"Creative Thinking about the future requires tension -- the tension of holding both the need and the possible in our awareness at the same time." Milenko Matanovic Constructing concrete open channels can provide a quick, efficient solution to help prevent an area from flash floods and water accumulation. However, such a solution does not take into consideration the increased land needs for housing and public open spaces, in addition to missing the opportunity for benefitting from rainwater and reusing the municipal water of cities in greening sustainable stormwater channels. The United Nations (2014) reported that 54% of the world's population is living in urban areas, and it is predicted to increase to 66% by 2050. Jeddah City, Saudi Arabia already struggles from both lack of open spaces while consuming spaces in constructing concrete open channels, only made worse by the rapid growth of population and urbanism. Although the rate of precipitation in arid regions is low, studies and evidence show that even in arid regions turning the majority of urban areas into impervious surfaces is restrictive and the result of doing so is devastating. This thesis aims to find an environmental alternative solution for an open drainage channel designed to function as a stormwater management facility as well as a central green finger for Jeddah City. It will take into consideration international and regional precedent design and future development of green channel case studies, to provide efficient design recommendations to planners and designers, who aim to redevelop constructed or proposed stormwater channels using sustainable green infrastructure practices to improve a city's livability. / Master of Landscape Architecture

Wastewaters that are produced by industrial processes are more challenging to treat than municipal wastewaters, primarily due to two reasons. Firstly, industrial wastewaters contain high concentrations of several different contaminants (e.g. metals, nutrients and organics etc.), which can be challenging for a single process to treat. Secondly, the compositional properties of the wastewaters can vary significantly as it is dependent on several upstream processes. Commercial membrane technologies have shown significant adoption in desalination and municipal wastewater treatment applications. Their favourable selectivity and tunable properties have garnered interest from both academia and industry to push these technologies into industrial wastewater treatment. Despite showing promising contaminant removal results, current studies have shown that fouling due to high contaminant loadings, and variable treatment efficacies due to feed property variations, limit the adoption of commercial membranes into these applications. Current research addresses these challenges through the new material development or surface modifications, however, there is a need to approach these challenges at a process level by integrating existing membrane technology into adaptive processes. This thesis aims to advance the adoption of commercial membrane technology into ‘tough-to-treat’ industrial wastewater applications. Firstly, the effects of high contaminant concentrations and variable feed properties on membrane treatment is studied by using advanced techniques, such as gas chromatography – mass spectrometry, to resolve the composition of feed and permeate streams from membrane processes treating real wastewaters. It was determined that fast and efficient screening tools are required to optimize and adapt membrane processes to respond to this variability. This thesis then introduces high-throughput and miniaturized screening platform that combines analytical centrifugation with filter plate technology to rapidly optimize two-stage coagulation-filtration processes with an extremely low material and time requirement. / Thesis / Doctor of Philosophy (PhD) / Wastewaters sourced from industrial processes are considered ‘tough-to-treat’ due to high contaminant concentrations and time-varying compositional properties. Recent advancements in membrane technologies have demonstrate great promise in treating industrial wastewaters, however, these membranes often need to be integrated with other treatment technologies to overcome challenges with treating these wastewaters. This thesis aims to push the adoption of integrated membrane processes for treating high-strength industrial wastewaters. By utilizing advanced analytical techniques to investigate the effects of high contaminant loadings and variable feed properties on membrane processes, it was determined that screening tools are needed to rapidly design and optimize membrane process that are tailored to the properties of the wastewater. This thesis introduces a high-throughput and miniaturized screening platform that combines analytical centrifugation and filter-plate technology to holistically screen two-stage coagulation-filtration processes with little time and material requirements.

The purpose of this dissertation was to broadly investigate the fate of antibiotic resistance genes (ARGs) and engineered nanomaterials (ENMs) as representative contaminants of emerging concern in wastewater treatment plants (WWTPs). WWTPs may have their performance impacted by ENMs and may also serve as a reservoir and point of release for both ENMs and ARGs into the environment. Of interest were potential adverse effects of ENMs, such as stimulation of antibiotic resistance in the WWTP, toxicity to microbial communities critical for WWTP performance, and toxicity to humans who may be exposed to effluents or aerosols containing ENMs and their transformation products. Response of nine representative ARGs encoding resistance to sulfonamide, erythromycin and tetracycline to various lab-scale sludge digestion processes were examined, and factors that drove the response of ARGs were discussed. Mesophilic anaerobic digestion significantly reduced sulI, sulII, tet(C), tet(G), and tet(X) with longer solids retention time (SRT) exhibiting a greater extent of removal. Thermophilic anaerobic digesters performed similarly to each other and provided more effective reduction of erm(B), erm(F), tet(O), and tet(W) compared to mesophilic digestion. Thermal hydrolysis pretreatment drastically reduced all ARGs, but they generally rebounded during subsequent anaerobic and aerobic digestion treatments. Bacterial community composition of the sludge digestion process, as controlled by the physical operating characteristics, was indicated to drive the distribution of ARGs present in the produced biosolids, more so than the influent ARG composition. Effects of silver (nanoAg), zero-valent iron (NZVI), titanium dioxide (nanoTiO2) and cerium dioxide (nanoCeO2) nanomaterials on nitrification function and microbial communities were examined in duplicate lab-scale nitrifying sequencing batch reactors (SBRs), relative to control SBRs received no materials or ionic/bulk analogs. Nitrification function was only inhibited by high load of 20 mg/L Ag+, but not by other nanomaterials or analogs. However, decrease of nitrifier gene abundances and distinct microbial communities were observed in SBRs receiving nanoAg, Ag+, nanoCeO2, and bulkCeO2. There was no apparent effect of nanoTiO2 or NZVI on nitrification, nitrifier gene abundances, or microbial community structure. A large portion of nanoAg remained dispersed in activated sludge and formed Ag-S complexes, while NZVI, nanoTiO2 and nanoCeO2 were mostly aggregated and chemically unmodified. Thus, the nanomaterials appeared to be generally stable in the activated sludge, which may limit their effect on nitrification function or microbial community structure. Considering an aerosol exposure scenario, cytotoxicity and genotoxicity of aqueous effluent and biosolids from SBRs dosed with nanoAg, NZVI, nanoTiO2 and nanoCeO2 to A549 human lung epithelial cells were examined, and the effects were compared relative to outputs from SBRs dosed with ionic/bulk analogs and undosed SBRs, as well as pristine ENMs. Although the pristine nanomaterials showed varying extents of cytotoxicity to A549 cells, and gentoxicity was observed for nanoAg, no significant cytotoxic or genotoxic effects of the SBR effluents or biosolids containing nanomaterials were observed. Studies presented in this dissertation provided new insights in the fate of ARGs in various sludge digestion processes and ENMs in nitrifying activated sludge system in lab-scale reactors. The study also yielded toxicity data of ENMs to biological wastewater treatment microbial communities and human lung cells indicated by a variety of toxicity markers. The results will aid in identifying appropriate management technologies for sludge containing ARGs and will inform microbial and human toxicity assessments of ENMs entering WWTPs. / Ph. D.

Wastewater treatment has developed as a mature technology over time. However, conventional wastewater treatment is a very energy-intensive process. Bioelectrochemical system (BES) is an emerging technology that can treat wastewater and also recover resources such as energy in the form of electricity/hydrogen gas and nutrients such as nitrogen and phosphorus compounds. Microbial electrolysis cell (MEC) is a type of BES that, in the presence of an additional voltage, can treat wastewater and generate hydrogen gas. This is a promising approach for wastewater treatment and value-added product generation, though it may not be sustainable in the long run, as it relies on fossil fuels to provide that additional energy. Thus, it is important to explore alternative renewable resources that can provide energy to power MEC. Waste heat is one such resource that has not been researched extensively, particularly at the low-temperature spectrum. This was utilized as a renewable resource by converting waste heat to electricity using a device called thermoelectric generator (TEG). TEG converted simulated waste heat from an anaerobic digester to power an MEC. The feasibility of TEG to act as a power source for an MEC was investigated and its performance compared to the external power source. Various cold sources were analyzed to characterize TEG performance. To explore this integrated TEG-MEC system further, a hydraulic connection was added between the two systems. Wastewater was used as a cold source for TEG and it was recirculated to the anode of the MEC. This system showed improved performance with both systems mutually benefitting each other. The operational parameters were analyzed for the optimization of the system. The integrated system could generate hydrogen at a rate of 0.36 ± 0.05 m3 m-3 d-1 for synthetic domestic wastewater treatment. For the practical application, it is necessary to estimate the cost and narrow the focus on the functions of the system. Techno-economic analysis was performed for MEC with cost estimation and net present value model to understand the economic viability of the technology. The application niche of the BES was described and directions for addressing the challenges towards a full-scale operation were discussed. The present system provides a sustainable method for wastewater treatment and resource recovery which can play an important role in human health, social and economic development and a strong ecosystem. / Doctor of Philosophy / An average person produces about 50-75 gallons of wastewater every day. In addition to the households, wastewater is generated from industries and agricultural practices. As the population increases, the quantity of wastewater production will inevitably increase. To keep our rivers and oceans clean and safe, it is essential to treat the wastewater before it is discharged to the water bodies. However, the conventional wastewater treatment is a very energy (and thus cost) intensive process. For low-income and developing parts of the world, it is difficult to adapt the technology everywhere in its present form. Furthermore, as the energy is provided mostly by fossil fuels, their limited reserves and harmful environmental effects make it critical to find alternative methods that can treat the wastewater at a much lower energy input. For a circular and sustainable economy, it is important to realize wastewater as a resource which can provide us energy, nutrients, and water, rather than discard it as a waste. Bioelectrochemical systems (BES) is an emerging technology that can simultaneously treat wastewater and recover resources in the form of electricity/hydrogen gas, and nitrogen and phosphorus compounds. Microbial electrolysis cell (MEC) is a type of BES that is used to treat wastewater and generate hydrogen gas. An additional voltage is supplied to the MEC for producing hydrogen. In the long run, this may not be sustainable as it relies on fossil fuels to provide that additional energy. Thus, it is important to explore alternative renewable resources that can provide energy to power MEC. Waste heat is a byproduct of many industrial processes and widely available. This was utilized as a renewable resource by converting waste heat to electricity using a device called thermoelectric generator (TEG). TEG converted simulated waste heat from an anaerobic digester to power an MEC. The mutual benefit for MEC and TEG was also explored by connecting the system electrically and hydraulically. Cost-estimation of the system was performed to understand the economic viability and functions of the system were developed. The present system provides a sustainable method for wastewater treatment and resource recovery which can play an important role in human health, social and economic development and a strong ecosystem.

Attached growth biological processes offer advantages over traditional water purification technologies through high biomass retention, easy sludge-water separation, multiple multispecies synergies in proximity, resilience to shock loading, low space requirements, and reactor operational flexibility. Traditionally, attached growth refers to biofilms that require abiotic carrying media for bacteria to attach and grow on. While biofilms have been broadly applied in wastewater treatment, its potential for potable reuse or stormwater treatment has not been well studied. The treatment trains of pre-ozonation followed by biologically active filtration (ozone- BAF) is an advanced biofilm technology for potable reuse that can generate high-quality potable water at reduced energy and chemical demands by removing pollutant through three different pathways: oxidation, adsorption, and biodegradation. However, these pathways can result in both desirable and undesirable effects, and the mechanism behind it is still unclear. To understand the mechanisms of various pollutant removal, parallel performance comparisons of ozone-BAF treatment trains with spent and regenerated granular activated carbon (GAC), along with a range of pre-oxidant ozone doses were performed. Another common issue of BAF is the headloss buildup during its operation, which has become a significant energy and maintenance burden at many utilities. Thus, a mathematical model was developed to predict BAF headloss buildup in response to organic removal and nitrification. For stormwater treatment, the feasibility of using biofilms for stormwater biological nitrogen removal (BNR) is still largely unknown, as very limited research effort has been dedicated to this aspect. Thus, a mathematical model was developed to evaluate the potential of using BNR techniques for stormwater nitrogen removal. Aerobic granules are an even more advanced attached growth process, which eliminates the need for abiotic carrying media. So far, aerobic granular sludge is only formed in sequential batch reactors but not in a continuous flow system. Therefore, continuous flow aerobic granulation from traditional activated sludge was investigated and, for the first time, successfully achieved in continuous flow plug-flow bioreactors fed with real municipal wastewater. Besides, the role and critical value of an essential operational parameter, feast/famine ratio, for continuous flow aerobic granulation were determined. / Doctor of Philosophy / Water scarcity and increasing water demand caused by urban population growth and climate change is a reality throughout the world. Thus, process intensification of the current water and wastewater technologies is gaining increasing attention globally. Comparing to traditional water purification technologies, attached growth biological processes offers advantages such as high biomass retention, easy sludge-water separation, multiple multispecies synergies in proximity, resilience to shock loading, small footprint requirement, and reactor operational flexibility. Traditionally, attached growth refers to biofilms that require abiotic carrying media for bacteria to attach and grow on. While biofilms have been broadly applied in wastewater treatment, its potential for potable reuse or stormwater treatment has not been well studied. For potable reuse, the treatment trains of pre-ozonation followed by biologically active filtration (ozone-BAF) is an advanced biofilm technology that can generate high-quality potable water at reduced energy and chemical demands by removing pollutant through different pathways. However, the mechanism behind it is still unclear. To understand the mechanisms of various pollutant removal, parallel performance comparisons of ozone-BAF treatment trains operated with different operational conditions were performed in this dissertation. Another common issue of BAF is the headloss buildup during its operation, which has become a significant energy and maintenance burden at many utilities. Thus, a mathematical model was developed to predict the headloss buildup during BAF operation. For stormwater treatment, the feasibility of using biofilms for stormwater biological nitrogen removal (BNR) is still largely unknown, as very limited research effort has been dedicated to this aspect. Thus, a mathematical model was developed to evaluate the potential of using BNR technique for stormwater. Aerobic granules are an even more advanced attached growth process. However, aerobic granular sludge is so far only formed in sequential batch reactors which are incompatible with the continuous flow nature of most wastewater treatment plants. Therefore, aerobic granulation from traditional activated sludge was investigated and, for the first time, successfully achieved in continuous flow plug-flow bioreactors fed with real municipal wastewater. Besides, the role of an essential operational parameter, feast/famine ratio, for continuous flow aerobic granulation was determined.

Yes / In this paper, a one-dimensional mathematical model based on coupled differential and algebraic equations has been developed for analysing the separation mechanism of a N-nitrosamine in a spiral-wound reverse osmosis process. The model is based on Spiegler and Kedem’s work on mass transport and Darcy’s law and concentration polarization to analyse the pressure drop and mass transfer coefficient in the module feed channel respectively. The model is built using the gPROMS software suite and validated using N-nitrosamine rejection experimental data from the literature, obtained by using a pilot-scale cross-flow reverse osmosis filtration system. Analysis results derived from the model corroborate experimental data.

Yes / Reverse Osmosis (RO) has already proved its worth as an efficient treatment method in chemical and environmental engineering applications. Various successful RO attempts for the rejection of organic and highly toxic pollutants from wastewater can be found in the literature over the last decade. Dimethylphenol is classified as a high-toxic organic compound found ubiquitously in wastewater. It poses a real threat to humans and the environment even at low concentration. In this paper, a model based framework was developed for the simulation and optimisation of RO process for the removal of dimethylphenol from wastewater. We incorporated our earlier developed and validated process model into the Species Conserving Genetic Algorithm (SCGA) based optimisation framework to optimise the design and operational parameters of the process. To provide a deeper insight of the process to the readers, the influences of membrane design parameters on dimethylphenol rejection, water recovery rate and the level of specific energy consumption of the process for two different sets of operating conditions are presented first which were achieved via simulation. The membrane parameters taken into consideration include membrane length, width and feed channel height. Finally, a multi-objective function is presented to optimise the membrane design parameters, dimethylphenol rejection and required energy consumption. Simulation results affirmed insignificant and significant impacts of membrane length and width on dimethylphenol rejection and specific energy consumption, respectively. However, these performance indicators are negatively influenced due to increasing the feed channel height. On the other hand, optimisation results generated an optimum removal of dimethylphenol at reduced specific energy consumption for a wide sets of inlet conditions. More importantly, the dimethylphenol rejection increased by around 2.51% to 98.72% compared to ordinary RO module measurements with a saving of around 20.6% of specific energy consumption.

Yes / Reverse osmosis system has been widely used for the separation of organic and non-organic pollutants present in wastewater. The main aim of this study is to develop a one dimensional steady state model based on the three-parameter Spiegler-Kedem methodology using the gPROMS software and validate it by assessing the performance of membrane rejection for the separation data of aqueous solutions of phenol under different concentrations and pressures. Considerations of the variance of pressure, flow rate, solute concentration, solvent and solute fluxes and mass transfer coefficient along the feed channel were included in the model. Furthermore, an optimization methodology for the gEST parameter estimation tool has been developed in the gPROMS and used with experimental data in order to estimate the best values of the separation membrane parameters and the friction parameter. The simulation results of this model have been corroborated by experimental data.

Yes / Reverse osmosis (RO) has found extensive applications in industry as an efficient separation process in comparison with thermal process. In this study, a one-dimensional distributed model based on a wastewater treatment spiral-wound RO system is developed to simulate the transport phenomena of solute and water through the membrane and describe the variation of operating parameters along the x-axis of membrane. The distributed model is tested against experimental data available in the literature derived from a chlorophenol rejection system implemented on a pilot-scale cross-flow RO filtration system with an individual spiral-wound membrane at different operating conditions. The proposed model is then used to carry out an optimisation study using a genetic algorithm (GA). The GA is developed to solve a formulated optimisation problem involving two objective functions of RO wastewater system performance. The model code is written in MATLAB, and the optimisation problem is solved using an optimisation platform written in C++. The objective function is to maximize the solute rejection at different cases of feed concentration and minimize the operating pressure to improve economic aspects. The operating feed flow rate, pressure and temperature are considered as decision variables. The optimisation problem is subjected to a number of upper and lower limits of decision variables, as recommended by the module’s manufacturer, and the constraint of the pressure loss along the membrane length to be within the allowable value. The algorithm developed has yielded a low optimisation execution time and resulted in improved unit performance based on a set of optimal operating conditions.

Yes / Reverse osmosis (RO) has long been recognised as an efficient separation method for treating and removing harmful pollutants, such as dimethylphenol in wastewater treatment. This research aims to study the effects of RO network configuration of three modules of a wastewater treatment system using a spiral-wound RO membrane for the removal of dimethylphenol from its aqueous solution at different feed concentrations. The methodologies used for this research are based on simulation and optimisation studies carried out using a new simplified model. This takes into account the solution-diffusion model and film theory to express the transport phenomena of both solvent and solute through the membrane and estimate the concentration polarization impact respectively. This model is validated by direct comparison with experimental data derived from the literature and which includes dimethylphenol rejection method performed on a small-scale commercial single spiral-wound RO membrane system at different operating conditions. The new model is finally implemented to identify the optimal module configuration and operating conditions that achieve higher rejection after testing the impact of RO configuration. The optimisation model has been formulated to maximize the rejection parameters under optimal operating conditions of inlet feed flow rate, pressure and temperature for a given set of inlet feed concentration. Also, the optimisation model has been subjected to a number of upper and lower limits of decision variables, which include the inlet pressure, flow rate and temperature. In addition, the model takes into account the pressure loss constraint along the membrane length commensurate with the manufacturer’s specifications. The research clearly shows that the parallel configuration yields optimal dimethylphenol rejection with lower pressure loss.