Tesi sul tema "Water quality"

Given the present constraints on capital expenditure for water quality improvements, it is essential that best management practices be adopted whenever possible. This research provides an evaluation of existing practices in use within the water industry for surface water quality classification and assesses water quality indices as an alternative method for monitoring trends in water quality. To this end, a new family of indices have been developed and evaluated and the management flexibility provided by their application has been examined. It is shown that water-quality indices allow the reduction of vast amounts of data on a range of determinand concentrations, to a single number in an objective and reproducible manner. This provides an accurate assessment of surface water quality which will be beneficial to the operational management of surface water quality. Previously developed water quality indices and classifications are reviewed and evaluated. Two main types of index are identified: biotic indices and chemical indices. The former are based exclusively upon biological determinands/indicators and are used extensively within the United Kingdom in the monitoring of surface water quality. The latter includes a consideration of both physico-chemical and biological determinands, but with an emphasis on the former variables. Their use is still the subject of much controversy and discussion. Four main approaches to the development of chemical indices can be identified in accordance with the aims and objectives of their design. Those developed for general application are known as General Water Quality Indices (WQIs) or Indices of Pollution, with the latter based predominantly upon determinands associated with man-made pollution. Those which reflect water quality in terms of its suitability for a specific use are termed use-related; whilst planning indices are those which attempt to highlight areas of high priority for remedial action on the basis of more wide-ranging determinands. The derivation and structure of previously developed indices have been evaluated and the merits and strengths of each index assessed. In this way, nine essential index characteristics were identified, including the need to develop an index in relation to legal standards or guidelines. In addition it was recognised that one requirement of an index should be to reflect potential water use and toxic water quality in addition to general quality as reflected by routinely monitored determinands. The development of river quality classifications within the United Kingdom is reviewed and the additional management flexibility afforded by the use of an index evaluated by comparing the results produced by the SOD (1976) Index with those of the National Water Council (NWC, 1977) Classification. The latter classification is that presently used to monitor water quality in Britain. The SOD Index was found to be biased towards waters of high quality and provided no indication of potential water use or toxic water quality. Nevertheless, it displayed a number of advantages over the NWC Classification in terms of the operational management of surface water quality. It was therefore decided to develop a new family of water quality indices, each based upon legally established water quality standards and guidelines for both routinely monitored and toxic determinands and each relating water quality to a range of potential water uses, thereby indicating economic gains or losses resulting from changes in quality. Four stages in the development of a water quality index are discussed: determinand selection; the development of determinand transformations and weightings; and the selection of appropriate aggregation functions. Four separate indices have been developed as a result of this research. These may be used either independently or in combination with one another where a complete assessment of water quality is required. The first of these is a General Water Quality Index (WQI) which reflects water quality in terms of a range of potential water uses. This index is based upon nine physico-chemical and biological determinands which are routinely monitored by the water authorities and river purification boards of England, Wales and Scotland. The second, the Potable Water Supply Index (PWSI) is based upon thirteen routinely monitored determinands, but reflects water quality exclusively in terms of its suitability for use in potable water supply (PWS). The two remaining indices, the Aquatic Toxicity (ATI) and Potable Sapidity (PSI) Indices are based upon toxic determinands such as heavy metals, pesticides and hydrocarbons which are potentially harmful to both human and aquatic life. Both indices are use-related, the former reflecting the suitability of water for the protection of fish and wildlife populations; the latter, the suitability of water for use in PWS. Each index is based upon nine and twelve toxic determinands respectively. These indices were developed in as objective and rigorous a manner as possible, utilising an intensive interview and questionnaire programme with members of both the water authorities and river purification boards. Rating curves were selected as the best way in which individual determinand concentrations could be transformed to the same scale. The scales selected for the WQI and PWSI are 10 - 100 and 0 - 100 respectively, whilst those of the ATI and PSI are 0 - 10. Each has been sub-divided in such a way as to indicate not only water quality, but also possible water use. Thus, the indices reflect both current and projected changes in the economic value of a water body which would occur as a result of the implementation of alternative management strategies. The curves were developed using published water quality standards and guidelines relating to specific water uses. Therefore, they contain information on standards which must be adhered to within the United Kingdom and this adds a further dimension to their management flexibility. Determinand weightings indicating the emphasis placed by water quality experts upon individual determinands were assigned to the determinands of the WQI and PWSI. However, weightings were omitted from the ATI and PSI due to the sporadic nature of pollution events associated with these determinands. These vary spatially and temporally, both in concentration and in terms of which determinand is found to be in violation of consent conditions. Therefore, on a national scale, no one determinand could be isolated as being more important than any other. Three aggregation formulae were evaluated for use within the developed indices: the weighted and unweighted versions of an arithmetic, modified arithmetic and multiplicative formulation. Each index was applied to data collected from a series of water quality monitoring bodies covering a range of water quality conditions. In each instance, the modified arithmetic formulation was found to produce index scores which agreed most closely with a predetermined standard, normally the classifications assigned using the NWC classification. In addition, this formulation produced scores which best covered the ascribed index range. However, the multiplicative unweighted formulation was retained for use within the ATI and PSI for the detection of zero index scores, i.e. when concentrations in excess of legal limits were recorded for these toxic determinands. The results from these studies validate the ability of each index to detect fluctuations in surface water quality. Therefore, the utility of the developed indices for the operational management of surface water quality was effectively demonstrated and the flexibility and advantages of an index approach in providing additional information upon which to base management decisions was highlighted.

Maintaining water quality in distribution systems has become a prominent issue in the study of water networks. This thesis concentrates on disinfectant and particle counts as two important indicators of water quality. The models discussed in this work are based on data collected by the author. The experimental set-up and procedure are described and observations of particle counts, particle counter size distributions, monochloramine as disinfectant, temperature, heterotrophic plate counts and epifluorescence microscopy counts are reported. A model of the response of particle counts to an increase in flow is developed. This model is obtained from specification derived from the data and assumptions, and is validated by its interpretability and its fit to data. A local shear-off density and an initial biofilm shedding profile were introduced and thus a linear model for this part of the water quality dynamics could be obtained. A procedure for the identification of the parameters of the local shear-off function and for the determination of the biofilm shedding profile is presented. This profile can be used to provide information about the status of the distribution system in terms of shear-off from the biofilm on the pipe walls. Monochloramine decay dynamics are investigated. The chlorine meter data is preprocessed with the help of titration data to correct meter drift. The data is then used in calibrating two different possible chlorine models: a model with a single decay coefficient and a model with bulk decay coefficient and wall demand (as used in Epanet). Important difficulties in identifying these parameters that come about because of the structure of the models are highlighted. Identified decay coefficients are compared and tested for flow, inlet chlorine and temperature dependence. The merits and limits of the approach to modelling taken in this work and a possible generalisation are discussed. The water industry perspective and an outlook are provided.

This study was designed to evaluate the safety of gray water for reuse purposes. The physical and chemical quality of treated gray water met water reuse standards set by the State of Arizona for surface irrigation purposes. The number of microorganisms in gray water significantly decreased after biological treatment and sand filtration. However, the number of fecal coliform bacteria in treated gray water was still higher than the standard for reuse as set by the State of Arizona for surface irrigation. This is also true for rain water which was stored in a tank. No indigenous Salmonella were isolated from gray water. It was found that both Salmonella typhimurium and Shigella dysenteriae, seeded into gray water, can persist for at least several days. This implied that there may be some risk associated with gray water reuse when the gray water contains these pathogenic bacteria.

The following document serves as a design guidebook to assist landscape architects, designers, planners, engineers, and architects in the practice of developing land while preserving water quality. This guidebook outlines methods for maximizing permeable surfaces by providing examples of ways to minimize impervious surfaces.
Master of Landscape Architecture

This dissertation involves two different studies. The first concerns the real-time detection of microbial contamination in drinking water using intrinsic fluorescence of the microorganisms. The prototype, “Blinky”, uses LEDs that emit light at 365nm, 590nm, and 635nm for ultraviolet, amber, and red light, respectively. At 365 nm, the cellular components excited include reduced pyridine nucleotides (RPNs), flavins, and cytochromes to distinguish viable bacteria; at 590 nm, the cellular components excited include cytochromes for non-viable bacteria; at 635 nm, the cellular components excited include calcium dipicolinic acid (DPA) for spores. By using these three different wavelengths, the prototype can differentiate between viable and non-viable organisms and also has the potential to detect spores. The aim of this study was to improve the detection limit by modifying the design of the instrument and to establish the detection limit of viable and non-viable bacteria and spores. The instrument was modified by replacing existing LEDs with LEDs that had 50% more intensity. Two additional LEDs were added for amber and red light, bringing the total to four LEDs for each. The LEDs were also positioned closer to the photomultiplier tube so as to increase sensitivity. For UV, only two LEDs were used as previous. The detection limit of the viable bacteria was ~50 live bacteria/L. No change in the intrinsic fluorescence below the concentration of ~10⁸ dead bacteria/L was observed. The results for spore measurements suggested that most of the spores had germinated before or during the measurements and could not be detected. The instrument was successful in detection of viable bacteria and also differentiating viable and non-viable bacteria. The instrument was not successful in detection of spores. The second study was designed to assess the water quality of well construction in southeastern Tanzania. Three designs were tested: Msabi rope pump (lined borehole and covered), an open well converted into a closed well (uncovered well into a covered and lined well), and an open well (uncovered and may or may not be lined). The study looked at the microbial and chemical water quality, as well as turbidity. The survey included 97 water collection points, 94 wells and three rivers. For microbial analysis, heterotrophic plate count (HPC), total coliforms and E. coli tests were performed. Fifteen of these wells were further analyzed for microflora and diversity for wells comparison purposes, using culture methods, followed by polymerase chain reaction (PCR) and genome sequencing. Ten wells out of the fifteen were analyzed for calcium (water hardiness), potassium, nitrates, nitrites, chloride, fluoride, bromide, sulfate, iron, and arsenic. Two water collection points were also selected for organic compound analysis (gasoline components). All samples tested positive for coliforms. Two samples tested positive for Escherichia coli for the lined borehole (Msabi rope pump) and four samples from closed wells. All open wells tested positive for E. coli. There was more microbial diversity in open wells than the closed wells and Msabi rope pumps. Potential bacterial pathogens were detected in seven wells out of the fifteen examined. The wells that tested positive were one Msabi rope pump, one closed well; the rest were from open water sources. Open wells had high turbidity followed by closed wells. Msabi rope pumps had low turbidity comparing to the two wells designs. No traces of gasoline components were detected in any of the water sources. One well out of ten had high amounts of nitrates-nitrogen (> 10 mg/L). The results of this study showed that the Msabi rope pumps performed comparably to the closed wells in terms of microbial quality but performed better with regard to turbidity. The open wells performed poorly in terms of microbial water quality as well and turbidity. There was a statistical difference in HPC, total coliforms, E.coli numbers and turbidity between open wells, closed wells and the Msabi rope pumps. However, there was no statistical difference in HPC, total coliforms and E.coli numbers between the closed wells and Msabi rope pumps. Msabi rope pumps performed better in turbidity

Thesis (M.S.)--University of New Orleans, 2003.
Title from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering"--Thesis t.p. Vita. Includes bibliographical references.

Source water quality plays a critical role in maintaining the quality and supply of drinking water, yet it can be negatively affected by human activities. In Pennsylvania, coal mining and treatment of conventional oil and gas drilling produced wastewaters have affected source water quality for over 100 years. The recent unconventional natural gas development in the Marcellus Shale formation produces significant volumes of wastewater containing bromide and has the potential to affect source water quality and downstream drinking water quality. Wastewater from coal-fired power plants also contains bromide that may be released into source water. Increasing source water bromide presents a challenge as even small amounts of bromide in source water can lead to carcinogenic disinfection by-products (DBPs) in chlorinated finished drinking water. However, bromide is not regulated in source water and is not removed by conventional drinking water treatment processes. The objective of this work is to evaluate the safe bromide concentration in source water to minimize the cancer risk of trihalomethanes - a group of DBPs - in treated drinking water. By evaluating three years of water sampling data from the Monongahela River in Southwestern Pennsylvania, the present analysis reached three conclusions. First, bromide monitoring for source water quality should be taken at drinking water intake points. Water sample types (river water samples vs drinking water intake samples) can lead to different water quality conclusions and thus affect regulatory compliance decision-making. Second, bromide monitoring at drinking water intake points can serve as a predictor for changes in heavily brominated trihalomethanes concentrations in finished water. Increasing bromide in source water can serve as an early warning sign of increasing formation of heavily brominated trihalomethanes and their associated cancer risks in drinking water. Finally, this work developed a statistical simulation model to evaluate the effect of source water bromide on trihalomethane formation and speciation and to analyze the changing cancer risks in water associated with these changing bromide concentrations in the Monongahela River. The statistical simulation method proposed in this work leads to the conclusion that the bromide concentration in source water must be very low to prevent the adverse health effects associated with brominated trihalomethanes in chlorinated drinking water. This method can be used by water utilities to determine the bromide concentration in their source water that might indicate a need for process changes or by regulatory agencies to evaluate source water bromide issues.

The conventional approach to water quality monitoring is to combine periodic sampling with batch analysis in the laboratory. Such a procedure is both labour intensive and time consuming, there are likely to be sample stability and contamination problems, and the information provided is unlikely to be continuous or immediate. This research focussed on the design and construction of fully automated and portable monitors based on flow injection analysis and incorporating solid state photometric detectors. A novel solid state photometric detector was constructed, incorporating light emitting diodes as the light source, which could be used in conjunction with flow injection analysis. Manifolds were studied for a range of species of interest (phosphate, nitrate, ammonia and aluminium) in the field of water quality monitoring and were optimised for their suitability for continuous use. An automated monitor for nitrate was constructed and long term evaluation trials were carried out at several locations for water quality monitoring. Results are also presented for the use of a nitrate monitor in hydroponic cultivation. An automated monitor was also built for the monitoring of ammonia levels in natural waters, which was field tested on the River Avon (Wiltshire). A manifold was also evaluated for the monitoring of residual aluminium levels in drinking water and is currently being commissioned at a water treatment works in Somerset.

The impounding of estuaries is currently a popular approach to urban regeneration in the UK, with barrages constructed (Tees, Wansbeck, Tawe, Cardiff Bay, Lagan and Clyde) or proposed (Usk, Loughor, Neath, Hayle, Avonmouth and Ipswich) nationwide. Impounding fundamentally alters the dynamics of estuaries with consequences in terms of sedimentation patterns and rates, ecology, flooding, groundwater, etc. This thesis presents the findings from research into the effects of impounding on estuarine water quality. A series of surveys of a range of physical and chemical parameters were carried out within four estuaries representing the complete range of tidal modification by barrage construction. Internal versus external controls on water quality are distinguished. General water quality in estuarine impoundments is good, but significant problems occur where water bodies show entrenched density stratification, with anoxia and associated increases in ammonia and metal concentrations developing. Stratification related problems are worse in partial than total tidal exclusion impoundments (although a higher rate of tidal overtopping shortens the isolation periods of deep anoxic waters), and low water quality at depth is observed over the majority of the year. The potential for eutrophication is increased by barrage construction, although phosphorus (generally the limiting nutrient) is shown to be catchment sourced, with internal cycling from sediment insignificant. Sediment thickness is shown not to be a control on water quality, although sediment build-up over time eventually leads to a loss of amenity value. Sterol fingerprints are used to identify sewage inputs to the impoundments. Advice for barrage planners and designers is given, including the exclusion and removal of saline water, provision of destratification/aeration devices, control of nutrient inputs, and modelling of sediment loads and deposition. This study has shown that catchment management is fundamental in the sustainability of estuarine impoundments.

The aim of this thesis is to provide a comprehensive view of surface water and groundwater quality management as in these recent years it has been a widely discussed topic of international relevance, with a particular focus on China's legislative and regulatory developments that had an impact on water quality related issues.

Thesis (MEng)--University of Stellenbosch, 2000.
ENGLISH ABSTRACT: The processes of monitoring, modelling and managing the water quality of a catchmerit system including all its unique complexities and interrelationships requires an innovative tool or set of tools to help water managers with their decision making. Numerous methods and tools have been developed to analyse and model the real world. However, many of these tools require a fair degree of technical expertise and training to operate correctly and their output may have to be translated or converted to meaningful information for decision-making using a further set of analytical and graphical display tools. A more appropriate technique for management would be to combine all these functions into a single system. The objective of this research was to develop one such tool, an integrated water quality information system (WQIS). A review of the literature revealed that there has been extensive research and development of tools for the management of individual aspects of water resource distribution, augmentation and quality. However, these tools have rarely been integrated into a comprehensive information system offering decision support to a wide variety of river users and managers. Many of the literature sources also noted that a process of interactive development and integration (i.e. including the intended users in the decision of which components to include, the interface design and the graphical display and output) was vital to ensuring the information system becomes an integral part of the users routine work and decision-making. The WQIS was developed using the recommendations from numerous knowledgeable persons in response to questionnaires, interviews and a prototype demonstration. It includes the results of hydrodynamic river and reservoir simulations and the ability to perform operational river scenario testing. However, the development process is continual and always evolving based on the current or local requirements of water managers. These further developments and research needs are discussed in more detail in the conclusion.
AFRIKAANSE OPSOMMING: Die proses om die waterkwaliteit van 'n opvanggebied, met al die unieke kompleksiteite en onderlinge verhoudings van so 'n stelsel te monitor, modelleer en bestuur, vereis 'n innoverende instrument om waterbestuurders te ondersteun in hul besluitnemings. Talle instrumente en metodes vir die ontleding en modellering van die werklikheid is reeds ontwikkel. Die gebruik van hierdie instrumente vereis gewoonlik 'n redelike mate van tegniese kundigheid en opleiding. Dit mag verder nodig wees om die uitvoer van sulke instrumente te vertaal en/of om te skakel na betekenisvolle inligting vir besluitneming deur die gebruik van bykomende analitiese en grafiese vertoon instrumente. 'n Meer toepaslike bestuurstegniek sou wees om al die funksies in 'n enkele stelsel te kombineer. Die doel van hierdie navorsing was om een so 'n instrument, naamlik 'n geïntegreerde waterkwaliteit inligtingstelsel (WQIS), te ontwikkel. 'n Hersiening van bestaande literatuur het getoon dat daar omvattende navorsing en ontwikkeling van instrumente gedoen is vir die bestuur van individuele aspekte van waterbronverspreiding, waterbronaanvulling en waterkwaliteit. Integrasie van hierdie instrumente, in 'n uitgebreide stelsel wat besluitnemingsondersteuning aan 'n verskeidenheid riviergebruikers en bestuurders bied, kom egter selde voor. Verskeie literatuurbronne het ook aangedui dat 'n proses van interaktiewe ontwikkeling en integrasie (m.a.w. in agname van die voorgenome gebruikers se behoeftes in die kense van komponente, die gebruiker raakvlak ontwerp en grafiese vertoon instrumente en uitvoer) noodsaaklik is om te verseker dat die inigtingstelsel 'n integrale deel word van die gebruiker se daaglikse roetine en besluitnemingsproses. Die WQIS is ontwikkel deur gebruikmaking van die insette en aanbevelings van verskeie kenners in reaksie op vraelyste, onderhoude en 'n demonstrasie van 'n prototype. Dit sluit in die resultate van hidro-dinamiese rivier en dam simulasies en die vermoë om operasionele rivier scenario ontledings uit te voer. Die ontwikkeling is egter 'n deurlopende proses, gebaseer op huidige of plaaslike behoeftes van waterbestuurders. Hierdie verdere ontwikkelings- en navorsingsbehoeftes word meer breedvoerig in die gevolgtrekkings bespreek.

When estimating economic value associated with changes in water quality, recreation demand models typically depend upon either (i) biophysical measures of water quality as collected by natural scientists or (ii) the perception of water quality by recreationists. Models based upon biophysical metrics (such as oxygen concentration, pollutant concentrations, Secchi depth measurements, etc.) operate on the assumption that people can perceive and respond to these metrics, or respond to factors that are, indeed, correlated with the biophysical measure. Economists have often estimated willingness-to-pay (WTP) measures associated with unit changes in biophysical measures without examining the degree to which the measures are truly correlated with perceptions. Recreation demand models that are based upon respondents’ perceptions of water quality necessarily assume that perceptions correlate well with the measures used by scientists to evaluate water quality. Again, WTP for unit changes in perceptions have been estimated without examining the relationship to the underlying biophysical measures. The relationship between biophysical metrics and perceptions is rarely addressed, yet it has profound implications for water quality management and policy. Consider a federal or state agency wishing to manage the quality of its waters in an economically efficient way. Through mandated water quality monitoring regulations, an agency may have many years of biophysical measurements, but these measures are in no way linked to people’s perceptions of water quality and, thus, to WTP. Using biophysical measures of water quality and recreation use data recently collected in Utah, this study links technical measures of water quality at a water body to survey respondents’ perceptions of water quality at the same site. This approach is akin to estimating an ecological production function wherein biophysical measures are “inputs” to water quality perceptions (the output). Truncated Negative Binomial models of water-based recreation are used to estimate welfare effects of changes in water quality as measured through (i) unit changes in biophysical measures, (ii) unit changes in perceptions, and (iii) unit changes in biophysical as they change perceptions through the ecological production function.

Problémy s vodou, zejména její nedostatek a znečištění, ovlivňují každodenní lidský život a hospodářský vývoj. Globální změny klimatu zvyšují pravděpodobnost a četnost extrémních událostí jako jsou sucho a záplavy. Rostoucí problémy s nepravidelnou dostupností a znečištěním vody vyžadují pokročilejší metodiky hodnocení vodních zdrojů, které povedou k efektivnímu využití a hospodaření s vodou. Tato práce se zabývá rozšířenými metodikami pro hodnocení vody z pohledu její kvality a kvantity a pro hodnocení spotřeby energie a produkce emisí souvisejících s vodou. Tři hlavní metodiky jsou navrženy na základě konceptu vodní stopy (Water Footprint) a pinch analýzy vody (Water Pinch Analysis) pro posouzení kvantitativních a kvalitativních hledisek využití a spotřeby vody. Použití těchto metod je rovněž demonstrováno pomocí numerických a empirických případových studií zaměřených na hodnocení a optimalizaci využití regionálních a průmyslových vodních zdrojůDále jsou diskutovány souvislosti mezi vodou a energií (Water-Energy Nexus) za účelem analýzy problémů týkající se vody z širší perspektivy. Z pohledu vody a vodních zdrojů je provedeno počáteční zhodnocení energetické náročnosti a produkce emisí skleníkových plynů v problematice odsolování mořské vody. Výsledky prezentované v této práci navazují na současné metodiky hodnocení vodních zdrojů. Stopa dostupnosti vody (Water Availability Footprint) byla navržena pro zohlednění dopadu degradace kvality vody ve stávajících postupech pro posuzování nedostatku vody, ve kterých nebyla dříve řešena. Druhým přínosem této práce je návrh konceptu kvantitativní-kvalitativní vodní stopy (Quantitative-Qualitative Water Footprint - QQWFP), ve kterém je definována vodní stopa z pohledu nákladů a následně je stanovena v souvislosti s celkovými náklady na spotřebu vody a odstraňování kontaminantů, které se do vody dostávají v průběhu jejího využití. Vodní stopa založená na nákladech poskytuje výsledky, které jsou intuitivnější jak pro management vodních zdrojů tak i pro veřejnost. Tento přístup umožňuje lépe kontrolovat a řídit průmyslové a regionální využívání a správu vody. Třetím přínosem této práce je rozšíření pinch analýzy nedostatku vody (Water Scarcity Pinch Analysis - WSPA), ve které je aplikována pinch analýzy vody na makroúrovni se zaměřením na regionální hodnocení a optimalizaci zdrojů a využívání vody. Všechny tři navržené metody jsou zaměřeny na stanovení dopadů využití vody z hlediska jejího množství a kvality, analýzy QQWFP a WSPA také pokrývají dopady vícečetných kontaminantů. Kromě hledání řešení se tato práce také pokouší naznačit potenciální směry pro budoucí výzkum v dané oblasti. Mezi významná potenciální témata k diskuzi patří 1) pokročilejší metoda kvantifikace vlivu více kontaminantů a 2) implementace a analýza ekonomické proveditelnosti přístupů WSPA a QQWFP s lokalizovanými daty s cílem nalézt přizpůsobené řešení pro optimální využití regionální a průmyslové vody.

Water distribution systems are vulnerable to intentional, along with accidental, contamination of the water supply. Contamination warning systems (CWS) are strategies to lessen the effects of contamination by delivering early indication of an event. Online quality monitoring, a network of sensors that can assess water quality and alert an operator of contamination, is a critical component of CWS, but utilities are faced with the decision of what locations are optimal for deployment of sensors. A sensor placement algorithm was developed and implemented in a commercial network distribution model (i.e. KYPIPE) to aid small utilities in sensor placement. The developed sensor placement tool was then validated using 12 small distribution system models and multiple contamination scenarios for the placement of one and two sensors. This thesis also addresses the issue that many sensor placement algorithms require calibrated hydraulic/water quality models, but small utilities do not always possess the financial resources or expertise to build calibrated models. Because of such limitations, a simple procedure is proposed to recommend optimal placement of a sensor without the need for a model or complicated algorithm. The procedure uses simple information about the geometry of the system and does not require explicit information about flow dynamics.

This thesis documents the relationship among the major water quality parametersduring a nitrification episode. Nitrification unexpectedly occurred in a chloraminated pilotdrinking water distribution system practicing with a 4.0 mg/L as Cl[subscript 2] residual dosed at 4.5:1Cl[subscript 2]:NH[subscript 3]-N. Surface, ground and sea water were treated and disinfected withmonochloramines to produce finished water quality similar to regional utility water quality.PVC, galvanized, unlined cast iron and lined iron pipes were harvested from regionaldistribution systems and used to build eighteen pilot distribution systems (PDSs). The PDSswere operated at a 5-day hydraulic residence time (HRT) and ambient temperatures.As seasonal temperatures increased the rate of monochloramine dissipation increaseduntil effluent PDS residuals were zero. PDSs effluent water quality parameters chloraminesresidual, dissolved oxygen, heterotrophic plate counts (HPCs), pH, alkalinity, and nitrogenspecies were monitored and found to vary as expected by stoichiometry associated withtheoretical biological reactions excepting alkalinity. Nitrification was confirmed in thePDSs. The occurrence in the PDSs was not isolated to any particular source water.Ammonia for nitrification came from degraded chloramines, which was common among allfinished waters. Consistent with nitrification trends of dissolved oxygen consumption,ammonia consumption, nitrite and nitrate production were clearly observed in the PDSs bulkwater quality profiles. Trends of pH and alkalinity were less apparent. To controlnitrification: residual was increased to 4.5 mg/L as Cl[subscript 2] at 5:1 Cl[subscript 2]:NH[subscript 3]-N dosing ratio, and theHRT was reduced from 5 to 2 days. Elimination of the nitrification episode was achieved after a 1 week free chlorine burn.
M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil and Environmental Engineering

Drinking water distribution systems (DWDSs) account for the majority of the infrastructure for transporting water from treatment plants to customers’ tap. During the transportation, water quality deteriorates due to the unavoidable accumulation of biofilm within the pipelines. The microbial activity and ecology within the biofilm have great impact on the water quality degradation process. Within DWDSs using chloramine as disinfectant, nitrification caused by nitrifying bacteria is increasingly becoming a concern as it poses a great challenge for maintaining water quality. In order to control nitrification in DWDSs, it is essential to consider both the nitrifying bacteria and their shelter. Hence, the overall aim of this study is to investigate nitrification properties under different operational conditions, in addition to biofilm characteristics in chloraminated water distribution systems. To achieve the aim, nitrifying biofilm was firstly incubated within a flow cell experimental facility. A total of four test phases were conducted to investigate the effects on the extent of nitrification of five flow rates (2, 4, 6, 8 and10 L/min) and four disinfection strategies (total chlorine=1mg/L, Cl2/NH3=3:1; total chlorine=1mg/L, Cl2/NH3=5:1; total chlorine=5mg/L, Cl2/NH3=3:1; and total chlorine=5mg/L, Cl2/NH3=5:1). Physico-chemical parameters and nitrification indicators were monitored during the tests. The main results from the study indicate that nitrification is affected by hydraulic conditions and the process tends to be severe when the fluid flow transforms from laminar to turbulent (2300 < Reynold number < 4000). Increasing disinfectant concentration and optimizing Cl2/NH3 mass ratio were found to have limited efficacy for controlling nitrification. Furthermore, several nitrification indicators were evaluated for their prediction efficiency and the results suggest that the change of nitrite, together with total organic carbon (TOC) and turbidity can indicate nitrification potential more efficiently. At the end of the tests, genomic DNA from biofilm and bulk water from each flow cell unit running at different operational conditions were subjected to a next generation sequencing (NGS) analysis by Illumina MiSeq. The results obtained showed that the microbial community and structure was different between biofilm and water samples. There was no statistical difference in microbial community in biofilm identified between different hydraulic regimes, suggesting that biofilm is a stable matrix to environment. Results further showed that Cl2/NH3 mass ratio had obvious effect on microbial structure in biofilm. This suggests that excessive ammonia is an influencing factor for microbial activity within biofilm. Within bulk water, species richness and diversity tended to be higher at lower hydraulic regimes. This confirms the influence of hydraulic condition on biofilm mechanical structure and further material mobilization to water. Opportunic pathogens such as Legionella and Mycobacterium were detected in abundance in the experimental system. This confirms that nitrification can lead to a decrease of water quality and microbial outbreaks. The characteristics of extracellular polymeric substance (EPS) from biofilm conditioned under different operational conditions were also analysed. Carbohydrate was found to be the main components within biofilm’s EPS. EPS composition and structure were found to be governed by operational conditions, but no simple linear relationship was found. This suggests the interactive effects of EPS properties, hydraulics and disinfectant strategies. EPS effects on disinfection were evaluated via disinfectant decay tests. EPS was confirmed to have an influencing in biofilm overcoming disinfection.

factors controlling groundwater quality is of great importance in the context of exploiting and supplying groundwater of good quality for public use. Groundwater quality is conditioned by aspects of geological and hydrological character, as well as involving physical, chemical and biological processes. Groundwater quality also depends on factors controlled by well performances and characteristics, as well as the operational routines at the waterworks in question. This research combines disciplines of hydrogeological, geological and geochemical character in order to describe and understand the water quality at the public water supply at Sunndalsøra in the county of Møre og Romsdal, Norway. The research is based on field and laboratory investigations in relation to the establishment of an additional production well in an aquifer exploited for public water supply in Sunndalen. Sediment samples have been collected in relation to the drilling of the well. Water sampling and groundwater level measurements have been conducted as part of an aquifer test and during the test pumping of the well. The test pumping also includes field analyses of groundwater, as well as water sampling for characterization of physical-chemical parameters of all wells, the infiltration basin and the river Driva. Collected sediment samples were analyzed in the laboratory at Department of Geology and Mineral Resources Engineering (IGB) using X-ray analyses, grains size analyses and loss on ignition. Water samples have been analyzed by the Geological Survey of Norway (NGU) combining tools of chromotography, mass spectrometry, nephelometry and titrations. In addition, water samples have been collected for microbiological analyses in relation to an ongoing ph.d-project at NTNU and by Sunndal municipality. A fluvial aquifer at Sjølandsøra is exploited for public drinking water supply, supplying the community of Sunndalsøra and surrounding areas. Problems related to terms of use result from too high values of iron in one of the production wells (well B). Elevated levels of iron have been a persisting problem affecting well constructions and transmission lines, as well as causing discoloration and staining experienced by the consumers. This problem and its concerns define the starting point of a series of improving actions, including the work related to this assignment. A new production well has been established with the aim of replacing well B. In order for any replacement to take place, the new well has to meet all requirements for good drinking water as stated in the drinking water regulations, as well as demands for well capacity. The mineralogical composition of the fluvial sediments comprising the aquifer, contribute with ferrous iron through chemical dissolution processes in a zone where the groundwater is sufficiently poor in oxygen and acidic in character. This mineral-groundwater interaction may explain the problems experienced with well B, which has the most deeply situated well screen. Relatively high concentrations of carbon dioxide in groundwater extracted from well B suggest that microbial decomposition is an important process in the aquifer sediments in vicinity of this well. This process of decomposition sets the stage for an anoxic groundwater evolution in the deeper and finer grained (fine sand/silt) parts of the aquifer, leading to efficient iron dissolution. Groundwater flow patterns and residence times gives an additional insight to factors influencing the geochemistry of the groundwater basin. It is documented that dissolved iron concentrations increase with reduced aquifer recharge. This is to a great extent linked to a decrease in infiltration of river water deriving from Driva. Studies and observations related to different operational situations at the works document the close link between functionality of different components of the works and water quality, as well as the relationships between quality and capacity aspects. The closing of well B resulted in an increase in dissolved iron concentrations in the overlying well A as this well now started to withdraw the deeper and more reduced groundwater. The infiltration basin also has an influence on water quality by means of contributing to aquifer recharge in vicinity of well D. Results and observations from the test pumping period prove that improving actions should be implemented at the groundwater works. The new production well meets all requirements in terms of capacity and quality. With this aspect accounted for, actions aiming at improving water quality with respect to the reduction of high values of iron are preferably implemented in the following order: 1. Establish a water supply from the newly established well (D), which then replaces well B as a production well of drinking water. 2. Well B should still be operative such that the withdrawal of groundwater equals an amount necessary to avoid extraction of reduced groundwater into the overlying well (A). Groundwater from well B (c. 10-15 l/s) could be pumped by means of diversion to Driva or function as an additional water supply for the infiltration basin. The latter option is feasible in that will contribute to an increase in pH and alkalinity from re-infiltration of groundwater relatively rich in CO2. Iron hydroxide is expected to precipitate in/on the filter mass of the basin, and the establishment of a second infiltration basin should be considered. 3. Improve the river intake by means of establishing a new tilted well beneath the river bed and/or extending the already existing river intake into the deeper parts of the river. This will secure a more predictable water supply on an annual basis. 4. Increases in surface area of the basin should be viewed in connection with the establishment of a second infiltration basin (basin 2). This will enhance water supply during periods of dry spells through an increase in aquifer recharge.Suggestions for actions contributing to an additional improvement of water quality: 5. It is strongly recommended that the degree of groundwater protection is increased, to better protect the aquifer from future activities and land use. This action should be accomplished with the definition of four protection zones, and with an extension of the protection zone south of well D. The well area and the infiltration basin must be secured with a lockable fence (zone 0). 6. Consider possible water reserves, as well as an improvement of the Kalken water works, to ensure a stable water supply on an annual basis. 7. Reduce the amount of bacterial counts in well D by means of disinfection with e.g. chlorine. Regeneration (disinfection) should also be conducted in relation to all wells and transmission lines. 8. Regenerate (refill) the filter mass of the infiltration basin with the aid of crushed limestone/marble. This action will increase the groundwater alkalinity, pH and calcium. If considered feasible, this step might replace the present use of Ca(OH)2 added at the treatment facility.
Forståelsen av hvilke faktorer som innvirker på grunnvannskvalitet er viktig ved bruk av grunnvann som tas ut i forbindelse med en kommunal vannforsyning. Grunnvannskvalitet betinges av geologiske og hydrologiske faktorer, så vel som fysiske, kjemiske og biologiske prosesser. I tillegg kontrolleres vannkvaliteten av forhold som knytter seg til brønnfunksjonalitet og konstruksjon, samt drifts- og vedlikeholdsrutiner hos det enkelte vannverk. Dette studiet kombinerer disipliner av hydrogeologisk, geologisk og geokjemisk karakter, for å kunne beskrive og forstå vannkvaliteten ved Sunndalsøra grunnvannsanlegg i Møre og Romsdal, Norge. Studiet baserer seg på felt og laboratorieundersøkelser knyttet til etableringen av en ny produksjonsbrønn i en akvifer i Sunndalen. Sedimentprøver ble samlet inn i forbindelse med boringen av den nye brønnen. Vannprøver for analyse av fysisk-kjemiske parametere samlet inn fra infiltrasjonsbasseng og brønner, samt registrering av grunnvannsnivåer, ble utført under prøvepumpingen. Prøvetaking for bakteriologiske analyser av grunnvannet ble gjort av Sunndal kommune. Utvalgte fysisk-kjemiske parametere ble analysert i felt. Sedimentprøvene ble analysert i Ingeniørgeologi-laboratoriet ved Institutt for geologi og bergteknikk, NTNU, med bruk av metoder for analyse av kornfordeling, røntgenanalyser og glødetapsanalyser. Norges geologiske undersøkelse i Trondheim analyserte vannprøvene med metoder som kromatografi, massespektrometri, nefelometri og titrering. I tillegg ble vannprøver samlet inn for analyse av mikrobiologi i forbindelse med et pågående ph.d.-prosjekt ved NTNU. En fluvial akvifer på Sjølandsøra benyttes i vannforsyningen av Sunndalsøra og tilgrensende områder. Bruksmessige problemer har oppstått som følge av for høye jernverdier i en av produksjonsbrønnene (brønn B). For høye verdier av jern har vært et vedvarende problem som har påvirket både brønnkonstruksjoner og ledningsnett, samt ført til problemer hos forbruker i form av blant annet misfarging og utfelling i vaskeservanter. Jernproblemene definerer utgangspunktet for flere utbedrende tiltak ved grunnvannsanlegget, i tillegg til arbeidet knyttet til denne masteroppgaven. En ny produksjonsbrønn er etablert og skal erstatte brønn B. For at det skal kunne opprettes vannforsyning fra den nye brønnen må den, i tillegg til kapasitetskrav, tilfredsstille alle krav kvalitet i henhold til Drikkevannsforskriften. Mineralsammensetningen i avsetningen bidrar med toverdig jern gjennom kjemiske forvitringsreaksjoner i de deler av magasinet der grunnvannet er tilstrekkelig oksygenfattig og surt. Denne interaksjonen mellom mineral og grunnvann kan forklare problemene som erfares med brønn B, som er den av produksjonsbrønnene som har det dypest plasserte filteret. Estimat av CO2-konsentrasjoner viser at nedbrytning av organisk materiale er en noe mer aktiv prosess i nærheten av denne brønnen. Aerob nedbrytning av organisk materiale etablerer reduserende forhold i de dypere delene av akviferen, som igjen leder til økt løselighet av toverdig jern. Det er vist at jernkonsentrasjonene øker under forhold med redusert grunnvannsnydannelse. Dette knyttes i størst grad til nedsatt infiltrasjon av elvevann fra Driva. Beskrivelser av grunnvannets strømningsmønster og oppholdstid gir større forståelse av forholdene i akviferen og bedre innsyn i faktorer som kan virke inn på de geokjemiske forhold som styrer løseligheten av jern. Studier og observasjoner av ulike styrings(drifts)forhold ved anlegget tilsier at det er en nær sammenheng mellom vannkvalitet og funksjonalitet av ulike installasjoner ved anlegget, så vel som mellom kvalitet og kapasitet. Avstengningen av brønn B ga en økning i jerninnhold i overliggende brønn A, som et resultat av at denne brønnen nå begynte å ta ut dypere og mer redusert grunnvann. Infiltrasjonsbassenget har også en betydning for vannkjemien I form at infiltrert elvevann fra bassenget bidrar i nydannelsen av grunnvann i nærheten av brønn D. Resultater og observasjoner fra prøvepumpingsperioden viser at utbedrende tiltak bør gjennomføres ved grunnvannsanlegget. Det er dokumentert at den nye produksjonsbrønnen tilfredsstiller alle krav til kapasitet og kvalitet. På bakgrunn av dette foreslås i prioritert rekkefølge følgende tiltak for å forbedre vannkvaliteten med hensyn på å redusere jerninnholdet i grunnvannet: 1. Etablere vannforsyning fra brønn D, som da erstatter brønn B som produksjonsbrønn. 2. Fra brønn B bør det fremdeles tas ut en viss mengde vann (ca. 10-15 l/s), slik at man unngår å trekke redusert grunnvann inn i overliggende brønn (A). Grunnvann fra brønn B kan pumpes ved avverging til Driva eller infiltrasjonsbassenget. Sistnevnte alternativ vil kunne bidra til økt pH og alkalitet gjennom re-infiltreringen som da vil foregå med grunnvann med noe høyere CO2-innhold. Det forventes at jernhydroksider vil felles ut på bassengbunnen, og derfor bør man vurdere å etablere et eget infiltrasjonsbasseng. 3. Utbedre elveinntaket ved å etablere en ny skråstilt brønn under elvebunnen og/eller forlenge eksisterende inntak lenger ut i elvens dypere parti. Dette vil sikre en mer stabil vannforsyning på årlig basis. 4. En økning i infiltrasjonsbassengets overflate må ses i sammenheng med etableringen av et nytt basseng (basseng 2), der vann fra brønn B infiltreres. Dette kan bidra til å sikre vannforsyningen i tørrværsperioder.Forslag til andre tiltak som kan bidra til å forbedre den generelle kvaliteten ved anlegget: 5. Det anbefales på det sterkeste at grunnvannsmagasinet sikres bedre gjennom en områdebeskyttelse (klausulering), slik at en framtidig konflikt med aktiviteter og arealbruk unngås. Områdebeskyttelsen bør innebære opprettelsen av fire sikkerhetssoner rundt anlegget og en utvidelse av sikkerhetssonen sørvest for brønn D. Brønnområdet (sone 0) må gjerdes inn og sikres med låsbar port. 6. Mulige reservevannskilder bør vurderes, så vel som en utbedring av Kalken vannverk, for å øke leveringssikkerheten på årlig basis. 7. Det bør foretas en desinfeksjon (kloring) av brønn D før denne tas i bruk, slik at kimtallet reduserer til godkjent nivå. Regenerering (desinfeksjon) bør også gjøres av brønner og ledningsnett. 8. Filtermassen i infiltrasjonsbassenget bør regenereres (byttes). Dette vil innebære tilsetting av knust kalk/marmor, slik at både alkalitet og pH øker. Oppnås ønsket virkning kan denne behandlingsmetoden erstatte eksisterende løsning med tilsetting av kalkhydrat fra vannbehandlingsanlegget.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2010.
"June 2010." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 50-52).
This thesis describes the process and results of applying the Soil and Water Assessment Tool (SWAT) to characterize bacterial fate and transport in the Kranji Catchment of Singapore. The goal of this process is to predict bacterial loading to Kranji Reservoir under the forcing of weather and other variables. Necessary data and input values were collected or estimated and input into the model. One of the most important of these values is the bacterial die-off rate. This rate must be accurate for the model to provide accurate predictions of bacterial loadings. In order to obtain a value for the bacterial die-off rate, an attenuation study was conducted. The results of this study were not typical. Bacterial growth was observed to occur during dark hours, and decay was observed to occur during sunlit hours. The resulting light and dark decay constants were combined for use in the model. The specific bacterial loading rates associated with the various agricultural activities occurring in the catchment are not available and thus were roughly estimated. Point source loadings were also estimated. Four years of model simulation daily output were analyzed, and results for specific subcatchments with differing character are discussed. This application of SWAT shows a good ability to make qualitative predictions of the presence or absence of bacteria; however, quantitative agreement between model predictions and field observations is poor. This run of the model is like a first draft-more refinement and more information are needed before it will make accurate predictions; however, the framework is in place.
by Erika C. Granger.
M.Eng.

The European Union (EU) has openly solicited advice on the development of EU bathing water quality policy and made calls for the development of remotely sensed operational real world solutions. This research demonstrates a new approach to estimating water quality using remote sensing and specifically to monitoring bathing water quality by using remote sensing to "flag" failing areas for manual survey. This method meets the environmental demands of the EU, the tourist industry, the water industry and environmental monitoring agencies throughout the world. The results show the genuine potential for a remotely sensed monitoring system that could, with further research, lead to an efficient and effective method of monitoring bathing water quality. These findings are particularly important given the imminent changes in EU Bathing Water policy, an expected increase in monitoring costs (currently estimated by the EU to be 15 million euros for 2001 (EU, 2002)) and the widespread availability of airborne sensors and satellites. Simultaneous water quality and spectral data were collected at Southend-on-Sea pier with a Natural Environment Research Council (NERC) loaned spectroradiometer and water sampling equipment. Simultaneous data enabled the accurate analysis of the relationship between water quality and reflectance, avoiding the normal delays experienced with flown or satellite data. The thesis successfully proposes and investigates a remotely sensed flagging system for bathing water quality monitoring using both statistical and visual analysis to identify optimum wavelengths which identify threshold levels of E.coli, suspended sediments, low pH, nitrates, chlorophyll, faecal coliform and temperature. The findings demonstrate that remote sensing could be used to monitor several of the water quality parameters that are relevant to the EU Bathing Water Directives and, in particular, the monitoring of effluent in bathing waters through the successful identification of high E.coli counts. Through the creation and integration of a localised water quality model, it demonstrates that it is possible to predict when water quality parameters exceed a threshold level through direct remote sensing or through the use of remotely sensed indirect water quality parameters. The success rate of remotely sensed "flagging" of samples above a threshold level was tested and used to yield a "predictor" rating for each parameter. Finally, a spectral physical model was constructed that identifies the parameters, wavelengths and secondary parameters that could be used to flag failing water quality areas. This model could be used to improve monitoring coverage and reduce overall costs. The application of the model, which was based on Case 2 coastal water, to other types of coastal area is suggested as needing further research before it could be widely exploited. Remote sensing information could lead to a greater understanding of the coastal environment and offers potential near real time monitoring, allowing for the first time reactive management of coastal water quality in failing water quality areas. This would provide a solution to many of the issues raised by the EU regarding the current bathing water quality directives and provides the remote sensing community with a practical solution to a real world problem.

The thesis is a treatise of the quantity and quality aspects of potable water in distribution systems. The privatisation of the UK Water Industry in 1989 has seen the requirement for the Water Companies in England and Wales to be responsible for the delivery of good quality water that meets the demand of all consumers. In respect of the quantity of supply, there have been many previous studies that have examined the hydraulic performance of distribution systems and there are now many proprietary mathematical models that have been successfully used in this study. However, in respect of water quality the literature review has highlighted that the modelling approach is not so well advanced, as water quality is a function of many concepts, processes and parameters that include the source and age of water, the condition and deterioration of the assets in the system, the microbiological, chemical and physical processes and the network hydraulic performance, including pressure transients. These processes are highly interactive and complex. In an attempt to better understand these processes a programme of research has been completed that has involved a field evaluation of the performance of a live system, including the development of instrumentation to continually measure water quality, and the development of a mathematical model to describe the processes associated with the age of water and the propagation of conservative and non-conservative substances. An initial attempt has also been made to develop a micro-biological model and a sediment transport model. New original concepts developed by the author include age, biological and diagnostic models that may be used to identify the source of any incident (hydraulic or pollution) and the application of the model in near real time.

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The disorderly growth of the capital of PiauÃ, marked mainly by housing occupancy on the banks of river Poti and the existence of clandestine connections of raw sewage in rainwater drainage pipes, has contributed significantly to the pollution of the waters of the river basin of the ParnaÃba River (semiarid region Brazil). This research consists of making water quality measuring campaigns in Poti river and sewage released that, via gallery rainwater, focusing on a river stretch of 36.8 km long, located in the city of Teresina / PI, as well as mathematical modeling of water quality of the river based on WHAT-UFMG platform. The research is presented as the first study involving modeling of water quality in a water body of the state of PiauÃ. Modeled components were: dissolved oxygen (DO), biochemical oxygen demand (BOD) and thermotolerant coliform (TC). The results of field measurements indicated TC parameter discontinuities with respect to CONAMA Resolution n 357/2005. The calibration of the decay coefficients for each parameter resulting in deviations between measured and modeled data of up to 20%, which shows that the QUALUFMG can be used as a basis for predicting the quality of water in rivers located in semiarid regions. The calibrated model was also compared to field data from the literature. Finally, simulations were performed for different flow scenarios (Q10, Q90 and Q7,10), with consistent results and that can be used for the management of water resources in the state of PiauÃ.
O crescimento desordenado da capital piauiense, marcado sobretudo pela ocupaÃÃo habitacional Ãs margens do rio Poti e pela existÃncia de ligaÃÃes clandestinas de esgoto bruto nas tubulaÃÃes de drenagem pluvial, tem contribuÃdo significativamente para a poluiÃÃo das Ãguas da bacia hidrogrÃfica do rio ParnaÃba (regiÃo semiÃrida do Brasil). A presente pesquisa consiste na realizaÃÃo de campanhas de mediÃÃo da qualidade da Ãgua no rio Poti e dos esgotos lanÃados no mesmo, via galeria de Ãguas pluviais, com foco em um trecho do rio de 36,8 km de extensÃo, localizado na cidade de Teresina/PI, bem como na modelagem matemÃtica da qualidade da Ãgua deste rio com base na plataforma QUAL-UFMG. A pesquisa apresenta-se como o primeiro estudo envolvendo modelagem da qualidade da Ãgua em um corpo hÃdrico do estado do PiauÃ. Os componentes modelados foram: oxigÃnio dissolvido (OD), demanda bioquÃmica de oxigÃnio (DBO) e coliformes termotolerantes (CT). Os resultados das mediÃÃes de campo indicaram desconformidades do parÃmetro CT com relaÃÃo à ResoluÃÃo CONAMA n 357/2005. A calibraÃÃo dos coeficientes de decaimento para cada parÃmetro resultou em desvios entre dados medidos e modelados de atà 20%, o que mostra que o QUAL-UFMG pode ser utilizado como base para prediÃÃo da qualidade da Ãgua em rios localizados em regiÃes semiÃridas. O modelo calibrado tambÃm foi comparado a dados de campo obtidos na literatura. Finalmente, foram realizadas simulaÃÃes para diferentes cenÃrios de vazÃo (Q10, Q90 e Q7,10), apresentando resultados coerentes e que podem ser utilizados para a gestÃo dos recursos hÃdricos do estado do PiauÃ.

Water is one of the most important resources in the world. It has direct impact on the daily life ofmankind and sustainable development of society. Water quality affects biological life and has to obeystrict regulations. Traditional water quality assurance methods, used today, involve manual samplingfollowed by laboratory analysis. This process is expensive due to high labour costs for sampling andlaboratory work. Moreover, it lacks real time analysis which is essential to minimise contamination.This thesis aims to find a solution to this problem using IoT sensors and Machine Learning techniquesto detect anomalies in the water quality. The spatial scalability is key requirement when selecting transmissionprotocols, as sensors could be spread around the water network. We consider solutions readilyavailable or soon to be in the market. The key LPWAN technologies studied are: SigFox, LoRaWANand NB-IoT. In general these protocols have many characteristics essential for fresh water monitoring,like long lasting battery life and long range, however, they have many limitations in terms of transmissiondata rates and duty cycles. It is therefore essential to find a solution that would correctly find anomaliesin the water quality but at the same time comply with limited transmission and processing capabilities ofthe node sensors and above mentioned protocols.A trial sensor is already in place in lake M¨alaren and its readings are used for this study. Supervisedmachine learning algorithms such as Logistic Regression, Artificial Neural Network, Decision Tree, OneClass K-NN and Support Vector Machine (SVM) are studied and discussed regarding the data available.SVM is then selected, implemented and optimised to comply with the limitations of IoT. The trade offbetween false anomalies and false normal readings was also discussed.
Vatten ä r en av de viktigaste resurserna i vä rlden. Det har direkt inverkan på mä nsklighetens dagliga liv och samhä llets hå llbara utveckling. Vattenkvaliteten på verkar det biologiska livet och må ste fö lja strikta fö reskrifter. Traditionella metoder fö r vattenkvalitetssä kring, som anvä nds idag, innefattar manuell provtagning fö ljt av laboratorieanalys. Denna process ä r dyr på grund av hö ga arbetskostnader fö r provtagning och laboratoriearbete. Dessutom saknar den realtidsanalys som ä r vä sentlig fö r att minimera‌fö rorening.Avhandlingen syftar till att hitta en lö sning på detta problem med hjä lp av IoT-sensorer och maskinlä rningsteknik fö r att upptä cka avvikelser i vattenkvaliteten. Den spatiala skalbarheten ä r ett viktigt krav vid val av ö verfö ringsprotokoll, eftersom sensorer kan spridas runt vattennä tverket. Vi diskuterar lö sningar som ä r lä ttillgä ngliga eller snart ska vara på marknaden. De viktigaste LPWAN-teknikerna som studerats ä r: SigFox, LoRaWAN och NB-IoT. Generellt har dessa protokoll må nga egenskaper som ä r nö dvä ndiga fö r ö vervakning av fä rskvatten, som lå ng batterilivslä ngd och lå ng rä ckvidd, men de har må nga begrä nsningar vad gä ller ö verfö ringshastighet och arbetscykel. Det ä r dä rfö r viktigt att hitta en lö sning som skulle hitta anomalier vid hö gt sä kerhet men samtidigt ö verensstä mmer med begrä nsade ö verfö ringsoch bearbetningskapaciteter hos sensorerna och de ovan nä mnda protokoll.En fö rsö kssensor finns redan på plats i Lake Mä laren och dess avlä sningar anvä nds fö r dennastudie.Ö vervakade maskininlä rningsalgoritmer, så som Logistic Regression, Artificial Neural Network,Decision Tree, One Class K-NN and Support Vector Machine (SVM) studeras och diskuteras beträ ffande tillgä ngliga data. SVM vä ljs sedan, implementeras och optimeras fö r att uppfylla IoTs begrä nsningarna.Balansen mellan falska avvikelser och falska normala avlä sningar diskuteras också .

Problem Saint-Petersburg is located at the Neva river and almost all drinking water for 5 million inhabitants is taken from it. Talking about water supply centralised source for Saint-Petersburg, one can mark a lot of negative factors influencing the water quality. Surely, agricultural pollution, transport and economical problems are among them. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/26726

Water quality management makes use of water quality models as decision making tools. Water quality management decisions need to be informed by information that is as reliable as possible. There are many situations where observational data are limited and therefore models or simulation methods have a significant role to play in providing some information that can be used to guide management decisions. Water quality modelling is the use of mathematical equations and statistics to represent the processes affecting water quality in the natural environment. Water quality data are expensive and difficult to obtain. Nutrient sampling requires a technician to obtain ‘grab samples’ which need to be kept at low temperatures and analysed in a laboratory. The laboratory analyses of nutrients is expensive and time consuming. The data required by water quality models are seldom available as complete datasets of sufficient length. This is especially true for ungauged regions, either in small rural catchments or even major rivers in developing countries. Water quality modelling requires simulated or observed water quantity data as water quality is affected by water quantity. Both the water quality modelling and water quantity modelling require data to simulate the required processes. Data are necessary for both model structure as well as model set up for calibration and validation. This study aimed to investigate the simulation of water quality in a low order stream with limited observed data using a relatively complex as well as a much simpler water quality model, represented by QUAL2K and an in-house developed Mass Balance Nutrient (MBN) model, respectively. The two models differ greatly in the approach adopted for water quality modelling, with QUAL2K being an instream water quality fate model and the MBN model being a catchment scale model that links water quantity and quality. The MBN model uses hydrological routines to simulate those components of the hydrological cycle that are expected to differ with respect to their water quality signatures (low flows, high flows, etc.). Incremental flows are broken down into flow fractions, and nutrient signatures are assigned to fractions to represent catchment nutrient load input. A linear regression linked to an urban runoff model was used to simulate water quality entering the river system from failing municipal infrastructure, which was found to be a highly variable source of nutrients within the system. A simple algal model was adapted from CE-QUAL-W2 to simulate nutrient assimilation by benthic algae. QUAL2K, an instream water quality fate model, proved unsuitable for modelling diffuse sources for a wide range of conditions and was data intensive when compared to the data requirements of the MBN model. QUAL2K did not simulate water quality accurately over a wide range of flow conditions and was found to be more suitable to simulating point sources. The MBN model did not provide accurate results in terms of the simulation of individual daily water quality values; however, the general trends and frequency characteristics of the simulations were satisfactory. Despite some uncertainties, the MBN model remains useful for extending data for catchments with limited observed water quality data. The MBN model was found to be more suitable for South African conditions than QUAL2K, given the data requirements of each model and water quality and flow data available from the Department of Water and Sanitation. The MBN model was found to be particularly useful by providing frequency distributions of water quality loads or concentrations using minimal data that can be related to the risks of exceeding management thresholds.

An experimental wetland system was constructed to upgrade the water quality of piggery wastewater. Transplanted aquatic macrophytes were successfully established within the wetland. The wetland experiment was concluded prematurely because of continual pipework blockages which prevented wastewater flow into the wetland. The precipitate in the pipework was identified as Struvite, MgNH4PO4.6H2O, a precipitate widely associated with wastewaters and kidney stones. The formation of struvite in the piggery wastewaters indicated that struvite may be an important process in the removal of nutrients. X-ray diffraction of lagoon sludge confirmed that struvite precipitation occurred in the three wastewater lagoons at the piggery. Magnesium, essential for the formation of struvite, entered the waste water system via groundwater used for wash down. Magnesium was also an important food supplement in the feed provided for the pigs. Magnesium coupled with ammonia and phosphorus at pH values greater than nine (9) can produce struvite. Up to 250 tonnes/annum of struvite could be removed from the final piggery effluent under correct pH and dosing conditions. Struvite is a valuable slow release fertilizer, and its formation and removal from wastewaters may be important in the reduction of eutrophication in receiving waters. Laboratory-scale batch and continuous anaerobic digestion of piggery effluent was undertaken. The removal of struvite from solution by chemical dosing with MgSO4 after digestion was determined. During anaerobic digestion of piggery wastewater, COD was reduced by 50%- 90%, as measured by biogas production. Concentrations of PO4-P in the supemate increased during batch digestion (21 to 33 mg/L) while a marked reduction in PO4-P concentration of the supemate from the continuous digestion (21 to 10 mg/L) occurred. The addition of MgSO4 to the supernate reduced PO4-P concentrations from 33 to 7 mg/L (batch) and from 10 to 0.1 mg/L (continuous). Struvite, aphthitalite (K3Na(SO4)2) and thermardite (Na2SO4) were precipitated from solution. A computer model was developed to describe struvite solubility chemistry; this included the electro-neutrality equation which allowed for greater variability in the input components. Relationships between the major ions were retained without approximation. The model results fitted data from both our laboratory results and published values. Equilibrium constants which markedly affect the output were identified and solubility constants derived. The computer model of the solution chemistry of struvite was then improved. Firstly, the algorithm was smaller and faster with ammonia as the prime calculation point in the liquid phase. Secondly, the incorporation of dissolved magnesium hydrogen phosphate (dMHP) in the model significantly increased concentrations in solution. Thirdly, estimates of activity coefficients were included. These improvements made a 5-10% improvement in the fit. This flexible modeling procedure allowed for the ready inclusion of all possible species. The addition of associated ammonium phosphates improved the fit. Estimates of the association constants were included. Applications of the model include waste-water treatment and the formation of kidney stones.

Knutsford redevelopment is part of the Local Government’s agenda to incorporate sustainable living into the residential sector at affordable prices. This development follows on from the newly established White Gum Valley (WGV) and currently constructing East Village. Both of the sites have newly developed technology to demonstrates sustainable living in a density wise design. East Village is being developed to show similar results with more sustainable and saving initiatives such as the use of solar energy, rainwater harvesting on a lot scale, and a community battery to provide for the residents. Knutsford is stage 4 of the development plan that is occurring in Fremantle. This site will follow along the footsteps of previous establishments with improvements to show better results. In order to achieve this, the site needs to meet specific criteria that allow the usage of the natural resources, and if those are not met, the savings initiatives will need to be reconsidered to the basic options that are used by the homes around Perth. Perth is one of the top cities per capita that has the highest usage and consumption of water in Australia with 123000 L/person (Water Corporation 2019). The Water Corporation is currently working on ways to reduce water usage by 15% before 2030 in order to ensure we have a healthy supply of water for future generations. The Water Balance Model that will be developed for the site at Knutsford needs to show and demonstrate that the reduction in consumption can occur not just in a household scale but a community-wide scale in Perth and that it is readily achievable when specific steps are taken into consideration.