Among current technologies used for the treatment of polycyclic aromatic hydrocarbons (PAHs) -contaminated media, adsorption has been reported to offer relatively high PAH removal efficiency while being rapid and cost-effective. Therefore, the main goal of this research was to assess and optimize the adsorption process for the removal of PAHs from contaminated water and soil using recoverable magnetic activated carbon-based composites. In the first phase, 6 different composites, 3 magnetic powder activated carbon (MPAC) composites and 3 magnetic granular activated carbon (MGAC) composites, were synthesized, and then, characterized using XRD, FE-SEM, EDS, and FTIR methods. The adsorption experiments revealed that all the recoverable MPACs and MGACs were capable of removing the PAHs from water, with removal percentages ranging from 87.2 to 99.3%. The PAH-loaded MPAC and MGAC with the highest PAH removal efficiency were also subjected to a series of desorption studies. The results indicated that the PAHs desorption was in the range 38.1-60.1% for low molecular weight (LMW) PAHs and 23.4 to 57.2% for the high molecular weight (HMW) PAHs. In the second phase, the adsorption kinetics and isotherms studies were performed on MPAC synthesized by a precipitation (MPAC-Prec.) method, which showed the highest PAH removal efficiency among the prepared magnetic activated carbons (MACs). The PAHs adsorption by MPAC-Prec. was rapid, reaching equilibrium in 6 h with the removal efficiency ranging from 95.6 to 100.0% under the conditions of this study. Among the studied kinetics models, pseudo-second order fitted the experimental data very well, implying that all the MPAC adsorption sites had an equal affinity for PAHs. The results of the kinetic studies also indicated that the greater molecular weight PAHs had a slower adsorption rate due to the slower transfer of their molecules to the MPAC adsorption sites. With an R2 in the range 0.73-0.96, the Langmuir model described the isotherms adsorption of LMW and HMW PAHs better than the other isotherms models. Furthermore, according to the Langmuir model, the maximum adsorption capacity of MPAC-Prec. was determined to be between 8.7 and 11.4 µg/mg for the LMW PAHs, and 8.4 and 20.2 µg/mg for the HMW PAHs. In the third phase, a series of soil washing tests using MGAC synthesized by co-precipitation (MGAC-CoP) method, were carried out to explore the effect of MAC on the PAHs removal from soil. The employed MGAC was the second most efficient MAC in the PAHs adsorption experiments (first phase of research), and it showed greater recovery from soil washing mixture compared to the MPAC-Prec. in the preliminary tests. The MGAC-CoP composite had a surface area and total pore volume of 837.9 m2/g and 0.5 cm3/g, respectively, which were approximately 10% lower than the bare GAC, according to BET test results. Soil washing parameters were optimized for the treatment of a real contaminated soil, which were MGAC-CoP dose of 2% (w/w), washing time of 24 h, liquid to soil ratio of 15:1, stirring speed of 100 rpm, pH of 8.3, and temperature of 25 ˚C. Under these optimized conditions, an average PAHs removal of 47.4% was obtained. Among the LMW and HMW PAHs, anthracene (ANT), and fluoranthene (FLUO) showed the highest affinity to MGAC during the treatment process, with 57.7% and 67.1% removal from soil, respectively. The thermodynamic studies revealed that the adsorption of the LMW and HMW PAHs onto MGAC in soil washing was non-spontaneous and endothermic as the values of Gibbs free energy (∆G˚>0) and Enthalpy change (∆H˚>0) were positive. In the fourth phase, the efficiency of MGAC-CoP in surfactant-enhanced soil washing for the PAH removal and the recovery of the surfactant solution was studied. The effective parameters of soil washing with the surfactant (Tween 80) were assessed using a real contaminated soil sample, and the results showed that 5% Tween 80, a liquid to soil ratio of 10:1, and a 72-hour washing time at 20°C were optimum operating conditions. Under these conditions, the average PAHs removal efficiency was 67.6%, which was higher than the 47.4% obtained for the same soil with no surfactant addition in phase 3. The possibility of recycling and reusing the Tween 80 solution was investigated by adding MGAC-CoP to the soil and surfactant solution mixture during the soil washing process. For this purpose, 5% Tween 80 and 2% (w/w) MGAC were used in 7 successive washing cycles, with no regeneration process for the MGAC composite. The results revealed that the combination of surfactant and MGAC was capable of removing 68.6, 70.7, 70.3, 61.6, 55.5, 50.2, and 39.4% of the PAHs from soil in the 7 washing cycles, respectively. Furthermore, the recycled Tween 80 and non-regenerated MGAC did not produce any waste or effluent after 6 times reuse in the treatment process, while successfully recovered and reused. This implies that soil washing with Tween 80 and MGAC is a very affordable, efficient, and practical method for remediation of PAH-contaminated soils.

Ceramic membranes offer more advantageous performances than conventional polymeric membranes. However, membrane fouling caused by Natural Organic Matters (NOM) contained in the feed water is still become a major problem for operational efficiency. A new method of ceramic membrane pre-coating with Powdered Activated Carbon (PAC), which allows extremely contact time for adsorbing aquatic contaminants, has been studied as a pre-treatment prior to ceramic microfiltration membrane. This bench scale study evaluated five different types of PAC (SA Super, G 60, KCU 6, KCU 8 and KCU 12,). The results showed that KCU 6 with larger pore size was performed better compared to other PAC when pre-coated on membrane surface. PAC pre-coating on the ceramic membrane with KCU 6 was significantly enhance NOM removal, reduced membrane fouling and improved membrane performance. Increase of total membrane resistance was suppressed to 96%. The removal of NOM components up to 92%, 58% and 56% for biopolymers, humic substances and building blocks, respectively was achieved at pre-coating dose of 30 mg/l. Adsorption was found to be the major removal mechanism of NOM. Results obtained showed that biopolymers removal are potentially correlated with enhanced membrane performance.

Proceeding from the aim to reduce global pollution emissions from the continuous burning of hydrocarbons stimulated by increasing energy demand, more efficient and ultra-low emissions’ combustion concepts such as the homogenous charge compression ignition engines (HCCI) have been developed. These new engines rely on the low temperature chemistry (LTC) combustion concept. A detailed investigation of the properties of cool flames, governed by LTC, is essential for the design of these new engines. The primary goal of this work was to build a fundamental counterflow experiment for cool flames studies in a diffusive system, to better understand combustion in LTC engines. The project was intended to provide a basic understanding of the low-temperature reactivity and cool flames properties of butane isomers under atmospheric pressure conditions. This was achieved by establishing self-sustaining cool flames through a novel technique of ozone addition to an oxygen stream in a non-premixed counterflow model. The ignition and extinction limits of butane isomers’ cool flames have been investigated under a variety of strain rates. Results revealed that establishment of cool flames are favored at lower strain rates. Iso-butane was less reactive than n-butane by showing higher ignition and extinction limits. Ozone addition showed a significant influence on cool flame ignition and sustenance; it was found that increasing ozone concentration in the oxidizer stream dramatically increased the reactivity of both fuels. Results showed increased fuel reactivity as the temperature of the fuel stream outlet increased. 4 A numerical analysis was performed to simulate ignition and extinction of the cool flame in diffusive systems. The results revealed that ignition and extinction limits of cool flames are predominantly governed by LTC. The model qualitatively captured experimental trends for both fuels; however, it overpredicted both ignition and extinction limits under all strain rates and ozone concentrations. The discrepancies were within a factor of eight for the ignition limit and a factor of two for the extinction limit. Finally, sensitivity analyses were conducted to understand the reactions responsible for cool flames ignition. It was found that majority of the sensitive reactions are those that occur at low temperatures.

Pharmaceuticals and personal care products (PPCPs) are widely used throughout the world. PPCPs are emerging as pollutants of concern and may pose a risk in the future to drinking water supplies. Two such compounds are sulfamethoxazole (SMXL) and fluoxetine (FLX). These ionizable compounds are not readily removed from water by conventional water treatment technologies. Powdered activated carbon (PAC) is a useful material for removing contaminants from water and is currently used in many water treatment applications. PACs may carry either a net positive or negative surface charge depending on the pH of solution. This study examined the hypothesis that the electrostatic interactions between three PACs’ surface charges and the charges of sulfamethoxazole’s and fluoxetine’s ionizable functional groups would lead to greater sorption efficiency than non-electrostatic interactions alone. Samples containing SMXL or FLX, were treated with varying doses of PAC, and mixed for three hours. The pH of samples were adjusted between experiments to determine if interaction between the polar contaminants and charged surface of PAC significantly impacted removal of the contaminant from solution. Analysis of the treated samples showed the effects of pH and varying PACs on the removal of SMXL and FLX from solution. It was observed that pH of the solution did play a significant role in the removal of contaminant in a number of the experiments, but that under other conditions where greater removal was anticipated based on predicted electrostatic interactions, it did not. These conditions included pH conditions where the contaminant existed predominantly in a negatively charged form. While not the initial focus of this study, it was observed that pore size distribution of the PACs may play a more significant role in the removal of ionizable compounds, especially in the case of fluoxetine, than electrostatic interactions.

Indiana University-Purdue University Indianapolis (IUPUI) / Neurofibromatosis type 2 (NF2) is an autosomal dominant cancer predisposition in which loss of heterozygosity at the NF2 gene locus leads to the development of tumors of neural crest derived origin, most commonly bilateral vestibular schwannomas. There are currently no FDA approved chemotherapeutic agents for treatment in patients with NF2. Development of therapeutic agents has been hampered by our incomplete knowledge of how Merlin, the protein product of the NF2 gene, functions as a tumor suppressor. In order develop a deeper understanding for how loss of Merlin leads to oncogenic transformation in Schwann cells we have developed a genetically engineered mouse model (GEMM) of Neurofibromatosis Type 2 in which functional expression of Merlin is lost in Schwann cell precursors. In parallel studies utilizing these mice, we have sought to understand the pathophysiology driving tumor formation in Merlin deficient Schwann cells. In Chapter 1, we explore the role of Merlin as a negative regulator of the Group A p21 activated kinases, PAK1 and PAK2. We demonstrate that PAK1, a previously well established oncogene in solid tumors and Merlin binding partner, is hyperactivated in Merlin deficient schwannomas. Through therapeutic interventions and genetic manipulations we demonstrate that inhibition of PAK1 was capable of reducing tumor formation and alleviating sensorineural hearing loss in our NF2 GEMM. In Chapter 2, we investigate the role of NF-kB inducing kinase (NIK) and NF-kB signaling in the formation and growth of Merlin deficient Schwann cell tumors. Prior work in our lab as well as by others demonstrated elevated NF-kB signaling in Merlin deficient Schwann cell tumors. We observed accumulation of a catalytically active fragment of NF-kB inducing kinase and present data that accumulation of a 55Kd constitutively active fragment of NIK is sufficient trigger wild type Schwann cells to form tumors. In vivo however, Schwann cell intrinsic expression of NIK is not required for tumor formation or growth. / 2 years (2021-05-24)

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18327号 / 農博第2052号 / 新制||農||1022(附属図書館) / 学位論文||H26||N4834(農学部図書室) / 31185 / 京都大学大学院農学研究科食品生物科学専攻 / (主査)教授 河田 照雄, 教授 金本 龍平, 教授 入江 一浩 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

A Research Report submitted to the Faculty of Medicine, University of the Witwatersrand, in part fulfilment of the requirements for the degree of Master of Medicine in the branch of Haematology Johannesburg, October 1997 / Venous thromboembolic disease is a common health problem. It contributes considerably to morbidity as well as to mortality. Thrombosis usually occurs due to an underlying risk factor which may be environmental or genetic in origin. The recently described activated Protein C (APC) resistance is the commonest cause of familial thrombophilia documented to date. The molecular lesion is a single point mutation in the factor V (FV) gene which abolishes a cleavage site whereby it is normally inactivated by APC. This defect, termed the FV Leiden mutation, is highly prevalent in normal Caucasian populations. Although it would appear to have arisen due to a founder effect, there is a paucity of data concerning non-Caucasian populations. / IT2018

Sediments can act as both reservoir and source of legacy organic contaminants such as polychlorinated biphenyls (PCBs). Due to their chemical stability and ubiquity, these contaminants remain as model class of compounds in the field of sediment contamination. Whole sediment and organism concentrations have been often used as exposure metrics for ecological risk assessments. However, whole sediment concentrations often overestimate the potential for exposure to contaminants; while organism concentrations based on bioassay provide a better estimate of exposure, bioassays can also be labor intense, time consuming and expensive. Alternatively, accessiblity-based techniques such as Tenax extractions have been gaining ground, in the last few decades, as a rapid, reliable, and cost-effective approach to estimate exposure to organic contaminants from sediments. Tenax extractions measure the bioaccessible fraction of the contaminant that desorbes from sediment. Despite the simplicity, accuracy and robustness of the Tenax technique to estimate bioaccessibility of organic contaminants, there are still some remaining questions regarding the methodological standardization, and the applicability of the technique in sediments containing diverse carbonaceous sorbents associated adsorption/desorption of the contaminant. Therefore, the chapters of this dissertation were designed to address these questions. To this end, PCBs were chosen as a model compound class to represent a wide range of physicochemical properties of persistent organic contaminants, and because these compounds remain a worldwide legacy contamination problem. The dissertation goals were to: determine the best operational conditions for Tenax technique (Chapter 2); monitor the changes in bioaccessibility of field-collected sediments with different holding time conditions (Chapter 3); examine the effects of the type and quantity of organic carbon on bioaccessibility (Chapter 4); and evaluate the applicability of the Tenax technique to assess remediation success in contaminated marine sediments (Chapter 5). To address the methodological standardization of the Tenax technique, the operational parameters of solvent extract volume, Tenax sorption rate from water, and Tenax:OC (Tenax:Organic Carbon) ratios were investigated in Chapter 2. The highest efficiency of extraction of sorbed PCBs from Tenax resulted from using a 10 mL per each solvent wash during Tenax extraction procedure. For the Tenax sorption, it was found that 0.01 g of Tenax cleared PCB in 40 mL of water in 30 min, thus it would clear the water 48 times in 24 h. When this is extrapolated to the 0.5 of Tenax, typical amount used, it was found that the amount should clear the typical volume of water used on Tenax extraction about 2400 times. This represents unequivocal evidence that the Tenax resin would remove PCBs dissolved in the liquid phase (e.g., overlying or interstitial water) present in the sediment sample and be limited only by compound desorption and not by the Tenax sorption capacity. The results examining the impact of the relationship between the amount of Tenax required and the amount of organic carbon in the sediment extraction indicated that a minimum of 5:1 Tenax:OC ratio be used to conduct Tenax extractions. This will reduce (eliminate) the possibility of re-adsorption by the native OC in the sediment in competition with the Tenax. After ascertaining the best operational conditions for Tenax extractions, two additional methodological uncertainties, the effect of storage time after collection and the preservation method associated with the handling of collected sediment samples were investigated in Chapter 3. The effect of holding time and the preservation method on PCB concentrations from field-collected sediments was examined for a period of 196 d. All samples were held at 4 ºC in the dark and several holding times were chosen. The parameters to track the changes in PCB concentration in two sediments used three exposure metrics: exhaustive solvent extraction, tissue concentrations and Tenax extractions (Chapter 3). The results showed that the total exhaustive concentrations representing the whole sediment concentrations did not significantly change (ANOVA, p> 0.05) in either sediment over the course of 196 d. Similar results were also found for the total Tenax concentrations that represented the bioaccessible sediment concentrations, and for the total organism tissue concentrations representing exposure. The likely equilibrium of PCB in the sediment, their chemical stability of PCB and slow degradation can be underlined as the main factors leading to these results. The long time that legacy contaminants such as PCBs have been in contact with contaminated sites (e.g., Superfund sites) might have contributed to an equilibrium to be reached between the sediment particles and PCB molecules. The significance of this chapter is that sediments collected from PCB-contaminated sites can be stored longer than the 14 d as recommended by current standard protocols without disturbing the measures of bioavailability. The role of organic carbon composition within sediment on contaminant sorption was also investigated to ascertain the effects of type and quantity of OC from different origins on the bioaccessibility of PCBs in contaminated sediments (Chapter 4). Changes in PCB bioaccessibility in sediments amended at either 3 or 6% by dry weight with black carbon (BC), humic acid (HA) or sawdust (SD), showed that the lowest and highest PCB bioaccessibilities were observed in the BC and SD amendments, respectively. Specifically, the total amount of PCBs desorbed ranges from 3 to 27% for BC amendments, 12 to 55% for HA amendments and 16 to 80% for SD amendments. The results showed the influence of OC quantity on bioaccessibility having a much slower desorption of PCBs in 6% amendments compared to 3% amendments, and this finding was most evident in HA and BC amendments. The results also showed that the Tenax technique can be applied to tract the variation in type of carbon and quantity of OC in contaminated sediment to estimate exposure. Finally, the applicability of the Tenax technique as tool to assess the remediation success of PCB-contaminated marine sediments upon AC amendment at either 4.3 or 0.026% AC by dw was examined in Chapter 5. The results showed that bioaccessibility of PCBs was greatly reduced in sediment amended at the higher AC dose (4.3%); while, reduction was also observed even in the sediment amended at 0.026% AC. Furthermore, the results revealed that Tenax concentrations reflected the PCB reduction among AC amended sediments in the same direction as the PCB reduction in the organism bioaccumulation. Overall, this dissertation provides further evidence that the Tenax technique is a rapid, reliable, and cost-effective tool for estimating exposure to recalcitrant organic contaminants such as PCBs from contaminated sites. The applicability of the technique to estimate bioaccessible compound from both freshwater and marine aquatic sediments underline the robustness of the technique to widen its use among risk ecological assessor and researchers.

Taking precautions to restrain aflatoxin M1 (AFM1) from milk is critical, particularly due to the health and economic impact AFM1 imposes. The predominant post-harvest means of reducing AFM1 in milk includes the addition of sequestering agents to feed to diminish the bioavailability of aflatoxin B1 (AFB1), the parent compound of AFM1 found in contaminated feed. Still, residual AFM1 has been found in the milk. Using sequestering agents added to raw milk, we found that activated carbon was the most effective binder to reduce AFM1 contamination. The combination of 0.75% granular activated carbon (GAC) and a flow rate of 0.4 mL/min to pump contaminated milk through a glass column were chosen as optimum conditions for the removal of AFM1. These conditions obtained a 98.4% reduction of 0.75 ng/mL AFM1 from raw milk. The treated milk was also analyzed to assess the effects of GAC on milk constituents. The results determined that GAC had no significant effect on major nutritive milk constituents: total protein, lactose, minerals, and fat. Additionally, we optimized an extraction method coupled to high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) that minimized matrix effects, lowered the levels of detection, and reduced analysis costs. The optimized extraction method was based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe). Results determined 5 mL milk (15°C) with 10 mL acetonitrile, 3200 g centrifugation, and 0.2 μm syringe filter were the optimum conditions for the extraction of 0.5 ng/mL AFM1 from raw milk. The method was validated according to AOAC guidelines. This study reports experimental results on AFM1 remediation from raw bovine milk. The use of GAC for the removal of AFM1 in raw milk has reduced the amount of AFM1 below the FDA action limit and European Union maximum regulatory level. This method could have a global health impact, particularly, for people in developing nations and for infants and children who are more susceptible to the adverse effects of AFM1.

A passive treatment alternative for the removal of metal and organic contaminants from runoff and effluent in CDFs was evaluated in this study. Activated carbon impregnated curtains have been used for different remediation projects; however, very little research has been conducted to understand its sorption behavior, breakthrough time, and exhaustion time of contaminants under high flow rates characteristic of CDF runoff and effluent. The major objectives of this study were to evaluate the efficiency of the curtain in removing contaminants from a synthetic effluent in a flow through regime and estimate the expected life of the curtains. Equilibrium tests, batch sorption tests and column tests were conducted to evaluate the feasibility of this alternative. The copper column tests showed that the curtain is not efficient in the removal of metals; whereas, the Aroclor1016 column tests showed that the curtains could potentially be used as a treatment alternative for organic contaminants.