au développement de modèle de génération d’eaux usées virtuelles. Les travaux ont consisté à échantillonner pendant plusieurs mois des eaux usées urbaines de temps sec en entrée de STEP (quartier vie-nouvelle à Cotonou et commune de Maxéville dans le Grand-Nancy) à travers des prélèvements horaires sur 24 h. A Cotonou, des prélèvements ont été aussi faits dans les collecteurs. In-situ ont été prises les mesures du débit. Au laboratoire sont faites sur les échantillons des analyses spécifiques de dosage des polluants. Une simulation des variabilités des eaux usées est également faite au moyen de modèle de génération des eaux usées virtuelles. Des travaux, il ressort les constats ci-après : - les débits en entrée de STEP (Grand-Nancy) présentent une variabilité journalière avec trois pics respectivement vers 10 h, 14 h et 21 h les jours ouvrés et caractérisée pendant les jours de week-end par une diminution de 2% (les samedis) et 9% (les dimanches) avec un retard de 2 h dans l’apparition du premier pic de la journée ; - les eaux usées de Cotonou présentent une plus forte pollution par rapport aux eaux usées urbaines du Grand-Nancy bien que l’Equivalent Habitant raccordé à La STEP de Cotonou (≈ 1 200 EH) soit de loin plus faible que celui du Grand-Nancy (≈ 275 000 EH) ; - néanmoins on note une plus forte conductivité électrique des eaux usées du Grand-Nancy ainsi qu’un excès en Europium plus élevé comparativement à ceux des eaux usées de Cotonou ; - la variabilité journalière pour l’ensemble des paramètres dans les bassins est très prononcée, exception faite pour le pH qui présente une similarité dans les deux contextes géographiques ; - le modèle de génération des eaux usées virtuelle en développement intègre bien le mode de vie du bassin de collecte du Grand-Nancy et a montré des simulations des variations du débit et de la pollution similaires aux variations expérimentales réelles ; - les recherches et le développement du modèle se poursuivent pour étendre ce dernier aux métaux lourds et l’appliquer aux bassins de collecte. Le modèle permet de combler des lacunes de données, de donner des fréquences plus élevées à la dynamique des données, de créer divers scénarii de perturbation de variabilité des eaux usées en situation virtuelle et de faire des prédictions de situations réelles pour une amélioration des performances des STEP / Untreated and / or inadequate treatment of wastewater is one of the main causes of water resource pollution. To remedy this it is important to establish functional sanitation infrastructure and optimize their performance. Improving control strategies is the main action of this optimization, and modeling is one of the challenges. To do this, the present work aims to provide specific knowledge on the variability of urban wastewater of Cotonou and Grand Nancy and to have experimental data to be used for short or medium term for the development of a generation model of virtual wastewater. The work consisted in sampling for several months the urban wastewater at the entrance of STEP (« Vie-Nouvelle » city in Cotonou and Maxéville in Grand-Nancy) through hourly samples over 24 hours. In Cotonou, samples were also taken from the collectors. In-situ were taken measurements of the flow. In the laboratory are made on samples specific analyses of pollutant dosing. Simulation of wastewater variability is also done using a virtual wastewater generation model. From the works, the following observations emerge: - flows from STEP (Grand-Nancy) show daily variability with three peaks respectively at around 10 am, 2 pm and 9 pm on weekdays and characterized on weekend days by a 2% decrease (Saturdays) and 9% (Sundays) with a delay of 2 hours in the appearance of the first peak of the day ; - Wastewater of Cotonou exhibit greater pollution than urban wastewater of Grand-Nancy although Population Equivalent connected to the STEP of Cotonou (≈ 1,200 PE) is far lower than that of Grand-Nancy (≈ 275,000 PE) ; - Nevertheless, there is a higher electrical conductivity of wastewater from Greater Nancy and a higher excess of Europium compared to that of Cotonou wastewater ; - The daily variability for all the parameters in the catchments is very pronounced, except for the pH which has a similarity in the two geographical contexts ; - the virtual wastewater generation model is well integrated with the lifestyle of the Grand-Nancy catchment basin and showed simulations of flow and pollution variations similar to actual experimental variations ; - research and model development is continuing to extend the model to heavy metals and apply it to collection basins ; The model allows to bridge data gaps, giving higher frequencies to dynamic data, create various wastewater variability distubance scenarios in virtual situation and make real situations predictions for improved performance of WWTP

The topic to Diploma Thesis is design of Biological Wastewater Treatment for 450 PE in Hvozd Commune (Region Olomoucký). First part is dedicated to description of multiple possible variants of design. In the following part is more detailed described chosen technology. Except from description of technology are also shown parameters calculations proposal. Some of the main reasons for preference of Biological Wastewater Treatment are low maintenance requirements, independence of energy supply or possibility of future sludge treatment. Foundational materials for the design were first, Local Zoning Plan which describes current and future drainage and wastewater disposal situation. Second, study aims at parameters calculations of French system. Project documentation is part and parcel of this thesis. Documentation will also be a basis for planning building permission.

PhD. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology. / Human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) causes morbidity and mortality in infected patients. These epidemics are significantly reduced and treated globally with antiretroviral drugs (ARVDs). However, the eventual disposal of the ARVDs, either by excretion or otherwise, enables them to end up as emerging hazardous contaminants in our environment. Of all the available methods to remove ARVDs from our water bodies, electrochemical methods are reckoned to be one of the most effective. As a result, it is imperative to acknowledge the interactive behavior of these pharmaceuticals on the surface of the electrode. In this study, iron nano-particles were deposited on the carbon cloth electrode by electrodeposition using chronoamperometry techniques. The synthesized electrode was characterized using scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and x-ray photoelectron spectroscopy (XPS) microanalysis. The electrochemical characterization of the material was also carried out using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrode's electrocatalytic activity toward the generation of hydrogen peroxide (H2O2) through a two-electron oxygen reduction reaction was assessed. Furtherance to this is the electrochemical degradation of nevirapine (NVP), lamivudine (LVD), and zidovudine (ZVD) in wastewater as a pharmaceutical model compound for organic pollutants in 50 mM K2SO4 electrolyte at a pH of 3. The SEM and EDX analysis showed the formation of iron nanoparticles within the matrix structure of the carbon cloth (CC) electrode. The XPS enlightened the presence of oxygen functional groups in the electrode's structure. EIS results are indicative that the modified electrode has a decreased charge transfer resistance (Rct)value as compared to the bare CC electrode. On the other hand, the CV result fosters good conductivity, enhanced current and large surface area of the modified electrode. More active and anchor sites were discovered on the iron-supported CC electrode which resulted in higher catalytic activity for the generation and accumulation of H2O2. The concentrations of “in-situ” generated H2O2 were found to be related to the current density supplied to the device after quantification. Although the accumulated H2O2 concentration appears to be low, it's possible that side reactions depleted the amount of H2O2 produced. As a result, the oxygen reduction reaction (ORR) through 2e- has a higher electrocatalytic activity with the improved iron assisted CC electrode than bare CC electrode. The electrochemical degradation studies conducted with the modified CC electrode by electro-Fenton process show a decrease in the initial ARVDs concentration (20 mg/L) as compared with the bare electrode. Their rate constants were 1.52 x 10-3 mol-1min-1 for ZVD, 1.20 x 10-3 mol-1min-1 for NVP and 1.18 x 10-3 mol-1min-1 for LVD. The obtained removal efficiencies indicate that the iron nanoparticle in the synthesised improves the degradation efficiency.

No description available.

Fecal shedding of SARS-CoV-2 leads to a renaissance of wastewater-based epidemiology (WBE) as additional tool to follow epidemiological trends in the catchment of treatment plants. As alternative to the most commonly used composite samples in surveillance programs, passive sampling is increasingly studied. However, the many sorbent materials in different reports hamper the comparison of results and a standardization of the approach is necessary. Here, we compared different cost-effective sorption materials (cheesecloths, gauze swabs, electronegative filters, glass wool, and tampons) in torpedo-style housings with composite samples. Despite a remarkable variability of the concentration of SARS-CoV-2-specific gene copies, analysis of parallel-deposited passive samplers in the sewer demonstrated highest rate of positive samples and highest number of copies by using cheesecloths. Using this sorption material, monitoring of wastewater of three small catchments in the City of Dresden resulted in a rate of positive samples of 50% in comparison with composite samples (98%). During the investigation period, incidence of reported cases of SARS-CoV-2 in the catchments ranged between 16 and 170 per 100,000 persons and showed no correlation with the measured concentrations of E gene in wastewater. In contrast, constantly higher numbers of gene copies in passive vs. composite samples were found for human adenovirus and crAssphage indicating strong differences of efficacy of methods concerning the species investigated. Influenza virus A and B were sporadically detected allowing no comparison of results. The study contributes to the further understanding of possibilities and limits of passive sampling approaches in WBE.

In wastewater management big variations in flowrates, caused by precipitation, leads to high peak loads forcing treatment facilities to maintain large over capacity. Wastewater management is a capital-intensive industry, meaning that new investments are costly and should therefore be avoided. But as peak load levels increase and stricter regulations are imposed it becomes increasingly hard to maintain sufficient reduction rates and facilities are likely to face new investments if the highest flowrates can’t be reduced. One way to reduce flowrates is to charge higher prices for the peak loads through an efficient tariff design. This thesis includes a literature review to define what constitutes an efficient tariff and then moves on to develop a model including marginal cost pricing and increasing block tariff design that examine how the marginal cost price is affected by constructing the tariff in different ways. The results show that the marginal price can be significantly increased by adapting this approach compared to a two part tariff with one fixed and one variable part which is commonly used by wastewater utilities today. The biggest deciding factor will be how the marginal block is defined.

Master of Science / Department of Civil Engineering / Natalie Mladenov / In the United States approximately 37% of the 4 trillion kWh of electricity is generated annually by combusting coal (USEPA, 2013). The abundance of coal, ease of storage, and transportation makes it affordable at a global scale (Ghose, 2009). However, the flue gas produced by combusting coal affects human health and the environment (USEPA, 2013). To comply with federal regulations coal-fired power plants have been implementing sulfur dioxide scrubbing systems such as flue gas desulfurization (FGD) systems (Alvarez-Ayuso et al., 2006). Although FGD systems have proven to reduce atmospheric emissions they create wastewater containing harmful pollutants. Constructed wetlands are increasingly being employed for the removal of these toxic trace elements from FGD wastewater. In this study the effectiveness of using a constructed wetland treatment system was explored as a possible remediation technology to treat FGD wastewater from a coal-fired power plant in Kansas. To simulate constructed wetlands, a continuous flow-through column experiment was conducted with undiluted FGD wastewater and surface sediment from a power plant in Kansas. To optimize the performance of a CWTS the following hypotheses were tested: 1) decreasing the flow rate improves the performance of the treatment wetlands due to an increase in reaction time, 2) the introduction of microbial cultures (inoculum) will increase the retention capacity of the columns since constructed wetlands improve water quality through biological process, 3) the introduction of a labile carbon source will improve the retention capacity of the columns since microorganisms require an electron donor to perform life functions such as cell maintenance and synthesis. Although the FGD wastewater collected possessed a negligible concentration of arsenic, the mobilization of arsenic has been observed in reducing sediments of wetland environments. Therefore, constructed wetlands may also represent an environment where the mobilization of arsenic is possible. This led us to test the following hypothesis: 4) Reducing environments will cause arsenic desorption and dissolution causing the mobilization of arsenic. As far as removal of the constituents of concern (arsenic, selenium, nitrate, and sulfate) in the column experiments, only sulfate removal increased as a result of decreasing the flow rate by half (1/2Q). In addition, sulfate-S exhibited greater removal as a result of adding organic carbon to the FGD solution when compared to the control (at 1/2Q). Moderate selenium removal was observed; over 60% of selenium in the influent was found to accumulate in the soil. By contrast, arsenic concentrations increased in the effluent of the 1/2Q columns, most likely by dissolution and release of sorbed arsenic. When compared to the control (at 1/2Q), arsenic dissolution decreased as a result of adding inoculum to the columns. Dissolved arsenic concentrations in the effluent of columns with FGD solution amended with organic carbon reached 168 mg/L. These results suggest that native Kansas soils placed in a constructed wetland configuration and amended with labile carbon do possess an environment where the mobilization of arsenic is possible.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Timothy D. Keane / All along the Gulf Coast, wetlands are disappearing due to saltwater intrusion from the draining of freshwater wetlands. Louisiana has about 40 percent of the coastal wetland in the lower 48 states but is currently losing approximately 24 square miles of wetlands a year (Louisiana Coastal 2009). Studies have shown that wetlands can help reduce the impact of a storm surge during a hurricane and have a cleansing ability from air to water. An increase in hurricane intensities due to climate change will likely result in bigger storm surges. Without wetlands to diffuse storm surges, disasters like Hurricane Katrina will recur. Cities spend millions of dollars on treating wastewater and stormwater with facilities and chemicals. Wetlands can treat wastewater through different processes without using chemicals, thus reducing costs and increasing sustainability. Bayou Bienvenue is a wetland located in New Orleans. This wetland was once a freshwater cypress swamp, but due to saltwater intrusion from the construction of Intracoastal Waterway and Mississippi River Gulf Outlet, has turned into a brackish lake. This wetland is separated from the Lower 9th Ward with a levee that creates a visual barrier which results in local residences not knowing that there is a former wetland behind the levee. Bayou Bienvenue’s Ecological Park’s discovery center with educational programs about successional wetland landscapes will educate people about the importance of wetlands to New Orleans. The restored of the bayou will be a landscape that functions as infrastructure through the treatment of stormwater and wastewater. The bayou will aid in reducing storm surge impacts, provide wildlife habitat, become part of schools’ curricula within the 9th Ward, stimulate the local economy and provide a community park for people to enjoy. Bayou Bienvenue’s Ecological Park will help spur further wetland projects of this caliber in and around New Orleans.

In recent decades, there has been a rapid expansion in the use of manufactured nanoparticles (MNPs). Experimental evidence and material flow models predict that MNPs enter wastewater treatment plants and partition to sewage sludge and majority of that sludge is land applied as biosolids. During wastewater treatment and after land application, MNPs undergo biogeochemical transformations (aging). The primary transformation process for silver MNPs (Ag-MNPs) is sulfidation, while zinc oxide MNPs (ZnO-MNPs) most likely undergo phosphatation and sulfidation. Our overall goal was to assess bioavailability and toxicogenomic impacts of both pristine, defined as-synthesized, and aged Ag- and ZnO-MNPs, as well as their respective ions, to a model organism, the soil nematode Caenorhabditis elegans. We first investigated the toxicity of pristine Ag-MNPs, sulfidized Ag-MNPs (sAg-MNPs), and AgNO3 to identify the most sensitive ecologically relevant endpoint in C. elegans. We identified reproduction as the most sensitive endpoint for all treatments with sAg-MNPs being about 10-fold less toxic than pristine Ag-MNPs. Using synchrotron x-ray microspectroscopy we demonstrated that AgNO3 and pristine Ag-MNPs had similar bioavailability while aged sAg-MNPs caused toxicity without being taken up by C. elegans. Comparisons of the genomic impacts of both MNPs revealed that Ag-MNPs and sAg-MNPs have transcriptomic profiles distinct from each other and from AgNO3. The toxicity mechanisms of sAg-MNPs are possibly associated with damaging effects to cuticle. We also investigated the effects pristine zinc oxide MNPs (ZnO-MNPs) and aged ZnO-MNPs, including phosphatated (pZnO-MNPs) and sulfidized (sZnO-MNPs), as well as ZnSO4 have on C. elegans using a toxicogenomic approach. Aging of ZnO-MNPs reduced toxicity nearly 10-fold. Toxicity of pristine ZnO-MNPs was similar to the toxicity caused by ZnSO4 but less than 30% of responding genes was shared between these two treatments. This suggests that some of the effects of pristine ZnO-MNPs are also particle-specific. The genomic results showed that based on Gene Ontology and induced biological pathways all MNP treatments shared more similarities than any MNP treatment did with ZnSO4. This dissertation demonstrates that the toxicity of Ag- and ZnO-MNPs to C. elegans is reduced and operates through different mechanisms after transformation during the wastewater treatment process.

The development of techniques for colloidal nanoparticle synthesis has allowed scientists to fabricate materials that can manipulate light on a scale that is small even compared to the wavelength of the light itself. This ability has led to the development of myriad and diverse applications of nanostructures in wide-ranging fields. This thesis focuses on the investigation and exploitation of nanoscale material properties in the fields of medicine and energy. The unique optical properties of nanoparticles arise from their size and their high surface area to volume ratios compared to bulk materials. As a result of this relationship, the surface characteristics of nanoparticles generally dominate their properties, whereas in bulk materials the surface atoms have very little bearing on the properties of the composite. Chapter 1 gives an introduction to nanoparticles and their optical properties, including a discussion of the plasmon resonance and the properties imbued upon nanoparticles possesing such a resonance as well as the applicability of these properties that will be explored in the subsequent chapters. Chapter 2 presents a study of the interaction of cationic, hydrophobic gold nanoparticles as probes to elucidate specific regions of interest on cell surfaces. The high imaging contrast of gold nanoparticles in electron microscopy allows for visual, macroscopic observation of the aggregation patterns formed by these nanoparticles on cell surfaces. Plasmon resonant coupling between proximal nanoparticles is exploited in order to monitor nanoprobe binding and localization over time with the use of extinction spectroscopy. The role of surface proteins in the nanoparticle-cell surface interaction is elucidated, generating composite data with relevance in pharmaceutical development and pharmacokinetics. Additionally, bacteria strain-dependent toxicity is observed and subsequently investigated for smaller gold nanoparticle probes, demonstrating a potential use for nanoparticles as strain-specific antibiotics. The development of affordable, effective antibiotic technology is one of the major scientific challenges of our time; infections from pathogen-infested drinking water alone account for millions of deaths each year worldwide. In Chapter 3, we investigate the use of titanium dioxide as an inexpensive method to harness solar energy to split water into reactive species and thereby decontamitate solutions of E. coli. Though titanium dioxide is an excellent catalyst for water splitting, it requires UV irradiation, which is fairly lacking in the solar emission spectrum. Further, recuperation of titanium dioxide nanoparticles from solution is non-trivial, and its immobilization into a film greatly limits its surface area and charge carrier efficiency, thereby limiting its activity. We treat both the poor visible light absorption capability as well as the surface area limitation in this study. CdS semiconductor nanocrystals are used to extend the absorption edge of TiO₂ further into the visible light region of the spectrum by providing for lower-energy photon absorption and charge injection into titanium dioxide. TiO₂ is also electrochemically anodized to generate TiO₂ nanotube arrays, which have greatly increased surface area as well as more efficient charge transfer properties compared to thin films of TiO₂ nanoparticles. The utility of nanoparticles in increasing the light absorption of other systems continues as a theme in the work presented in the next two chapters. Chapter 4 ex- amines the plasmonic enhancement of the solar energy conversion in a biomimetic system. In this endeavor, we enhance the photocurrent generated by a light-transducing, proton-pumping protein, bacteriorhodopsin, in a 3-dimensional wet electrochemical cell. First, we increase the overall charge carrier separation with the use of a proton- selective membrane in order to minimize ionic depolarization in the cell. We then use plasmonic nanoparticles to exploit an irregularity in the bacteriorhodopsin photocycle known as the blue light effect. This effect shortens the timescale of the photocyle by more than 99% via blue photon absorption, but it has a very low natural occurrence. Plasmonic nanoparticles tuned to the blue wavelength region increase the flux of blue photons on a local level and thereby increase the overall photocurrent generation. We first examine the importance of nanoparticle field strength to photocurrent enhancement using silver nanospheres with different capping shell thicknesses. We then consider the trade-off between (1) using a nanoparticle with a plasmon resonance tuned perfectly to the blue wavelength region and (2) using a nanoparticle with a stronger field intensity but weaker energetic presence in the blue. By minimizing ionic depolarization, minimizing shielding of the plasmon electromagnetic field, and maximizing the field strength while maintaining the plasmon frequency at the proper wavelength, we demonstrate an enhancement of 5,000-fold in the photocurrent production by bacteriorhodopsin. Chapter 5 explores a variation on the theme of Chapter 4 with an application in cancer therapeutics. Here, a photodynamic cancer drug, protoporphyrin IX (PpIX), is incorporated into complexes with silver nanospheres, gold nanospheres, and gold nanorods. Each of these nanoparticles displays a plasmon resonance in a different region of the spectrum, with consequent different overlap with the absorption or emission of the drug. Photodynamic therapeutic potential is measured in situ and in vivo, and the drug activity is shown to be strongest when drug absorption overlaps with plasmon resonance. Absorption by electronic excitations in the particle crystal lattice is shown to function as a competitive light filter and decrease drug activity. Additionally, the method of attachment of the drug to the nanoparticle is examined. Maximum enhancement of drug activity is shown to require the drug to remain bound close to the nanoparticle surface, where the electromagnetic field strength is highest. This plasmonic enhancement effect on drug activity is shown to outstrip the increase in drug activity seen when using the nanoparticle solely as a delivery platform. In Chapter 6, some synthetic techniques are presented for various nanomaterials. Included are syntheses for gold, silver, and semiconductor nanoparticles of a variety of shapes and sizes as well as for TiO₂ nanotube arrays. The relationship of the ratio of capping agent to metal salt is explored for gold nanospheres, and a method for facile tuning of the longitudinal plasmon resonance displayed by gold nanorods is presented. Synthetic techniques are also presented for the nanoparticles whose applications are explored in the preceding chapters.