This report is a thesis in mechanical engineering with a focus on development assistance. The thesis was carried out in collaboration with the Gombe Youth Development Organization. The task was to develop an adequate system to collect, purify and store water in the two rural villages Gombe and Kayunga in Uganda. The system takes into account local weather, water quality, population, water consumption and types of water sources. The final system has a low manufacturing cost, simple maintenance, low operating cost, is electrical independent and can be manufactured and repaired with local available components. The report presents various types of sources of water and purification of varying suitability for these conditions. The report also includes operation and maintenance manual and an approximate budget. The result of this work is a combined system of rainwater harvesting, flocculation and one "up flow" rapid sand filter with built-in storage tank. Given that only rainwater collection is not enough to cover a normal sized family of 10 individuals consumption of water, due to this water from natural sources is also used. / Den här rapporten är ett examensarbete i maskinteknik med inriktning mot bistånd. Examensarbetet utfördes i samarbete med Gombe Youth Development Organization. Uppgiften bestod i att ta fram ett lämpligt system för att samla in, rena och lagra vatten i de två byarna Gombe och Kayunga på Ugandas landsbygd. Systemet tar hänsyn till lokalt väder, vattenkvalité, population, vattenkonsumtion och typer av vattenkällor. Det slutliga systemet har låg tillverkningskostnad, är lätt att underhålla, har låg driftskostnad, är inte beroende av elektricitet och kan tillverkas och repareras av lokalt tillgängliga komponenter. Rapporten presenterar olika typer av insamlingskällor av dricksvatten och metoder för rening med varierande lämplighet för dessa förutsättningar. Rapporten innefattar även drift- och underhållsmanual och en ungefärlig budget. Resultatet av arbetet är ett system kombinerat av regnvatteninsamling, flockning och ett ”up flow” snabbt sandfilter med inbyggd förvaringstank. Med tanke på att endast regnvatteninsamling inte räcker till för att täcka behovet för en normalstor familj på 10 personer, kommer även vatten från naturliga källor även att användas.

Water is the most essential resource for life. In cases where drinking water is processed from surface water it is important to ensure the raw water is of good quality, and is suitable for processing through the water treatment plant. The drinking water for Västerås is sourced from Västeråsfjärden, in the western side of Lake Mälaren. The city itself is home to marinas, ports, a wastewater treatment plant, the Svartån outlet, sewage pumping stations and stormwater outlets. Because of the negative effects these activities have on surface water quality, Mälarenergi AB is interested in relocating the raw water intake point to Granfjärden, 10 km east of Västeråsfjärden. At Granfjärden the intake point would be less exposed to the activities in Västerås, and could be placed at a greater depth, resulting in better water quality. In this Master’s thesis the water quality and the pollution risks at Västeråsfjärden and Granfjärden sites are compared. Existing water quality data were compared, and pollution risks were investigated in two ways. Firstly potential risks in the catchment area were identified through compiling previously reported information and map analysis. Secondly, possible accident scenarios from shipping were identified. Following this, SMHI simulated the accident scenarios and their estimated effects on the two sites were then assessed.   This research shows that the water quality difference between sites is small but key differences exist in the levels of organic matter, color, transparency and temperature, making the Granfjärden location preferable. Potential problems associated with the low oxygen levels found during the end of summer at Granfjärden may be addressed by temporarily raising the intake point. It should be noted however that this temporary solution may increase the exposure to pollution. In conclusion, accident scenario simulations showed the potential concentration of pollutants at both sites is low, with effluents diluted at least 1000 times. Prevailing southwesterly and westerly winds occuring at both intake points generate a clockwise circulation in Västeråsfjärden.  This causes all effluents from urban activities to reach that intake point, which is the most notable risk associated with this site.  In contrast, the two largest risks for the Granfjärden site are shipping effluents and the microbiological load from individual sewage treatment systems and animal waste. / Vatten är vårt viktigaste livsmedel och en förutsättning för allt liv. I de fall där råvatten för beredning av dricksvatten tas från ytvatten är det ytterst viktigt att säkerställa en bra vattenkvalitet, lämpat för dricksvattenberedning. Västerås stad tar idag sitt råvatten från Västeråsfjärden, i Mälarens västra delar, 3 km från Västerås stad. I staden finns bl.a. småbåtshamnar, oljehamn, avloppsreningsverk, Svartåns utlopp, nödbräddavlopp, avloppspumpstationer och dagvattenutsläpp. Dessa aktiviteter påverkar vattenkvaliteten i fjärden negativt och därför har Mälarenergi AB valt att undersöka möjligheterna att flytta intaget till Granfjärden, 10 km öster om Västeråsfjärden. Där skulle råvattenintaget inte vara lika utsatt för samhällets direkt negativa vattenpåverkan. Intaget kan läggas på ett större djup och där kan vattenkvaliteten vara bättre och mindre riskutsatt. I detta examensarbete har vattenkvaliteten och föroreningsriskerna jämförts mellan fjärdarna. Analysresultat från provtagningar i Granfjärden jämfördes med prover från Västeråsfjärden. Riskerna behandlades i två delar. I den första delen identifierades föroreningsrisker genom att sammanställa material från tidigare projekt samt genom att studera kartor. I den andra delen togs olycksscenarion inom sjöfarten fram. SMHI simulerade dessa scenarion och en bedömning gjordes sedan över hur riskutsatta de båda råvattenintagen är. Trots det stora avståndet från Västerås stad till Granfjärden var skillnaden i vattenkvalitet mellan fjärdarna förvånansvärt liten, men skillnader påvisades för några av de analyserade parametrarna. Granfjärdens bottenvatten hade signifikant lägre halter organiskt material, lägre färgtal och lägre temperatur än det nuvarande råvattenintaget. Däremot förekom lägre syrgashalter i slutet av sommaren än vid råvattenintaget i Västeråsfjärden. Om problem skulle uppstå i dricksvattenberedningen till följd av låga syrgashalter finns möjlighet att byta till ett grundare intag vid samma punkt. Det grundare intaget är dock mer utsatt för risker än det djupare. Samtliga utsläpp från de simulerade olyckorna späddes ut minst 1000 gånger innan de spred sig till råvattenintagen. Båda råvattenintagen är som mest utsatta vid sydvästlig och västlig vind. I Västeråsfjärden ger dessa vindriktningar en medurs strömningsbild i fjärden, vilket innebär att föroreningsutsläpp från staden förs mot råvattenintaget. De största riskerna för råvattenintaget i Granfjärden är utsläpp i farleden och den mikrobiologiska belastningen från enskilda avlopp och djurhållning. I Västeråsfjärden är den största riskfaktorn utsläpp från stadens aktiviteter och verksamheter längs den östra stranden.

Slow sand filtration is a proven and sustainable technology for drinking water treatment in small communities. The process, however, is sensitive to lower water temperatures that can lead to decreased biological treatment, and high raw water turbidity levels that can lead to premature clogging of the filter and frequent cleaning requirements, resulting in increased risk of pathogen breakthrough. Multistage filtration, consisting of roughing filtration followed by slow sand filtration, can overcome these treatment limitations and provide a robust treatment alternative for surface water sources of variable water quality in northern climates, which typically experience water temperatures ranging down to 2&deg;C. Prior to this study, however, multistage filtration had yet to be systematically challenged in colder climates, including testing of its performance under increased hydraulic loadings and elevated influent turbidity together with cold water conditions. The primary goal of this research was to demonstrate the reliability of multistage filtration for small communities in northern climates with reference to the Ontario Safe Drinking Water Act. In this research, testing was conducted on two different pilot multistage filtration systems and fed with water from the Grand River, a municipally and agriculturally impacted river in Southern Ontario. One system featured pre-ozonation and post-granular activated carbon (GAC) stages, and shallower bed depths in the roughing filter and slow sand filter. The other system featured deeper bed depths in the roughing filter and slow sand filter, two parallel roughing filters of different design for comparison, and a second stage of slow sand filtration for increased robustness. Removal of turbidity, total coliforms, and fecal coliforms under a range of influent turbidities (1 to >100 NTU), water temperatures (~2 to 20&deg;C), and hydraulic loading rates (0. 2 to 0. 8 m/h) were investigated. In addition, the slow sand filters in each pilot system were challenged with high concentrations (~10⁶ oocyst/L) of inactivated <i>Cryptosporidium parvum</i> oocysts. The performance of both pilot multistage filtration systems was highly dependent on the biological maturity of the system and its hydraulic loading rate. In a less mature system operating in cold water conditions (<5&deg;C), effluent turbidity was mostly below 0. 5 NTU during periods of stable influent turbidity (no runoff events) and a hydraulic loading of 0. 4 m/h, however, runoff events of high influent turbidity (>50 NTU), increased hydraulic loadings (0. 6 m/h), and filter cleaning occasionally resulted in effluent turbidity above 1 NTU. Furthermore, in a less mature system operating during runoff events of high turbidity, reducing the hydraulic loading rate to 0. 2 m/h was important for achieving effluent turbidity below 1 NTU. However, in a more mature system operating in warm water conditions (19-22&deg;C), effluent turbidity was consistently below 0. 3 NTU at a hydraulic loading rate of 0. 4 m/h, and below 0. 5 NTU at 0. 8 m/h, despite numerous events of high influent turbidity (>25 NTU). It remains to be seen whether this performance could be sustained in colder water temperatures with a fully mature filter. Removal of coliform bacteria was occasionally incomplete in a less mature multistage system, whereas, in a more mature system operating in warm water conditions (>9&deg;C), removal was complete in all measurements. Furthermore, the average removal of <i>Cryptosporidium</i> was greater than 2. 5 logs in both systems (with hydraulic loading rates ranging from 0. 4 to 0. 8 m/h) and improved with increased filter maturity. Each individual stage of the multistage system was an important treatment barrier in the overall process of turbidity and pathogen removal. The roughing filter was not only important for protecting the slow sand filter from solids loading and increasing its run length, but was also a significant contributor to coliform removal when the system was less mature. Removal of turbidity was significantly improved when the roughing filter was more mature, suggesting that biological treatment was an important treatment mechanism in the roughing filter. Although pre-ozonation was used mainly for the removal of organic carbon and colour, it achieved complete removal of coliform bacteria and was also suspected to be important for enhanced removal of turbidity. The second slow sand filter in series provided additional robustness to the process by reducing effluent turbidity to below 1 NTU during cold water runoff events of high turbidity and increased hydraulic loadings (0. 6 m/h), while achieving effluent below 0. 3 NTU during normal periods of operation. It also provided additional removals of coliforms under challenging operating conditions, and contributed an additional average removal of <i>Cryptosporidium</i> of 0. 8 logs, which resulted in cumulative removal of 3. 7 logs, approximately 1 log greater than all the other challenge tests. Collectively, the entire multistage system performed well with water temperatures ranging down to 2&deg;C, limited filter maturity, elevated raw water turbidities, and increased hydraulic loading rates. Its ability to meet the current Ontario turbidity regulations and greater than 2 log removal of <i>Cryptosporidium</i> over a range of operating conditions, with little or no process adjustment, is a testament to the robustness and minimal maintenance requirements of the process, which are desirable attributes for small water systems that are often located in rural areas. While this research demonstrated the performance of multistage filtration using pilot scale testing, it is important to note that full-scale plants tend to produce significantly better results than pilot facilities, due to long term biological maturation of the system. Overall, multistage filtration is a sustainable and cost-effective technology that, through this research, appears to be a safe, reliable, and robust treatment alternative for small and non-municipal water systems in North America and the developing world. Further, based on its performance with challenging influent water quality and cold water conditions, multistage filtration holds particular promise for small communities in northern climates that are required to meet safe drinking water regulations, but are dependent on surface water sources of variable water quality and temperatures.

<p>This report is a thesis in mechanical engineering with a focus on development assistance. The thesis was carried out in collaboration with the Gombe Youth Development Organization.</p><p>The task was to develop an adequate system to collect, purify and store water in the two rural villages Gombe and Kayunga in Uganda. The system takes into account local weather, water quality, population, water consumption and types of water sources.</p><p>The final system has a low manufacturing cost, simple maintenance, low operating cost, is electrical independent and can be manufactured and repaired with local available components.</p><p>The report presents various types of sources of water and purification of varying suitability for these conditions. The report also includes operation and maintenance manual and an approximate budget.</p><p>The result of this work is a combined system of rainwater harvesting, flocculation and one "up flow" rapid sand filter with built-in storage tank. Given that only rainwater collection is not enough to cover a normal sized family of 10 individuals consumption of water, due to this water from natural sources is also used.</p> / <p>Den här rapporten är ett examensarbete i maskinteknik med inriktning mot bistånd. Examensarbetet utfördes i samarbete med Gombe Youth Development Organization.</p><p>Uppgiften bestod i att ta fram ett lämpligt system för att samla in, rena och lagra vatten i de två byarna Gombe och Kayunga på Ugandas landsbygd. Systemet tar hänsyn till lokalt väder, vattenkvalité, population, vattenkonsumtion och typer av vattenkällor.</p><p>Det slutliga systemet har låg tillverkningskostnad, är lätt att underhålla, har låg driftskostnad, är inte beroende av elektricitet och kan tillverkas och repareras av lokalt tillgängliga komponenter.</p><p>Rapporten presenterar olika typer av insamlingskällor av dricksvatten och metoder för rening med varierande lämplighet för dessa förutsättningar. Rapporten innefattar även drift- och underhållsmanual och en ungefärlig budget.</p><p>Resultatet av arbetet är ett system kombinerat av regnvatteninsamling, flockning och ett ”up flow” snabbt sandfilter med inbyggd förvaringstank. Med tanke på att endast regnvatteninsamling inte räcker till för att täcka behovet för en normalstor familj på 10 personer, kommer även vatten från naturliga källor även att användas.</p>

Den största akuta risken inom dricksvattenförsörjningen är vattenburen smittspridning. Dricksvattenrelaterad smittspridning förekommer i störst utsträckning i utvecklingsländer med dåliga sanitära förhållanden. Under 2000-talet har de nordiska länderna drabbats av flertalet dricksvattenburna sjukdomsutbrott vilket har lett till att mikrobiella föroreningar uppmärksammats som ett problem även i Norden. För att säkerställa att det dricksvatten som distribueras är av god mikrobiologisk kvalitet krävs att säkerhetsbarriärerna i vattenverket är tillräckligt effektiva för alla typer av mikrobiella föroreningar. Vissa mikroorganismer har uppmärksammats som mer tåliga mot olika desinfektionsmetoder, till exempel klorering, än vad som tidigare varit känt. För ett säkrare dricksvatten är det därför viktigt att öka kunskapen om mikroorganismers varierande motståndskraft mot olika desinfektionsmedel samt undersöka alternativ till de avskiljnings- och inaktiveringsmetoder som traditionellt används idag. Examensarbetets syfte var att studera de bakterier och virus som har störst relevans för dricksvattenkvaliteten och som tros kunna utgöra ett hot mot nordiskt dricksvatten, att undersöka orsakerna bakom dricksvattenburna utbrott samt att undersöka effektiviteten hos olika avskiljnings- och inaktiveringsmetoder för bakterier och virus. Detta gjordes genom en utförlig litteraturstudie samt en fallstudie. Fallstudiens syfte var att belysa problematiken inom dricksvattenberedning samt distribution i Norden genom verkliga exempel.  Studien visade att vattenburna sjukdomsutbrott normalt orsakas av kontaminering från avloppsvatten till dricksvatten. Detta sker antingen direkt till råvattnet, ofta till följd av kraftig nederbörd, eller under distributionen på grund av driftstörningar. Att kontamineringen tillåts nå konsumenten är ett resultat av inadekvata reningsmetoder i vattenverken. Problematiken inom dricksvattenområdet beror bland annat på användandet av bristfälliga indikatororganismer vilka är mindre tåliga och har sämre överlevnadsförmåga än många sjukdomsalstrande mikroorganismer. Tidskrävande och osäkra analysmetoder utgör också ett stort problem. Svårigheter i att identifiera den orsakande mikroorganismen samt att bekräfta utbrottet som dricksvattenrelaterat har lett till att mörkertalet gällande antalet vattenburna sjukdomsfall är stort. Det finns ett stort behov av ökad kunskap gällande olika mikroorganismers tålighet mot desinfektion samt ett behov av reglering för kontroll av råvattenkvaliteten och den mikrobiologiska säkerheten. Utifrån studien kunde även konstateras att antalet vattenburna utbrott tros öka med kraftigare nederbörd och extremväder till följd av klimatförändringarna. / Waterborne diseases are considered a major problem in the water supply. Spreading of infection through drinking water occurs predominantly in developing countries with poor sanitation. During the 21th century the Nordic countries have been affected by several waterborne outbreaks associated with drinking water. As a result, microbial contamination of drinking water has been recognized as a problem in the Nordic countries as well. To ensure high quality drinking water it is required that the hygienic barriers used in the water treatment plant are efficient in reducing all types of microbial contaminants. Some microorganisms have shown a greater resistance against commonly used disinfectants then previously known. To secure the distribution of safe drinking water it is essential to increase the knowledge regarding the varying resistance of microorganisms and to investigate alternative water treatment processes to those traditionally used in drinking water treatment today.  The objective to this master thesis was to study the bacteria and viruses that are most relevant for drinking water quality and may compose a threat to the drinking water quality in the Nordic countries, to investigate the cause of waterborne outbreaks and to study the effectiveness in reducing bacteria and viruses for various water treatment processes. The study was performed through a thorough literature review and a case study. The purpose of the case study was to illustrate the issues in drinking water treatment and distribution in the Nordic region. The study showed that the majority of the outbreaks are caused by contamination from sewage water to drinking water. The contamination is allowed to reach the consumer as a result of inadequate treatment in the water works. Usage of inappropriate indicator organisms that are less resistant to disinfectants than a lot of pathogens are a big problem in drinking water treatment. Time-consuming and uncertain analytical methods also compose a great issue. Due to difficulties in identifying the causative microorganism and verify the outbreak as drinking water related it is believed that there is a large number of unrecorded cases of illness. There is a great need of increased understanding of the varying resistance of microorganisms to disinfectants and a need for regulation for monitoring raw water quality and microbiological safety. Based on the study it was also found that waterborne outbreaks are believed to increase as a result of extreme weather caused by climate change.

The United Nations Millennium Development goals aim to make improvements in access to potable water. In the Bocas del Toro region of Panama, rainwater harvesting systems are making that goal more attainable. Rainwater harvesting, especially in rural, difficult access areas, may be a viable water source improvement that will allow a greater population to access improved water. This study uses the Carnegie Mellon University Economic Input-output Life Cycle Assessment tool to assess the embodied energy of plastic and ferrocement rainwater harvesting systems in rural Panama. Rainwater harvesting systems are assessed as source improvement technologies that increase access to potable water. This study adds to and compares its results to other source improvement LCAs that would potentially benefit developing communities in lesser developed countries.

Biological filtration (biofiltration) of drinking-water is gaining popularity due the potential for biodegradation of an array of contaminants not removed by traditional drinking-water processes. However, previous research has suggested that biomass growth on biofilter media may lead to increased headloss, and thus, greater energy and water requirements for backwashing. Research has suggested that the main cause of headloss might be due to extracellular polymeric substances (EPS) rather than the bacterial cells themselves. As EPS production has been shown to increase under nitrogen- and phosphorus-limited or -depleted conditions, the goal of this research was to add to the body of knowledge regarding biofiltration by studying the relationship between EPS production and nutrient limitations in drinking-water. Batch experiments with a synthetic groundwater were run with a mixed community of drinking-water bacteria under nutrient-balanced (a molar carbon to nitrogen to phosphorus ratio [C:N:P] of 100:10:1), nutrient-limited (e.g., C:N:P of 100:10:0.1), and nutrient-depleted conditions (C:N:P of 100:0:1 or 100:10:0). After 5 days, growth was measured as the optical density at 600 nanometers (OD600), and the concentrations of free and bound carbohydrates and proteins, the main components of EPS, were measured. In batch experiments with 2.0 and 0.2 g/L as carbon (mixture of acetic acid, mannitol and sucrose) increases in EPS production per OD600 and decreases in growth were noted under nutrient-depleted conditions. When the same experiments were conducted with a pure culture of Bacillus cereus, bound polysaccharides normalized to OD600 increased under nitrogen- and phosphorus-depleted conditions. Since previous research suggested that Bradyrhizobium would be an important player in EPS production in drinking-water biofilters, similar batch experiments were conducted with Bradyrhizobium. However, due to experimental challenges with Bradyrhizobium japonicum USDA 110, differences in EPS production under nutrient limitations could not be reliably assessed. Additional work is required with Bradyrhizobium. Recommendations for future work include the replication of these batch conditions in steady-state chemostats containing biofilm attachment media and in bench-scale columns. Additionally, future work should include experiments at carbon concentrations as low as 2 mg/L to match typical carbon concentrations in drinking-water biofilters. / text

D. Tech. Water care. / Groundwater is the main source of drinking in most rural areas of South Africa and is supplied to the communities without prior treatment. However, the contamination of groundwater sources by pathogenic bacteria poses a public health concern to these communities. This study was aimed at developing and evaluating the effectiveness of filter materials coated with silver nanoparticles for the removal of pathogenic microorganisms from groundwater as well as the inhibition of biofilm formation in drinking water systems.

<p>This study assesses the present level of household water access and the willingness to pay in South Africa. Although the general literature informs that progress has been made in positing South Africa above the levels found in most African countries, there are some marked inequalities among the population groups and across the provinces, with some performing well and others poorly in this regard. The study looks at the extent to which households differ in terms of water access and willingness to pay according to the province of residence. The study focuses on household heads / male and female, through different social and demographic attributes, by taking account of variables such as age, education&nbsp / attainment, geographic areas, and population group to name but a few. The data used in this study comes from the 2007 General Household Survey (GHS) conducted by Statistics South Africa. The scope is national and employs cross tabulation and logistic regression to establish relationships and the likelihood of living in a household with access to safe&nbsp / drinking water in South Africa. Results presented in this study suggest that the difference is determined by socio- demographic characteristics of each household such as age, gender, population group, level of education, employment status income, dwelling unit, dwelling ownership, living quarters,household size and income. It throws more light as to what needs to be taken into account when considering demand and supply of and priorities for water intervention from the household perspective.</p>

Per- and polyfluoroalkyl substances are a large group of global environmental contaminants. They can be divided into two sub-groups, 1) perfluoroalkyl acids (PFAAs) and 2) so called precursors, i.e. compounds that can potentially be transformed to form PFAAs. PFAAs are today ubiquitous in wildlife and humans. Food and drinking water are assumed to be the dominant human exposure pathways for PFAAs. The main aim of this doctoral thesis was to develop highly sensitive and fully validated analytical methods for the determination of a range of PFAAs and selected precursors in dietary samples. The methods were based on liquid chromatography coupled to mass spectrometry. Samples were extracted by solvent extraction followed by a cleanup step employing solid phase extraction. The cleanup step could at the same time be used as a fractionation of ionic PFAAs and neutral precursors. Paper I and II describe the development of methods for simultaneous analysis of three groups of PFAAs including perfluoroalkyl phosphonic acids (PFPAs) in drinking water and food. Methyl piperidine was used as ion pairing agent, leading to highly sensitive analysis of PFPAs. A first screening of tap water samples and different food items revealed that human dietary exposure to PFPAs in Europe is currently not of concern. A novel method for simultaneous analysis of perfluoroalkyl carboxylic acids (PFCAs) and polyfluoroalkyl phosphate esters (PAPs) in food and packaging materials is described in paper III. Targeted food samples and their packaging were analyzed. The results showed that PAPs may contribute to human exposure to PFCAs. In paper IV temporal trends (1991-2011) of perfluorooctane sulfonic acid (PFOS) and its precursors in herring were investigated. Rapidly decreasing trends were found for precursors, whereas PFOS did not show a significant change over time. Precursors in fish may have played an important role for human exposure to PFOS in the 1990s but are probably negligible today. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p> / PERFOOD project (KBBE-227525)