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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Survey on Satisfaction of Indirect Water Supplies in A Distribution System and Varriation of THMs Concentration in Kaohsiung City

Huang, Hsiu-fang 15 July 2008 (has links)
The quality of drinking water effects not only human health, but also plays a decisive role in daily life. Although the Taiwan water corporation has improved water quality of Kaohsiung in recent years and most of the random testing results of the drinking water done by the EPB could meet the drinking water standards, many people still lack confidence in the tap water. This study (1) select 500 multi-unit residences from 11 districts in Kaohsiung and survey the water quality of the indirect water supply storage devices to understand the tap water quality of indirect water distribution network in Kaohsiung. (2) Aiming at the inhabitants living in multi-unit residences, a questionnaire about the satisfaction with the tap water in Kaohsiung is undergone by random sampling in order to understand the satisfaction with the tap water of the public. (3) The monitoring values of total trihalomethanes (TTHMs) in tap water distributional network in four seasons from December 2006 to September 2007 are used to analysis the seasonal changes, the equal concentration distribution figure, and the ration of all kinds of compounds of the THMs to the total amounts. The results of above analyses can be offered to Taiwan Water Corporation to make improvement and as the references of following studies. The result of the survey of satisfaction shows that 47% people incline to use tap water as drinking water¡F53% people don¡¦t have confidence in tap water and choose to the bottled water from water stations as drinking water source. 49.1% people living in cluster housing in Kaohsiung consider the quality of tap water common¡F15.4% people are satisfied with the tap water quality and 35.7% people are not satisfied with it. The main reason is the old pipelines, and the secondary reason is about the distasteful water. Most people wish to renew old pipelines as soon as possible, and give priority to strictly control the tap water quality. The analysis result of THMs concentrations shows that the average value of THMs in each district is highest in spring and lowest in autumn, especially in Cianjhen, Siaogang, and Cijin districts. The THMs concentration distribution of Cianjhen district is higher in the spring and winter. The proportion of CHCl3 (chloroform) to total amount of THMs is the highest in the water supply network, and it is also the major source of THMs.
2

Determination Of Thmfp Of The Reservoirs In Turkey : Kinetics Aspect

Artug, Mine 01 November 2004 (has links) (PDF)
Chlorine is still the most commonly used disinfectant in many water treatment plants all over the World. However, studies conducted demonstrated that the chlorine reacts with the natural organic matter (NOM) in source waters, and leads to the formation of a variety of chlorinated organic compounds, disinfection by-products (DBPs). Among these, the most common are the trihalomethanes (THMs). In this study, kinetics of the THM formation was investigated. Kinetic experiments were carried out with the raw waters from Devege&ccedil / idi and Atat&uuml / rk Reservoirs as well as with water containing a model compound, humic acid. THM and Chlorine concentrations were measured for 6 weeks on a seasonal basis. The simulation model developed by USEPA was used for predicting THM concentrations. The results of this study have shown that THM formation increases with increasing time and higher chlorine doses result in higher THM formation. Also, higher organic matter concentrations resulted in higher chlorine demands and both these parameters increased the TTHM concentrations. But, on the contrary to the standard THMFP testing, THM formation did not complete in seven days. In addition, THM formation and chlorine consumption were very rapid during the first 24 hr followed by a more gradual formation and decay after 24 hr. THM formation rates ranged between 35-66 &micro / g/L.day for Atat&uuml / rk Reservoir, between 80-167 &micro / g/L.day for Devege&ccedil / idi Reservoir and between 85-248 &micro / g/L.day for humic acid during the first 24 hr, and ranged between 2-6 &micro / g/L.day for Atat&uuml / rk Reservoir, between 7-16 &micro / g/L.day for Devege&ccedil / idi Reservoir and between 3-14 &micro / g/L.day for humic acid after 24 hr.
3

Monitoring of fouling and clean-in-place (CIP) using the Rotoscope and microscopy and monitoring of trihalomethanes (THMs) produced from electro chemically activated (ECA) water during CIP

Mashangoane, Boitumelo Francina 07 February 2012 (has links)
The unwanted occurrence of biofilms in various industries requires critical remedial action in order to prevent their detrimental effects which potentially result in huge economic losses. Adequate monitoring of biofilms is a powerful tool to aid their thorough understanding and ultimate control. The Rotoscope is an instrument based on the principle of light absorption and reflection that was used in this study to monitor and study biofilms. Biofilm development of cocci and bacilli species was monitored using the Rotoscope and microscopy. Light reflectance decreased over time as the biofilm developed. Information on the different stages of biofilm development could also be deduced from light reflectance assays of the Rotoscope. Microscopy validated results which were obtained from light reflectance assays. Information on the morphology of the bacteria, depth of the biofilm as well as the different stages of biofilm development was deduced from EM and CLSM images. The Rotoscope was an easy, effective, on-line monitoring device for the development of biofilms. It was a lso showed to be useful in coll ecting informati on to help characterize bacteria species present within a biofilm The Rotoscope was integrated into a simulated soft drink (SO) production line to monitor biofouling and the efficacy of a clean-in-place (CIP) regime using electrochemically acti vated (ECA) water. During CIF the Catholyte and Anolyte (components of ECA) were effective as detergent and disinfectant respecti vely. This was indi cated by results obtained from microbial analysis of removable slides from the MPD, microscopic analysis, as well as pH, ORP and EC analysis. The absence of microbial growth and soil on microscope slides from the Rotoscope were a good indication of the high efficacy of Catholyte and Anolyte (components of ECA) as detergent and disinfectant respectively in a crp system. In addition, the re latively constant values reported for pH, ORP and EC before and aft er CIP suggests that the Catholyte and Anolyte were effective during CIF. The effect of Anolyte on trihalomethane (THM) formation was observed because of the presence of chl orine compounds. Low levels of THMs were obtained from CIP effluent which provided a good indicati on that Anolyte is an environmentally friendly alternative disinfectant compared to conventional disinfectants currently used in CIP. Increased pH and the presence of bromide resulted in an overall increase of THMs in systems using dissolved organic carbon (DOC) models (Glucose, maltose and phenol). There was however variation in the amount of THM produced using the three DOC models. The differences were attributed to the composition of organic matter in particular the aromacity and the nature and position of the functional groups of the model DOCs. / Dissertation (MSc)--University of Pretoria, 2012. / Microbiology and Plant Pathology / unrestricted

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