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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.
81

Determination of trihalomethanes (THMs) in water by GC/MS.

January 1998 (has links)
by Lai-nor Cheng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 51-55). / Abstract also in Chinese. / TABLE OF CONTENTS --- p.i / ABSTRACT --- p.v / LIST OF FIGURES --- p.vi / LIST OF TABLES --- p.vii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Water Treatment Process --- p.1 / Chapter 1.2 --- Disinfectants --- p.3 / Chapter 1.3 --- THMs formation --- p.4 / Chapter 1.4 --- Various Guideline Values --- p.6 / Chapter 1.5 --- WHO Guideline Values in 1993 (used in HK) --- p.6 / Chapter 1.6 --- THM-FP --- p.7 / Chapter 1.7 --- Removal Methods --- p.7 / Chapter Chapter 2 --- "Sample Collection, Pretreatment & Storage" --- p.8 / Chapter 2.1 --- Cleaning of Sample Bottles --- p.8 / Chapter 2.2 --- Sample Collection --- p.8 / Chapter 2.3 --- Sample Pretreatment & Storage --- p.8 / Chapter Chapter 3 --- Experimental --- p.9 / Chapter 3.1 --- Analysis Methods --- p.9 / Chapter 3.1.1 --- Sample Preparation Methods --- p.9 / Chapter 3.1.1.1 --- Liquid-liquid Extraction (LLE) --- p.9 / Chapter 3.1.1.2 --- Purge & Trap (P&T) --- p.9 / Chapter 3.1.1.3 --- Static and Dynamic Headspace (HS) --- p.9 / Chapter 3.1.1.4 --- Direct Aqueous Injection --- p.10 / Chapter 3.1.2 --- GC Detectors --- p.10 / Chapter 3.1.3 --- Sensitivity --- p.10 / Chapter 3.2 --- LLE & GC/MS (SIM) --- p.11 / Chapter 3.3 --- Reagents & Apparatus --- p.12 / Chapter 3.3.1 --- Reagents --- p.12 / Chapter 3.3.2 --- Apparatus --- p.12 / Chapter 3.4 --- Procedure --- p.13 / Chapter 3.4.1 --- Pentane Extraction --- p.13 / Chapter 3.4.2 --- Instrument Configuration --- p.14 / Chapter 3.4.3 --- GC Parameters --- p.14 / Chapter 3.4.4 --- MS Parameters --- p.19 / Chapter 3.5 --- Preparation of Standards --- p.19 / Chapter 3.5.1 --- Stock Standard Solution --- p.19 / Chapter 3.5.2 --- Primary Dilution Standard --- p.20 / Chapter 3.5.3 --- Secondary Dilution Standard --- p.20 / Chapter 3.5.4 --- Calibration Standards --- p.20 / Chapter 3.6 --- Validation of the method --- p.21 / Chapter 3.6.1 --- Calibration Graphs --- p.21 / Chapter 3.6.2 --- Recovery & Precision --- p.27 / Chapter 3.6.3 --- Detection Limits --- p.30 / Chapter 3.7 --- Quality Control --- p.30 / Chapter Chapter 4 --- THMs levels and THM-FP of Tapwater --- p.31 / Chapter 4.1 --- Sample Collection Sites in HK --- p.31 / Chapter 4.2 --- Data Acquisition --- p.31 / Chapter 4.3 --- Calculations --- p.31 / Chapter 4.3.1 --- Blank Correction --- p.31 / Chapter 4.3.2 --- Calculation of THMs concentration --- p.31 / Chapter 4.3.3 --- "Mean, Standard Deviation & RSD %" --- p.32 / Chapter 4.4 --- Summary of THMs levels & THM-FP in tapwater of HK --- p.32 / Chapter 4.4.1 --- THMs levels in tapwater of HK --- p.33 / Chapter 4.4.2 --- THM-FP in tapwater of HK --- p.34 / Chapter 4.5 --- THMs levels & THM-FP in the 19 districts of HK --- p.34 / Chapter Chapter 5 --- "THMs levels of Well, Distilled & Mineral water" --- p.42 / Chapter 5.1 --- THMs levels and THM-FP of Well water --- p.42 / Chapter 5.2 --- THMs levels of Distilled water --- p.42 / Chapter 5.2 --- THMs levels of Mineral water --- p.43 / Chapter Chapter 6 --- Removal Methods --- p.44 / Chapter 6.1 --- Heating --- p.44 / Chapter 6.1.1 --- Procedure --- p.44 / Chapter 6.1.2 --- Results --- p.45 / Chapter 6.2 --- Activated Carbon Filter --- p.47 / Chapter 6.2.1 --- Procedure --- p.48 / Chapter 6.2.2 --- Results --- p.48 / Chapter Chapter 7 --- Conclusion --- p.49 / References --- p.51 / Appendix --- p.56 / Chapter A. --- Properties & Toxicity of THMs --- p.57 / Chapter B. --- Collection Date & Time of Tapwater samples & Well water samples --- p.59 / Chapter C. --- THMs levels of Tapwater in the 57 collection sites of HK --- p.62 / Chapter D. --- THM-FP of Tapwater in the 57 collection sites of HK --- p.69 / Chapter E. --- Raw data ofTHMs levels (μg/L) in Tapwater of HK --- p.76 / Chapter F. --- Raw data of THM-FP levels (μg/L) in Tapwater of HK --- p.90 / Chapter G. --- Raw data of THMs concentrations in Well,Distilled & Mineral water --- p.104 / Chapter H. --- Specification of Activated Carbon Filter --- p.106 / Chapter I.(1) --- Mass Spectrum of Chloroform --- p.108 / Chapter (2) --- Mass Spectrum of Chlorodibromomethane --- p.109 / Chapter (3) --- Mass Spectrum of Bromodichloromethane --- p.110 / Chapter (4) --- Mass Spectrum of Bromoform --- p.111
82

\"Desenvolvimento de metodologia analítica para a determinação de hidrocarbonetos policíclicos aromáticos (PAHs) em amostras de água utilizando uma interface SPME/HPLC/DAD\" / \"Development of an analytical methodology for polycyclic aromatic hydrocarbons (PAH\'s) analysis in water samples using a SPME/LC/DAD interface\"

Ferreira, Fernanda Cristine Spoljaric 20 March 2006 (has links)
Este trabalho descreve a otimização e validação de um método analítico para a análise de hidrocarbonetos policíclicos aromáticos (PAHs) em água usando uma interface SPME/LC/DAD. Parâmetros como tipos de fibra, tempo de extração, temperatura e força iônica foram estudados no modo \"off line\" e a influência destes na eficiência de extração foi avaliada. Os melhores resultados foram obtidos com a fibra Carbowax/templeted resin. Uma interface \"lab made\" foi utilizada para a etapa de validação e as curvas de calibração mostraram boa linearidade (r>0,99) para a maioria dos compostos analisados, tanto na linearidade da amostra como na linearidade do padrão. Os dados de precisão obtidos na concentração de trabalho variaram de 1 a 3%, aproximadamente, e os valores de recuperação se mantiveram na faixa de 4 a 27%. Os PAHs foram determinados na faixa de 0,025 micro g até 0,5 micro g. Pode-se considerar os valores obtidos nos itens de precisão e linearidade satisfatórios para a análise dos PAHs, considerando-se os critérios internacionais estabelecidos para esta classe de compostos, mas o método não atende as especificações relacionadas a recuperação e faixa de concentração. / This work describes the optimization and validation of an analytical method to determine Polycyclic Aromatic Hydrocarbons (PAHs) in water using a SPME/LC/DAD interface. Parameters as fibers kind, sampling time, temperature and ionic strength were studied and their influence on the extraction efficiency were evaluated. The best results were obtained with the Carbowax/templeted resin fiber. A \"lab made\" interface was used to validate the method and the calibration curves showed good linearity (r > 0,99) to almost all the compounds analyzed, considering both the sample linearity and the standard linearity. The data obtained for precision showed a variation from 1 to 3 % and the recovery values were bellow 27%. The PAHs analysis was performed for concentrations from 0,025 micro g/fiber to 0,5 micro g/fiber. The method does not show good recoveries values but the data obtained for precision and linearity can be considered satisfactory according to international criteria established for theses compounds.
83

Analysis for certain selected trace inorganic ions in York-Prairie Creek Pond

Mapetla, Shadrack K. January 1980 (has links)
As a result of rapid growth in technology, efforts to remove pollutants from the natural environment have not been able to keep pace with the increasing amount of waste materials and a growing population that further aggravates the situation. This has resulted in the transformation of lakes and ponds into pollution depots. A pilot study for monitoring certain selected trace elements entering and leaving YorkPrairie Creek Pond, situated inside the campus of Ball State University, was undertaken with the view to establishing whether or not this pond has been polluted, like many lakes and ponds, by metal corrosion, engine exhaust gases, and runoff from fertilizers and streets.This investigation involved sampling pond waters at two sites, viz., Influx surface and Effluent surface. Samples were collected once daily at the same time over a total time period of 23 days. Each sample was analyzed, in duplicate, for the heavy metal cations iron, lead, and cadmium, and for the inorganic anions nitrate, orthophosphate, and chloride. Metals were analyzed by atomic absorption spectrophotometry (A. A. S.), while titrimetric and cotorimetric procedures were utilized for the anion analyses.Results have indicated that iron and chloride are the most abundant of all analytes. Precipitation tends to Increase concentrations of analytes in general, possibly due to increased runoff and the lowering of the pH of these waters; leading to increased elemental release into solution. The relative responses of the analyzed ion levels in pond influx and effluent waters have been shown to be similar although their levels were significantly different.Analyte levels were found to be generally higher in effluent than in Influx waters; only chloride was found to depart from this general behavior. This finding led to the conclusion that the selected Ions, with the exception of chloride, tend not to accumulate in the waters of the pond but rather to escape with its effluent. This conclusion is subject to modification by future researchers, to whom the author has recommended a more expanded sampling program that would include the surface and sediment of the pond's interior since the nature of the results (especially for Pb and Cd) would seem to indicate not only that the pond does not exhibit thorough mixing of its constituents (homogeneity) but also the presence of an active remobilization process within its interior.
84

Ultraviolet disinfection kinetics for potable water production.

Amos, Steve A. January 2008 (has links)
Irradiation with ultraviolet (UV) light is used for the disinfection of bacterial contaminants in the production of potable water, and in the treatment of selected wastewaters. However, efficacy of UV disinfection is limited by the combined effect of suspended solids concentration and UV absorbance. Limited published UV disinfection data are available that account for the combined effects of UV dose, suspended solids concentration and UV absorbance. This present lack of a rigorous quantitative understanding of the kinetics of UV disinfection limits process optimisation and wider application of UV treatment. The development and validation of an adequate model to describe UV disinfection kinetics presented in this thesis can therefore be justified by an increased confidence of reliability of design for UV disinfection. Using the published data of Nguyen (1999), four established model forms were assessed to account for the combined effect of suspended solids and/or soluble UV absorbing compounds, and UV dose on the efficacy of disinfection. The four model forms were: a log-linear form, Davey Linear-Arrhenius (DL-A), Square-Root (or Ratkowsky- Belehradek) and a general nth order Polynomial (nOP) form that was limited to a third order. Criteria for assessment of an adequate predictive model were established including: accuracy of predicted against observed values, percent variance accounted for (%V), and; appraisal of residuals. The DL-A model was shown to best fit the data for UV disinfection of Escherichia coli (ATCC 25922); followed by the nOP, log-linear and Square-Root forms. However, the DL-A form must be used in conjunction with a first-order chemical reaction equation, and was shown to predict poorly at high experimental values of UV dose (> 40,000 μWs cm-2). The DL-A model was not amenable to extrapolation beyond the observed UV dose range. To overcome the shortcomings of the Davey Linear-Arrhenius model synthesis of two new, non-linear model forms was undertaken. The two models were a modified exponentially damped polynomial (EDPm) and a form based on the Weibull probability distribution. The EDPm model has three terms: a rate coefficient (k), a damping coefficient (λ), and; a breakpoint dose ([dose]B). The rate coefficient governs the initial rate of disinfection prior to the onset of tailing, whilst the breakpoint is the UV dose that indicates the onset of tailing. The damping coefficient controls curvature in the survivor curve. The Weibull model has just two terms: a dimensionless scale parameter (β0), and; a shape parameter (β1). The scale parameter represents the level of disinfection in the tail of the survivor curve (as log10 N/N0), whilst the shape parameter governs the degree of curvature of the survivor data. Each model was assessed against the independent and published UV disinfection data of Nelson (2000) for treatment of faecal coliforms in a range of waste stabilisation pond effluents. Both models were found to be well suited to account for tailing in these UV disinfection data. Overall, the EDPm model gave a better fit to the data than the Weibull model form. To rigorously validate the suitability of the new EDPm and Weibull models a series of experimental trials were designed and carried out in a small-scale pilot UV disinfection unit. These trials included data determined specifically at low values of UV dose (<10,000 μWs cm-2) to fill the gap in the experimental data of Nguyen (1999). The experimental trials were carried out using a commercially available, UV disinfection unit (LC5TM from Ultraviolet Technology of Australasia Pty Ltd). Purified water contaminated with Escherichia coli (ATCC 25922) with a range of feed water flow rates (1 to 4 L min-1) was used. E. coli was selected because it is found in sewage, or water contaminated with faecal material, and is used as an indicator for the presence of enteric pathogens. E. coli should not be present in potable water. The hydrodynamics of water flow within the disinfection unit were established using digital video photography of dye trace studies with Methylene Blue. Nominal UV dose (2,700 to 44,200 μWs cm-2) was controlled by manipulating the flow rate of feed water through the UV disinfection unit (i.e. residence time), or by varying the exposed length of the control volume of the disinfection unit. The transmittance of the feed water (at 254 nm) was adjusted by the addition of either a soluble UV absorbing agent (International RoastTM instant coffee powder; 0.001 to 0.07 g L-1), or by addition of suspended matter as diatomaceous earth (Celite 503TM; 0.1 to 0.7 g L-1, with a median particle size of 23 μm). The absorbing agent (instant coffee), when in a comparable concentration, was found to produce a greater reduction in water transmission than the suspended material (Celite 503TM). It therefore contributed to a greater reduction in the initial rate of disinfection. Neither agent was found to produce a systematic reduction in the observed efficacy of disinfection however. Experimental results highlight that in the absence of soluble absorbing agents, or suspended solids, the initial rate of disinfection is higher when fewer viable bacteria are initially present. Both the new EDPm and Weibull forms gave a good fit to the experimental data. The EDPm better fitted the data on the basis of residual sum-of-squares (0.03 to 2.13 for EDPm cf. 0.16 to 4.37 for the Weibull form). These models are both of a form suitable for practical use in modelling UV disinfection data. Results of this research highlight the impact of water quality, as influenced by the combined effect of UV dose, suspended solids concentration and UV absorbance, on small-scale UV disinfection for potable water production. Importantly, results show that the concentration of soluble UV absorbing agents and suspended solids are not in themselves sufficient criteria on which to base assessment of efficacy of UV disinfection / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342403 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008
85

Ultraviolet disinfection kinetics for potable water production.

Amos, Steve A. January 2008 (has links)
Irradiation with ultraviolet (UV) light is used for the disinfection of bacterial contaminants in the production of potable water, and in the treatment of selected wastewaters. However, efficacy of UV disinfection is limited by the combined effect of suspended solids concentration and UV absorbance. Limited published UV disinfection data are available that account for the combined effects of UV dose, suspended solids concentration and UV absorbance. This present lack of a rigorous quantitative understanding of the kinetics of UV disinfection limits process optimisation and wider application of UV treatment. The development and validation of an adequate model to describe UV disinfection kinetics presented in this thesis can therefore be justified by an increased confidence of reliability of design for UV disinfection. Using the published data of Nguyen (1999), four established model forms were assessed to account for the combined effect of suspended solids and/or soluble UV absorbing compounds, and UV dose on the efficacy of disinfection. The four model forms were: a log-linear form, Davey Linear-Arrhenius (DL-A), Square-Root (or Ratkowsky- Belehradek) and a general nth order Polynomial (nOP) form that was limited to a third order. Criteria for assessment of an adequate predictive model were established including: accuracy of predicted against observed values, percent variance accounted for (%V), and; appraisal of residuals. The DL-A model was shown to best fit the data for UV disinfection of Escherichia coli (ATCC 25922); followed by the nOP, log-linear and Square-Root forms. However, the DL-A form must be used in conjunction with a first-order chemical reaction equation, and was shown to predict poorly at high experimental values of UV dose (> 40,000 μWs cm-2). The DL-A model was not amenable to extrapolation beyond the observed UV dose range. To overcome the shortcomings of the Davey Linear-Arrhenius model synthesis of two new, non-linear model forms was undertaken. The two models were a modified exponentially damped polynomial (EDPm) and a form based on the Weibull probability distribution. The EDPm model has three terms: a rate coefficient (k), a damping coefficient (λ), and; a breakpoint dose ([dose]B). The rate coefficient governs the initial rate of disinfection prior to the onset of tailing, whilst the breakpoint is the UV dose that indicates the onset of tailing. The damping coefficient controls curvature in the survivor curve. The Weibull model has just two terms: a dimensionless scale parameter (β0), and; a shape parameter (β1). The scale parameter represents the level of disinfection in the tail of the survivor curve (as log10 N/N0), whilst the shape parameter governs the degree of curvature of the survivor data. Each model was assessed against the independent and published UV disinfection data of Nelson (2000) for treatment of faecal coliforms in a range of waste stabilisation pond effluents. Both models were found to be well suited to account for tailing in these UV disinfection data. Overall, the EDPm model gave a better fit to the data than the Weibull model form. To rigorously validate the suitability of the new EDPm and Weibull models a series of experimental trials were designed and carried out in a small-scale pilot UV disinfection unit. These trials included data determined specifically at low values of UV dose (<10,000 μWs cm-2) to fill the gap in the experimental data of Nguyen (1999). The experimental trials were carried out using a commercially available, UV disinfection unit (LC5TM from Ultraviolet Technology of Australasia Pty Ltd). Purified water contaminated with Escherichia coli (ATCC 25922) with a range of feed water flow rates (1 to 4 L min-1) was used. E. coli was selected because it is found in sewage, or water contaminated with faecal material, and is used as an indicator for the presence of enteric pathogens. E. coli should not be present in potable water. The hydrodynamics of water flow within the disinfection unit were established using digital video photography of dye trace studies with Methylene Blue. Nominal UV dose (2,700 to 44,200 μWs cm-2) was controlled by manipulating the flow rate of feed water through the UV disinfection unit (i.e. residence time), or by varying the exposed length of the control volume of the disinfection unit. The transmittance of the feed water (at 254 nm) was adjusted by the addition of either a soluble UV absorbing agent (International RoastTM instant coffee powder; 0.001 to 0.07 g L-1), or by addition of suspended matter as diatomaceous earth (Celite 503TM; 0.1 to 0.7 g L-1, with a median particle size of 23 μm). The absorbing agent (instant coffee), when in a comparable concentration, was found to produce a greater reduction in water transmission than the suspended material (Celite 503TM). It therefore contributed to a greater reduction in the initial rate of disinfection. Neither agent was found to produce a systematic reduction in the observed efficacy of disinfection however. Experimental results highlight that in the absence of soluble absorbing agents, or suspended solids, the initial rate of disinfection is higher when fewer viable bacteria are initially present. Both the new EDPm and Weibull forms gave a good fit to the experimental data. The EDPm better fitted the data on the basis of residual sum-of-squares (0.03 to 2.13 for EDPm cf. 0.16 to 4.37 for the Weibull form). These models are both of a form suitable for practical use in modelling UV disinfection data. Results of this research highlight the impact of water quality, as influenced by the combined effect of UV dose, suspended solids concentration and UV absorbance, on small-scale UV disinfection for potable water production. Importantly, results show that the concentration of soluble UV absorbing agents and suspended solids are not in themselves sufficient criteria on which to base assessment of efficacy of UV disinfection / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342403 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008
86

Ultraviolet disinfection kinetics for potable water production.

Amos, Steve A. January 2008 (has links)
Irradiation with ultraviolet (UV) light is used for the disinfection of bacterial contaminants in the production of potable water, and in the treatment of selected wastewaters. However, efficacy of UV disinfection is limited by the combined effect of suspended solids concentration and UV absorbance. Limited published UV disinfection data are available that account for the combined effects of UV dose, suspended solids concentration and UV absorbance. This present lack of a rigorous quantitative understanding of the kinetics of UV disinfection limits process optimisation and wider application of UV treatment. The development and validation of an adequate model to describe UV disinfection kinetics presented in this thesis can therefore be justified by an increased confidence of reliability of design for UV disinfection. Using the published data of Nguyen (1999), four established model forms were assessed to account for the combined effect of suspended solids and/or soluble UV absorbing compounds, and UV dose on the efficacy of disinfection. The four model forms were: a log-linear form, Davey Linear-Arrhenius (DL-A), Square-Root (or Ratkowsky- Belehradek) and a general nth order Polynomial (nOP) form that was limited to a third order. Criteria for assessment of an adequate predictive model were established including: accuracy of predicted against observed values, percent variance accounted for (%V), and; appraisal of residuals. The DL-A model was shown to best fit the data for UV disinfection of Escherichia coli (ATCC 25922); followed by the nOP, log-linear and Square-Root forms. However, the DL-A form must be used in conjunction with a first-order chemical reaction equation, and was shown to predict poorly at high experimental values of UV dose (> 40,000 μWs cm-2). The DL-A model was not amenable to extrapolation beyond the observed UV dose range. To overcome the shortcomings of the Davey Linear-Arrhenius model synthesis of two new, non-linear model forms was undertaken. The two models were a modified exponentially damped polynomial (EDPm) and a form based on the Weibull probability distribution. The EDPm model has three terms: a rate coefficient (k), a damping coefficient (λ), and; a breakpoint dose ([dose]B). The rate coefficient governs the initial rate of disinfection prior to the onset of tailing, whilst the breakpoint is the UV dose that indicates the onset of tailing. The damping coefficient controls curvature in the survivor curve. The Weibull model has just two terms: a dimensionless scale parameter (β0), and; a shape parameter (β1). The scale parameter represents the level of disinfection in the tail of the survivor curve (as log10 N/N0), whilst the shape parameter governs the degree of curvature of the survivor data. Each model was assessed against the independent and published UV disinfection data of Nelson (2000) for treatment of faecal coliforms in a range of waste stabilisation pond effluents. Both models were found to be well suited to account for tailing in these UV disinfection data. Overall, the EDPm model gave a better fit to the data than the Weibull model form. To rigorously validate the suitability of the new EDPm and Weibull models a series of experimental trials were designed and carried out in a small-scale pilot UV disinfection unit. These trials included data determined specifically at low values of UV dose (<10,000 μWs cm-2) to fill the gap in the experimental data of Nguyen (1999). The experimental trials were carried out using a commercially available, UV disinfection unit (LC5TM from Ultraviolet Technology of Australasia Pty Ltd). Purified water contaminated with Escherichia coli (ATCC 25922) with a range of feed water flow rates (1 to 4 L min-1) was used. E. coli was selected because it is found in sewage, or water contaminated with faecal material, and is used as an indicator for the presence of enteric pathogens. E. coli should not be present in potable water. The hydrodynamics of water flow within the disinfection unit were established using digital video photography of dye trace studies with Methylene Blue. Nominal UV dose (2,700 to 44,200 μWs cm-2) was controlled by manipulating the flow rate of feed water through the UV disinfection unit (i.e. residence time), or by varying the exposed length of the control volume of the disinfection unit. The transmittance of the feed water (at 254 nm) was adjusted by the addition of either a soluble UV absorbing agent (International RoastTM instant coffee powder; 0.001 to 0.07 g L-1), or by addition of suspended matter as diatomaceous earth (Celite 503TM; 0.1 to 0.7 g L-1, with a median particle size of 23 μm). The absorbing agent (instant coffee), when in a comparable concentration, was found to produce a greater reduction in water transmission than the suspended material (Celite 503TM). It therefore contributed to a greater reduction in the initial rate of disinfection. Neither agent was found to produce a systematic reduction in the observed efficacy of disinfection however. Experimental results highlight that in the absence of soluble absorbing agents, or suspended solids, the initial rate of disinfection is higher when fewer viable bacteria are initially present. Both the new EDPm and Weibull forms gave a good fit to the experimental data. The EDPm better fitted the data on the basis of residual sum-of-squares (0.03 to 2.13 for EDPm cf. 0.16 to 4.37 for the Weibull form). These models are both of a form suitable for practical use in modelling UV disinfection data. Results of this research highlight the impact of water quality, as influenced by the combined effect of UV dose, suspended solids concentration and UV absorbance, on small-scale UV disinfection for potable water production. Importantly, results show that the concentration of soluble UV absorbing agents and suspended solids are not in themselves sufficient criteria on which to base assessment of efficacy of UV disinfection / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342403 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008
87

Caracterização da qualidade da água pluvial retida em módulos experimentais de telhados verdes e o seu estudo como alternativa tecnológica para redução do volume da água pluvial escoada

Vacari, Thaisa Camila 11 December 2015 (has links)
Submitted by Jordan (jordanbiblio@gmail.com) on 2017-03-18T14:30:48Z No. of bitstreams: 1 DISS_2015_Thaisa Camila Vacari.pdf: 1558380 bytes, checksum: dcb4da4099b9976d50084ce1abf2a5e3 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2017-03-18T15:15:38Z (GMT) No. of bitstreams: 1 DISS_2015_Thaisa Camila Vacari.pdf: 1558380 bytes, checksum: dcb4da4099b9976d50084ce1abf2a5e3 (MD5) / Made available in DSpace on 2017-03-18T15:15:39Z (GMT). No. of bitstreams: 1 DISS_2015_Thaisa Camila Vacari.pdf: 1558380 bytes, checksum: dcb4da4099b9976d50084ce1abf2a5e3 (MD5) Previous issue date: 2015-12-11 / CAPES / FAPEMAT / A alternativa tecnológica de telhados verdes tem sido usada há muitos anos por países europeus e norte-americanos, porém somente na última década tem ganhado mercado no Brasil. Entre seus benefícios estão a redução de ilhas de calor, a diminuição das variações de temperatura, a minimização de ruídos e poluição do ar. Também podem aumentar a biodiversidade urbana e tornar o ambiente esteticamente mais agradável. Ainda podem melhorar a gestão de águas pluviais e a sua qualidade desta água. Por isso este estudo teve como objetivo caracterizar qualitativamente as águas pluviais captadas de módulos experimentais de telhados verdes, com três tipos diferentes de vegetações localizados no município de Cuiabá, MT. E também, avaliar a porcentagem de retenção das águas pluviais captadas pelos mesmos módulos experimentais de telhados verdes e analisar se a intensidade da chuva influencia o volume de água pluvial retido. Para isso foram construídos três módulos de telhados verdes testando três vegetações diferentes que foram comparados a um telhado convencional. Na água captada dos telhados foram analisadas quinze variáveis de qualidade da água. Assim com relação à qualidade da água captada pelos módulos experimentais de telhados verdes foi possível observar que aumentaram as características da cor e turbidez e atuaram como concentradores de todos os nutrientes analisados. As concentrações de DBO, bactérias heterotróficas e fungos cultiváveis não apresentaram diferenças entre telhado convencional e telhados verdes. Em relação aos coliformes totais nos telhados verdes os resultados apresentaram valores de concentrações superiores ao telhado convencional, porém, o contrário ocorreu em relação à Escherichia coli. Também se notou que não há vegetação mais adequada para melhorar a qualidade da água, pois diversos são fatores que a influenciam e que cada vegetação atua de forma diferente. Os telhados verdes podem ser usados como minimizadores de problemas relacionados à drenagem urbana, já que os resultados demostraram que os telhados verdes podem reter de 46 a 61% da água. Ainda se observou que o tipo de vegetação do telhado verde tem efeito sobre as quantidades de retenção de escoamento e que os telhados verdes de herbácea e gramínea foram os que apresentaram maior porcentagem de retenção da água pluvial drenada por eles. Também se observou que existe uma relação inversa entre a intensidade da precipitação e a porcentagem de águas pluviais que é retida pelos telhados verdes, pois quanto menor a intensidade da chuva maior é o volume retido de água pluvial. / The alternative technology of green roofs has been used for many years by European and North American countries, but only in the last decade has gained market in Brazil. Among its benefits are the reduction of heat islands, the decrease of temperature variations, minimizing noise and air pollution. They can also increase urban biodiversity and make more aesthetically pleasing environment. Still can improve stormwater management and the quality of this water. Therefore, this study aimed to qualitatively characterize the rainwater captured experimental modules of green roofs, with three different types of vegetation located in the city of Cuiabá, MT. Also, evaluate the percentage of retention of rainwater captured by the same experimental modules of green roofs and analyze the intensity of rain influences the volume of retained rainwater. For that it was built three modules of green roofs testing three different vegetations were compared to a conventional roof. The water collected from the roofs were analyzed fifteen variables of water quality. So with regard to the quality of water abstracted by the experimental modules of green roofs has been observed that increased color characteristics and turbidity and acted as hubs of all analyzed nutrients. The concentrations of BOD, heterotrophic bacteria and fungi cultivated no differences between conventional roof and green roofs. In relation to total coliforms in green roofs results showed values of concentrations exceeding the conventional roof, however, the opposite occurred with respect to Escherichia coli. It was also noted that there is no longer adequate vegetation to improve the quality of the water, as are many factors that influence and that each vegetation operates differently. Green roofs can be used as minimizing problems related to urban drainage, since the results showed that green roofs can retain 46-61% water. Yet it was observed that the type of green roof vegetation has an effect on the flow retention amounts and green roofs of herbaceous and grassy showed the highest percentage of retention of rainwater drained by them. It was also observed that there is an inverse relationship between the intensity of precipitation and the percentage of rainwater is retained by green roofs, because the lower the intensity of the rain is higher retained volume of rainwater.
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Análise bacteriológica da água utilizada nos equipos odontológicos do serviço público de Aracaju/SE

Paixão, Mônica Silveira 28 September 2006 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Through bacteriological analyses, quality of water used in odontologic equipment of the Public Service in Aracaju was evaluated. 118 water samples were collected from 59 equipments and distributed in three groups according to the localization of the reservoirs and the system availability of Flush Antisepsis. The present research was supposed to investigate the contamination with total and fecal coliforms in the water used in 24 equipments of Odontology Department and 35 equipments of Health Basic Units, which corresponds to 50% of total odontologic equipment in functioning in the Federal and Municipal Public Service. Also, the relation between quality of water and mark of Odontologic Equipment/Time of working of the same ones was analyzed. The samples were analyzed in Applied Microbiology Laboratory in the Federal University of Sergipe, from April 2005 to March 2006, using the Multiple Pipes Technique. Among 118 analyzed samples, 03 (three) them were unsuitable for human consumption and, consequently, for odontologic use, according to the current law in Brazil. The bactericidal effects of the Flush system were not observed, independent of the mark and time of the equipment functioning. / Através de análises bacteriológicas, avaliou-se a qualidade da água utilizada nos Equipos Odontológicos do Serviço Público de Aracaju. Foram coletadas 118 amostras de água procedentes de 59 Equipos distribuídos em três grupos, de acordo com a localização dos reservatórios e a disponibilidade do sistema de anti-sepsia Flush. A presente pesquisa se propôs a investigar a contaminação por coliformes totais e fecais na água utilizada em 24 Equipos do Departamento de Odontologia e 35 Equipos das Unidades Básicas de Saúde, o que corresponde a 50% do total de Equipamentos Odontológicos em funcionamento no Serviço Público Federal e Municipal, respectivamente. Também foi analisada a relação entre qualidade da água e Marca dos Equipamentos Odontológicos/Tempo de Funcionamento dos mesmos. As amostras foram analisadas no Laboratório de Microbiologia Aplicada da Universidade Federal de Sergipe/UFS, no período de abril/2005 a março/2006, utilizando-se a Técnica de Tubos Múltiplos. Das 118 amostras analisadas 03 (três) apresentaram-se impróprias para consumo humano e, conseqüentemente, impróprias para uso odontológico, de acordo com a legislação vigente no Brasil. Não foram observados os supostos efeitos bactericidas do sistema Flush, independente da marca e tempo de funcionamento dos equipamentos.
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\"Desenvolvimento de metodologia analítica para a determinação de hidrocarbonetos policíclicos aromáticos (PAHs) em amostras de água utilizando uma interface SPME/HPLC/DAD\" / \"Development of an analytical methodology for polycyclic aromatic hydrocarbons (PAH\'s) analysis in water samples using a SPME/LC/DAD interface\"

Fernanda Cristine Spoljaric Ferreira 20 March 2006 (has links)
Este trabalho descreve a otimização e validação de um método analítico para a análise de hidrocarbonetos policíclicos aromáticos (PAHs) em água usando uma interface SPME/LC/DAD. Parâmetros como tipos de fibra, tempo de extração, temperatura e força iônica foram estudados no modo \"off line\" e a influência destes na eficiência de extração foi avaliada. Os melhores resultados foram obtidos com a fibra Carbowax/templeted resin. Uma interface \"lab made\" foi utilizada para a etapa de validação e as curvas de calibração mostraram boa linearidade (r>0,99) para a maioria dos compostos analisados, tanto na linearidade da amostra como na linearidade do padrão. Os dados de precisão obtidos na concentração de trabalho variaram de 1 a 3%, aproximadamente, e os valores de recuperação se mantiveram na faixa de 4 a 27%. Os PAHs foram determinados na faixa de 0,025 micro g até 0,5 micro g. Pode-se considerar os valores obtidos nos itens de precisão e linearidade satisfatórios para a análise dos PAHs, considerando-se os critérios internacionais estabelecidos para esta classe de compostos, mas o método não atende as especificações relacionadas a recuperação e faixa de concentração. / This work describes the optimization and validation of an analytical method to determine Polycyclic Aromatic Hydrocarbons (PAHs) in water using a SPME/LC/DAD interface. Parameters as fibers kind, sampling time, temperature and ionic strength were studied and their influence on the extraction efficiency were evaluated. The best results were obtained with the Carbowax/templeted resin fiber. A \"lab made\" interface was used to validate the method and the calibration curves showed good linearity (r > 0,99) to almost all the compounds analyzed, considering both the sample linearity and the standard linearity. The data obtained for precision showed a variation from 1 to 3 % and the recovery values were bellow 27%. The PAHs analysis was performed for concentrations from 0,025 micro g/fiber to 0,5 micro g/fiber. The method does not show good recoveries values but the data obtained for precision and linearity can be considered satisfactory according to international criteria established for theses compounds.
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Análise do gerenciamento de água mediante o controle de poços injetores em reservatórios heterogêneos e fraturados / Analysis of water management by injector wells control in heterogeneous and fractured reservoirs

Muñoz Mazo, Eduin Orlando, 1976- 23 August 2018 (has links)
Orientador: Denis José Schiozer / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-23T13:02:13Z (GMT). No. of bitstreams: 1 MunozMazo_EduinOrlando_D.pdf: 5130890 bytes, checksum: d577582a347f8585e79c27a461f4bf93 (MD5) Previous issue date: 2013 / Resumo: A injeção de água como método para auxiliar na recuperação de hidrocarbonetos e na manutenção da pressão em reservatórios tem sido aplicada de maneira crescente nas últimas décadas devido às suas características de eficiência, baixo custo e alta disponibilidade da água, o que faz com que este procedimento seja considerado com frequência na fase de desenvolvimento de campos de petróleo, como parte da estratégia inicial de produção. No entanto, volumes cada vez maiores de água produzida são reportados pelas companhias operadoras, com grandes implicações técnicas e econômicas para as mesmas. Esta situação pode, em alguns casos, fazer com que a água deixe de ser considerada como um recurso e passe a ser vista como um empecilho à produção. Outro problema associado à injeção de água em reservatórios é a perda de injetividade causada pela diminuição da permeabilidade na região vizinha aos poços injetores, decorrente do dano de formação. Portanto, implementar soluções ao problema da perda de injetividade e considerar o controle da água injetada e produzida na etapa de lançamento e otimização de estratégias de produção têm um impacto significativo no desempenho produtivo e financeiro de um projeto de exploração e produção (E&P), especialmente em reservatórios heterogêneos e fraturados, onde as propriedades petrofísicas trazem consequências importantes no escoamento dos fluidos de injeção e produção. Nesse trabalho é realizada uma análise da aplicação do processo de injeção com pressão de propagação de fratura (Injection with Fracture Propagation Pressure - IFPP) mediante a modelagem dos processos de perda de injetividade e propagação de fratura utilizando ferramentas de simulação de uso comercial. Posteriormente, uma metodologia para o gerenciamento de água baseada no controle dos volumes de injeção e produção de água é proposta e aplicada para casos de reservatório heterogêneo e naturalmente fraturado. Os resultados apontam que a injeção de água com propagação de fratura pode ser utilizada para remediar os efeitos nocivos da perda de injetividade, permitindo, em alguns casos, um aumento significativo da recuperação de óleo. Apontam também que a sua modelagem pode ser estudada como um problema de otimização de vazão, evidenciando a necessidade de inclusão do controle da injeção (otimização de vazão e determinação da data de fechamento do poço injetor) na fase de proposta e posterior otimização de estratégias de produção. Finalmente, mostram o efeito positivo do controle da injeção de água, aliado ao controle da produção, como mecanismo para o gerenciamento de água, possibilitando um melhor desempenho produtivo e financeiro de reservatórios heterogêneos e fraturados que utilizam a injeção de água como método de recuperação secundária / Abstract: Water injection as a method to assist hydrocarbon recovery and reservoir pressure maintenance has been applied increasingly in recent decades because of its characteristics of efficiency, low cost and high availability of water. This makes this procedure often considered in the development of oil fields as part of the initial production strategy. However, increasing volumes of produced water have been reported by the operating companies, with major technical and economic implications for them. This may cause the water to stop being regarded as a resource and to start to be seen as a constraint to the production. Another problem associated with water injection into the reservoir is the injectivity loss caused by the permeability decrease in the region adjacent to the injection wells due to the formation damage. Therefore, implementing solutions to the problem of injectivity loss and considering the control of injected and produced water in the proposal and optimization of production strategy stage have a significant impact on the productive and financial performance of exploration and production (E&P) projects. This happens in heterogeneous and fractured reservoirs, where the petrophysical properties have a significant impact on the flow of injection and production fluids. In this work is carried out an analysis of the application of the injection with fracture propagation pressure (IFPP) process by modeling injectivity loss and fracture propagation using commercial simulation tools. Subsequently, a methodology for water management based on control of injection volumes and water production is proposed and applied to cases of heterogeneous and naturally fractured reservoirs. The results show that water injection with fracture propagation can be used to remedy the harmful effects of injectivity loss allowing, in some cases, a significant increase in oil recovery. Also indicate that its modeling can be studied as a flow rate optimization problem, highlighting the need for the inclusion of the injection control (optimization of the injection rate and shutting time of the injection well) at the proposal and subsequent optimization stage of production strategies. Finally, show the positive effect of the control of water injection, coupled to the control of water production, as a mechanism for managing water, providing better productive and financial performance for heterogeneous and fractured reservoirs using water injection as a method of improved oil recovery / Doutorado / Reservatórios e Gestão / Doutor em Ciências e Engenharia de Petróleo

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