Thesis (Ph.D)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Aral, Mustafa; Committee Member: Guan, Jiabao; Committee Member: Jang, Wonyong; Committee Member: Kim, Seong-Hee; Committee Member: Uzer, Turgay. Part of the SMARTech Electronic Thesis and Dissertation Collection.

The goal of this research was to maintain excellent water quality at reduced chemical operations cost. Chemical usage data at the Austin water treatment plants were examined by identifying trends and investigating suspected inefficiencies. The investigation consisted in jar test experiments, plant-scale experiments, and equilibrium modeling. Lime and ferric sulfate were suspected to be added inefficiently with respect to cost while the other treatment chemicals were assessed to be added efficiently. Lime was investigated in greater depth than ferric sulfate because ferric sulfate was better characterized in its effect on finished water quality within the range of interest. The goal of lime addition is to remove hardness from the water by a process called lime softening. Hardness removal decreases corrosion in transmission lines and prevents deposition of unwanted solids in household appliances. Additionally, lime softening aids in particle removal and disinfection-by-product precursor reduction. The efficiency of lime addition was evaluated based on settled water pH and causticity goals, which serve as the operating parameters for the water treatment plants. The most efficient lime softening occurs when multiple softening goals are simultaneously achieved. First, the dissolved calcium concentration must achieve a minimum. Second, the dissolved magnesium concentration must be reduced by at least 10 mg/L as CaCO₃. Third, total alkalinity must be preserved at its maximum concentration while also achieving excellent hardness removal. Fourth, natural organic matter (NOM), which serves as a precursor for disinfection-by-products, must be removed sufficiently to achieve DBP reduction goals. Finally, the turbidity in the effluent from the settling basin must be below 2.0 NTU. Through the chemical investigation of lime based on existing scientific literature, computer modeling, jar test experiments, and full-scale testing, it was determined that the optimal condition operating condition for lime softening was a settled water pH range from 10.0 - 10.1. / text

Silver nanoparticles (Ag NPs) are frequently added as a disinfectant to ceramic filters used for household drinking water treatment. To provide suspension phase particle stability, Ag NPs can be synthesized using a number of different molecules to cap the metal core. The goal of this doctoral work was to advance the fundamental understanding of how stabilizing agents influence the attachment and detachment of Ag NPs from ceramic water filters. To achieve this goal, deposition experiments onto Al₂O₃ membranes and clay-based ceramic filters were performed using Ag NPs stabilized by three different agents: citrate, polyvinylpyrrolidone (PVP), and branched polyethylenimine (BPEI). Laboratory and field- scale filtration experiments were also conducted to evaluate the removal of Ag NPs from ceramics under different water conditions -- the presence of hardness and natural organic matter (NOM). Citrate-stabilized Ag NPs were found to have the highest attachment densities, regardless of filter material. Differing attachment densities for the three types of Ag NPs were extensively explained using a combination of classic Derjaguin, Landau, Verwey and Overbeek (DLVO) theory, steric forces, and particle-particle interaction energy calculations. A multilevel statistical model was built to describe the removal of Ag NPs from ceramic water filters under different water conditions. The type of Ag NP was found to affect the initial release of Ag from the filters, while the interaction of the type of Ag NP and water were found to affect the rate of removal. Hardness and NOM prolonged the release of Ag from ceramic water filters.

M. Tech. Water Care. / Aims to evaluate promising technologies for local application in the removal of viruses and protozoan parasites and to provide guidelines for the selection and use of appropriate home water treatment systems that could be used in rural households.

The current computer models used for simulating water quality in potable water distribution systems assume perfect mixing at pipe junctions and non-dispersive solute transport in pipe flows. To improve the prediction accuracy, the present study examines and expands these modeling assumptions using transport phenomena analyses. Whereas the level of solute mixing at a cross-type junction is evaluated numerically via Computational Fluid Dynamics (CFD), the axial transport in laminar flows is investigated with both CFD simulations and corresponding experimental runs in a single pipe. The findings show that solute mixing at junctions is rather incomplete owing to the limited spatio-temporal interaction that occurs between incoming flows with different qualities. Incomplete mixing shifts the expected propagation patterns of a chemical or microbial constituent from widely-spread to narrowly-concentrated over the service area. On the other hand, solute dispersion is found to prevail over advective transport in laminar pipe flows. Thus, this work develops axial dispersion rates through parameter optimization techniques. By accounting for axial dispersive effects, the patterns of solute delivery shifted from high concentrations over short time periods to lower doses at prolonged exposure times. In addition, the present study integrates the incomplete mixing model into the optimal placement of water quality monitoring stations aimed at detecting contaminant intrusions.

Denna rapport är en sammanställning av de 100 undersökta enskilda brunnarna i Landskrona kommun vid årsskiftet 05/06. Det utfördes analyser på mikrobiologisk-, nitrat-, nitrit- och även kemiska bekämpningsmedelspåverkan. Syftet med denna rapport är att bearbeta och presentera analysresultaten av de 100 enskilda brunnarna i Landskrona kommun och försöka dra slutsatser kring dessa. Alla analysresultaten sammanställdes i tabeller och så småningom kundes vissa slutsatser dras kring varför resultatet såg ut som det gjorde. Resultatet visade att endast åtta av de 100 brunnarna var otjänliga gällande mikrobiologisk påverkan. Denna parameter är väldigt varierande beroende mycket på yttre omständigheter men det kan ge en indikation på att brunnen inte är tillräckligt tät och därför kan ytvatten tränga in i brunnen. När det gäller nitritpåverkan blev bara en brunn otjänlig. Men när det gällde nitrat var det istället 17 % av brunnarna som visade sig vara otjänliga. Detta är ändå ett relativt bra resultat beroende på hur landskapet ser ut i Skåne med stor påverkan från enskilda avlopp, jordbruk och gödsling. Sist men inte minst analyserades kemiska bekämpningsmedel och gav ett oroande resultat. Hela 35 % av brunnarna var otjänliga pga. kemiska bekämpningsmedel. Detta resultat är inget ovanligt utan kan genom danska undersökningar bara bekräftas. Kemiska bekämpningsmedel kan sprida sig långa sträckor och inte bara vid den plats där ämnena använts eller spillts. De slutsatser som kan dras genom denna undersökning är att grävda brunnar i ytliga jordlager löper störst risk att i framtiden bli otjänliga då dessa utsetts för störst påverkan av föroreningar och ytvatten. Brunnar placerade på gårdsplan är speciellt utsatta och är starkt påverkade av både mikroorganismer och kemiska bekämpningsmedel. När det gäller kemiska bekämpningsmedel är resultaten från Landskrona liknande de från både Danmark och övriga Skåne. / The problem with bad drinking water in wells are a wide problem in an landscape such as Skåne. The purpose of this report is to work up all the data from the different analysis regarding drinking water quality from wells in Landskrona municipality. The parameters that were analysed were microorganisms, the content of nitrate and nitrite and also the concentration of pesticides. Many reports in the field of the subject were collected to get a good picture and a better knowledge of the different problems that lie ahead. This resulted in various conclusions but some of the conclusions was confirmed from other examinations. That wells in the ground are more exposed than wells in mountain. The concentration of pesticides were very high in many of the wells wich shows that this will be a great problem for us to deal with in the future. Examinations in both Denmark and remaining parts of Sweden also show high concentration of pesticides. This only confirm that the problem isn’t just a local here in the municipality.

Chlorine is the most widely used disinfectant for drinking water treatment. Chlorine canreact with natural organic matter (NOM) in water sources resulting in the formation of potentially carcinogenic disinfection by-products (DBPs). The most common DBPs measured in chlorinated drinking water distribution systems are trihalomethanes (THMs) and haloacetic acids (HAAs). In 2005, the City of Kamloops, British Columbia upgraded the drinking water treatment system to ultrafiltration membrane treatment. The objective of this study was to determine the extent to which upgrades to a drinking water treatment system, specifically, implementation of an ultrafiltration treatment process, impacted DBP formation within a distribution system. This study used a two-phase research approach. Phase I of the study was a distribution system monitoring program that collected water samples and physical and chemical information using data loggers at five sampling sites within the distribution system. Phase II of the study used bench-scale simulations that modeled DBP formation using a flow-through reactor system, the material-specific simulated distribution system (MS-SDS), constructed of pipe material resurrected from the City of Kamloops distribution system. Phase I results suggested that implementation of the ultrafiltration treatment process and accompanying treatment system upgrade was not effective at reducing the concentration of DBPs delivered to consumers. Concentrations of THMs remained relatively constant at sampling sites, while concentrations of HAAs increased following implementation of the ultrafiltration treatment process. The increase in HAA formation was likely due to an increase in retention time of the water within the distribution system following implementation of the ultrafiltration treatment process, rather than due to the treatment process itself. The results of this study are consistent with previous work on South Thompson River water DBP precursors, which suggested that THM and HAA precursors of this source water are small and hydrophilic, and therefore cannot be removed by ultrafiltration processes. Phase II results showed that the MS-SDS was more representative of distribution system c onditions than traditional glass bottles to estimate DBP formation. It is recommended that the MS-SDS be used in parallel with a simultaneous distribution system monitoring program to estimate distribution system retention times from THM and HAA concentrations.

Norint išvengti apšvitos nuo pavojingo žmogaus sveikatai radono ir jo skilimo produktų, reikia daugybės tyrimų, kurie nustatytų radono tūrinį aktyvumą mus supančioje aplinkoje, gyvenamosiose patalpose. Radonas patalpose atsiranda iš įvairių šaltinių: grunto, statybinių medžiagų, vandens. Radono tūrinis aktyvumas labai priklauso nuo namo konstrukcijos, vėdinimo ir nuo grunto, ant kurio jis pastatytas. Nors darbų skaičius, nagrinėjantis šią problemą, yra didelis, vienas iš faktorių, kuris sąlygoja radono tūrinius aktyvumus gyvenamojoje aplinkoje, yra regiono, kuriame radono tūrinis aktyvumas matuojamas, ypatumai – grunto sudėtis, poringumas, namo konstrukcijų tipai ir kiti. Nėra visiškai aišku, kurie iš faktorių lemia radono tūrinio aktyvumo kitimą pastatuose konkrečioje vietoje. Šio darbo tikslas – ištirti, kokį sąryšį radono tūrinis aktyvumas turi grunto ore, geriamajame vandenyje ir radono tūrinis aktyvumas patalpose, tyrimams pasirenkant palyginti nedidelį regioną – šalies pietryčiuose esančios Vilniaus apskrities Vilniaus, Šalčininkų ir Širvintų rajonus. Palyginimui naudotas radono tūrinis aktyvumas, tirtas pastatuose kituose šalies regionuose. Taip pat įvertinta radono tūrinio aktyvumo kaita skirtingais metų sezonais gyvenamajame pastate, kiek aktyvumui įtakos daro grunto pralaidumas ir namo sandarinimo ypatybės. / Indoor radon is most important expose for human population. It is necessary to investigate reasons of increasing of radon concentration. It is known that radon concentrations are highly variable within a region. This work deals with the investigations of indoor radon and radon in water in dwellings of Vilnius region. Measurements of radon in soil ware performed as well. Measurements were made at 22 private dwellings and surrounding off them in 2008 year. Statistically estimated that this region is not different from others Lithuanian districts. Effective dose for public due to indoor radon and radon in water were estimated. Results showed that the highest effective dose due to the indoor radon for public in Vilnius region is 2.1 mSv per year, highest effective dose due to radon in drinking water 5.7 μSv per year. No correlation funded between radon in soil and indoor radon in may investigation. So there are other factors that influence increase of radon concentration in buildings: engineering barrier, air conditions and others. Variation of indoor radon concentrations in a dwelling survey has been carried out in Panevezys districts in the village of Pinava. Indoor radon levels were measured in selected dwelling in autumn, winter, spring and summer seasons using radon monitor AlphaGuard. The average radon concentrations vary from 52 Bq/m3 in summer to 289 Bq/m3 in winter. Relation between first and second flour was estimated, its shows that radon concentrations on first flour... [to full text]

Magistro darbe išanalizuoti ir susisteminti įvairių autorių teoriniai geriamojo vandens kokybės vadybos procesai, svarbiausia sudedamoji proceso dalis, kuri užtikrina tolimesnį kokybės vykdymą yra vandens ėminių kokybės nustatymas. Įvertinta geriamojo vandens kokybė, bei jo gerinimo būdai Šiaulių regione. Kiekybinio tyrimo metu apklausti 384 Šiaulių regiono gyventojai. Išsiaiškinta, kad respondentai apie vandens kokybę informuojami retai, daugiausiai informacijos apie geriamojo vandens kokybę gauna iš šeimos narių, draugų, kaimynų. Nustatyta, kad vartotojai nepatenkinti geriamojo vandens, kuris teka iš jų čiaupo, kokybe, o buitiniai vandens valymo filtrai – priimtiniausia vandens kokybės gerinimo priemonė. Hipotezė, jog gyventojai neieško priemonių geriamojo vandens kokybės gerinimui, nes per mažai yra informuoti apie vartojamo vandens kokybės būklę, nepasitvirtino. / Master‘s study analyzes the structure of various authors and theoretical drinking water quality Management processes, the most important constituent part of the process to ensure continued quality performance is the abstraction of quality. The quality of the drinking water and its ways for improvement were estimated in the region of Siauliai. During the Quantities research 384 residents of region Siauliai were questioned. It was elucidated that the participants are rarely informed about the quality of the drinking water they receive from the members of the family, friends and neighbours. It was established that the users are not satisfied with the quality of drinking water, which comes from their faucets, and that the domestic filters are the most acceptable remedy for water quality‘s improvement. The hypothesis that residents aren't looking for remedies for the drinking water's improvement because the aren't informed enough about the quality of the used water, was not confirmed.

The aim of this study was to investigate the microbiological quality of drinking water at the source (taps at eThekwini laboratories, standpipes and mobile community tankers) and corresponding point-of-use (storage containers and ground tanks) supplied to peri-urban areas in Durban by eThekwini Municipality. It also aimed to identify factors associated with deterioration in water quality such as storage of water, household demographics, hygiene and sanitation practices. In order to determine the microbial quality of drinking water, the pour plate method (for enumeration of heterotrophic organisms) and the membrane filtration technique (for total coliforms and E. coli enumeration) were used. Conductivity, turbidity, pH and total and residual chlorine levels of drinking water were measured. Microbial and physico-chemical data was collated and statistically analysed with epidemiological data from an associated study to determine the link between microbial quality of drinking water, household demographics, health outcomes, socio-economic status, hygiene and sanitation practices. Findings showed that all point-of-use water was unsafe for human consumption as a result of either poor source water quality, in the case of standpipes, and microbial contamination at the point-of-use, in the case of ground tanks and community tankers. The latter could be attributed to unsanitary environments, poor hygiene practices or poor wateruse behaviour. Households which included children aged 0-5 years and in which open-top containers were used for water storage had the highest rates of diarrhoea and vomiting. Water from ground tanks had the best microbial quality but people in households using this water presented with the highest rate of diarrhoea. Therefore provision of microbially safe drinking water will not reduce the rate of health outcomes if addressed in isolation. In order to reduce water-associated illness, provision of safe and adequate amounts of water, hygiene and sanitation education and education on water-use behaviour should be provided as a package. The provision of improved water delivery systems does not ensure that drinking water is safe for human consumption. Measures, such as point-of-use water treatment should be considered to ensure that drinking water provided at the source and point-of-use is microbially safe for human consumption. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2009.