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Innovative techniques for the quantification of waterborne microbial risks in field studiesZimmer, Camille 30 August 2019 (has links)
In low-resource contexts, household-level point-of-use water treatment (POUWT) techniques are the final, and sometimes only, barrier against waterborne illnesses, and in these and other water-related applications, health risks can be quantified using one of two methods. Firstly, Escherichia coli (or other indicator organism) counts can be used to monitor water and determine adherence to a health-based limit (i.e. compliance monitoring). Secondly, E. coli can be used to conduct a quantitative microbial risk assessment (QMRA), indicating the level of protection conferred by a given POUWT device by spiking test water with E. coli to ascertain a reduction efficacy relative to that target organism, a process referred to as challenge testing, which is typically carried out in a laboratory context. Although both methods are well established, both have scope for improvement for effective field application in low-resource contexts. Regarding compliance monitoring, I assessed the performance of a new low-cost field kit for E. coli enumeration, which was designed by others. I also assessed the feasibility of re-using some disposable materials, in terms of sterility and mechanical wear. The use of the new low-cost field kit was successful during the fieldwork campaign; however, re-using disposable materials introduced a relatively high occurrence of false positive results during E. coli enumeration. Use of the new low-cost field kit can reduce financial barriers, thus enabling greater water quality testing coverage.
Regarding challenge testing, the aim of this study was to adapt current protocols to assess the household performance (as opposed to laboratory performance) of POUWT techniques. I developed a conceptual framework to conduct Field Challenge Tests (FCT’s) on POUWT techniques, using a probiotic health supplement containing E. coli as the challenge organism. I successfully carried out a FCT in Malawi with limited resources, verifying FCT viability. Applications of such FCT’s include quality control practices for manufactured devices, guiding QMRA and recommendations by public health organizations regarding POU device selection, and assessing the impact of user training programmes regarding POUWT techniques. / Graduate
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ELABORAÇÃO E APLICAÇÃO DE UM ÍNDICE DE QUALIDADE DA ÁGUA EM CONSONÂNCIA COM A LEGISLAÇÃO BRASILEIRACicilinski, Alana Deduck 02 April 2018 (has links)
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Previous issue date: 2018-04-02 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O índice de qualidade da água (IQA) é uma importante ferramenta para avaliar o status da qualidade da água; sintetizando as informações fornecidas por parâmetros físicos, químicos e biológicos. Este trabalho teve como objetivo geral a elaboração e aplicação de um índice de qualidade da água em conformidade com a legislação brasileira. Para o desenvolvimento de um novo índice, denominado IQAc, vinculou-se a informação dos parâmetros que o compõe e a praticidade de cálculo à legislação vigente no Brasil. Para tanto, foram selecionadas 30 estações de monitoramento da água, nos domínios da unidade hidrográfica do Alto Iguaçu- Paraná, Brasil. A estes dados, aplicaram-se três metodologias de cálculo de IQAs: o método NSF (IQANSF), Bascarán (IQAb) e o método proposto nesta pesquisa denominado Bascarán-CONAMA (IQAc). Os índices foram comparados nos diferentes períodos pluviométricos e estações do ano. Posteriormente, o IQAc foi aplicado nas Bacias Hidrográficas do Rio Tibagi e do Rio das Cinzas, localizadas no Estado do Paraná, onde foram definidos 24pontos de monitoramento da água, monitorados entre julho de 2014 e junho de 2016.Foram realizadas ponderações sob um ponto de vista pluviométrico de períodos anuais mais chuvoso e menos chuvoso, bem como numa perspectiva sazonal. Foram elaborados mapas georreferenciados, utilizando o método de interpolação do Inverso da Distância Ponderada (IDW), a fim de obter a distribuição espacial dos valores estimados. Análises estatísticas foram realizadas ao nível de significância de 1%. A partir dos resultados obtidos nesta pesquisa, pôde-se concluir que o novo índice de qualidade da água desenvolvido se demonstrou adequado para avaliação de qualidade da água. Observou-se que o desenvolvimento de IQAs em função da regionalidade é um aspecto importante para avaliação da qualidade da água nos corpos hídricos. Foi constatado que a qualidade da água na área avaliada dos rios Tibagi e Cinzas está em conformidade com os requisitos mínimos de qualidade da água que constam na legislação brasileira para rios Classe 2. Foi concluído que o fator sazonal não exerceu influência significativa na qualidade da água, uma vez que na comparação tanto entre períodos pluviométricos, quanto entre as estações do ano, não foram verificadas diferenças estatisticamente significativas nos pontos de monitoramento. / The water quality index (WQI) is an important tool for assessing the status of water quality; synthesizing the information provided by physical, chemical and biological parameters. This work had as general objective the elaboration and application of a water quality index in accordance with the Brazilian legislation. For the development of a new index, denominated IQAc, the information of the parameters that compose it and the practicality of calculation was linked to the legislation in force in Brazil. For this purpose, 30 water monitoring stations were selected, in the domains of the hydrographic unit of Alto Iguaçu- Parana, Brazil. To these data, three methodologies for calculating WQIs were applied: the NSF method (NSFWQI), Bascarán (WQIb) and the method proposed in this research denominated Bascarán-CONAMA (IQAc). The indices were compared in different pluviometric periods and seasons. Subsequently, the IQAc was applied to the Hydrographic Basins of the Tibagi River and the Cinzas River, located in the State of Parana, where 24 water monitoring points were monitored from July 2014 to June 2016.Ponderations were made from a viewpoint of more and less rainy annual periods, as well as a seasonal perspective. Georeferenced maps were elaborated using the Weighted Distance Inverse (IDW) interpolation method, in order to obtain the spatial distribution of the estimated values. Statistical analyzes were performed at a significance level of 1%. From the results obtained in this research, it was concluded that the new water quality index developed was adequate for water quality assessment. It was observed that the development of WQI as a function of regionality is an important aspect for assessing water quality in water bodies. It was found that the water quality in the evaluated area of the Tibagi and Cinzas rivers complies with the minimum water quality requirements in Brazilian legislation for Class 2 rivers. It was concluded that the seasonal factor hasn’t had a significant influence on water quality, since in the comparison between rainfall periods and seasons, no statistically significant differences were observed in the monitoring points.
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Drinking Water Quality In Ankara: A Monitoring StudyTezce, Gozde 01 December 2010 (has links) (PDF)
ABSTRACT
DRINKING WATER QUALITY IN ANKARA: A MONITORING STUDY
Tezce, Gö / zde
MS, Department of Environmental Engineering
Supervisor: Prof. Dr. Ü / lkü / Yetis
Co-Supervisor: Prof. Dr. Filiz B. Dilek
December 2010, 124 pages
Following the event of severe drought experienced in 2007, it was decided to use Kesikkö / prü / Reservoir as an additional source of water supply for the city of Ankara. Thereupon, there have been debates on the quality of Kesikkö / prü / Reservoir water with the claims that some parameters, primarily sulfate and arsenic, were not complying with the quality standards and therefore there was a threat to public health. This study aims to determine whether the water quality in the distribution network in Ankara exceeds water quality standards, and to assess the status of water quality of Ankara. To this end, monthly samples were collected from 24 districts as distribution network water and also from the Kesikkö / prü / Reservoir as source water, and were monitored in terms of certain water quality parameters during the period of July 2008 through June 2009. Sulfate concentration in Kesikkö / prü / Reservoir water was measured as 300-500 mg/l and this high sulfate concentration in the source water led to high sulfate values in distribution system. On the other hand, the arsenic concentration in Kesikkö / prü / water was analyzed between 9-11 µ / g/l which is lower than the expected high arsenic concentration in Kizilirmak water. Moreover, monitoring of THM and HAA in distribution network was carried out to follow DBPs formation. The highest THM concentration was observed as 109 µ / g/l for Bilkent in July 2008. Although for some districts and some months throughout the year THM concentration was higher than the EPA Stage-I (80 µ / g/l) and Stage-II (40 µ / g/l) limits, mean annual THM concentrations for districts in distribution system satisfies the standards. Furthermore, the highest HAA5 concentrations were determined as 75 µ / g/l for Dikmen in February 2009. However, annual average HAA5 in any of the districts did not exceed USEPA limit of 60 µ / g/l. Nonetheless, total/fecal coliform bacteria, which are the indicators of microbiological contamination, were detected in distribution system between the months of July 2008 and January 2009. However, the coliform bacteria did not appear with the increasing residual chlorine in the distribution system since January 2009. Results from this study demonstrate a temporal variability in water quality / indicating water quality deterioration in the distribution system during some months, while almost full compliance with the water quality standards during other months. Overall / due to Kesikkö / prü / raw water, sulfate content appears to be the major concern in the water quality when considered the one-year monitoring period.
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Surveiller et agir : le rôle du territoire dans la mobilisation et la mise en oeuvre d’un réseau de suivi de la qualité des cours d’eau bretons (1992-2017) / Monitor and act : the role of the territory in the mobilization and implementation of a network for monitoring the quality of Breton rivers (1992-2017)Boccarossa, Alexandra 11 October 2018 (has links)
Depuis la mise en place de la première surveillance de la qualité des cours d’eau et des rivières à l’échelle nationale en 1971, plusieurs types de mesures cohabitent à l’échelle du bassin-versant : les réseaux de surveillance pris en charge par les services de l’Etat, d’une part, les suivis qualité des eaux du bassin-versant (SQE-BV) assurés par des acteurs décentralisés d’autre part. L’acquisition de connaissances complémentaires sur l’eau issues de la mesure sur le terrain a accompagné l’évolution des pratiques locales de gestion de l’eau, de manière contrastée selon les régions, les bassins et sous-bassins. A la faveur de la contrainte réglementaire et d’un attelage partenarial Etat-Région, les cours d’eau bretons ont fait l’objet d’une politique de surveillance très développée. L’urgence d’agir face à une visibilité plus marquée de la pollution a motivé cette démarche dans les années 1990. Cette thèse illustre cette démarche régionalisée par plusieurs études de cas, dont celle du bassin précurseur de l’Yvel-Yvet. L’ensemble de la thèse, appuyée sur l’étude de ces suivis locaux et sur une temporalité de plus de vingt ans, mobilise le concept d’instrument d’action publique pour expliquer les étapes, les ressorts socio-politiques et les échelles de la mise en oeuvre de cette politique territorialisée de reconquête de la qualité des eaux. / Since the establishment of the first national waterways and rivers quality monitoring in 1971, several types of measures coexist at the drainage basin scale: on the one hand, the monitoring networks supported by the State services; on theother hand, the water quality monitoring of the drainage basin (SQE-BV) provided by decentralized actors. The acquisition of complementary knowledge on water from the field measurement has accompanied the evolution of local practices of water management, in a different way depending on the regions, the basins and sub-basins. Thanks to the regulatory constraint and a State-Region partnership, Breton waterways have been the subject of a highly developed surveillance policy. This approach was motivated in the 1990s because of the urgency to act in front of a greater pollution visibility. This thesis illustrates the regionalised approach by several case studies, including that of the precursor basin of Yvel-Yvet. The whole thesis, based on the study of these local follow-ups and on a temporality of more than twenty years, mobilizes the concept of instrument of public action to explain the stages, the socio-political motivations and the implementation scales of this territorialized policy of regaining water quality.
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Dynamic Behavior Of Water And Air Chemistry In Indoor Pool FacilitiesLester Ting Chung Lee (11495881) 22 November 2021 (has links)
<p>Swimming is the
second most common form of recreational activity in the U.S. Swimming pool
water and air quality should be maintained to allow swimmers, pool employees,
and spectators to use the pool facility safely. One of the major concerns
regarding the health of swimmers and other pool users is the formation of
disinfection by-products (DBPs) in swimming pools. Previous research has shown
that volatile DBPs can adversely affect the human respiratory system. DBPs
are formed by reactions between chlorine and other compounds that are present
in water, most of which are introduced by swimmers, including many that contain
reduced nitrogen. Some of the DBPs formed in pools are
volatile, and their transfer to the gas phase in pool facilities is promoted by
mixing near the air/water interface, caused by swimming and pool features.</p>
<p><a>Swimming pool water treatment processes can play significant roles
in governing water and air quality.</a> Thus, it is reasonable to hypothesize that
water and air quality in a swimming pool facility can be improved by renewing
or enhancing one or more components of water treatment.</p>
<p>The first phase of the study was designed to identify and quantify changes
in water and air quality that are associated with changes in water treatment at
a chlorinated indoor pool facility. Reductions of aqueous
NCl<sub>3 </sub>concentration were observed following the use of secondary
oxidizer with its activator. This inclusion also resulted in significant
decreases in the concentrations of cyanogen chloride (CNCl) and
dichloroacetonitrile (CNCHCl<sub>2</sub>) in pool water. The concentration of
urea, a compound that is common in swimming pools and that functions as an
important precursor to NCl<sub>3</sub> formation, as well as a marker compound
for introduction of contaminants by swimmers, was also reduced after the
addition of activator.</p>
<p>The second phase
of this study involved field measurements to characterize and quantify the
dynamic behavior of indoor air quality (IAQ) in indoor swimming pool
facilities, particularly as related to volatile compounds that are transferred
from swimming pool water to air. Measurements of water and air quality were
conducted before, during, and after periods of heavy use at several indoor pool
facilities. The results of a series of measurements at different swimming pool
facilities allowed for examination of the effects of swimmers on liquid-phase
DBPs and gas-phase NCl<sub>3</sub>. Liquid-phase NCl<sub>3</sub> concentrations
were observed to gradually increase during periods of high swimmer numbers (<i>e.g.</i>, swimming meets), while liquid-phase
CHCl<sub>3</sub> concentration was nearly constant in the same period. Concentrations
of urea displayed a steady increase each day during these periods of intensive
use. In general, the highest urea concentrations were measured near the end of
each swimming meet. </p>
<p>Measurements of IAQ
dynamics during phase 2 of the study demonstrated the effects of swimmers on
the concentrations of gas-phase NCl<sub>3 </sub>and CO<sub>2</sub>, especially
during swimming meets. The measured gas-phase NCl<sub>3</sub> concentration often exceeded the suggested upper
limits of 300 µg/m<sup>3</sup> or 500 µg/m<sup>3 </sup>during swimming
meets, especially during and immediately after warm-up periods, when the
largest numbers of swimmers were in the pool. Peak gas-phase NCl<sub>3</sub> concentrations
were observed when large numbers of swimmers were present in the pools;
measured gas-phase concentrations were as high as 1400 µg/m<sup>3</sup>.<sup> </sup>Concentrations of gas-phase NCl<sub>3</sub> rarely reached
above 300 µg/m<sup>3</sup> during regular hours of operation. Furthermore, the
types of swimmers were shown to affect the transfer of volatile compounds, such
as NCl<sub>3</sub>, from water to air<sub> </sub>in pool facilities. In
general, adult competition swimmers promoted more rapid transfer of these
compounds than youth competition swimmers or adult recreational swimmers. The
measured gas-phase CO<sub>2</sub> concentration often exceeded 1000 ppm<sub>v</sub>
during swimming meets, whereas the gas-phase CO<sub>2</sub> concentration
during periods of non-use of the pool tended to be close to the background
(ambient) CO<sub>2</sub> concentration or slightly more than 400 ppm<sub>v</sub>.
This phenomenon was largely attributed to the activity of swimmers (mixing of
water and respiratory activity) and the normal respiratory activity of
spectators. </p>
<p>IAQ models for
gas-phase NCl<sub>3</sub> and CO<sub>2</sub> were developed to relate the characteristics
of the indoor pool environment to measurements of IAQ dynamics. Several
assumptions were made to develop these models. Specifically, pool water and
indoor air were assumed to be well-mixed. The reactions that were responsible
for the formation and decay of the target compounds were neglected. Two-film
theory was used to simulate the net mass-transfer rate of volatile compounds
from the liquid phase to the gas phase. Advective transport into and out of the
air space of the pool were accounted for. The IAQ model was able to simulate
the dynamic behavior of gas-phase NCl<sub>3</sub> during regular operating hours.
Predictions of gas-phase NCl<sub>3</sub> dynamics were generally less accurate during
periods of intensive pool use; however, the model did yield predictions of
behavior that were qualitatively correct. Strengths of the model include that
it accounts for the factors that are believed to have the greatest influence on
IAQ dynamics and is simple to use. Model weaknesses include that the model did
not account liquid-phase reactions that are responsible for formation and decay
of the target compounds. The IAQ model for NCl<sub>3</sub> dynamics could still
be a useful tool to form the basis for recommendations regarding the design and
operation of indoor pool facilities so as to optimize IAQ.</p><p>Measurements of
CO<sub>2</sub> dynamics indicated qualitatively similar dynamic behavior as NCl<sub>3</sub>. Because of this, it was hypothesized that CO<sub>2</sub>
may represent a surrogate for NCl<sub>3</sub> for monitoring and control of IAQ
dynamics. To examine this issue in more detail, a conceptually similar model of
CO<sub>2 </sub>dynamics was developed and applied. The model was developed to
allow for an assessment of the relative contributions of liquid®gas transfer and respiration by swimmers and spectators to CO<sub>2</sub>
dynamics. The results of this modeling effort indicated that the similarity of
CO<sub>2</sub> transfer behavior to NCl<sub>3</sub> may allow use of CO<sub>2</sub>
as a surrogate during periods with few to no spectators in the pool; however,
when large numbers of spectators are present, the behavior of CO<sub>2</sub>
dynamics may not be representative of NCl<sub>3</sub> dynamics because of
spectator respiration.</p><p></p>
<br>
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Avaliação dos índices de qualidade da água bruta de um manancial em área urbana /Coneglian, Milena Guirado January 2020 (has links)
Orientador: Paulo Cesar Lodi / Resumo: A Política Nacional de Recursos Hídricos (Lei nº 9.433/1997) estabelece o enquadramento dos corpos hídricos como um dos instrumentos de gestão das águas. A CETESB – Companhia Ambiental do Estado de São Paulo, que compõe o Sistema Nacional de Gerenciamento de Recursos Hídricos criado por esta Lei, mantém Programa de Monitoramento da qualidade das águas e utiliza índices de qualidade das águas como ferramenta para a interpretação de dados ambientais complexos, com a finalidade de auxiliar no processo decisório das políticas públicas municipais além de informar técnicos e público em geral. Nesse sentido, com o objetivo de avaliar a evolução da qualidade de um manancial em área urbana e a sua conformidade em relação ao enquadramento, este estudo de caso apresenta uma análise sobre os Relatórios de Qualidade das Águas Interiores do Estado de São Paulo emitidos pela CETESB com ênfase nos arquivos relativos aos resultados dos parâmetros e indicadores de qualidade das águas do ponto de interesse, o Rio Lençóis, situado na UGRHi-13, de 2009 a 2018. O índice de conformidade ao enquadramento (ICE) foi aplicado anualmente e, também, bienalmente separados o período chuvoso do seco. Os principais resultados demonstram que as variáveis que mais apresentaram-se em desacordo com a Resolução CONAMA nº 357/2005 foram ‘ferro dissolvido’, ‘Escherichia coli’, ‘fósforo’ e ‘PFTHM’, proveniente de fontes difusas de poluição e em concentrações mais elevadas após ocorrência de chuvas, relacionadas ao a... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
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Combined effects of bioavailable organic contaminants in the aquatic environmentEmelogu, Emmanuel Steven January 2013 (has links)
Passive sampling, as opposed to the conventional spot or bottle water sampling technique, has shown to be reliable and efficient in monitoring the toxicologically relevant, freely dissolved (e.g. bioavaialable) concentrations of a wide range of organic contaminants in water. At the same time, partitioning controlled delivery (passive dosing; PD) techniques promise to overcome many of the challenges associated with toxicity testing of hydrophobic substances that may bias the interpretation of toxicity data. The present study investigated the feasibility of coupling silicone rubber passive sampling devices (SR-PSDs) with bioassay techniques for both chemical and ecotoxicological assessment of complex mixtures of organic contaminants in the aquatic environment. SR-PSDs were deployed in water at various locations within the Ythan catchment (north east, Scotland, UK), Forth estuary and the Firth of Forth (east coast of central Scotland, UK) for 7 to 9 weeks. Following retrieval, extracts from the SR-PSDs were analysed for dissolved concentrations of a variety of organic contaminants including PAHs and PCBs using GC-MS and GC-ECD respectively and were screened for a wide range of pesticides using GC-MS/MS and LC-MS/MS. The extracts were further evaluated for acute cytotoxicity (i.e. neutral red uptake assay) and EROD induction potential using rainbow trout liver cell line (Oncorhynchus mykiss; RTL-W1) and for phytotoxicity and developmental toxicity potential using algal growth inhibition test (with a marine phytoplankton, Diacronema lutheri) and fish embryo toxicity test (with embryos from zebrafish Danio rerio) respectively. Overall, the individual and total dissolved concentrations of PAHs (ΣPAH40; parent and branched) and PCBs (ΣPCB32; ortho and mono-ortho) measured in water from the Ythan, Forth estuary and Firth of Forth were relatively low compared with other studies using PSDs. A number and level of pesticides, including insecticides, herbicides and fungicides of varying hydrophobicity (log KOWs ~2.25 to ~5.31) were detected in the silicone rubber (SR) extracts from the Ythan catchment, the Forth estuary and the Firth of Forth, suggesting input mainly from agricultural run-off and possibly from direct discharges. No statistically significant (p<0.05) acute cytotoxicity was observed following 48 h exposure of RTL-W1 cells to SR extracts from the Ythan catchment. But, on a sublethal level, for every site, statistically significant EROD activity was observed to some degree following 72 h exposure. In addition, developmental and algal toxicities on embryos of D. rerio and D. lutheri respectively, were measured in all the deployed samples compared with the procedural controls (undeployed samples). Interestingly, extracts of SR-PSDs from the Forth estuary and the Firth of Forth exhibited growth inhibitions on D. lutheri that were similar to those of extracts from the Ythan, even though, fewer numbers of pesticides were detected in the Forth estuary and Firth of Forth than the Ythan. This suggests that pesticides were not solely responsible for the observed effects in the Ythan catchment. To further improve data from toxicity testing of hydrophobic substances, the study identified the use of SR O-rings as a suitable passive dosing format in in vitro toxicity tests and was partially validated through their use in dosing RTL-W1 cells with two individual PAHs and subsequently determining cytotoxicity and EROD-activity.
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Development of monitoring program for water safety in small-scale water treatment plants in rural areas of EcuadorSigrell, Tone January 2018 (has links)
Globally a major health concern according to the World health organization (WHO, 2011) is gastro-intestinal infections caused by fecally contaminated water. The access to drinking water has increased due to international efforts, however the long-term sustainability and safety of the water accessed have gained criticism, and many water sources have proven to be both contaminated (UN, 2016) and badly managed (WHO, 2016a). This thesis aims to design a monitoring program for small-scale water treatment in order to make the water supply sustainable in terms of providing safe water in a long-term perspective. A case-study was conducted for three treatment systems under constructed in rural Ecuador. The monitoring program design was based on a literature review and conducting a quantitative microbial risk assessment (QMRA). QMRA is a tool for estimating microbial risks, by using quantitative data on microbial contamination and estimating health risks. Data for the QMRA was gathered from literature and in field, and the reference pathogens used in the QMRA were E.coli O157:H7, Rotavirus and Giardia. In order to estimate infection risk from drinking water consumption for the community a QMRA-model called MRA, developed by Abrahamsson et al. (2009) was used. Observations of the catchment areas and measurement of water quality regarding aspects other than microbial contamination indicated that the main risk was microbial contamination from fecal contaminations in the catchment area. The results from the QMRA indicated that the treatment using chlorination reduces E.coli O157:H7 under the acceptable risk level of 1/1000 infections per person and year, while the systems using biosand filters (BSF) are more effective in reducing rotavirus and Giardia. If the BSF are combined with chlorination the annual probability of infection caused by consumption of the treated water per year and person was 0.42/1000 for E.coli O157:H7, 570/1000 for Rotavirus and 25/1000 for Giardia. The resulting monitoring program was divided into two parts: one part aimed to prevent contamination and one part designed to measure pH, temperature, conductivity, turbidity on a weekly basis and microbial indicator tests using a presence/absence method monthly. Additional testing is to be done in case of events of such character that the water quality could be effected, for example an extreme weather event. It was concluded that the designed monitoring program could help improve the water quality in a long-term perspective, but it is dependent on the possibilities to get the necessary support, especially in the implementation phase. Recommended further studies includes collection of more site-specific data to make the QMRA results more representative, and evaluation of the monitoring program design by implementing it and optimizing it in the communities. / Runt om i världen skapar en otillräcklig tillgång på rent vatten och sanitet mycket lidande. Enlig världshälsoorganisationen WHO (2011) är ett av de ledande världshälsoproblem mag- och tarminfektioner som orsakats av vattenburna fekala patogener. Trots att antalet människor med tillgång till en dricksvattenkälla har ökat till följd av internationella ansträngningar, är hållbarheten och säkerheten för vattenkvalitén problematisk. Många dricksvattenkällor har visat sig vara både förorenade (UN, 2016) och undermåligt skötta (WHO, 2016a). Målet med denna studie är att ta fram ett vattenkvalitetsövervakningsprogram för tre småskaliga vattenreningsverk, för att dessa ska producera säkert vatten i ett långsiktigt perspektiv. En fallstudie utfördes i byar på landsbygden i Ecuador där systemen planerats. Metoden för att ta fram ett kvalitetsövervakningsprogram var litteraturstudie och mikrobiell riskanalys. Den mikrobiella riskanalysen genomfördes med en metod som kallas Kvantitativ Mikrobiell Risk Analys (QMRA). I QMRA kan hälsorisker från mikrobiell kontamination estimeras med kvantitativdata på mikrobiell förorening. Data för att genomföra QMRA samlades från litteraturen och fältbesök. För att estimera hälsorisker i byarna i fallstudien användes en QMRA-modell som heter MRA framtaget av Abrahamsson et.al. (2009). Observationer i fält och data på ingående vatten tydde på att de största riskerna för vattenkvalitén var fekal kontamination från djur och människor. Resultaten från QMRA:n visade att reningsverket med klorering reducerade E.coli O157:H7 till en nivå under den accepterade risknivå, satt till 1/1000 infekterade per år och person. Reningsverken med biosandfilter (BSF) var mer effektiva i reduktionen av rotavirus och Giardia. Då klor kombinerades med BSF i modellen blev den årliga infektionsnivån per person 570/1000 för Rotavirus och 25/1000 för Giardia. Vattenkvalitetsövervakningsprogrammet delades in två delar: en kontaminationsförebyggande och en för att mäta pH, temperatur, konduktivitet och turbiditet veckovis, samt mikrobiella indikatortest med en metod som noterar förekomst av bakteriekolonier (presence/absence metod) månadsvis. Extra tester ska även göras vid sådan händelse som kan komma att påverka vattenkvalitén avsevärt, exempelvis en kraftig storm. Slutsatsen är att det framtagna vattenkvalitetsövervakningsprogrammet kan göra att vatten-källan blir mer säker och hållbar i ett långsiktigt perspektiv, men att framgången är beroende av att rätt hjälp finns tillhanda speciellt i implementeringsfasen. Fortsatta studier behövs för att göra resultaten från QMRA:n mer representativa, exempelvis genom att samla mer områdesspecifikdata. Vidare skulle det vara intressant att implementera kvalitetsövervakningsprogrammet för att utvärdera och optimera det.
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Análises espaço temporais da qualidade da água bruta do Aquífero Bauru na área urbana de Araguari, MGBorges, Eduardo Humberto Campos 21 March 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / O Aquífero Bauru é considerado a unidade hidrogeológica mais importante de Araguari,
Minas Gerais. A água deste aquífero é intensamente explorada devido ao baixo custo de
captação, que está relacionado ao fato de ser um aquífero freático, pouco profundo e
local, submetido a uma abundante recarga. No entanto, essas características o torna
potencialmente vulnerável aos agentes poluidores. Este trabalho teve como objetivo
oferecer um panorama geral sobre a qualidade da água bruta do aquífero Bauru, na zona
urbana de Araguari, identificando possíveis fontes de poluição. As amostras de água
foram coletadas em poços da concessionária de abastecimento público. Os critérios para
seleção dos poços foram: distribuição espacial, operacionalidade, estrutura e zonas de
risco. As amostras foram coletadas a montante do ponto de aplicação do desinfetante,
garantindo os aspectos qualitativos da água bruta. Foram amostrados 68 poços,
correspondendo a 80 % do poços em operação. Foram realizadas 2 campanhas de
campo, sendo a primeira em novembro de 2012 e a segunda em dezembro de 2014. A
amostras foram submetidas a ensaios de pH, nitrato, nitrito, fósforo, DQO, DBO5, cor
aparente, turbidez, sólidos totais, sólidos dissolvidos totais, sólidos suspensos totais,
sólidos voláteis totais e fixos totais. Os resultados das etapas de campo e laboratoriais
permitiram o mapeamento dos parâmetros de qualidade e a identificação das áreas
críticas em termos de poluição. Os resultados indicaram que vazamentos de esgoto
sanitário, em áreas que apresentam elevados índices de vulnerabilidade, podem ser a
causa da presença nitrato e sólidos voláteis em alguns poços analisados. Apesar disso, a
água bruta do Aquífero Bauru ainda apresenta boa qualidade com propriedades físico-
químicas e bacteriológicas adequadas a diversos usos. Apesar das concentrações
encontradas ainda serem inferiores aos limites estabelecidos pela legislação vigente, fica
evidente a importância do monitoramento contínuo da qualidade da água subterrânea
extraída para o abastecimento urbano. / The Bauru Aquifer is considered the most important hydrogeological unit of the city of
Araguari, Minas Gerais. The water from this aquifer is exploited due to low cost, which
is related to the fact of being a shallow and local subjected to an abundant recharging.
However, these characteristics makes it potentially vulnerable to pollutants. This work
aimed to provide an overview of the quality of raw water from the aquifer Bauru
underlying the urban area of Araguari, identifying possible sources of pollution. Water
samples were collected in wells of public water utility. The criteria for selection of the
wells were: spatial distribution, operation, structure and risk areas. The samples were
collected upstream of disinfectant application point, ensuring the qualitative aspects of
raw water. 68 wells were sampled corresponding to 80% of the wells in operation. Were
held two field campaigns, the first in November 2012 and the second in December
2014. The samples were subjected to pH tests, nitrate, nitrite, phosphorus, COD, BOD,
apparent color, turbidity, total solids, solids total dissolved, total suspended solids, total
volatile solids and total fixed. The results of field and laboratory steps allowed the
mapping of quality parameters and the identification of critical areas in terms of
pollution. The results indicated that wastewater leaks in areas that have high levels of
vulnerability may be the cause of nitrate and volatile solids present in some wells
examined. Nevertheless, the raw water from the aquifer Bauru still has good quality
with physical-chemical and bacteriological appropriate to different uses. Although the
concentrations found are still below the limits established by law, it is clear the
importance of continuous monitoring of groundwater quality extracted for urban supply. / Dissertação (Mestrado)
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Optimisation of water quality monitoring network design considering compliance criterion and trade-offs between monitoring information and costsNguyen, Thuy Hoang 03 February 2022 (has links)
Water quality monitoring (WQM) is crucial for managing and protecting riverine ecosystems. There has been a plethora of methods to select the monitoring sites, water quality parameters (WQPs), and monitoring frequencies; however, no standard method or strategy has been accepted for the river systems. Water managers have faced difficulties in adopting appropriate WQM network design methods to their local boundary conditions, monitoring objectives, monitoring costs, and legal regulations. With the elevated cost and time consumption of monitoring, approaches to evaluate and redesign the monitoring networks based on monitoring goal achievements are crucial for water managers. Hence, the overall aim of this thesis is to develop and employ a reliable yet straightforward approach to optimise and quantify the effectiveness of the WQM network in rivers. The objectives are to (i) identify the commonly used methods and the boundary conditions to apply these methods in assessing and designing of WQM networks in rivers; (ii) optimise river WQM network design based on compliance criteria; (iii) optimise river WQM network design based on the trade-offs between information provided by the monitoring network versus the monitoring expenses.
A systematic review of the commonly used design methods and their resulting monitoring setups in Chapter 2 shows that multivariate statistical analysis (MVA) is a promising tool to contract the number of monitoring sites and water quality parameters. Most of the reported studies often overlook small streams and trace pollutants such as heavy metals and organic microcontaminants in the analysis. Data availability and expertise’s judgments seem to affect the selection of design methods rather than river size and the extent of the monitoring networks.
The commonly found statistical methods are applied to the case study of the Freiberger Mulde (FM) river basin in eastern Germany to optimise its current monitoring network. Chapter 3 dedicates to redesign the monitoring network for compliance monitoring purposes. In Chapter 3, 82 non-biological parameters are initially screened and analysed for their violations to the environmental quality standards. The subsequent result suggests that polycyclic aromatic hydrocarbons, heavy metals, and phosphorus have been the abundant stressors that caused more than 50% of the streams in the FM river basin failing to achieve good status. The proposed approach using hierarchical cluster analysis and weighted violation factor from 22 relevant WQPs allows a reduction of 42 monitoring sites from the current 158 sites. The Mann-Kendall trend test recommends an increase in monitoring frequency of the priority substances by 12 times per annual, and a decrease in the number of sampling events for metals and general physicochemical parameters by quarterly. Overall, the results suggest that the authorities of the Saxony region should develop proper management measures targeting heavy metals and organic micropollutants to be able to achieve good WQ status by 2027 at the latest.
In Chapter 4, regularly monitoring parameters with less than 15% of censored data are analysed. A combination of principal component analysis and Pearson’s correlation analysis allows the identification of 14 critical parameters that are responsible for explaining 75.1% of data variability in the FM river basin. Weathering processes, historical mining, wastewater discharges, and seasonality have been the leading causes of water quality variability. Both sampling locations and periods are observed, with the resulting mineral contents vary between locations, and the organic and oxygen content differs depending on the time period that was monitored. The monitoring costs are estimated for one monitoring event and based on laboratory, transportation, and sampling costs. The results show that under the current monitoring-intense conditions, preserving monitoring variables rather than sites seems to be more economical than the opposite practice.
The current study provides and employs two statistical approaches to optimise the WQM network for the FM river basin in eastern Germany. The proposed methods can be of interests to other river basins where the historical data are available, and the monitoring costs become a constraint. The presented research also raises some concerns for future research regarding the applications of statistical methods to optimise WQM networks, which are presented in Chapter 5.
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