Solute transport studies frequently rely on numerical solutions of the classical advection-diffusion equation. Unfortunately, solutions obtained with traditional finite difference and finite element techniques typically exhibit excessive numerical diffusion or spurious oscillation when advection dominates, especially when velocity field is highly variable. One recently developed technique, the finite analytic method, offers an attractive alternative. Finite analytic methods utilize local analytic solutions in discrete elements to obtain the algebraic representations of the governing partial differential equations, thus eliminating the truncation error in the finite difference and the use of approximating functions in the finite element method. The finite analytic solutions have been shown to be stable and numerically robust for advection-dominated transport in heterogeneous velocity fields. However, the existing finite analytic methods for solute transport in multiple dimensions have the following disadvantages. First, the method is computationally inefficient when applied to heterogeneous media due to the complexity of the formulation. Second, the evaluation of finite analytic coefficients is when the Peclet number is large. Third, the method introduces significant numerical diffusion due to inadequate temporal approximation when applied to transient problems. This thesis develops improved finite analytic methods for two-dimensional steady as well as unsteady solute transports in steady velocity fields. For steady transport, the new method exploits the advantages of the existing finite analytic and finite difference methods. The analytically difficult diffusion terms are approximated by finite difference and numerically difficult advection and reaction terms are treated analytically in a local element in deriving the numerical schemes. The new finite analytic method is extended to unsteady transport through application of Laplace transformation. Laplace transformation converts the transient equation to a steady-state expression that can be solved with the steady version of the improved finite analytic method. Numerical inversion of the transformed variables is used to recover solute concentration in the physical space-time domain. The effectiveness and accuracy of the new finite analytic method is demonstrated through stringent test examples of two dimensional steady-state transport in highly variable velocity fields. The results clearly demonstrated that the improved finite analytic methods are efficient, robust and accurate.

DeKalb and Fulton Counties, which share the metropolitan Atlanta area, have seen an increase in West Nile infected vector mosquitoes; the increase is associated with close proximity to combined sewer overflow facilities. Despite completion of the remediation system in 2008, the mosquito population testing positive for West Nile virus has increased each year from 2010 through 2012. Guided by the Geographical Information System framework and using spatial analysis and regression analyses, this study described and quantified the relationship between sewer system overflows and amplification of vector mosquitoes; an additional goal was to investigate their proximity to human cases of West Nile VIrus (WNV) infections. Comparing the prominence of all WNV vectors revealed how different mosquito species occupy the area. The Culex species was not detected in adult surveillance in 2012; however, the infection rate of mosquito pools increased by 15% and the human infection more than doubled. The influence of sewer system overflows became pronounced when this study analysis also identified that a proportion of West Nile-virus positive mosquito pools was significantly higher in approximately 58% of trap sites within 1 km of sewer overflow events and 30% over 1 km distance from sewer overflow events. Thus, the research contributes to shared information both in support of previous findings and considering novel sources that contribute to the proliferation of WNV. This research can help reduce the rate of WNV infection and decrease the resources needed to protect the public.

Pentachlorophenol (PCP) is a biocide which is widely used for its toxicity to microorganisms. Its major application is in wood preservation, and PCP at abandoned wood preserving sites is a major source of environmental pollution. Although much of the literature documents aerobic treatment for PCP, research indicates that there is great potential for anaerobic dechlorination of these compounds. The objectives of this investigation were to study the acidogenesis phase of the anaerobic biodegradation process; how acidogenesis is affected by PCP toxicity alone and in the presence of zinc; what role acidogenesis plays in the biodegradation of PCP; and how operating parameters, such as organic loading rate (OLR) and solids retention time (SRT) affect the degradation of PCP during acidogenesis. Batch anaerobic toxicity assays (ATAs) were performed to quantify the toxicity threshold for PCP and zinc, and to study the effect of these toxicants on volatile acids production. Continuous reactors (chemostats) were operated at SRTs of 0.25-0.61 day to kinetically exclude methanogenesis from acetate, so that the effects of the toxicants on acidogenesis could be evaluated PCP was found to have a toxicity threshold of 2.7-3.0 mg/L and zinc 23-27 mg/L in batch systems. Acetate utilizers showed the first signs of inhibition in PCP spiked systems, whereas hydrogen utilizers were the first organisms affected in response to a zinc spike. In the continuous systems, PCP in spike concentrations of 7.0 mg/L did not affect the quantity or composition of volatile acids produced in the chemostats. A rise in headspace hydrogen at 30 mg/L zinc indicated that hydrogen utilizers became inhibited in the presence of high zinc concentrations PCP was degraded, with approximately half of the degradation occurring during acidogenesis. GC/MS analysis detected no intermediate chlorophenols in the effluent. The efficiency of degradation varied indirectly with spike concentration and directly with SRT / acase@tulane.edu

Anaerobic biological waste treatment is a complex microbiological process involving many types of bacteria. The anaerobic conversion of organic matter occurs in three steps, the last step being the conversion of volatile acids, mainly acetate, to gaseous end products. In the anaerobic treatment of wastewater containing sulfates, sulfate reducing bacteria (SRB) and methane producing bacteria (MPB) affect the last step. Since acetate is a common substrate for both SRB and MPB, there exists competition between them for available acetate. The outcome of the competition between SRB and MPB for acetate has a significant influence on effluent quality, treatment efficiency, and quality and quantity of biogas produced. The major objectives of this research were to study the effects of COD/SO$\sb4$ ratio and redox potential on the interaction between SRB and MPB and to study the relative effectiveness of SRB and MPB in degrading selected phenolic compounds Batch serum bottle studies were conducted to verify if sulfate utilization by SRB followed stoichiometric sulfate utilization and to determine Monod kinetic parameters for acetate uptake. Results indicated that sulfate reduction followed closely the stoichiometric sulfate reduction (COD/SO$\sb4$:0.62/1). Monod kinetic constants, K$\sb{\rm s}$ and k were found to be 103 mg acetate/L and 2.52/d, respectively, for SRB, 133 mg acetate/L and 3.24/d, respectively, for MPB, and 196 mg acetate/L and 4.30/d, respectively, for mixed culture of SRB and MPB The effect of COD/SO$\sb4$ ratio on the interaction between SRB and MPB was studied in batch (serum bottle) and continuous (chemostat) systems. Chemostats were run at a solids retention time (SRT) of 10 days. Results from both batch and continuous systems indicated that as the COD/SO$\sb4$ ratio decreased, the percent acetate utilized by SRB increased The effect of redox potential on the interaction between SRB and MPB was studied in the Eh ranges of $-$50 to $-$100, $-$150 to $-$200, and $-$250 to $-$300 mV. Results indicated that as the redox potential increased, the percent acetate utilized by SRB increased Biodegradation of 2,4,6-trichlorophenol (2,4,6-TCP) was studied with enrichments of SRB, MPB and mixed cultures. The concentrations of 2,4,6-TCP studied were 15, 30, and 45 mg/L. Results from this experiment indicated that SRB enrichment was more effective than MPB and mixed cultures in removing 2,4,6-TCP Biodegradation of 2-chlorophenol (2-CP), 2,3-dichlorophenol (2,3-DCP), 2,5-dichlorophenol (2,5-DCP) and 2,3,5-trichlorophenol (2,3,5-TCP) was studied at concentrations of 2.5, 5, and 10 mg/l of each of the toxicants using enrichments of SRB, MPB and mixed cultures. All these cultures were found to remove all the chlorophenols studied with very high efficiency (between 70 to 100%). 2,3,5-TCP was found to be reductively dehalogenated to end products via 3,5-dichlorophenol and 3-chlorophenol, while, 2,3-DCP and 2,5-DCP were dehalogenated via 2-CP. 2-nitrophenol, 4-nitrophenol, and 2,4-dinitrophenol were also found to be removed at concentrations of 5, 10 and 15 mg/L each, by enrichments of SRB, MPB and mixed cultures. The removals ranged from 83 to 100%. 2,4-DNP was found to be transformed via 4-NP. The removals of chlorophenols and nitrophenols compare well with those reported in the literature / acase@tulane.edu

El presente trabajo de investigación busca describir las dificultades que ha ocasionado el protocolo técnico de registro sanitario de importación de productos pesqueros y acuícolas congelados impuesto por la autoridad sanitaria competente del Perú respecto a la importación y comercialización del filete de tilapia congelado proveniente de un nuevo productor chino a partir de la experiencia de la empresa Umi Foods S.A.C., por lo tanto nuestro estudio se divide en cuatro (4) capítulos, los cuales son detallados a continuación. El primer capítulo se centra en el plan de investigación, por medio del cual planteamos la pregunta, el problema y los objetivos, tanto principales como específicos y la formulación de la hipótesis inicial de la investigación. El segundo capítulo da a conocer los antecedentes de la investigación, tanto nacionales como internacionales y el marco teórico del estudio, así como las restricciones para la importación y los requisitos para la comercialización del filete de tilapia congelado. El tercer capítulo se centra en la metodología de la investigación, donde detallamos el tipo, propósito, categorías, delimitación, diseño y tamaño de muestra de la investigación. Asimismo, en este capítulo desarrollamos las entrevistas de profundidad, las cuales serán de utilidad para el recojo de información. Finalmente, el cuarto capítulo se enfoca en el respectivo análisis y discusión de resultados de nuestra investigación para así encontrar los hallazgos y realizar tanto las conclusiones como las recomendaciones finales por medio del análisis de documentos y de la información obtenida mediante las entrevistas de profundidad desarrolladas en nuestro estudio. / The present research seeks to describe the difficulties caused by the technical protocol of import sanitary registration for frozen fishery and aquiculture products from the sanitary authority of Peru regarding the import and commercialization of frozen tilapia fillet that comes from a new Chinese producer and according to the experience of the company Umi Foods S.A.C., therefore our study is divided into four chapters that are detailed as below. The first chapter focuses on the planning research, which is about proposing the research question, the main and specific problems and objectives. In this chapter we also make known about the starting hypothesis of our working research. In the second chapter we present the national and international backgrounds and the theory framework of the research as well as the import restrictions and the commercialization requirements of the frozen tilapia fillet. The third chapter explains the methodology research, which we detail the type, purpose, categories, delimitation, design and sampling size of the research. Also, in this chapter we develop depth interviews that will be very useful for the research’s collecting information. Finally, the fourth chapter is about the respective analysis and discussion of the research´s results in order to get the findings of the study and make the final conclusions and recommendations according to the documents’ analysis and to the obtained information from held depth interviews in our research. / Tesis

xv, 179 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--University of Adelaide, Dept. of Medicine, 1974

Treatment of waste sludge has become an important issue in recent years around the world. However, the trend of waste sludge treatment has shifted from volume minimization and stabilization to reuse of the sludge and recover the energy potential of it. Therefore, anaerobic treatment of sludge is gaining popularity because of byproduct methane production and high percentage of VSS reduction. Pre-treatment of sludge before anaerobic digestion in order to increase methane production, and ozone pre-treatment in this context, is one such option. Domestic sludge also contains the recently recognized, so called, emerging compounds such as Endocrine Disrupting Compounds (EDCs). Therefore treatment of EDCs in sludge is another challenge in waste sludge treatment since direct discharge of such chemicals may harm the environment by causing gender shifts within the fauna. In this context two hormones (estrone and progesterone), three pharmaceuticals (acetaminophen, carbamazepine and diltiazem) and one plasticizer (benzyl-butyl phthalate) were routinely analyzed in sludge samples which were subjected to treatment during this study. Treatment of EDCs during anaerobic digestion and the effect of ozonation both on the performance of digestion and the treatability of EDCs were investigated in this study. Four 2.5L anaerobic jars were used for anaerobic digestion connected to four 1L plastic graduated cylinders immersed in salt-water to collect the off gas. Anaerobic sludge culture of the reactor and the sludge feed to the reactors were obtained from Ankara Tatlar Wastewater Treatment Plant anaerobic digester and return activated sludge (RAS) line, respectively. One of the anaerobic digesters was used as control (no ozonation) and the others were fed with sludge samples ozonated at three different ozone doses 0.65, 1.33 and 2.65 mg ozone/g biomass. Sludge ages of the reactors were initially set to 25 days and the reactors were fed once every 2 days. The TSS, VSS, total gas volume, COD, pH, CH4 percentage and EDCs were analyzed routinely. In the reactors, operated at 25 days, because of the observation of reduction of TSS, SRT was set to infinity / thus, sludge wastage was terminated. Following the startup it was seen that at 2.65 mg ozone/g biomass dose TSS and VSS did not stay constant in the reactor and dropped sharply in the course of operation, indicating that system was not steady at this SRT. However, upon stoppage of sludge wastage from the reactors, thereby setting SRT to infinity, a steady culture could be maintained in the reactors. Both total gas production and CH4 percentage increased with the increasing doses of ozone with respect to control reactor. For 2.65 mg/g ozonated reactor total gas volume doubled the amount produced in the control reactor. All the EDCs within the scope of this study were analyzed in sludge using ultrasound-aided sequential sludge extraction method twice a week and the results showed that ozonation affected treatment of EDCs for up to 96%. The highest removal rate was obtained with natural hormones. Rates of treatment of pharmaceuticals were the second best.

Treatment of waste sludge has become an important issue in recent years around the world. However, the trend of waste sludge treatment has shifted from volume minimization and stabilization to reuse of the sludge and recover the energy potential of it. Therefore, anaerobic treatment of sludge is gaining popularity because of byproduct methane production and high percentage of VSS reduction. Pre-treatment of sludge before anaerobic digestion in order to increase methane production, and ozone pre-treatment in this context, is one such option. Domestic sludge also contains the recently recognized, so called, emerging compounds such as Endocrine Disrupting Compounds (EDCs). Therefore treatment of EDCs in sludge is another challenge in waste sludge treatment since direct discharge of such chemicals may harm the environment by causing gender shifts within the fauna. In this context two hormones (estrone and progesterone), three pharmaceuticals (acetaminophen, carbamazepine and diltiazem) and one plasticizer (benzyl-butyl phthalate) were routinely analyzed in sludge samples which were subjected to treatment during this study. Treatment of EDCs during anaerobic digestion and the effect of ozonation both on the performance of digestion and the treatability of EDCs were investigated in this study. Four 2.5L anaerobic jars were used for anaerobic digestion connected to four 1L plastic graduated cylinders immersed in salt-water to collect the off gas. Anaerobic sludge culture of the reactor and the sludge feed to the reactors were obtained from Ankara Tatlar Wastewater Treatment Plant anaerobic digester and return activated sludge (RAS) line, respectively. One of the anaerobic digesters was used as control (no ozonation) and the others were fed with sludge samples ozonated at three different ozone doses 0.65, 1.33 and 2.65 mg ozone/g biomass. Sludge ages of the reactors were initially set to 25 days and the reactors were fed once every 2 days. The TSS, VSS, total gas volume, COD, pH, CH4 percentage and EDCs were analyzed routinely. In the reactors, operated at 25 days, because of the observation of reduction of TSS, SRT was set to infinity / thus, sludge wastage was terminated. Following the startup it was seen that at 2.65 mg ozone/g biomass dose TSS and VSS did not stay constant in the reactor and dropped sharply in the course of operation, indicating that system was not steady at this SRT. However, upon stoppage of sludge wastage from the reactors, thereby setting SRT to infinity, a steady culture could be maintained in the reactors. Both total gas production and CH4 percentage increased with the increasing doses of ozone with respect to control reactor. For 2.65 mg/g ozonated reactor total gas volume doubled the amount produced in the control reactor. All the EDCs within the scope of this study were analyzed in sludge using ultrasound-aided sequential sludge extraction method twice a week and the results showed that ozonation affected treatment of EDCs for up to 96%. The highest removal rate was obtained with natural hormones. Rates of treatment of pharmaceuticals were the second best.

Rainfall derived inflow and infiltration (RDII) is a cause of sanitary sewer overflows and sewers exceeding capacity before the end of their design lives, but it is not well understood. Several methods exist to model RDII in existing sanitary sewers. These models are not applicable for design, which is frequently accomplished by applying constant unit rates. Two analytical probabilistic models are developed to estimate the contribution of RDII to peak flow and volume. The analytical models have been tested against computer simulations using long-term rainfall records and parameters calibrated using actual field data. One model relies on calibrated parameters from the RTK method; a commonly used method requiring a time-consuming calibration process. The second model relies on the R-value parameter of the RTK method, and a time of concentration parameter. By providing better information to designers, these analytical models aim to improve engineering decision-making in the design of sewer systems.

Rainfall derived inflow and infiltration (RDII) is a cause of sanitary sewer overflows and sewers exceeding capacity before the end of their design lives, but it is not well understood. Several methods exist to model RDII in existing sanitary sewers. These models are not applicable for design, which is frequently accomplished by applying constant unit rates. Two analytical probabilistic models are developed to estimate the contribution of RDII to peak flow and volume. The analytical models have been tested against computer simulations using long-term rainfall records and parameters calibrated using actual field data. One model relies on calibrated parameters from the RTK method; a commonly used method requiring a time-consuming calibration process. The second model relies on the R-value parameter of the RTK method, and a time of concentration parameter. By providing better information to designers, these analytical models aim to improve engineering decision-making in the design of sewer systems.