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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.
291

Arizona: Know Your Water (Spanish) [Conoces tu Agua Arizona?]

Artiola, Janick, Moxley, Jacqueline C., Farell-Poe, Kathryn L. 06 1900 (has links)
110 pp.
292

Operational hydrology and water quality investigations of the stream-reservoir system in the Upper Pampanga River Project, Philippines

Liongson, Leonardo Quesada,1948- January 1976 (has links)
The compilation, collection, analysis, and simulation of UPRP streamflow and water-quality information were undertaken in order to assess the expected levels and variability of the quantity and quality of the surface waters in relation to the meteorology and hydrology of the area--the intended objectives of the project--and the modes of system operation. Under the two major phases of the study, important aspects which were examined were the availability and adequacy of the data base, and the applicability of modeling schemes to simulate the observed properties of the data. The major objective in the operational hydrology phase was to test the applicability of operational hydrology in a tropical environment. A stochastic model was fitted to the streamflow data of the extended UPRP inflows in order to serve as a generator of synthetic monthly streamflows which are used as inputs to operational studies of the project. As an initial requirement, the historical record was augmented by means of regional estimation techniques and a statistical data augmentation scheme. The percent deviation method of data augmentation was selected and applied, based on the results of a comparison of four augmentation methods. Two normalizing transformations were applied on the augmented-historical data in order to express them as statistical variables amenable to synthesis. These were the logarithmic transformation and Harter's table interpolation scheme. A time series analysis applied on the normalized data prescribed the adoption of the separate-monthly Matalas model for synthesis. The application of the model yielded synthetic streamflows which satisfactorily reproduced the correlation coefficients, means, and standard deviations of the augmentedhistorical monthly flows. Model extensions and refinements were recommended in order to surmount model limitations. In general, the applicability of operational hydrology in a tropical environment has been demonstrated. The quality of the UPRP surface water was characterized in order to provide background information which is essential in determining the suitability of the water for fishery development in the reservoir, for irrigation, and for domestic and industrial use. The Pantabangan reservoir was characterized in terms of observed patterns of temperature, dissolved oxygen, and salinity. An annual cycle was observed which exhibits intermittently disturbed and moderate stratification in the wet season, full circulation and isothermal condition during the cool, windy, and dry months, and a short warm period favorable to stratification prior to the heavy rains. Atmospheric reaeration was identified to be the major contributor of dissolved oxygen to the reservoir water. The application of the Markofsky-Harleman predictive model for reservoir temperature and dissolved oxygen emphasized the need for substantial data on the hydrology, meteorology, hydrodynamics, and water quality in the reservoir which are required as model inputs. The best agreement between observed and predicted temperature and DO was obtained for cool, windy, and dry months of December to February. Limitations in the input data and in the assumed parameters were observed. The available and collected water-quality data in the reservoir and streams of the UPRP indicated a salinity level as low as or less than 100 ppm in the headwaters to as high as 300 ppm in the outflows from the irrigation service area. The surface water is essentially the alkaline-bicarbonate type. The heavy runoff during the wet season produces a dilution of the TDS, but causes the conveyance of considerable amounts of sediment to the reservoir and river channels. An approximate salt balance for the project area yielded estimates of net amounts of salts leached from the area per season.
293

A multi-criteria water quality index for optimal allocation of reclaimed municipal wastewater

Yu, John Kuo-an,1944- January 1977 (has links)
Use-oriented benefits and treatment cost analysis have been incorporated into a water quality index to derive economically optimized pollutant concentrations for use in the development of waste water treatment programs. This multi-criteria water quality index can be used in decision-making at federal and local governmental levels. Five major pollutants (coliforms, nitrogen, phosphorus, suspended solids, and detergent) were considered in the treatment of municipal wastewater. With each higher level of improvement, the treatment costs increase proportionally, but the benefits associated with the reuse of this treated wastewater also increase in all cases except that of nutrient removal for agricultural use. Listed in descending order of their general utility, possible uses of reclaimed water include water supply, recreation, irrigation, industrial use, waste disposal, transportation, and commercial fishery. The optimal concentration of a pollutant was defined as that point at which the marginal costs of its removal equal the marginal benefits thereby obtained. The optimum net benefits associated with each kind of reclamation are derived simultaneously. The multicriteria water quality index is a combination of the maximum net benefits and the water quality index of the optimal individual concentrations. Walski and Parker's water quality index was used in rating water quality. This methodology was applied to the Tucson region for the expediency of acquiring data. Possible uses considered for the reclaimed municipal wastewater included agricultural irrigation and recreational lakes in the Tucson metropolitan area. Results from this study indicate that the multi-criteria water quality index is zero dollars, or (NB = $1.83•10⁶, WQI = 0). Similar evaluations for other cities, made in the same way, would permit ranking of this index. This ranking would be useful for making decisions concerning the allocation of regional funds for treating municipal wastewater. This approach could also be used on a local level for determining optimal concentrations of pollutants and for optimal allocation of the treated water.
294

The Chemical Composition of Representative Arizona Waters

Smith, H. V., Caster, A. B., Fuller, W. H., Breazale, E. L., Draper, George 11 1900 (has links)
No description available.
295

Arizona: Know Your Water

Artiola, Janick F., Farrell-Poe, Kathryn L., Moxley, Jacqueline C. 10 1900 (has links)
Revised; Originally Published: 2004, 2006 / 106 pp.
296

Photocatalysis of aquatic humic substances prior to chlorination

Palmer, Fiona Lorraine January 1998 (has links)
No description available.
297

The treatment of a secondary municipal effluent by ozone

Paraskeva, Panagiota January 1998 (has links)
No description available.
298

Linking ecology and management of water quality : the distribution and growth of phytoplankton in coastal lakes of British Columbia

Davies, John-Mark. 10 April 2008 (has links)
Processes regulating the growth and successional pattern of phytoplankton and the production of odour compounds in lakes of coastal and interior British Columbia were examined. An emphasis was placed on the role of nutrients, the role of size in determining nutrient deficiency, and the importance of winter for understanding the functioning of coastal lakes. Although the study lakes were all phosphorus limited (TN:TP molar ratio >22), plankton, especially the greater than 3 pm size fraction, were often nitrogen deficient. This demonstrates the importance of nitrogen as a growth regulating nutrient for larger plankton in these lakes. Seasonal patterns of productivity varied among lakes, and Maxwell Lake was found to reach maximal photosynthetic rates in February. Lakes without a dominant seasonal physical influence (e.g. ice-cover) and those subject to short-scale stochastic events that play dominant roles may not have their "successional clock" set. This can lead to an apparent chaotic seasonal pattern of species distribution. In coastal lakes the lack of strong seasonal patterns is more likely to occur in lakes with lower nutrients (e.g. <10 pg TP-L-') than in lakes with relatively high nutrients (>I5 pg TP.L-') because of the seasonal cycling of nutrients within eutrophic lakes. The origin of odours in drinking water was examined from nineteen lakes and reservoirs to determine links between limnological variables and classification and intensity of odour. Total phosphorus (TP) was the best single predictor of odour intensity. Vegetation and grassy odours were more prevalent in lakes with TP less than 13 pgL-', while earthy odours were common at higher TP. Drinking water quality issues were reviewed and the relationship between policy, management and science was examined. This work stresses the importance of sound science to ensure the legality, legitimacy, efficiency and effectiveness of implementing water quality policies and for establishing best management practices.
299

Determining the pathogenicity and quantities of Escherichia coli in selected South African water types using molecular biology techniques

15 August 2008 (has links)
Escherichia coli (E. coli) is a universally accepted indicator of faecal pollution in water, and can be divided into several groups of which one group would be commensal E. coli (generally the indicator organism), and five diarrhoeagenic E. coli types. Pathogenic E. coli offers attractive possibilities to model the pathogenicity of polluted water that people drink. To date, techniques used for the detection of these pathogens include standard culturing techniques, the use of molecular probes directed against known pathogens and polymerase chain reaction (PCR) for the amplification of known virulence genes, usually after a pre-culturing step. There is however a need to speed up the process and to accurately quantify (for risk purposes) the type and number of E. coli (commensal and pathogenic) present in any given water sample. The use of more recently developed techniques such as real-time PCR and competitive PCR (c-PCR) offers us a way of quantifying the target organism and has been successfully applied in various parts of the world. The aim of this study was to adapt and use developed methodologies that employs both c-PCR and multiplex PCR (m-PCR) to quantify total E. coli, detect and distinguish between the diarrhoeagenic E. coli patho-types present in selected South African water samples without prior culture or enrichment. Using E. coli as a model pathogen, a technique was developed for the concentration of bacteria from water samples, isolation of DNA from bacteria and performing PCR’s on the extracted DNA. Three m-PCR’s were developed directed towards the housekeeping (Mdh) and virulence (eaeA, Stx1, Stx2, ST, LT, Ial and Eagg) genes associated with entero-pathogenic E. coli. c-PCR was performed using the Mdh housekeeping gene, with our modified version of the PCR product used as competitor DNA. Results obtained lead to a protocol consisting of the filtration of 100 mℓ environmental water, DNA extraction directly from the membranes, followed by quantitative c-PCR to screen for PCR inhibition as well as to quantify isolated DNA, thereafter screening of the DNA for the presence of virulence genes with m-PCR. Initial testing with known pathogens showed that this methodology was a viable option. DNA could be recovered from the filters, yielding PCR-ready templates. A total of 49 water samples were collected, these samples included household containers from rural areas, river water from three provinces in South Africa and wastewater from 4 different wastewater treatment plants around Johannesburg (Gauteng province). These water samples were subjected to the above-mentioned protocol with 100 % (49/49) of the samples testing positive for presence of the E. coli Mdh house keeping gene. Of the samples tested, 57 % (28/49) tested positive for EAEC, 0 % (0/49) tested positive for EIEC, 92 % (45/49) tested positive for ETEC, 2 % (1/49) tested positive for atypical EHEC and 0 % (0/49) tested positive for atypical EPEC. 38 percent of the water samples could be successfully quantified by c-PCR and were able to detect as low as 3 cells/mℓ. However, the remaining 62 percent DNA samples (isolated from water samples) was diluted to overcome PCR inhibition but failed to be quantified by c-PCR because the level of target DNA was too low to detect which allowed over competition of the Mdh competitor DNA. In conclusion, this method could successfully isolate E. coli DNA from various water samples. The isolated DNA could be used as PCR template and PCR inhibition could be overcome in all the samples by either diluting the sample or adding PCR facilitators. The PCR was able to amplify low levels of isolated E. coli DNA from most of the water samples and the presence of pathogens could be detected in the water with the m-PCR. Molecular quantification could be used to quantify DNA isolated from the water samples, but one limitation is the detection of very low numbers of E. coli DNA due to the nature of c-PCR, i.e. co-amplification of the target and competitor DNA. / Prof. Paul Jagals Dr. T.G. Barnard Mr. K. Maclean
300

Water Quality Modeling of a Storm Water Channel

Sangameswaran, Sivaramakrishnan 07 August 2003 (has links)
The fate of nutrients and their relationships in the London Avenue Canal is very complex. This study was undertaken to assess the water quality of the canal in wet and dry weather conditions, and to develop a 2 "“ layer model to predict the response of the canal to storm water discharges. Samples were collected at specific locations and at five different depths during wet and dry weather periods. These were used as background values in the model and for comparing the model output with the actual field results to verify the validity of the model. A 2-layer model has been developed to predict the response time of the system during and after a pumping event. This model has been used to predict various scenarios and the corresponding response times. The results by and large confirm the field data observed for certain parameters.

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