<p>Bentonite clays and Fe-reducing bacteria have been independently identified as important geochemical agents possessing the ability to influence metal(loid) mobility in aqueous environments. In the context of metal(loid) immobilization, however, the interactions occurring between Fe-reducing bacteria and bentonite clays remain largely undescribed. This thesis examines the immobilization of Cu²⁺, Cd²⁺, and As⁵⁺ from aqueous solution by natural bentonite clays, and compares sorption to sterile bentonite clays with sorption in the presence of Fe-reducing bacteria. The research questions under investigation in this thesis are: 1) What are the influences of potentially metal-tolerant Fe-reducing bacteria on metal(loid) uptake by bentonite clay sorbents of varying smectite content and on the stability of bentonite clay-sorbed metal(loid)s?; and 2) Are there differences in the influence of Fe-reducing bacteria on Cd²⁺ and Cu²⁺ sorption to bentonite clays when As⁵⁺, a reducible, metabolically-available metalloid, is present in solution?</p> <p>While the influence of bacterial augmentation on Cu²⁺ sorption was negligible in these experiments, Cd²⁺ sorption was enhanced in the presence of Fe-reducing bacteria, and most profoundly, As displayed time-dependent desorption during the experimental timeframe in the presence of Fe-reducing bacteria. These results highlight the existence of potential limitations to the use of bentonite clay sorbents for metal(loid)-contaminated wastewater reclamation, identifying the microbially-vulnerable nature of metal(loid) sorption reactions. Abundant facets concerning clay-bacterial-metal(loid) interactions exist which require further characterization and experimentation to generate deeper understanding of the potential utility of, as well as limitations to, the use of clay mineral-based sorbents for the sequestration of toxic metal(loid)s from aqueous solution.</p> / Master of Science (MSc)

Yes / Reverse osmosis (RO) has become a common method for treating wastewater and removing several harmful organic compounds because of its relative ease of use and reduced costs. Chlorophenol is a toxic compound for humans and can readily be found in the wastewater of a wide range of industries. Previous research in this area of work has already provided promising results in respect of the performance of an individual spiral wound RO process for removing chlorophenol from wastewater, but the associated removal rates have stayed stubbornly low. The literature has so far confirmed that the efficiency of eliminating chlorophenol from wastewater using a pilot-scale of an individual spiral wound RO process is around 83 %, compared to 97 % for dimethylphenol. This paper explores the potential of an alternative configuration of two-stage/two-pass RO process for improving such low chlorophenol rejection rates via simulation and optimisation. The operational optimisation carried out is enhanced by constraining the total recovery rate to a realistic value by varying the system operating parameters according to the allowable limits of the process. The results indicate that the proposed configuration has the potential to increase the rejection of chlorophenol by 12.4 % while achieving 40 % total water recovery at an energy consumption of 1.949 kWh/m³.

Yes / The character of dissolved organic matter (DOM) present in drinking water treatment systems greatly impacts its treatability by coagulation–flocculation. Powdered activated carbon dosing has been suggested to enhance DOM removal when combined with coagulation–flocculation. However, optimising powdered activated carbon (PAC) dosing requires further research. In this study, fluorescence spectroscopy combined with parallel factor analysis (PARAFAC) and liquid chromatography with organic carbon detection (LC–OCD) has been used to characterise DOM removal in three ways: (a) coagulation–flocculation–sedimentation without PAC dosing, (b) PAC dosing prior to- and (c) PAC dosing during coagulation–flocculation–sedimentation treatment. It was shown that only coagulation–flocculation–sedimentation preferentially removed biopolymer and humic substance chromatographic fractions and fluorescent DOM, whereas dosing PAC preferentially removed building blocks and low molecular weight neutral chromatographic fractions. The DOM treatability that was achieved when PAC was dosed both prior to- and during coagulation–flocculation–sedimentation was comparable, but higher than what was achieved without any PAC dosing. Introduction of PAC to the coagulation–flocculation–sedimentation process significantly improved DOM removal, with fluorescent components removed by 97%. This study also highlights that a combination of fluorescence spectroscopy and LC–OCD is essential to track the removal of both, fluorescent and non-fluorescent DOM fractions and understand their impacts on DOM treatability when using different treatment processes. Overall, lower residual DOM concentrations were obtained in the treated water when PAC adsorption and the coagulation–flocculation–sedimentation processes were combined when compared to treating the water with only one of the processes, despite differences in source water character of DOM.

An investigation into the reasons behind the water shortage on Gotland. The project investigated several key factors and proceeded with the design of a surface water treatment plant in one of Gotlands old quarries left behind by the cement industry. The project also investigated and questioned the traditional methods of designing infrastructural buildings through a more architectural lens. The hope was to show a proposal that works but also acts as a pedagogical invitation to learn about where our most important resource comes from.

Termen koliforma bakterier beskriver en grupp indikatororganismer som används för att bedöma renligheten och integriteten hos reningsverk samt distributionssystem som nyttjas vid dricksvattenproduktion. För närvarande ställer styrande förvaltningsmyndigheter endast krav på detektion av antalet koliforma bakterier i dricksvatten via odlingsbaserade metoder. Dessa odlingsbaserade metoder särskiljer och upptäcker koliforma bakterier, och Escherichia coli specifikt, baserat på deras tillväxt samt enzymatiska aktivitet på selektiva kromogena och fluorogena agarplattor. Den definition av koliforma bakterier som dessa lagstiftningar ger upphov till identifierar endast koliforma bakterier baserat på deras metabolism och enzymatiska aktivitet, vilket är otillräckligt för att taxonomiskt identifiera olika bakterier inom denna grupp. För att uppnå detta krävs en definition baserad på fylogenetik. Detta masterexamensarbete beskriver undersökandet av metoder för taxonomisk identifiering av koliforma bakterier baserade på en kombination av odlingsbaserade och molekylära metoder. Vattenprover från Mälaren och Lovös vattenverk i Stockholm användes för att isolera koliforma bakterier via membranfiltrering, följt av odling på selektiva medier. De isolerade kolonierna och membranfiltrerna användes för att extrahera genomiskt DNA, följt av amplifiering av specifika gener associerade med E. coli och koliforma bakterier via PCR. Dessa inkluderade lacZ-genen, uidA-genen, yaiO-genen och 16S rRNA-genen. Produkterna från lyckade genamplifieringar sekvenserades för att taxonomiskt klassificera sekvenserna och identifiera olika koliforma bakterier. Två vattenprover med inloppsvatten skickades även för metagenomisk analys av dess mikrobiom. Dessa resulta indikerade att ett odlingssteg var nödvändigt för att producera tillräckligt med biomassa och genomiskt DNA för att lyckas med genamplifieringar utan att behöva filtrera enorma mängder vattenprover. De utvalda primrarna uppvisade även varierande framgång i att amplifiera målgenerna hos koliforma bakterier. Bakteriekoloniernas fysiska utseende på de selektiva agarplattorna och resultaten från genamplifieringarna uppvisade inte sammanhängande resultat, vilket indikerar ett behov av att ytterligare undersöka och optimera de utförda PCR-protokollen. Trots detta visade metoden potential för taxonomisk identifiering av koliforma bakterier. 16S rRNA-gensekvenserna möjliggjorde identifieringen av potentiella kontaminanter som grampositiva bakterier (Micrococcus and Staphylococcus) och andra, icke-koliforma, gramnegativa bakterier (Pseudomonas and Aeromonas) på de selektiva agarplattorna. Denna information kombinerat med bakteriekoloniernas utseende på agarplattorna och resultaten från övriga genamplifieringar kan möjliggöra ett sätt att skilja på falska positiva, falska negativa, sanna positiva och sanna negativa resultat från nuvarande detektionsmetoder för koliforma bakterier. Ytterligare optimering av olika aspekter av metoderna och arbetsflödet kring identifiering av koliforma bakterier är nödvändig innan man kan införa ett liknande tillvägagångssätt i ett reningsverk. / The term coliform bacteria describes a group of indicator organisms used to measure the cleanliness and integrity of drinking water treatment plants and distribution systems. Currently, the only legal requirement set by government agencies pertains to the detection and enumeration of these bacteria via cultivation-based methods. These methods distinguish coliform bacteria and Escherichia coli based on their growth and enzymatic activity on selective chromogenic and fluorogenic agar plates. However, the legislative definition concerning their metabolism and enzymatic production is insufficient to identify bacteria within this group taxonomically. Instead, a definition based on phylogenetics is required. This master’s thesis describes the exploration of methods for the characterization and identification of coliform bacteria via a combination of cultivation-based and molecular methods. Water samples from Lake Mälaren and the Lovö drinking water treatment plant in Stockholm were used to isolate coliform bacteria via membrane filtration and cultivation on a selective agar medium. The isolated colonies and filtered membranes were subjected to DNA extraction, followed by gene amplification of target genes associated with E. coli and coliform bacteria via PCR. This included the lacZ gene, the uidA gene, the yaiO gene, and the 16S rRNA gene. Successful gene amplicons were sent for sequencing to assign taxonomic values to the sequences and identify coliform bacteria. Two inlet water samples were also sent for metagenomic analysis of the microbiome. An incubation step was necessary to gather enough biomass to extract sufficient genomic DNA for gene amplifications and avoid the need to filtrate large volumes of water. The selected primer pairs exhibited various degrees of success in amplifying the targeted genes of coliform bacteria. The physical appearance of coliform colonies on the selective chromogenic agar plates and the results from the gene amplifications displayed no discernable pattern, indicating the need to further investigate and optimize the PCR procedures. However, the method indicated a potential for coliform bacteria identification. 16S rRNA gene sequences allowed for the distinction of potential contaminants on the selective agar media in gram-positive bacteria (Micrococcus and Staphylococcus) and other non-coliform, gram-negative bacteria (Pseudomonas and Aeromonas). In conjunction with the physical appearance of bacterial colonies on selective media and successful gene amplicons of the targeted genes, this information could allow one to distinguish between false positive, false negative, true positive, and true negative results from current coliform detection and enumeration methods. Further optimization of various aspects of the coliform bacteria identification methods is necessary before introducing a similar approach to a water treatment plant context.

There has been a recent increase in the adoption of point-of-use (POU) household water filters as an alternative to untreated tap water or bottled water. POU filters certified for lead removal have recently been distributed by the hundreds of thousands in communities amid water lead crises, as a temporary solution to protect consumers from elevated water lead levels. This thesis rigorously examines the efficacy of POU lead certified filters in removing lead under a wide range of conditions, and evaluates premature clogging due to iron and associated impacts on the cost analysis of using filters instead of bottled water. In testing ten brands of POU devices against up to four different waters for lead removal, most devices consistently removed lead to below the 5 µg/L FDA bottled water standard. However, several failures were documented, including manufacturing flaws, premature clogging, and inconsistency between duplicate filters. When waters containing more difficult to treat lead particulates were synthesized, treated water often had lead concentrations greater than the 5 µg/L bottled water standard and sometimes were even over the 15 µg/L EPA action level. In some cases, less than 50% of the particulate lead was removed by the filter, thereby replicating some problems with these devices identified in the field. While POUs usually reduced water lead concentrations by at least 80%, a combination of manufacturing issues and difficult to treat waters can cause treated water to exceed expectations. Consumers often purchase POU devices to remove particles and lead in waters that also contain high iron, prompting studies to examine the role of iron on filter performance. When we exposed two brands of pour-through POUs to waters with both high lead and iron, lead removal performance was generally not compromised, as treated water typically had lead concentrations less than 5 µg/L. One case was observed in which lead passed through a set of filters at high levels in association with iron, confirming expectations that in some waters iron could cause formation of lead particulates that are difficult to remove. High levels of iron sometimes rapidly clogged the POU filters, preventing them from reaching their rated capacity and increasing operational costs and time to filter water. Specifically, 50% (3/6) of the filters tested clogged prematurely at an iron concentration of 0.37 mg/L, 66% (4/6) at 1 mg/L and 100% (6/6) at 20 mg/L. A cost analysis for POUs vs. bottled water demonstrated that in waters with higher iron, store-brand bottled water was often the more cost-effective option, especially when iron levels were significantly higher than the EPA Secondary Maximum Contaminant Level (0.3 mg/L). The lower costs of bottled water in these situations was even more apparent if consumer time was factored into the analysis. / Master of Science / There has been a recent increase in the use of household water filters as an alternative to tap water or bottled water. Filters that are certified for lead removal have recently been distributed by the hundreds of thousands in communities amid water lead crises, as a temporary solution to protect consumers from elevated water lead levels. This thesis rigorously examines the effectiveness of these filters under a wide range of conditions. When tested against up to four different waters for lead removal, most filters consistently reduced lead to below the concentrations allowed in bottled water. In cases where the filters did not perform as expected, several filter failure modes were identified, including manufacturing flaws, filter clogging, and inconsistency between duplicate filters. In addition to these failures, when a water that contained particulate lead that was difficult to filter, as little as 50% of the lead was removed. While household filters often significantly reduce water lead concentrations, a combination of manufacturing issues and difficult to treat waters can cause poor performance. In many cases, consumers purchase filters to remove particles or lead in waters that also contain iron, which caused us to investigate the effect of iron on filter performance. When two brands of pour-through filters were tested against waters with both lead and iron, lead removal performance was generally not compromised. One exceptional case was observed where both high levels of lead and iron passed through the filters, leading us to believe that iron in some waters could create conditions where lead is more difficult to remove. In many cases, the presence of iron caused filters to dramatically slow down or clog. Premature clogging due to iron prevented filters from reaching their rated capacity and, in doing so, significantly increased cost and filter times. A cost analysis for filters vs. bottled water demonstrated that in waters with higher iron, store-brand bottled water was often the more cost-effective option, especially in waters with higher levels of iron. The lower costs of bottled water in these situations was even more apparent if consumer time was factored into the analysis.

The study examines the management of Legionella in the Swedish merchant fleet by mapping existing methods and proposing measures. Through a literature review and interviews with shipping company employees and industry experts, three research questions are analyzed: What are the most common preventive measures on board, common sanitation methods and how can these be made more efficient when it comes to eliminate Legionella. The results point to common methods such as UV irradiation and hot water flushing. The discussion highlights the reliability of the method and the industry's need for increased knowledge and clearer guidelines. The conclusions emphasize the need for measures such as Legionella filters, regular testing of fresh water, and long-term solutions focusing on the source of the problem, such as risk assessments. Education, awareness, and preventive measures are crucial for combating this hidden and costly problem in modern shipping.

Wastewater, recycled irrigation water, and agricultural runoff can contain high levels of pathogenic bacteria, which pose a threat to human and ecosystem health. The use of a bioreactor containing mycelial mats of filamentous fungi is a novel treatment technology that incorporates physical, biological, and biochemical processes to remove bacterial pathogens from influent water. Although a relatively new concept, fungal bioreactors have demonstrated the ability to dramatically reduce fecal coliform bacteria in water, but no studies have attempted to explicitly identify the bacterial pathogen removal mechanisms exhibited by the fungi. This study evaluated several different species of fungi for use in fungal bioreactor systems and aimed to identify the modes of action responsible for the removal of bacterial pathogens. The species evaluated were Daedaleopsis confragosa, Pleurotus eryngii, and Piptoporus betulinus. Experimental results showed that all species of fungi assessed were capable of removing E. coli in a synthetic water solution. Significant concentrations of hydrogen peroxide, an antiseptic, were produced by all species of fungi evaluated. The fungal bioreactors containing P. eryngii produced the highest concentrations of hydrogen peroxide, generating a maximum concentration of 30.5 mg/l or 0.896 mM. This maximum value exceeds reported minimum concentrations required to demonstrate bacteriostatic and bactericidal effects when continually applied, providing evidence that a major bacterial removal mode of action is the production of antimicrobial compounds. In addition to its promising application to improve water quality, fungal bioreactors are a low cost and passive treatment technology. The development a hyper-functional system could be a have a substantial impact on the use of recycled irrigation water and on the water/wastewater treatment industry, for both municipal and agricultural wastewater. / Master of Science

"This study examined the fate of manganese in manganese oxide (MnO_x(s)) coated filter media. Specific objectives of the project included the following: 1. Determination of the effect of influent pH upon Mn(II) sorption and oxidation and upon the physical characteristics of the coating on the media. 2. Determination of the effect of backwash rate upon MnO_x(s) coatings. 3. Examination of the effect of air scour upon MnO_x(s) coatings. 4. Observation of the effect of an increasing MnO_x(s) coating on the physical characteristics of anthracite coal filter media. 5. Development of an overall mass balance on manganese loading and accumulation on the filter media. Resolution of the stated objectives involved construction, optimization, and continuous operation of a pilot-scale filtration system for the purpose of removing manganese from filter-applied water. The pilot-scale filter system functioned like a typical water treatment plant filtration system with similar hydraulic loading rates, influent manganese concentrations, free chlorine dosage, filter media bed depths, filter run times, and backwash rates. With regard to the fate of manganese in MnO_x(s)-coated filter media, it was determined that as long as free chlorine was present to oxidize sorbed manganese, manganese continued to accumulate and remained on the media in sufficient concentrations to promote continual removal of soluble Mn(II). While oxide coating that was susceptible to breakage was removed in backwash, some portion of coating remained on the media. The combination of MnO_x(s) accumulation during filtration and its partial removal during backwash maintained a net amount of MnO_x(s) coating optimal for catalyzing further manganese removal and, yet, did not hinder filtration for turbidity by significantly altering the size of the media. The results of the pilot-scale study also indicated the following pertinent conclusions: 1. Neutral or slightly acidic pH conditions (7 ≥ pH ≥ 6) inhibited Mn(11) oxidation before filtration and, instead, promoted sorption and oxidation of Mn(II) on MnO_x(s)-coated media. Alkaline filter influent pH (pH > 7) allowed some Mn(II) oxidation before filtration, resulting in significant manganese removal by MnO_x(s) particle filtration. 2. Although the intent of MnO_x(s)-coating on the filter media was to remove influent Mn(II) from filter-applied water, MnO_x(s) that was removed by particle filtration also provided MnO_x(s) surface area within the filter and, thus, additional sorption sites for Mn(II) removal. 3. Increases in fluid backwashing rate tended to produce greater amounts of MnO_x(s) release from filter media for the duration of these backwash operations. However, backwashing did not result in complete MnO_x(s) release from the media surface; rather, there was always sufficient Mn0O_x(s) retained to permit efficient soluble Mn(II) removal after the filtration operations were restarted. Removal of soluble Mn(II) by sorption and oxidation proved to be a dependable, low-maintenance Mn(II) removal technique that worked well within a wide range of raw water influent conditions. Because the process is cost-effective and easily integrated into new or existing water treatment facilities, it is an economical and competitive alternative for removal of soluble Mn(II)." / Master of Science

The metabolism of white-rot fungi has many proposed biotechnological applications. Their unique capability to depolymerize and catabolize lignin, the most recalcitrant component of lignocellulosic biomass, could be instrumental to the sustainable production of fuels, chemical, and materials from waste biomass feedstocks. The non-specific, oxidative nature of this lignin-degrading metabolism of white-rot fungi renders them capable of degrading a wide range of complex refractory organic compounds beyond lignin, including emerging micropollutants such as pharmaceuticals and pesticides which current wastewater treatment processes were not designed to remove. However, harnessing these metabolic capabilities into engineered bioprocesses has proven to be challenging. Common bioreactor design strategies were developed for traditionally-used unicellular bacteria and yeasts and are not necessarily appropriate for the more complex, filamentous white-rot fungi. Due to a lack of specific engineering strategies and other knowledge gaps, the realization of white-rot fungal bioprocesses has been hampered by low process efficiencies and operational challenges. This dissertation aims to expand the engineering toolbox for harnessing the metabolism of white-rot fungi in bioprocesses. Specifically, it proposes the addition of Fenton chemistry as an avenue to unlock the biotechnological potential of white-rot fungi. The production of hydroxyl radicals through the Fenton reaction is generally understood to be part of the lignin-degrading machinery of white-rot fungi and the addition of Fenton chemistry has been shown to synergistically enhance lignin degradation by white-rot fungi. Overall, the research presented here aims to demonstrate that incorporating Fenton chemistry into white-rot fungal bioprocesses not only synergistically increases lignin degradation efficiency, but also offers a potential solution for the operational challenges that have prevented the implementation of white-rot fungal bioprocesses. This dissertation was guided by five objectives aimed at illustrating the utility of coupling Fenton chemistry and white-rot fungi in engineered bioprocesses. The first objective was to demonstrate, optimize, and uncover the underlying mechanisms driving the synergistic degradation of lignin by white-rot fungi and Fenton chemistry. Through this assessment, it was found that lignin degradation increased synergistically from 58.8% to 80.2% in the presence of Fenton chemistry at the optimum concentration. This work also showed that Fe(II)/Fe(III) cycling and the induction of auxiliary ligninolytic pathways mediate this synergistic interaction. The second objective was to elucidate how Fenton chemistry influences the regulating mechanisms of ligninolytic activity in white-rot fungi, specifically C:N ratio. This showed that C:N ratio significantly influences lignin degradation in the absence of Fenton, but that this effect is blunted in the presence of Fenton. The third objective was to investigate how Fenton chemistry modulates the relationship between the concentration of fungal biomass and the extent of lignin. In the absence of Fenton, fungal biomass concentration was strongly correlated to the extent of lignin degradation. While this was also the case in the presence of Fenton chemistry at very low fungal biomass concentrations, this relationship became uncoupled at sufficiently high fungal biomass concentrations. The fourth objective was to evaluate Fenton chemistry as a selective disinfectant to allow for the persistence or enrichment of white-rot fungi in non-sterile settings. The model competitor E. coli became completely inactivated within hours at the optimal concentration of Fenton reagents, whereas the white-rot fungus P. chrysosporium survived and grew. Lastly, the fifth objective was to demonstrate the long-term performance of a continuously-operated bioreactor which integrated Fenton chemistry and white-rot fungal metabolism. A rotating biological contactor (RBC) combined with a rotating cathode electro-Fenton was constructed and a kinetic model based on batch tests was successfully developed and validated. The reactors were operated for over 100 days and reached stable lignin degradation performance at ~55%. Analysis of the microbial ecology of these reactors showed the persistence of the inoculated P. chrysosporium within the biofilms, as well as the enrichment for other lignin-degrading fungi and bacteria with aromatic catabolism and iron-reduction capabilities. Overall, this research provides insight into the potential and practical implications of integrating Fenton chemistry with white-rot fungi in bioprocesses. The lignin-degrading metabolism of white-rot fungi has long been of interest for biotechnological purposes, but attempts to operationalize them have thus far been unsuccessful at scale. In order to consider scaling white-rot fungi to full-scale operations such as wastewater treatment plants, a better understanding and tighter controls on the growth, ligninolytic activity, and ecological interactions of white-rot fungi are needed. This work proposes Fenton chemistry as a synergetic actor, selective promoter and regulator of white-rot fungal biomass and their production of lignin degrading enzymes.