Groundwater contamination by landfill generated leachate is a problem that is increasingly addressed for proposed and existing landfill sites.This thesis examines groundwater contamination movement from the abandoned Delaware County Municipal landfill. The site is located in the crest of a highly permeable sand and gravel glacial esker which allows for rapid movement of ground water and any contaminants introduced into it.The landfill site was originally investigated in the late 1970's by Ed Lusch, a graduate student at the Ball State University Geology Department. That study showed some indications of ground water contamination movement to about 400 feet west of the site, in the direction of ground water flow. This indicated position of a contamination plume suggested that leachate, generated from the landfill site, had moved to that position since (or possibly before) the closing of the landfill in 1971.The present study, using a combination of surface resistivity methods, on-site test wells, and chemical analyses of ground water, attempted to determine the degree of contamination movement from the site since the original study and the extent to which the local aquifer had been affected. Results of this investigation revealed an apparent slow movement of leachate from the landfill westward towards the Mississinewa River, also in the direction of ground water flow. Surface resistivity methods of this study revealed the plume of contamination (indicated by resistivity "low" area) to now exist at approximately the same location as indicated in the earlier study, but to have expanded laterally. This investigation also found indications of the contamination plume well into the underlying fractured dolostone.Chemical analyses of nearby residential wells also revealed slightly elevated amounts of chloride, ammonia and specific conductivity in the ground water of the glacial esker south of the abandoned landfill site. The presence of three other dump sites, including a sludge dump, along the esker south of the landfill, offers questions as to the source of ground water contamination.Ball State UniversityMuncie, IN 47306

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

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

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

[Truncated abstract] This thesis explores the risk factors and perinatal outcomes associated with prelabour rupture of membranes, with a particular focus on the environmental context. Prelabour rupture of membranes is defined as the rupture of fetal membranes before the onset of labour. It is a relatively common obstetric endpoint, occurring in approximately 8-10% of pregnant women at term (PROM) and in up to 40% of all preterm deliveries (pPROM). Despite the high prevalence of the condition, the biological mechanisms and risk factors, and in particular the role of environmental predictors, behind the development of PROM and pPROM remain largely unclear. A record-based prevalence design was used to analyse a population of 16,229 nulliparous, Caucasian women residing in Perth, Western Australia who gave birth to a single newborn during 2002-2004. Maternal age, socioeconomic status and threatened preterm labour during pregnancy were identified as risk factors for prelabour rupture of membranes. Term PROM was significantly associated with fetal distress (OR 1.19; 95%CI 1.00-1.43) and post-partum haemorrhage (OR 1.99; 95%CI 1.60-2.48). A number of perinatal complications were observed to be associated with the presentation of preterm PROM, including prolapsed cord (OR 13.95; 95%CI 4.57-42.61), ante-partum haemorrhage (OR 3.29; 95%CI 2.20-4.91), post-partum haemorrhage (OR 2.12; 95%CI 1.54-2.91), low birth weight (OR 17.79; 95%CI 13.87-22.82), very low birth weight (OR 20.01; 95%CI 14.12-28.35) and stillbirth (OR 5.42; 95%CI 2.87-10.21). However, the outcomes were similar between pPROM patients and other preterm deliveries, indicating that the complications arose due to the timing of the delivery. In contrast though, the risk factors between the two outcomes varied which may suggest that a different aetiological pathway exists between preterm PROM and other preterm deliveries. The frequency of complications decreased with increasing gestational age at delivery until the pregnancy reached full-term, whereupon an increase in gestational age at delivery resulted in an increased risk of fetal distress and post-partum haemorrhage. This finding is novel and may have important implications for the management of prelabour rupture of membranes, specifically with regard to the relative risks and benefits of expectant management (that is, the patient is admitted to an obstetric facility or hospital and closely monitored) versus planned delivery. ... This study represents the first attempt to investigate the potential associations between environmental risk factors and prelabour rupture of membranes. The results of the thesis provide a substantial contribution to our knowledge on prelabour rupture of membranes, including findings of direct relevance to clinical practice as well as a potentially contributing environmental exposure pathway. These original findings suggest a possible preventative approach to reducing the occurrence and associated morbidity of prelabour rupture of membranes may be feasible, and should be pursued if future research confirms the preliminary findings of this thesis.

Made available in DSpace on 2014-06-11T19:26:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-14Bitstream added on 2014-06-13T19:13:18Z : No. of bitstreams: 1 montero_rc_me_bauru.pdf: 2401420 bytes, checksum: edf8873c33a227bcb3f0d5bb72554719 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A crescente demanda por recursos subterrâneos nas Bacias Hidrográficas dos Rios Aguapaí e Peixe, localizadas no oeste do Estado de São Paulo e a presença cada vez maior de substâncias em condições de acesso e contaminação das águas em subsuperfície têm pressionado de forma negativa a disponibilidade hídrica nessas bacias. Neste contexto de degradação, esta Dissertação objetiva a caracterização e avaliação da vulnerabilidade natural e dos perigos de contanimação das unidades aquíferas aflorantes nas subunidades de gestão de recursos hídricos denominados Alto Aguapeí e Alto Peixe. A caracterização da Vulnerabilidade foi realizada com aplicação do método GOD (Foster & Hirata, 1988). O perigo de contaminação dos aquíferos foi avaliado mediante a interpolação da vulnerabilidade natural com as fontes potencias de contaminação, identificadas e classificadas quanto o seu potencial de gerar carga contaminante, a partir da aplicação do método POSH (FOSTER et al, 2006). Os procedimentos de geoprocessamento foram realizados com auxílio do SIG ArcMap TM 9.3. Os resultados demonstraram que vulnerabilidades de classificação Extrema estão restritas as planícies fluviais dos rios Aguapeí e Tibiriça, ocupando cerca de 2% da área de estudos, as classes de vulnerabilidade Alta e Alta Baixa ocupam 41,5% e 23,7% respectivamente, enquanto 28,4% da área correspondem à vulnerabilidade Média. Para o restante da área obteve-se a classificação Média e Média Baixa Vulnerabilidade. A correlação das vulnerabilidades com as fontes potenciais de contaminação demonstraram que independente da localização, os postos de combustível e os locais de disposição de resíduos sólidos apresentam Alto perigo de contaminação. As atividades da indústria, por sua vez, apresentam Alto perigo de contaminação para os distritos... / The increasing demand for groundwater resources in the Watersheds of Aguapeí and Peixe Rivers, located in the western part of São Paulo province, and also the increasing presence of substances in access condition and water contamination in the subsurface have been pressuring negatively the water availability in both basins. In this degradation context, this dissertation aims to characterize and evaluate the natural vulnerability and contamination risks of aquifers outcropping units in the sub water resources management units called. Alto Aguapeí and Alto Peixe. The vulnerability characterization was made applying the GOD method (Foster & Hirata, 1988). The aquifers contamination risk was estimated by interpolation of the natural vulnerability and the potential contamination sources that was identified and classified by their potential to generate contaminant load, using the POSH method (Foster et al, 2006). The geoprocessing producers were performed with assisting of some tools from the GLS ArcMap TM 9.3. The results evidenced that extreme classification vulnerability are restricted just for river plaints of Aguapeí and Tibiriça rivers, occupying around 2% of the studied area. The High and High Low vulnerability classes occupy 41.5% and 23.7% respectively and average vulnerability 28.4%. For the rest of the area was obtained medium and low vulnerability classification. The correlation of vulnerabilities and potential sources of contamination demonstrated that regardless of location, gas stations and solid waste disposal spots have high risks of contamination. The industrial activities have a high risk of contamination due the industrial district of Garça and Marilia and moderate for units in the food sector, located outside these districts. Furthermore, it is evident the importance of introducing the territory management policies... (Complete abstract click electronic access below)

Thesis submitted in partial fulfilment of the requirements for the degree of MAGISTER TECHNOLOGIAE: CHEMICAL ENGINEERING in the FACULTY OF ENGINEERING at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY 2013 / This study focused on quantifying two types of internationally regulated contaminants found in drinking water: 1) Trihalomethanes (THMs) and 2) Perfluorinated compounds (PFCs). The first contaminants monitored were THMs, classified as a group of chemicals that are formed along with others during the disinfection of water using liquid chlorine, chlorine dioxide or chlorine gas. Hence, the resulting compounds are called disinfection by-products (DBPs). The disinfectant reacts with natural organic matter in water to form common THMs, which include chloroform (CHCl3 or CF), bromodichloromethane (CHCl2Br or BDCM), dibromochloromethane (CHClBr2 or DBCM) and bromoform (CHBr3 or BF), with chloroform being the most common in chlorinated water systems. The current study has focused on THMs for two primary reasons: 1) THMs have raised significant concern as a result of evidence that associate their presence in drinking water with potential adverse human health effects, including cancer and 2) the levels of THMs in drinking water post-treatment is not monitored regularly in South Africa and thus far, there is inadequate and limited information about their concentration levels for drinking water treatment plants (DWTPs) and distribution stations (DWDSs) of the Western Cape, South Africa before, distribution to various suburbs, including townships. THMs normally occur at higher levels than any other known DBPs and their presence in treated water is a representative of the occurrence of many other DBPs. THMs were quantified in chlorinated drinking water obtained from seven (7) DWTPs, namely; Atlantis, Blackheath, Faure, Brooklands, Steenbras, Voelvlei and Wemmershoek, and one DWDS in Plattekloof. This included determining THMs concentration in tap water collected from various suburbs including townships, to assist local authorities in obtaining information on their concentration and whether or not the presence of residual chlorine and organic matter on post-treatment results has increased THMs at the point of use. THM analysis was performed using liquid-liquid extraction/gas chromatography with electron capture detector (LLE-GC-ECD) analytical process according to the EPA method 501.2, which was used with minor modifications. The instrument operational conditions were as follows: Column → DB5-26, 30 mm, 0.53 mm, 1.0 μm df HP-1 (Agilent Technologies, USA); Carrier gas → Helium at a constant inlet pressure of 15 kPa; Make-up gas → 99.9% Nitrogen gas at 60 L/min; Injector temperature → 40°C; Oven temperature → 270°C and Detector temperature → 300°C. Since natural organic matter (NOM) in raw water is a precursor for THM formation, NOM analysis was performed as total organic carbon (TOC) using Spectroquant TOC test kits. Other drinking water quality parameters analysed were pH, residual free chlorine, conductivity and total dissolved solids (TDS). The average Total THM concentrations detected from seven of the DWTPs, including the DWDS, ranged from 26.52 μg/L (for Plattekloof) to 32.82 μg/L (for Brooklands), with the observed concentrations being comparable. The average chloroform concentrations were the highest in all the water samples, ranging from 11.74 μg/L (for Plattekloof) to 22.29 μg/L (for Voelvlei), while DBCM had the lowest concentration. The only DWTP that was not comparable with the seven DWTPs was Atlantis, with the highest average TTHM concentration of 83.48 μg/L and a chloroform concentration of 46.06 μg/L. From the tap water samples collected from 14 Western Cape suburbs, the average TTHM concentrations ranged from 5.30 ug/L (for Mandalay) to 13.12 μg/L (for Browns Farm, Philippi), and all these concentrations were lower than the TTHM concentrations detected in the water samples from the DWTP. Overall, the average total THM and individual THM species concentrations were below the recommended SANS 241:2011 and WHO drinking water guideline limits. This included the observed pH (6.39 to 7.73), residual free chlorine (0.22 to 1.06 mg/L), conductivity (121 to 444 μS/cm), TDS (93.93 to 344.35 mg/L) and TOC (0.38 to 1.20 mg/L). All these water quality parameters were within the specification limits stipulated in SANS 241. However, the average residual free chlorine concentration for Atlantis was very low (0.06 mg/L), which was below the WHO minimum residual free chlorine concentration guideline value of 0.2 mg/L for a distribution network – an indication that suggested the need for a re-chlorination station prior to distribution to households. Low chlorine content might result in the formation of unwanted biofilms in the distribution network, thus reducing the organoleptic properties of the water. Additionally, there was no direct link between several water quality parameters quantified (i.e. pH, TOC and water temperature) to TTHM formation. However, a high chlorine dose was observed to result directly in a higher concentration of chloroform in treated water prior to distribution. The second contaminants monitored were Perfluorinated compounds (PFCs), which are non-biodegradable, persistent and toxic organic chemicals known for their ability to contaminate environmental matrices, including drinking water sources. In recent years, many researchers considered it essential to identify and quantify PFC levels in drinking water worldwide with the main focus being on the two most abundant PFCs; namely Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS). Their toxic effects to human health, plants and wildlife were also evaluated, classifying them as possible carcinogens. We know from the literature reviewed that, although the presence of PFCs in drinking water has been documented worldwide, there is limited information about their presence specifically in South African drinking water sources, even about less studied PFCs such as Perfluoroheptanoic acid (PFHpA), Perfluorododecanoic acid (PFDoA), Perfluorononanoic acid (PFNA), Perfluoroundecanoic acid (PFUA), Perfluorodecanoic acid (PFDeA) and the well-known PFOA including PFOS. Although several other PFCs have been detected in water sources and reported in various studies, the USEPA only issued drinking water guideline limits for Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS) of 400 ng/L and 200 ng/L, respectively, with no mention of the other PFCs. However, these PFCs have similar properties to those of PFOA and PFOS as they have been shown to impose similar detrimental health effects on human health. This study thus focused on the detection of PFCs in both raw and treated drinking water in the Western Cape DWTPs such as Atlantis, Blackheath, Faure, Brooklands, Steenbras, Voelvlei and Wemmershoek, and one DWDS in Plattekloof. Water samples (raw and treated water) used in this study for PFC analysis were collected in 2L polypropylene screw capped bottles. PFC analysis was performed in four sample batches for each location collected through the period of October to December 2012 (summer). PFCs were analysed in accordance with a modified EPA method 537, which entails solid phase extraction (SPE) followed by analysis using a liquid chromatography/tandem mass spectrometer (LC/MS/MS). The slight modification was with the water sample volume used for extraction, which was increased from 250 mL to 500 mL. The instrument used was an HPLC - Ultimate 3000 Dionex HPLC system and MS model - Amazon SL Ion Trap, with the following MS/MS operational conditions and Ion mode: MS Interface → ESI; Dry temp → 350C; Nebulizing pressure → 60 psi; Dry gas flow → 10 L/min; Ionisation mode → negative; capillary voltage → +4500V; End plate offset → −500V while the separation column was a Waters Sunfire C18, 5 μm, 4.6 × 150 mm column (Supplier: Waters, Dublin, Ireland) with an operational temperature of 30C. From the results obtained in this study, seven different PFCs (i.e. PFHpA, PFDoA, PFNA, PFUA, PFDeA, PFOA and PFOS), were detected in raw and treated water with PFOA and PFOS being the least detected PFCs as they were detected only in raw water (PFOA) from Faure, as well as raw and treated water (PFOS) from Brooklands. The highest concentration observed in treated water was for PFHpA, which was quantified at a maximum average concentration of 43.80 ng/L (Plattekloof). The maximum average concentrations of other PFCs detected were as follows: PFDoA - 4.415 ng/L for Faure raw water; PFNA - 2.922 ng/L for Plattekloof outlet; PFUA - 7.965 ng/L for Brooklands treated water and PFDeA - 2.744 ng/L for Faure raw water. Another observation from the results was that the concentration of the majority of the PFCs detected in treated water was higher than that quantified in raw water, suggesting possible contamination by materials used during water treatment. In conclusion, THMs detected in treated water from various DWTPs and one DWDS in the Western Cape met the required local and international drinking water quality guidelines, while the presence of PFOS, PFOA, PFHpA, PFDoA, PFNA, PFUA and PFDeA in treated water requires that local water professionals continue to monitor their presence to ensure that measures for their reduction are in place. Furthermore, the National standards (SANS 241) for municipal drinking water guidelines must be updated to include the monitoring of PFCs, including the lesser known and less studied PFCs such as PFHpA, PFDoA, PFNA, PFUA and PFDeA.

MESCH / Department of Hydrology and Water Resources

Manganese is a problem at the Ni River Water Treatment Plant in Spotsylvania County, Virginia. The Ni River Reservoir (the water source) is a eutrophic reservoir. In the summer, the dissolved oxygen decreases to near or zero at depths greater than two meters. As a result, soluble manganese increases to levels of nearly 6.0 mg/L at the bottom. It is released from the sediments under anaerobic conditions. Total organic carbon levels ranging from 4.0 to 7.25 mg/L were noted with increasing depth. Plant profiles were developed to indicate the performance of the sedimentation and filtration units in reducing manganese concentration. Essentially, all the particulate manganese was removed by sedimentation, and some removal of soluble manganese was evident. The filters removed additional soluble manganese. Soluble manganese removal probably was due to the adsorption of manganese on solid manganese dioxide in the sludge blanket and on the filter media with subsequent further oxidation. Ozone was effective at a dose of approximately 5 mg/L. Chlorine and chlorine dioxide were marginally effective as pretreatments at dosages of 5 and 2 rng/L, respectively. Potassium permanganate proved effective at dosages of 0.5 to 0.625 mg/L (1.5 to 1.9 times the theoretical requirement). Aeration proved effective in reducing levels of approximately 0.1 mg/L to below the secondary maximum contaminant level (0.05 mg/L) and, in addition, somewhat effective in reducing a concentration of nearly 2 mg/L by 31 percent. Aeration appears to be a viable means of reducing the anaerobic conditions in the reservoir that lead to the high soluble manganese concentrations. / M.S.

Groundwater aquifers are precious resources that has been serving human consumption for many centuries. This resource is pristine in comparison with surface waters such as lakes and canals, however, as population grows exponentially so does the demand for groundwater and the need to study the potential of groundwater replenishment programs. The injection of treated water or wastewater into an aquifer is a method to protect this resource for current and future generations. Health concerns would be expected since migration of water of “impaired quality” can affect the drinking water by contamination. Regulatory barriers resulting from the perceived risks of adverse health effects from pathogens such as viruses have limited the concept of this impaired water resources from being used for groundwater replenishment programs. The objective of this study is to examine the risk assessment using computational modeling with MODFLOW and MT3D groundwater transport simulation. The results from the simulation showed that after two years, the risk of contamination based on concentration contours from the injection well to the production wellfields for the City of Hollywood stabilized below 10- 6. The risk assessment provided important aspect to demonstrate the concept of using injection of treated water as an option for groundwater replenishment. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection