No / Extracting waterborne contaminants to ozone-loaded Volasil¿245 (a siloxane solvent in which ozone is ten times more soluble than water) has been studied as a means of enhancing reaction kinetics and thus, providing more rapid wastewater decontamination. Investigation was carried out with respect to 2-chlorophenol and dichloromethane. Using a pilot scale continuous flow liquid¿liquid/ozone water treatment system, 2-chlorophenol was extracted to the ozone-loaded solvent phase and considerable extents of destruction were achieved. However, the approach was demonstrated to yield slightly less destruction than direct gas contact for the same utilization of ozone and enhanced reaction kinetics were not shown to occur. This was suggested to be due to increased interfacial mass transfer resistance and/or the promotion of less destructive reaction pathways. Modification of the existing pilot system, by conversion from co- to counter-current solvent-loading, enabled greater dissolved ozone concentrations to be achieved within the solvent. Increasing the counter-current exchange column height to not, vert, similar2.5 m was suggested for achieving a near optimum level of performance. The liquid¿liquid/ozone approach was demonstrated to be an effective means of indirectly exposing wastewater contaminants to concentrated ozone. As such the technology may be applicable as an alternative to direct gas contact in instances where the avoidance of contaminant sparging is desired (i.e. where contaminants are highly volatile, pungent and/or toxic) or foaming occurs

Yes / For the first time, an Euler-Lagrange model for Computational Fluid Dynamics (CFD) is used to model a full-scale gas-mixed anaerobic digester. The design and operation parameters of a digester from a wastewater treatment works are modelled, and mixing is assessed through a novel, multi-facetted approach consisting of the simultaneous analysis of (i) velocity, shear rate and viscosity flow patterns, (ii) domain characterization following the average shear rate value, and (iii) concentration of a non-diffusive scalar tracer. The influence of sludge’s non-Newtonian behaviour on flow patterns and its consequential impact on mixing quality were discussed for the first time. Recommendations to enhance mixing effectiveness are given: (i) a lower gas mixing input power can be used in the digester modelled within this work without a significant change in mixing quality, and (ii) biogas injection should be periodically switched between different nozzle series placed at different distances from the centre. / The first author is funded via a University of Birmingham Postgraduate Teaching Assistantship award.

As climate change exacerbates water scarcity and alters available water and fertilizer resources, it is vital that take appropriate measures to ensure sustainable treatment of water, wastewater, and other waste streams that are protective of public health and support recovery and reuse of water and nutrients. The overarching theme of this dissertation is the advancement of next-generation DNA sequencing (NGS) and computational tools for achieving these goals. A suite of relevant fecal and environmental opportunistic pathogens are examined using both culture-based and NGS-based methods. Of particular concern to this research was not only the attenuation and inactivation of pathogens, but also ensuring that optimal treatment approaches reduce antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). Key systems that were the focus of this effort included nutrient reuse (wastewater-derived biosolids and cattle-derived manure), water reuse, and drinking water systems disrupted by a major hurricane. A field study was carried out to survey a suite of pathogens from source-to tap in six small drinking water systems in Puerto Rico six months after Hurricane Maria. The study revealed that pathogenic Leptospira DNA was detected in all systems that were reliant on surface water. On the other hand, Salmonella spp. was detected in surface and groundwater sources and some distribution system waters both by culture and PCR. The study provided comparison of molecular-, microscopic-, and culture-based analysis for pathogen detection and highlighted the need for disaster preparedness for small water systems, including back-up power supply and access to chlorination as soon as possible after a natural disaster. A second field-study examined wastewater derived solids across an international transect of wastewater treatment plants in order to gain insight into the range of ARG concentrations encountered. It was found that, while total ARGs did not vary between treatment or continent of origin, clinically-relevant ARGs (i.e., ARGs encoding resistance to important classes of antibiotics used in humans) were significantly higher in solids derived from Asian wastewater treatment plants. Estimated loading rates of ARGs to soil under a scenario of land application were determined, highlighting in all cases that they are orders of magnitude higher than in the aqueous effluent. Livestock manure, derived from control cattle and cattle undergoing typical antibiotic treatment, and corresponding composts were also evaluated as common soil amendments in a separate study. In this study, the amendments were applied to two soil types in a greenhouse setting, in order to compare the resulting carriage of ARGs on a root (radish) versus leafy (lettuce) vegetable. Remarkably, radishes were found to harbor the highest relative abundance of total ARGs enumerated by metagenomics, even higher than corresponding soils or manures. Although the total microbial load will be lower on a harvested vegetable, the results suggest that the vegetable surface environment can differentially favor the survival of ARBs. The role of wastewater and water reuse treatment processes in reducing ARB and ARGs was also investigated at field-scale. Two independent wastewater treatment plants both substantially reduced total ARG relative and absolute abundance through biological treatment and settling according to metagenomic analysis. The subsequent water reuse treatment train of one system produced water for non- potable purposes and found further reduction in ARGs after chlorination, but a five hundred percent increase in the relative abundance of ARGs in the subsequent distribution system. In the second plant, which employed a membrane-free ozone-biologically-activated carbon-granular activated carbon treatment train for indirect potable reuse, there were notable increases in total ARG relative abundance following ozonation and chlorination. However, these numbers attenuated below background aquifer levels before recharge. Culture-based analysis of these systems targeting resistant ESKAPE pathogens (Escherichia coil, Staphylococcus aureus, Klebsiella spp., Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterococcus spp.) indicated similar trends as the metagenomic ARG analysis for both systems, but was challenged by sub-optimal media for wastewater samples and low confirmation rates, limiting statistical analysis. In order to advance the application of NGS, molecular, and associated bioinformatic tools for monitoring pathogens and antibiotic resistance in environmental systems, newly emerging methods and field standards for antibiotic resistance assessment were also evaluated. Hybrid assembly, the assembly for both short and long metagenomic sequencing reads, were assessed with an in silico framework in order to determine which available assemblers produced the most accurate and long contigs. Hybrid assembly was found to produce longer and more accurate assemblies at all coverages by reducing error as compared to short read assembly, though the outputs differed in composition from long read assembly. Where it is possible, it is beneficial to sequence using both long- and short-read NGS technologies and employ hybrid assembly, but further validation is recommended. Genome resolved metagenomics has also emerged as a strategy to recover individual bacterial genomes from the mixed metagenomic samples though this is often not well validated. In order to address this, genomes were assembled from reclaimed water systems and were compared against whole-genome sequences of antibiotic resistant E.coli isolates. Metagenome-derived genomes were found to produce similar profiles in wastewater treatment plant influents. A final theme to this dissertation addresses the need to standardize targets, methodologies, and reporting of antibiotic resistance in the environment. A systematic literature review was conducted on assays for the enumeration of key ARGs across aquatic environments and recommendations are summarized for the production of comparable data. In sum, this dissertation advances knowledge about the occurrence of pathogens, ARB, and ARGs across aquatic and agricultural systems and across several countries. Advances are made in the application of NGS tools for environmental monitoring of antibiotic resistance and other targets and a path forward is recommended for continued improvement as both DNA sequencing technologies and computational methodologies continue to rapidly advance. / Doctor of Philosophy / Understanding bacteria in our engineered systems is critical to ensuring drinking water, recycled water, and manure-derived soil amendments are safe for downstream applications. As novel approaches for assessing bacteria are developed, standardized methods and evaluations much be developed to ensure that sound conclusions are made that can appropriately inform policy and practice for the protection of public health. This dissertation focuses on combining bacterial culture and DNA sequencing methods for the study of pathogens (i.e., disease-causing organisms) and antibiotic resistance (i.e., ability of some bacteria to survive antibiotic treatments) in agricultural manure management, water reuse, and drinking water systems. Additionally, this work sought to advance emergent metagenomic analysis tools, which provides a new and potentially powerful pathogen and antibiotic resistance monitoring approach through direct extraction and sequencing of DNA from environmental samples. Antibiotic resistance is a global health challenge and it has been widely recognized that wastewater and agriculture are key control points. When antibiotics are ingested by people or livestock, they select for resistant bacteria in the gut. Mitigation efforts are needed, particularly at wastewater treatment plants and on farms, to ensure that excreted antibiotics and resistant bacteria do not further propagate and pose a risk. However, additional challenges such as climate change have spurred the need for more efficient use of our water and nutrient resources. In this work I examined how nutrient and water reuse treatment methods affect antibiotic resistant bacteria and antibiotic resistance genes using DNA sequencing as well as culture-based methods. In order to assess agricultural practices, a systems approach was conducted at the greenhouse scale to identify key control points to stem the spread of antibiotic resistance when vegetables are grown in soils amended with cattle-derived manure fertilizers. Along the food production chain, vegetables (i.e., radish and lettuce) were found to harbor higher proportions of bacteria carrying antibiotic resistance genes, although the estimated numbers of these bacteria were lower. Solids from an international transect of wastewater treatment plants (Sweden, Switzerland, USA, India, Hong Kong, Phillippenes) were examined because they are also foten used as soil amendments. DNA sequencing of these solids revealed that total measured antibiotic resistance genes did not vary between treatment or continent of origin. Calculations were made to determine the range of total hypothetical outputs of ARGs if the biosolids are land applied. Wastewater reuse systems were also examined using culture and metagenomic DNA analysis so that living pathogens could be compared alongside the total (dead and alive) antibiotic resistance genes. While standard wastewater and subsequent water reuse treatments were found to reduce the absolute numbers of antibiotic resistance genes and bacteria in a treatment plant producing water for non-potable reuse (i.e., irrigation), increases in culturable resistant pathogens and antibiotic resistance genes were apparent in the distribution system (i.e., in the pipes conveying treated water to the point of use). Similar reductions in antibiotic resistant bacteria and resistance genes were also seen in a plant using more advanced treatment (ozonation paired with biofiltration) to produce water suitable for indirect potable reuse via aquifer recharge, but there were indications that ozone and chlorine can increase the proportion of antibiotic resistant bacteria. Finally, genomes were recovered from the metagenomic sequencing analysis and were compared to sequenced culture isolates to validate the capabilities of metagenomic analysis to re-assemble genomes at the strain level, which is often required for pathogen confirmation. Pathogens were also assessed in disrupted drinking water systems in Puerto Rico after Hurricane Maria. Small scale systems that were disrupted by the storm were sampled to identify if pathogens were measurable six months after the hurricane. This work revealed that genes attributed to pathogenic Leptospira were detected in all surface water reliant systems while Salmonella spp. were detected by culture and DNA methods, but only in the source surface and groundwaters, not in the distribution systems delivering water to from the treatment site to the tap. This research also contributed to the advancement of big data analysis pipelines as well as to the standardization of methods to ensure that data produced across studies are comparable. Hybrid assembly, an emergent method that combines both short and long metagenomic DNA sequences generated by different technologies to more accurately recover genomes, was found to improve reliability and accuracy of algorithms aimed at reassembling DNA fragments. Antibiotic resistance is a global challenge, but without standardized methodologies for environmental monitoring, it will be difficult to compare measurements across countries and treatment processes in order to identify effective mitigation strategies. A critical literature review was conducted on assays for the enumeration of key antibiotic resistance genes across aquatic environments so that comparable data can be generated. This will be critical to tap into the tremendous volumes of antibiotic resistance monitoring data being generated around the globe to help identify trends and inform solutions. Collectively, this dissertation advances knowledge about the occurrence of pathogens, antibiotic resistant bacteria and antibiotic resistance genes across aquatic and agricultural systems while also critically evaluating emerging methods for the detection of antibiotic resistance in the environment.

Advanced pipeline risk management is contingent on accurately locating the buried pipelines, the milieu, and also the physical condition of the pipelines. The web-based and geospatially enabled tool presented in this thesis provides an improved way to assess the risks associated with the failure of water and wastewater pipelines. This thesis focuses on the development of a web-based and geospatially enabled tool and a network level risk model for the quantitative risk assessment of water and wastewater pipelines by taking into account the likelihood and consequence of pipeline failure. The parameters used in the risk model are evaluated by water and wastewater utility asset managers in the United States, and derived by GIS using advanced geospatial tools. A web-based and geospatially enabled proof of concept is developed as a tool for utilities to access the risk model results for the water and wastewater pipelines. An exclusive working environment will be provided for each utility with access to their respective data and risk model results. Also, this is a risk model for strategic infrastructure risk management, and it is to be used for asset allocation, financial planning, and determining condition assessment methods on a network level. / Master of Science

This research investigated the efficacy of chlorine dioxide (ClO₂), ultraviolet (UV) irradiation, UV in combination with chlorine dioxide (UV/ClO₂), and UV in combination with hydrogen peroxide (UV/H₂O₂) for decolorizing three reactive azo dyes (sultan red, indigo blue and cypress green) and treated textile-manufacturing wastewater. The objective was to determine the best treatment for reducing color to the Virginia Pollutant Discharge Elimination System (VPDES) permit level of 300 American Dye Manufacturers Institute (ADMI) units. The effects of the three chemical oxidation treatments provided color reduction for all three dyes. The results suggested UV/H₂O₂ and UV/ClO₂2 treatments provided maximum color reduction of the red and blue dyes, and UV/H₂O₂ was the most effective for maximum reduction of the green dye. A research goal was to provide predictive models of the wastewater effluent for the treatment processes, including the UV exposure time required to reach the 300 ADMI permit value and the effective ClO₂ dose necessary to achieve the 300 units. The results of the investigations regarding the effluent indicated that UV/H₂O₂ and UV/ClO₂ (5 mg/L) provided reduction to 300 units in less than 10 minutes UV exposure when the initial effluent color was less than 500 ADMI units. Without the addition of oxidant, contact times longer than 10 minutes were required for UV to decolorize these effluents to 300 ADMI units. Chlorine dioxide dosages between 10 and 30 mg/L both with and without UV irradiation achieved the same results. / Master of Science

Tesis por compendio / [EN] Anaerobic membrane bioreactors for urban wastewater treatment present interesting advantages when compared with aerobic treatments, such as less sludge production, lower energy demand and biogas generation. However, the generated effluent cannot generally be discharged without further ammonium and phosphate elimination. This thesis studies the removal of these inorganic nutrients by means of microalgae cultivation. The main objective of this work is therefore to obtain an autochthonous microalgal culture and to investigate its ability to grow on an already existing anaerobic effluent, as well as to research the extent to which ammonium and phosphate can be removed. Moreover, this thesis aims at providing the kinetic expressions which reproduce the main processes involved, in order to provide the basis for process simulation and design. Microalgae were isolated from a local wastewater treatment plant and their ability to grow on the anaerobic effluent -while successfully removing ammonium and phosphate- was demonstrated. An excellent water quality was obtained with a semicontinuous cultivation mode under constant illumination. The Scenedesmus and Chlorococcum genus proliferated more efficiently and thus became predominant in the culture. Results also showed that phosphorus was the limiting nutrient in the anaerobic effluent to be treated. The influence of phosphorus limitation on ammonium and phosphate removal, as well as the influence of temperature in ammonium removal, were then studied under laboratory conditions. Kinetic expressions which reproduce the observed effects were proposed and validated, taking also into account the effect of light intensity. Additionally, a Scenedesmus-dominated culture was grown under varying light and temperature in an outdoor flat-plate photobioreactor, with constant monitoring of light intensity, temperature and ammonium concentration. Acceptable results were obtained in the reproduction of the experimental data, albeit with less accuracy than under laboratory conditions. The work here presented demonstrates the feasibility of coupling a microalgal cultivation system to an anaerobic membrane bioreactor for urban wastewater treatment. The basic factors affecting microalgal nutrient removal are researched, and mathematical models are provided which reproduce these effects. This Ph.D. thesis is enclosed in a national research project funded by the Spanish Ministry of Economy and Competitiveness entitled "Estudio experimental de la recuperación como biogás de la energía de la materia orgánica y nutrientes del agua residual, acoplando un AnBRM y un cultivo de microalgas" (MINECO project CTM2011-28595-C02-01/02). This research was also supported by the Spanish Ministry of Education, Culture and Sport via a pre doctoral FPU fellowship to the author (AP2009-4903) / [ES] En el tratamiento de aguas residuales urbanas, los bioreactores anaerobios de membranas presentan ventajas interesantes frente a los tratamientos aerobios. Algunas de estas ventajas son la menor producción de fangos, un menor consumo energético y la producción de biogás. Sin embargo, y generalmente, el efluente obtenido no puede ser vertido al medio sin una etapa previa de eliminación de amonio y fosfato. La presente tesis estudia la eliminación de dichos nutrientes inorgánicos empleando para ello un cultivo de microalgas. El objetivo principal de este trabajo es, por tanto, la obtención de un cultivo autóctono de microalgas y la evaluación de la capacidad que éstas tienen tanto de crecer en un efluente anaerobio como de eliminar el amonio y el fosfato presentes. Asimismo, se pretenden proporcionar las bases para la simulación y el diseño del sistema de depuración propuesto, mediante la obtención de las expresiones cinéticas que reproducen los principales procesos involucrados. En primer lugar se ha demostrado la capacidad de las microalgas, aisladas en una estación depuradora de aguas residuales, de crecer en el efluente anaerobio y de eliminar con éxito el amonio y fosfato en éste presente. El agua tratada, obtenida a mediante un proceso semicontinuo y con iluminación constante, presenta una excelente calidad. Los géneros Scenedesmus y Chlorococcum han proliferado más eficientemente y han llegado a ser los predominantes en el cultivo. Los resultados obtenidos indican que el nutriente limitante en el efluente a tratar es el fósforo, y por tanto la influencia de la limitación de fósforo en la eliminación de nutrientes ha sido estudiada en condiciones de laboratorio, junto con la influencia de la temperatura en la velocidad de eliminación de amonio. Han sido propuestas y validadas las correspondientes expresiones cinéticas que reproducen los efectos observados, teniendo en cuenta en todo momento la influencia de la intensidad de la luz. Por otro lado, un cultivo de Scenedesmus ha sido cultivado en el exterior, bajo condiciones cambiantes de luz y temperatura, que a su vez han sido monitorizadas constantemente, junto con la concentración de amonio. Los datos obtenidos han sido reproducidos mediante modelación matemática con resultados aceptables, aunque la precisión obtenida es menor que en condiciones de laboratorio. La presente tesis demuestra la viabilidad de combinar un cultivo de microalgas con un bioreactor de membranas para el tratamiento de agua residual urbana. Se exponen asimismo los factores básicos que influyen en la velocidad de eliminación de nutrientes, y se presentan los modelos matemáticos necesarios para reproducir los efectos observados. La presente tesis doctoral se incluye en el marco de un proyecto nacional de investigación financiado por el Ministerio de Economía y Competitividad de título "Estudio experimental de la recuperación como biogás de la energía de la materia orgánica y nutrientes del agua residual, acoplando un AnBRM y un cultivo de microalgas" (CTM2011-28595-C02-01/02). La presente tesis doctoral ha sido también financiada por el Ministerio de Educación, Cultura y Deporte a través de una ayuda para contratos predoctorales de Formación del Profesorado Universitario (AP2009-4903). / [CA] En el tractament d'aigües residuals urbanes, els bioreactors anaerobis de membrana tenen avantatges interessants respecte als tractaments aerobis. Alguns d'aquests avantatges són: menys producció de fangs, menys consum energètic i la producció de biogàs. No obstant això, i en general, l'efluent obtingut no es pot tornar al medi sense una etapa prèvia d'eliminació d'amoni i fosfat. Aquesta tesi estudia l'eliminació d'aquests nutrients inorgànics emprant per a fer-ho un cultiu de microalgues. L'objectiu principal d'aquest treball és, per tant, l'obtenció d'un cultiu autòcton de microalgues i l'avaluació de la capacitat que aquestes tenen tant de créixer en un efluent anaerobi com d'eliminar l'amoni i el fosfat presents. Així mateix, volem proporcionar les bases per a la simulació i el disseny del sistema de depuració proposat, mitjançant l'obtenció de les expressions cinètiques que reprodueixen els principals processos involucrats. En primer lloc, s'ha demostrat la capacitat de les microalgues, aïllades en una estació depuradora d'aigües residuals, de créixer en l'efluent anaerobi i d'eliminar amb èxit l'amoni i el fosfat presents. L'aigua tractada, obtinguda mitjançant un procés semicontinu i amb il·luminació constant, presenta una qualitat excel·lent. Els gèneres Scenedesmus i Chlorococcum han proliferat més eficientment i han arribat a ser els predominants en el cultiu. Els resultats obtinguts indiquen que el nutrient limitant en l'efluent per tractar és el fòsfor, i per tant la influència de la limitació de fòsfor en l'eliminació tant d'amoni com de fosfat ha sigut estudiada en condicions de laboratori, juntament amb la influència de la temperatura en la velocitat d'eliminació d'amoni. S'han proposat i validat les expressions cinètiques corresponents que reprodueixen els efectes observats, tenint en compte en tot moment la influència de la intensitat de la llum. D'altra banda, s'ha cultivat a l'exterior un cultiu predominat per Scenedesmus, sota condicions canviants de llum i temperatura, que al seu torn s'han monitorat constantment, juntament amb la concentració d'amoni. Les dades obtingudes s'han reproduït mitjançant simulació matemàtica amb resultats acceptables, encara que la precisió obtinguda és més baixa que en condicions de laboratori. La nostra tesi demostra la viabilitat de combinar un cultiu de microalgues amb un bioreactor de membrana per al tractament d'aigua residual urbana. La tesi exposa així mateix els factors bàsics que influeixen en la velocitat d'eliminació de nutrients, i presenta els models matemàtics necessaris per a reproduir els efectes observats. Aquesta tesi doctoral s'inclou en el marc d'un projecte nacional de recerca finançat pel Ministeri d'Economia i Competitivitat amb el títol "Estudio experimental de la recuperación como biogás de la energía de la materia orgánica y nutrientes del agua residual, acoplando un AnBRM y un cultivo de microalgas" (CTM2011-28595-C02-01/02). La tesi doctoral ha sigut també finançada pel Ministeri d'Educació, Cultura i Esport a través d'una ajuda per a contractes predoctorals de formació del professorat universitari (AP2009-4903). / Ruiz Martínez, A. (2015). Nutrient removal from an anaerobic membrane bioreactor effluent using microalgae. Study and modeling of the process [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59409 / Compendio

Yes / This study investigated adsorption kinetics, adsorption equilibrium, and adsorption isotherm of three dyes [i.e., methylene blue (MB), rhodamine-B (RB), and safranin T (ST)] onto polyacrylonitrile (PAN) and ethanolamine (EA) grafted PAN nanofibers (NFs) membranes (EA-g-PAN). The membranes were characterized by field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR) spectroscopy, and Brunauer–Emmet–Teller (BET). FE-SEM showed a smooth morphology for the NFs before and after grafting, while FT-IR confirmed EA grafting into the nitrile group of PAN. The grafting percentage with no change in the physical nature of the membrane was 12.18%. The nitrogen adsorption–desorption isotherms for PAN and EA-g-PAN NFs membranes were similar and classified as a Type IV according to the International Union of Pure and Applied Chemistry. The surface area, pore-volume, and pore size of the EA-g-PAN increased to 21.36 m2 g−1, 0.16 cm3 g−1, and 304.93 Å, respectively. The pores were cylindrical mesopores with bimodal openings, which means that pores were open at both ends. The adsorption of the MB, RB, and ST dyes onto the PAN and EA-g-PAN NFs membranes leveled off at ~ 60 min. The adsorption kinetics showed good fitting to pseudo-second-order kinetic model and multi-step diffusion process. The order of the dye adsorption was PAN / the Deanship of Scientific Research, King Saud University [RG-1440-060]

Recovering valuable resources from wastewater will transform wastewater management from a treatment focused to sustainability focused strategy, and creates the need for new technology development. An innovative treatment concept - osmotic bioelectrochemical system (OsBES), which is based on cooperation between bioelectrochemical systems (BES) and forward osmosis (FO), has been introduced and studied in the past few years. An OsBES can accomplish simultaneous treatment of wastewater and recovery of resources such as nutrient, energy, and water (NEW). The cooperation can be accomplished in either an internal (osmotic microbial fuel cells, OsMFC) or external (microbial electrolysis cell-forward osmosis system, MEC-FO) configuration. In OsMFC, higher current generation than regular microbial fuel cell (MFC) was observed, resulting from the lower resistance of FO membrane. The electricity generation in OsMFC could greatly inhibit the reverse salt flux. Besides, ammonium removal was successfully demonstrated in OsMFC, making OsMFCs a promising technology for "NEW recovery" (NEW: nutrient, energy and water). For the external configuration of OsBES, an MEC-FO system was developed. The MEC produced an ammonium bicarbonate draw solute via recovering ammonia from synthetic organic solution, which was then applied in the FO for extracting water from the MEC anode effluent. The system has been advanced with treating landfill leachate. A mathematical model developed for ammonia removal/recovery in BES quantitatively confirmed that the NH4+ ions serve as effective proton shuttles across cation exchange membrane (CEM). / Ph. D. / Nowadays, wastewater is no longer considered as waste. Instead, it is a pool for different kinds of resources, such as nutrient, energy, and water (NEW). Various technologies were developed to achieve NEW recovery from wastewater. A novel concept, osmotic bioelectrochemical system (OsBES) has been introduced and studied in the past few years. OsBES is based on two technologies: bioelectrochemical systems (BES) and forward osmosis (FO); and the corporation between these two technologies could accomplish simultaneous wastewater treatment and resource recovery. We investigated two kinds of OsBES: one is osmotic microbial fuel cells (OsMFC), and the other is microbial electrolysis cell-forward osmosis system (MEC-FO). For OsMFC, a mathematical model was built to understand the internal resistance, which will affect the current generation according to Om’s law (I=U/R). The salt transport across the cation exchange membrane (CEM) is related to the current generation. The ion transport, especially ammonium/ammonia transport, across CEM membrane in BES was modelled, which will help the BES design and operation for ammonia recovery systems. The system performance for wastewater treatment and resource recovery in MEC-FO was fully investigated with both synthetic wastewater and landfill leachate. The results indicated that MEC-FO is a promising system for NEW recovery.

<p dir="ltr">This study investigates the optimization of nitrogen removal in wastewater treatment through a comparative analysis of conventional nitrification-denitrification (N/D) and partial nitritation-anammox (PN/A) processes integrated with anaerobic digestion (AD). Using Bio-Win 6.0 simulations, the research examined system performance across various operational conditions, including temperature ranges (15-35°C), dissolved oxygen levels (0.1-2.0 mg/L), and total Kjeldahl nitrogen concentrations (40-1000 mg/L). Results demonstrated that the PN/A-AD system achieved superior nitrogen removal efficiency (up to 97.5% at 100 mg/L TKN) compared to conventional N/D processes, particularly in treating high-strength nitrogen wastewater. The PN/A system maintained 54.3% removal efficiency even at 1000 mg/L TKN, while requiring less energy (4,614 kW versus 4,682 kW) and producing significantly less sludge (0.57 kg/kg versus 8.07 kg/kg nitrogen removed). Temperature significantly influenced system performance, with optimal conditions observed at 35°C and DO levels between 1-1.5 mg/L. Sensitivity analysis revealed system stability across multiple operational parameters, suggesting robust performance in realworld applications. This research provides valuable insights for designing and optimizing nitrogen removal processes in wastewater treatment plants, particularly for facilities targeting energy efficiency and reduced operational cost.</p>

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