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Premise plumbing can contain copper and lead bearing fixtures, and although copper is considered primarily an aesthetic issue, the neurotoxic effects of lead present a significant public health concern. Utilities approach corrosion control in low alkalinity water by increasing the pH (>9) or adding a phosphate inhibitor at neutral pH. Phosphate inhibitors, pH and chlorine are known to affect lead and copper release through their direct action as corrosion inhibitors or oxidizing agents or through an indirect action via microbial growth. Biofilms are often an implied cause of premise plumbing corrosion, although little is known about their community structure or ability to store metals. The central hypothesis of this thesis is that biofilm contributes to lead and copper release in premise plumbing. This thesis addresses a unique gap in corrosion literature by integrating traditional corrosion chemistry methods with microbiological and molecular biology techniques. The experiments used three distinct approaches: (i). electrochemical cell experiments to determine the key factors in decreasing lead and copper corrosion in galvanically coupled systems while maintaining microbial control (ii). galvanic macrocells using premise plumbing components to examine the unintended consequences of adding a phosphate based corrosion inhibitor and (iii). an annular reactor study to examine the impacts of two commonly applied corrosion control strategies. In the electrochemical cell experiments, the pH 9.2 with zinc orthophosphate and chlorine treatment achieved both goals: decreased lead and copper release and limited microbial growth. In galvanic macrocells experiments with premise plumbing components, zinc orthophosphate addition was shown to be positively correlated with increased bulk water bacteria, biofilm growth and biofilm community structure as measured by DGGE. Biofilm was also observed to sorb 3-29% of lead and 3-16% of copper from the bulk water. The comparison of the two corrosion control strategies showed that the majority of lead released was in the particulate form, and the results further alluded to the potentially significant role lead particles play in biofilm formation.

In potable water preparation, chlorination is the last step before the potable water enters the distribution network. Umgeni Water Wiggins Waterworks feeds the Southern areas of Durban. A reservoir at this facility holds treated water before it enters the distribution network. To ensure an adequate disinfection potential within the network, the free chlorine concentration in the water leaving the reservoir at the Umgeni Water Wiggins Waterworks should be between 0.8 and 1.2 mg/L. The aim of this study was to develop an effective strategy to predict and control the chlorine concentration at the exit of the reservoir. This control problem is made difficult by the wide variations in flow and level in the reservoirs, together with reactive decay of the chlorine concentration. A Computational Fluid Dynamic study was undertaken to gain understanding of the physical processes operating in the reservoir (FLUENT software). As this kind of modelling is not yet applicable for real-time control, compartment models have been created to simulate the behaviour of the reservoir as closely as possible, using the results of the fluid dynamic simulation. These compartment models were initially used in an extended Kalman filter (MATLAB software). In a first step, they were used to estimate the kinetic factor for chlorine consumption and in a second step, they predicted the chlorine concentration at the outlet of the reservoir. The comparison between predictions and data, allowed the validation of the compartment models. A predictive control strategy was developed using a Dynamic Matrix Controller, and tested offline on the compartment models. The controller manipulated the chlorine concentration in the inlet of the reservoir in order to control the chlorine concentration in the outlet of the reservoir. Finally, the simplest compartment model was implemented on-line, using the Adroit SCADA system of the plant, in the form of a Kalman filter to estimate the chlorine decay constant, as well as a predictive model, using this continuously-updated decay parameter. The adaptive Dynamic Matrix Controller using this model was able to control the outlet chlorine concentration quite acceptably, and further improvements of the control performance are expected from ongoing tuning. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.

Recently some chemicals has been accused of mimicking the female hormone estrogen. The mode of action is termed estrogen-mimicking, because of the effects that is produced by these chemicals. Playing canary in a coal mine, wildlife was the first to indicate that something was wrong. Reproductive abnormalities such as abnormal sperm, reduced sperm production, cryptorchidism (undescended testes). abnormal hormone levels – particularly high estrogen ratios to that of testosterone. infertility, and genital abnormalities were all evidence that something in the environment was affecting the reproductive status of these animals. Also in humans instances like rising cases of infertility, abnormal sperm conditions and cases of breast cancer raised an increased concern about the potential disruptive effects of these substances on the human existence. After investigations were conducted, it was found that substances which enhance the quality of life like some detergents, agricultural products, additives to plastic, dyestuffs, paint components and pharmaceuticals to name but a few, all caused an abnormal reproductive status as seen in animals. The aims of this study were not to focus on the effect of these substances, but rather to identify estrogen and estrogen - mimics in the South African environment and to evaluate their presence in the water environment qualitatively and quantitatively with the most suitable analytical methods. Estrogen - mimics such as nonylphenol. o'p' and p'p' DDE, o'p' DDD, lindane, atrazine and the PCB's : Arochlor 1254 & Arochlor 1260 were found to contaminate the environment. The drinking water tested of the PWV area indicated that the water was free of these substances, and thus indicated a present safe situation. / Thesis (MSc (Farmaseutika))--PU for CHE, 1998

Befolkningen i Stockholms län väntas öka med omkring 445 000 personer från år 2010 till år 2030. Det ställer krav på många samhällsfunktioner, däribland dricksvattenförsörjningen. Idag försörjs mer än 90 % av länets invånare med vatten från Mälaren. Vattenförsörjningen kommer behöva anpassas efter befolkningsutvecklingen, både för att producera tillräckliga dricksvattenvolymer och för en driftsäker leverans. Vid problem med den reguljära dricksvattenförsörjningen kan vattenleveranserna säkerställas genom tillgång till reservvatten-täkter. Redan idag (2014) är reservvattenförsörjningen i länet bristfällig och behöver utvecklas för att möta även det framtida vattenbehovet. Hur stora volymer reservvatten som behöver säkerställas, och till vilka områden, beror på vilka scenarier för driftsavbrott som ska kunna hanteras. Länets vattenresurser är geografiskt ojämnt fördelade och reservvatten-behovet är större i vissa delar av länet än i andra. Det innebär att för ett effektivt utnyttjande av de tillgängliga vattenresurserna krävs samordning mellan länets dricksvattenaktörer. Därför bör alternativ till hur reservvattenförsörjningen kan förbättras tas fram och utvärderas på regional nivå.   Syftet med examensarbetet var att studera scenarier och alternativ för reservvattenförsörjning i Stockholms län, framför allt genom en hållbarhetsanalys. Alternativen togs fram baserat på resultaten av tidigare studier av länets vattentillgångar. Fyra scenarier för avbrott i den reguljära vattenförsörjningen valdes ut. Med hänsyn till dessa och utifrån en uppskattning av vattenbehovet år 2030 identifierades två alternativ för reservvattenförsörjning, A och B, som kunde klara att ersätta hela vattenbehovet. Alternativen studerades med en hållbarhetsanalys, där de jämfördes med avseende på hållbarhetskriterier inom sex huvudkategorier: Hälsa och hygien, Miljö, Ekonomi, Sociokultur, Teknisk funktionalitet samt Grad av oberoende. Alternativen skiljde sig principiellt åt genom att systemalternativ A utnyttjade andra vattenresurser än Mälaren, medan systemalternativ B var fullständigt beroende av Mälaren.   Resultatet av hållbarhetsanalysen var att systemalternativ B är mer hållbart än system-alternativ A. Det beror framför allt på att systemalternativ B presterade bättre med avseende på de ekonomiska och miljömässiga kriterierna. Dock förutsattes i hållbarhetsanalysen att reservvattenlösningarna inte behövde vara oberoende av den ordinarie dricksvattentäkten (Mälaren). Om krav hade funnits på att reservvattenförsörjningen ska vara fullständigt oberoende av den reguljära vattentäkten skulle systemalternativ B inte uppfylla kravet. Om hållbarhetskategorin Grad av oberoende inte skulle ingått i analysen hade systemalternativ B blivit överlägset mer hållbart än systemalternativ A. Utifrån analysen kan konstateras att eventuella krav på reservvattenförsörjningens oberoende av den reguljära täkten behöver diskuteras i länet. Det är också intressant att diskutera om fördelarna med avseende på övriga hållbarhetsaspekter (förutom Grad av oberoende) överväger tillräckligt mycket hos system-alternativ B för att bortse från beroendet av Mälaren, även om det är olika delar av Mälaren som utnyttjas. / The population of Stockholm County will increase by approximately 445 000 people from 2010 until 2030. This makes demands on many societal services, including drinking water supply. Today more than 90 % of the Stockholm County inhabitants receive drinking water from Lake Mälaren. An adaption of the water supply to the population growth is necessary in order to produce enough water and to ensure reliable water supply. In case of problems in the regular water sources, water supply can be ensured by the use of backup water resources. Even today (2014), the backup water supply in the county is insufficient, and needs development in order to meet also the future water demand. The volumes of backup water needed, and their spatial distribution, depend on the scenarios for disruption of the regular supply to be handled. The water resources in the county are unevenly distributed and the need for backup water is greater in some parts of the county than in others. This means that in order to ensure an efficient use of the available water resources, coordination between the county’s different drinking water actors is necessary. Therefore, alternatives for improvements of the backup water supply should be developed and evaluated on a regional level.   The aim of the master’s thesis was to study scenarios and alternatives for backup water supply in Stockholm County, mainly by the use of sustainability analysis. The alternatives were developed based on results from earlier studies of the water recourses in the county. Four scenarios for disruption of the regular water supply were chosen. In regards to these scenarios and based on an estimation of the water need 2030, two alternatives for backup water supply were identified, systems alternative A and B. The alternatives were assessed by a sustainability analysis, where they were compared based on six main categories: Health and hygiene, Environment, Economy, Socio-culture, Technical robustness and Magnitude of independence. The alternatives were principally different in that systems alternative A included exclusively other water resources than Lake Mälaren, while systems alternative B was fully dependent on Lake Mälaren.   The result of the sustainability analysis was that systems alternative B is more sustainable than systems alternative A. This is mainly due to the fact that systems alternative B had a better performance in terms of the economic and environmental criteria. However, in the sustainability analysis it was assumed that the backup water systems did not have to be independent of the regular water source (Lake Mälaren). If there would have been a requirement of the backup water supply to be fully independent of the regular water supply, then systems alternative B would not have been qualified. If the sustainability category Magnitude of independence would not have been included in the analysis, then systems alternative B would have been far superior to systems alternative A. From the analysis it is clear that possible requirements of independency of the backup water supply from the regular water supply, need to be discussed in the Stockholm County. It is also interesting to discuss whether the advantages in terms of the other sustainability aspects (besides Magnitude of independence) are large enough for systems alternative B to motivate a disregard of the dependency of Lake Mälaren, which however uses different parts of Lake Mälaren.

D.Phil. / Clean water (i.e. water that is free of toxic chemicals and pathogens) is essential to human health and in South Africa the demand is fast exceeding the supply. The prevalence of toxic contaminants in water remains a huge challenge for water supplying companies and municipalities. However, the presently used water treatment technologies either fail to remove these contaminants to acceptable levels or they transform them into more toxic substances (e.g., DBPs). Nanocatalysts, especially TiO2 (titania) have a proven potential to treat ‘difficult-to-remove’ contaminants and hence are expected to play an important role in solving many serious environmental and pollution challenges. In this study TiO2 nanocatalysts were used for the degradation of Rhodamine B dye both under UV and visible light irradiation. Two phases of titania, i.e. anatase and rutile phases, were compared for the degradation of Rhodamine B under UV light irradiation. The anatase titania was found to be more photocatalytically active for the degradation of Rhodamine B than the rutile phase. It completely degraded 100 mg ℓ–1 (100 mℓ) of Rhodamine B within 270 min and was two times more photocatalytically active than the rutile phase (Kapp of 0.017 min–1 compared to 0.0089 min–1). To extend the band edge of the titania nanocatalysts towards visible-light, TiO2 was doped with metal ions (Ag, Co, Ni and Pd). These metal-ion-doped titania nanocatalysts were photocatalytically active under visible-light illumination. The Pd-doped titania had the highest photodegradation efficiencies, followed by Ag-doped and Co-doped, while Ni-doped had the lowest. The optimum metal-ion loading percentage was found to be at 0.4%, with the exception of Co-doped titania as it had the highest efficiencies at 1% loadings. The free and metal-ion-doped titania nanocatalysts were embedded on carbon-covered alumina (CCA) supports. The CCA-supported TiO2 nanocatalysts were more photocatalytically active under visible light illumination than they were under UV-light irradiation. The CCA-supported metal-ion-doped titania nanocatalysts were more photocatalytically active under visible light than their unsupported counterparts. The CCA-supported Pd-TiO2 nanocatalysts were the most active while CCA-supported Ni-TiO2 catalysts were the least active. The improved photocatalytic activities observed were as a result of increased surface areas of the CCA-supported nanocatalysts. Also, supporting the nanocatalysts did not destroy the anatase phase of the titania while doping with metal ions and supporting on CCAs resulted in decreased band gap energies, hence the visible-light photocatalytic activities. Finally, the metal-ion-doped titania nanocatalysts were supported on glass slides using the layer-by-layer thin film self-assembly technique. This was to overcome the aggregation and post treatment problems associated with the use of TiO2 in suspension form. PAH and PSS were the polyelectrolytes used. These metal-ion-doped titania thin films were highly porous and strongly adhered by the polyelectrolytes onto the glass slides. The thin films were photocatalytically active for the degradation of Rhodamine B under visible light irradiation. The photocatalytic degradation efficiencies observed were similar for all four metal-ions (i.e. Ag, Co, Ni and Pd) with average degradation of 30%, 50%, 70% and 90% for 5 catalysts (5 glass slides) of 1, 3, 5 and 10 bi-layers, respectively, after 330 min. Although, these were less active than the suspended titania nanocatalysts, this study proved as a stepping stone towards large scale use of titania nanocatalysts using solar energy as the irradiation source. Also, catalyst reusability studies were performed and the PAH/PSS m-TiO2 thin films were found to be highly stable over the five cycles it was tested for.

Beyond the expected DBP exposure from drinking water, dermal from bathing, and inhalation, occurrence in food and beverage items can provide an additional occurrence pathway. Synthetic dyes are often added to beverages for aesthetic purposes and many are in the form of a reactive azo (-N=N-) dye or triarylmethane dye, both with a characteristic aromatic ring. The presence of dyes in beverages that are reconstituted with disinfected tap water pose the risk of reactions with the residual chlorine in the drinking water resulting in decolorization, and of greater concern, disinfection byproduct formation. Additionally, oral over-the-counter (OTC) medications contain chemical constituents that when reconstituted with tap water present a risk of DBP formation. Several studies were performed to evaluate the kinetic decay rates of the dyes and drugs in disinfectants, and the effects of water quality conditions on DBP formation. Commercial beverage products and OTC medications were evaluated for the DBPs that were detected in the free chlorine-treated precursor samples. The dye and drugs precursors followed second order kinetics, with the fastest rates for brilliant blue and phenylephrine in chlorinated water. The effects of water properties on precursor degradation and DBP formation was complex due to the influence of characteristics of precursor molecules. The cytotoxic and anti-estrogenic responses were measured in the dye and drug precursors and their respective beverages and OTC medications, to determine potential links. Mio Energy showed estrogenic character and Alka Seltzer induced an anti-estrogenic and cytotoxic response, however there were no clear linkages between the beverage/ medication and their respective dye and drug precursors.

Dans la plupart des pays en voie de développement, l'un des défis majeurs à révéler par les pouvoirs publics demeure la couverture des besoins des populations en services sociaux de base (Eau potable, Électricité, Infrastructure d'assainissement, etc.). A Bamako, les problématiques liées à ces services se posent avec beaucoup plus d'acuité que la ville connaît un des taux de croissance démographique et spatiale les plus importants du continent (3,5%) . Malheureusement, cet étalement n'a pu être accompagné par un développement proportionnel des infrastructures adéquates à cause de la faiblesse des ressources de l'Etat. Les difficultés énormes rencontrées par ces pays dans ce domaine ont amené la communauté internationale à initier les OMD. Au Mali, comme partout ailleurs, un impressionnant arsenal institutionnel et juridique a été mis en place à cet effet (PNAEP, Code de l'eau, PNE, PNA, etc.). Grâce à ce dispositif, même si beaucoup reste encore à faire dans le domaine de l'assainissement, les objectifs seront atteints dans le domaine de l'eau. Et pour une meilleure efficacité de la société de distribution de l'eau potable, l'Etat malien a ouvert son capital aux investisseurs privés. Après une expérience de 5 années de partenariat public-privé, marquée par un environnement économique mondial difficile et un contexte sociopolitique complexe, le bilan est diversement apprécié. Bamako et plusieurs autres centres urbains restent partiellement privés d'eau potable. Pour pallier cette présence insuffisante de l'Etat, aussi bien dans le domaine de l'eau potable que de l'assainissement liquide, des initiatives locales se sont développées à travers toute la ville de Bamako. / In the majority of developing countries, one of the major challenges the authorities have to take up is to provide the populations' basic social services needs (drinking water, electricity, cleaning-up infrastructure, etc.). In Bamako, the set of problems linked to these services comes with more severity, as the city has one of the most significant population and spatial growth rate of the African continent (3.5%)1. Unfortunately, this spreading out of Bamako did not go with a proportional development of adequate infrastructures, due to the weakness of the resources the State has. The huge difficulties encountered by these countries in this field led the international community to initiate the Millennium Development Goals (MDGs). In Mali, like everywhere else, an impressive array of institutional instruments and legal arsenal has been enacted for this purpose (the National Drinking Water Access Plan, the Water Code, the National Environmental Policy, the National Sanitation Policy, etc.). Through this mechanism, the goals will be achieved in the area of water, though there is still much to be done in the area of sanitation. In order to ensure a better effectiveness of the drinking water supply company, the Malian government has even opened it up to private investors. After an experience of 5 year public-private partnership, characterized by a tough global economic environment and a complex socio-political context, assessments of the results achieved vary greatly. Bamako and many other urban centers partially remain without drinking water.

This diploma thesis is aimed at the evaluation of the efficiency of surface water treatment technology in water treatment plant U svaté Trojice (Kutná Hora, Vrchlice reservoir). The plant performs destabilisation of impurities by coagulant aluminium sulphate (Al2(SO4)3 . 18 H2O) followed by aggregation induced by mixing with perforated baffles. Suspension is removed by double-stage separation process by means of sedimentation and filtration. When increased concentrations of manganese occur in raw water, manganese is removed by means of oxidation by potassium permanganate. Firstly, the quality of raw water was analysed. Then, the reaction conditions for the effective destabilisation (pH, dose of coagulant) were set using the jar tests. Moreover, sedimentation analysis was used to evaluate the properties of formed suspension and the length of filter cycles was assessed. Measurements were conducted between September 2012 and February 2013. Average value of raw water pH was 7.3, alkalinity was 1.64 mmol/l. DOC concentrations during September and October 2012 were equal to 6.7 mg/l and during November 2012 - February 2013 were 7.6 mg/l. Very low concentrations of aluminium (< 0.02 mg/l) were ascertained throughout the whole period investigated. Results of the jar tests showed that the optimum pH for...

A research report submitted to the Faculty of Engineering an the built environment, University of the Witwatersrand, Johannesburg in partial fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg, October 2016. / The study investigates the effectiveness of Rand Water’s Scientific Services’ skills development strategy for the assurance of quality drinking water as prescribed by the SANS 0241 National Drinking Water Quality Standard. The aim is to establish whether: 1) the present skills are adequate to provide the scientific data required for affirming drinking water quality and 2) the skills development taking place in the Scientific Services division is adequate for the level and quantity of scientific skills required for the future. There is also some discussion to understand the motivation for maintaining and increasing skills within the Scientific Services division for Rand Water. Assuring drinking water quality within Rand Water is the sole responsibility of the Scientific Services division. The division provides regular routine and non-routine drinking water quality monitoring, testing, data collection, analyses and reporting on the organisation’s performance against the SANS 0241 Drinking Water Quality Standards (SANS, 2006).The focus of the analysis is Scientific Services Division in Rand Water, although the discussion in view of the topic is not limited to the division. Production of drinking water encompasses two key aspects that must be investigated they are quality and quantity, however the close up analyses could only be successful completed for quality in the context of the quantity produced. Skills development planning within Scientific Services has always been based on the division’s feeder pipelines to be able to recruit from and retain scientific skills within the organisation. The division concentrates on Graduate, Bursar and Experiential Learner development ensuring a sustainable, trained and readily available pipeline of skills from which to recruit. Employees currently within the division both permanent and temporary form the type of scientific skills required for water quality monitoring and drinking water standard production and assurance. Employees have been placed within the functional scientific streams of the division and further by their levels of appointment and qualifications. The data analysis has also been done for the increasing of skills using the same framework. Age and gender was also included to show performance of the division in respect to transformation and equity. Equity in relation to growth is currently a global matter that is under scrutiny. The World Economic Forum has put equity in the spotlight to ensure countries look at their performance. The significance is that it has an impact on how the water resources in a country are distributed and managed. The Water Reforms in most developing countries have sparked large scale discussions around provisioning of water for all. Human Development and Water Resource Management are agendas that countries need to handle collectively with the ultimate outcome being achieving equity for all (UNDP, 2013). Rand Water’s Scientific Service skills data indicates that it has adequate scientific capacity to meet its present mandate of providing drinking water quality assurance for the organisation. There is some concern that the aging workforce is concentrated at management and specialists levels, therefore developing these skills for the next 5 to 10 years requires immediate attention. Transfer of skills and retention of skills requires careful strategic planning in order to attract a younger transformed workforce. The study shows that in as much as routine quality assurance is core, it is also equally critical to have employees who can troubleshoot within the context of the new environmental pressures and diverse operational conditions. The demand for quality drinking water over the last 110 years has increased throughout the country. The mandatory expansion of the organisation translates into sharing of human resources with other parts of the country to produce quality drinking water. Rand Water has been entrusted to take on the responsibility of other water utilities in the country and ensure that they reach the required standard for the production of quality drinking water. The full scope of the organisation’s mandate requires that it provide skills to handle the treatment of drinking water and wastewater in the near future. Although wastewater treatment is currently managed by the local municipalities, Rand Water will be having an active role to improve services. This would mean distributing the existing capacity within the organisation over a greater area of work along with a significant increase in the demand for scientific analyses of drinking water quality. The pace at which skills development takes place in Rand Water Scientific Services division shows that it will be able to meet the present needs. There are questions raised on the sustainability of the skills for the future. Maintaining and developing skills within the division is critical to be able to sustain the nature, structure and functioning of the division in its current form. The other factor that must also be maintained is the transformational equity demands of the country. The notion that there is a lack of experienced previously disadvantages scientists must be addressed directly to meet all the future demands of the sector, region and continent in a short space of time. / MT2017