This is the first study to compare total arsenic (As) and other trace elements in the agricultural soils and grain of Eastern, Western and Southern Libya, North Africa and the Middle East (NA &amp; MIDEA). Soil pot experiments and field experiments were conducted to determine the levels of As within wheat grains in Libya. In the soil pot experiments, wheat genotypes were planted in similar soils and yet differences in grain As concentration were found among the cultivars. The highest As accumulation was found in <i>T. durum; </i>however, in the field data the highest levels were found in <i>T. aestrivum.</i> The levels of As and other trace elements found in agricultural soils from the Eastern Western and Southern regions of Libya are examined. Mean As concentrations in the clay mineral agricultural soils of the Eastern Region were nearly 4.8 and 4.1 times higher than in the southern and western regions, respectively. It is possible that the parent material of that region contains elevated levels of As, which are then exhibited in the overlying soil. Differences in the levels of As and other trace elements found in the irrigated agricultural soil of Southern Libya were compared with non-irrigated soil from the same region.  Concentrations of P, Zn and As in soil were higher in irrigated compared to non-irrigated soils, while the concentration of Cd is nearly the same in all soil samples. A market basket investigation was conducted to determine the total levels of As and Se in rice purchased from supermarkets. The average level of As in rice from NA &amp; MIDEA is 0.22 mg/kg, comparable with average levels in Australia.

South Africa remains the 5th largest producer and 4th largest exporter of coal in the world. It is also the largest supplier of coal to the European Union. This fact is significant as the European Union has recently supported the environmental lobby that threatens the combined full scale use of coal in Europe and other first world countries. This promotes the development of clean coal technologies in order to counter the ever increasing number of environmental constraints threatening the export market. One critical development in clean coal technologies is coal beneficiation, which allows the reduction of ash and inert content. Permian coals from South Africa have characteristically high ash and inertinite contents and therefore require further beneficiation. The Witbank coalfield No. 4 seam is no exception. It can be described as being more inert and having a higher mineral content compared to the No. 2 seam in the same coalfield also mined for export purposes. With the increase in environmental legislation and the push towards “clean coal” this raises a concern in terms of the performance and marketability of export coal produced from the No. 4 seam. This seam will in the future be economically significant and is still a great source for export steam coal. Due to the nature and composition of the No. 4 seam, coal beneficiation is essential to reduce the mineral and inert content to be in line with export quality specification levels. Washability characteristics of the No. 4 seam coal indicate that the No. 4 seam is difficult to beneficiate. Until recently the main clean-ability parameters evaluated in South African export coals as per customer specification included mainly heating value, moisture and ash reduction with little to no work being done on trace element concentration reduction. This paper focuses on the partitioning of the trace elements within the seam in relation to the organic and inorganic affinity of the trace elements and possible methods of trace element reduction by removal using coal beneficiation techniques. The techniques investigated include reduction by washing using dense medium beneficiation and flotation. In each evaluation the focus was on trace-element-tomineral and trace-element-to-organic matter relationship and hence setting the basis for liberation analysis to evaluate reducibility. By the evaluation of the coal mineralogy, petrography and trace element relationships, methods of optimum trace element reduction can be established. With the focus on marketing it was shown that carbon loss need not be sacrificed in the reduction of specific trace elements in the No. 4 seam and that the trace element distribution itself allows for beneficiation whilst maintaining acceptable yields. Processes and possible beneficiation techniques for optimum trace element reduction and marketability in the case of the No.4 seam are proposed.

Thesis (MTech (Physical Sciences))--Peninsula Technikon, Cape Town, 1999. / Wet deposition of toxic trace metals is the dominant mode of deposition in terrestrial ecosystems and contributes very significantly to their pollution burden. Wet deposited metals are dissolved in rainwater. They reach the vegatation in a form most favourable for uptake. Reliable analysis of toxic trace metals in rainwater is important in order to determine the impact they make on the environment. In this study, trace metals in rainwater and in dry deposition (as a control measure), have been analysed over a period of a year. These metals include cadmium, copper, cobalt, lead, nickel and zinc. The rainwater was filtered, acidified to pH2 and irradiated with UV-light. Dry deposition samples, were digested by heating in nitric acid before analysis. Differential-pulse anodic stripping voltammetry was used to determine cadmium, lead and zinc. Copper was determined by adsorptive cathodic stripping at pH7 after complexation with catechol. Cobalt and nickel were measured at pH9 by adsorptive cathodic stripping after formation of their dimethylglyoximes. Sampling was done on a daily basis from April 1996 to March 1997, on the campus of the Peninsula Technikon. The samples were collected over a 24-hour period. The total average concentration for the metals was 16.11 flg/dm3 for rainwater and 427flg/dm3 for dry deposition. Meteorological factors such as wind speed, humidity and temperature affect the distribution of pollutants and thus the trace metal levels. The levels of the metallic pollutants were thus evaluated against meteorological data. Differential-pulse stripping voltammetry is shown to be applicable for heavy metal analysis of rainwater.

Os contaminantes lançados no ambiente decorrente das atividades humanas podem se movimentar de um compartimento ambiental para o outro e assim chegar nos corpos hídricos, onde se associam rapidamente ao material particulado e incorporam-se aos sedimentos. Desta forma, a relação água com o sedimento faz deste compartimento um dos principais alvos de preocupação e análise, dada sua importância na ciclagem de matéria e na biodisponibilidade de diversos compostos químicos para o ambiente aquático. O objetivo deste trabalho foi avaliar o comportamento geoquímico dos elementos Al, Fe, Cr, Cu, Zn, Mn, e P em sedimento superficial do reservatório Guarapiranga por meio da técnica de extração sequencial constituída de quatro etapas, seguido pela detecção em espectrometria de emissão ótica com plasma acoplado indutivamente (ICP-OES). Foram coletadas amostras de sedimento superficial em 14 (quatorze) estações estrategicamente escolhidas, de modo a conhecer a heterogeneidade do sistema e determinar a mobilidade de elementos-traço persistentes e sua distribuição espacial no compartimento sedimentar da represa. As amostras passaram por processo de secagem e foi separada a fração silte/argila. A extração sequencial foi realizada em quatro etapas, a fração 1 ácido solúvel ligada a carbonatos, a fração 2 redutível a óxidos de ferro e manganês, a fração 3 oxidável ligada a matéria orgânica e a fração 4 residual. Todo o processo foi feito em triplicata e as concentrações dos elementos foram determinadas no ICP-OES. Com base nos resultados obtidos da extração sequencial, foi possível avaliar a distribuição dos elementos nas quatro frações geoquímicas distintas bem como o fator de mobilidade individual e total desses elementos no reservatório. A soma das três primeiras frações compõe a fração considerada biodisponível enquanto que a diferença do total extraído representou a fração residual. A partir dos resultados obtidos infere-se que o reservatório do Guarapiranga apresenta dois compartimentos distintos, um mais degradado que vai do ponto GU-05 ao GU-14 que sofre os impactos da ocupação do seu entorno e um mais preservado que vai do ponto GU-01 a GU-04, com pouca influência de ocupação urbana no seu entorno. O grau de mobilidade global segue uma tendência de montante à jusante do reservatório, próxima a barragem. / The contaminants produced by human activities released in the environment may move from one environmental compartment to another and reach the water bodies, where they rapidly associate to particulate matter and are incorporated to the sediments. Thus, the relationship between water and sediment makes this compartment on of the main targets for concern and analysis, given its importance in cycling matter and in bioavailability of various chemical compounds to the water environment. The objective of this work was to study the geochemical behaviour of the elements Al, Fe, Cr, Cu, Zn, Mn and P in the surface sediments of the Guarapiranga reservoir (23°47\'S and 46°32\"W) by means of the sequential extraction technic consisting of four stages, followed by the detection in inductively coupled plasma optical emission spectroscopy (ICP-OES). Samples were collected from the superficial sediment in 14 (fourteen) stations strategically chosen, this way being able to know the heterogeneity of the system and to determinate the mobility of persistent trace elements and their spatial distribution in the sedimentary compartment of the reservoir. The samples were subjected to a drying process and then separating the silt fraction. The sequential extraction was made in four steps, fraction 1 acid soluble linked to carbonates, fraction 2 reducible to iron and manganese oxides, fraction 3 oxidable linked to organic matter and fraction 4 residual. All the process was done in triplicate and the concentration of the elements was determined by ICP-OES. Based on the results obtained by the sequential extraction, it was possible to evaluate the distribution of the elements in the four distinct geochemical fractions, as well as the individual mobility factor of those elements in the reservoir. The sum of the first three fractions composes the fraction considered bioavailable, while the difference from the total extracted represented the residual fraction. Parting from the results obtained it is inferred that the Guarapiranga reservoir has two distinct compartments, one more degraded that goes from point GU-05 to GU-14 that suffers from the impacts of the occupations in the surroundings and one more preserved that goes from point GU-01 to GU-04, with little influence from urban occupation in the surroundings. The degree of global mobility follows the tendency of up and down stream in the reservoir, next to the barrage.

by Leung Ho-yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references. / Abstract also in Chinese. / Acknowledgement --- p.i / Abstract --- p.ii / Table of Contents --- p.iv / List of Tables and Figures --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Methodology --- p.12 / Chapter Chapter 3 --- Experimental --- p.17 / Chapter 3.1 --- Sample Collection --- p.17 / Chapter 3.2 --- Preliminary Sample Treatment --- p.18 / Chapter 3.3 --- Dissolution Test Apparatus --- p.18 / Chapter 3.4 --- Reagents --- p.20 / Chapter 3.5 --- ICP Experimental Conditions --- p.21 / Chapter Chapter 4 --- Determination of Total Contents in Chinese Mineral Drugs --- p.28 / Chapter 4.1 --- Procedure --- p.28 / Chapter 4.2 --- Results --- p.39 / Chapter Chapter 5 --- Determination of the Effective Contents --- p.51 / Chapter 5.1 --- General Procedure --- p.51 / Chapter 5.2 --- Results --- p.52 / Chapter Chapter 6 --- Recovery Test for Dissolution --- p.77 / Chapter 6.1 --- General Procedure --- p.77 / Chapter 6.2 --- Results --- p.78 / Chapter Chapter 7 --- Discussion --- p.80 / Chapter 7.1 --- The Presence of Toxic Elements in many CMD --- p.80 / Chapter 7.2 --- Mass of Samples Added in the Dissolution --- p.80 / Chapter 7.3 --- Height of the Dissolution Paddle of the Dissolution --- p.81 / Chapter 7.4 --- Particle Sizes of the Sample in the Dissolution --- p.83 / Chapter 7.5 --- The Total and the Effective Contents --- p.83 / Chapter 7.6 --- Discussion for each CMD --- p.84 / Chapter 7.7 --- Conclusion --- p.103 / Appendix English 一 Chinese table of CMD --- p.108

Digitized by Kansas Correctional Industries

Thesis. 1978. Ph.D. cn--Massachusetts Institute of Technology. Dept. of Chemistry. / Includes bibliographical references. / Ph.D.cn

Os contaminantes lançados no ambiente decorrente das atividades humanas podem se movimentar de um compartimento ambiental para o outro e assim chegar nos corpos hídricos, onde se associam rapidamente ao material particulado e incorporam-se aos sedimentos. Desta forma, a relação água com o sedimento faz deste compartimento um dos principais alvos de preocupação e análise, dada sua importância na ciclagem de matéria e na biodisponibilidade de diversos compostos químicos para o ambiente aquático. O objetivo deste trabalho foi avaliar o comportamento geoquímico dos elementos Al, Fe, Cr, Cu, Zn, Mn, e P em sedimento superficial do reservatório Guarapiranga por meio da técnica de extração sequencial constituída de quatro etapas, seguido pela detecção em espectrometria de emissão ótica com plasma acoplado indutivamente (ICP-OES). Foram coletadas amostras de sedimento superficial em 14 (quatorze) estações estrategicamente escolhidas, de modo a conhecer a heterogeneidade do sistema e determinar a mobilidade de elementos-traço persistentes e sua distribuição espacial no compartimento sedimentar da represa. As amostras passaram por processo de secagem e foi separada a fração silte/argila. A extração sequencial foi realizada em quatro etapas, a fração 1 ácido solúvel ligada a carbonatos, a fração 2 redutível a óxidos de ferro e manganês, a fração 3 oxidável ligada a matéria orgânica e a fração 4 residual. Todo o processo foi feito em triplicata e as concentrações dos elementos foram determinadas no ICP-OES. Com base nos resultados obtidos da extração sequencial, foi possível avaliar a distribuição dos elementos nas quatro frações geoquímicas distintas bem como o fator de mobilidade individual e total desses elementos no reservatório. A soma das três primeiras frações compõe a fração considerada biodisponível enquanto que a diferença do total extraído representou a fração residual. A partir dos resultados obtidos infere-se que o reservatório do Guarapiranga apresenta dois compartimentos distintos, um mais degradado que vai do ponto GU-05 ao GU-14 que sofre os impactos da ocupação do seu entorno e um mais preservado que vai do ponto GU-01 a GU-04, com pouca influência de ocupação urbana no seu entorno. O grau de mobilidade global segue uma tendência de montante à jusante do reservatório, próxima a barragem. / The contaminants produced by human activities released in the environment may move from one environmental compartment to another and reach the water bodies, where they rapidly associate to particulate matter and are incorporated to the sediments. Thus, the relationship between water and sediment makes this compartment on of the main targets for concern and analysis, given its importance in cycling matter and in bioavailability of various chemical compounds to the water environment. The objective of this work was to study the geochemical behaviour of the elements Al, Fe, Cr, Cu, Zn, Mn and P in the surface sediments of the Guarapiranga reservoir (23°47\'S and 46°32\"W) by means of the sequential extraction technic consisting of four stages, followed by the detection in inductively coupled plasma optical emission spectroscopy (ICP-OES). Samples were collected from the superficial sediment in 14 (fourteen) stations strategically chosen, this way being able to know the heterogeneity of the system and to determinate the mobility of persistent trace elements and their spatial distribution in the sedimentary compartment of the reservoir. The samples were subjected to a drying process and then separating the silt fraction. The sequential extraction was made in four steps, fraction 1 acid soluble linked to carbonates, fraction 2 reducible to iron and manganese oxides, fraction 3 oxidable linked to organic matter and fraction 4 residual. All the process was done in triplicate and the concentration of the elements was determined by ICP-OES. Based on the results obtained by the sequential extraction, it was possible to evaluate the distribution of the elements in the four distinct geochemical fractions, as well as the individual mobility factor of those elements in the reservoir. The sum of the first three fractions composes the fraction considered bioavailable, while the difference from the total extracted represented the residual fraction. Parting from the results obtained it is inferred that the Guarapiranga reservoir has two distinct compartments, one more degraded that goes from point GU-05 to GU-14 that suffers from the impacts of the occupations in the surroundings and one more preserved that goes from point GU-01 to GU-04, with little influence from urban occupation in the surroundings. The degree of global mobility follows the tendency of up and down stream in the reservoir, next to the barrage.

The goal of this research was to aid in the fight against the heroin and opioid epidemic by developing new methodology for heroin provenance determination and forensic sample comparison. Over 400 illicit heroin powder samples were analyzed using quadrupole and high-resolution inductively-coupled plasma mass spectrometry (Q-ICP-MS and HR-ICP-MS) in order to measure and identify elemental contaminants useful for associating heroin samples of common origin and differentiating heroin of different geographic origins. Additionally, 198 heroin samples were analyzed by multi-collector ICP-MS (MC-ICP-MS) to measure radiogenic strontium isotope ratios (87Sr/86Sr) with high-precision for heroin provenance determination, for the first time. Supervised discriminant analysis models were constructed to predict heroin origin using elemental composition. The model was able to correctly associate 88% of the samples to their region of origin. When 87Sr/86Sr data were combined with Q-ICP-MS elemental data, the correct association of heroin samples improved to ≥90% for all groups with an average of 93% correct classification. For forensic sample comparisons, quantitative elemental data (11 elements measured) from 120 samples, 30 from each of the four regions, were compared in order to assess the rate of discrimination (5400 total comparisons). Using a match criterion of ±3 standard deviations about the mean, only 14 of the 5400 possible comparison pairs were not discriminated resulting in a discrimination rate of 99.7%. For determining the rate of correct associations, 3 replicates of 24 duplicate samples were prepared and analyzed on separate days. Only 1 of the 24 correct pairs were not associated for a correct association rate of 95.8%. New methods for provenance determination and sample comparison are expected to be incredibly useful to intelligence agencies and law enforcement working to reduce the proliferation of heroin.

The prevalent and ongoing exposures to polychlorinated biphenyls (PCBs) demands an understanding of the threat they pose and also a means in which to mitigate their potential toxicity. This thesis set out to investigate a phenomenon associated with a specific PCB congener, 3,3',4,4',5-pentachlorobiphenyl (PCB126), for the underpinnings of its mechanism, and also its usefulness as a toxin against which to establish a mitigative strategy. The phenomenon in particular is the disruption of hepatic trace elements, specifically an increase in copper and decreases in zinc, selenium, iron, and manganese in the liver. Four questions were posed to address the overarching goals: 1) When does micronutrient disruption occur in the context of liver pathology? 2) What metal transporters or chaperones are involved? 3) Can the previously shown beneficial micronutrient, zinc, alter the disruption and improve outcome? 4) What is occurring spatially within the liver acinus where micronutrients are distributed? By answering these four questions, a fundamental understanding of this occurrence will be ascertained. A chronology of PCB126-hepatotoxicity showed onset of liver pathology at 36 hours and later alterations in micronutrients at 3 days, suggesting disruption of hepatic trace elements is likely the result of liver degeneration. In addition, a key metal transport protein, metallothionein, was induced by PCB126. Utilizing a double knockout animal model, metallothionein was shown to abrogate some toxicity but had little involvement of micronutrient perturbation. Previous investigations have suggested the unique property of zinc in rescuing/preventing hepatic damage by a variety of toxic agents. Dietary zinc had a modest effect in ameliorating PCB126 hepatotoxicity and preserving micronutrient homeostasis. This suggests that the mitigative potential of zinc supplementation on PCB126 exposure is limited. Finally, a fine spatial investigation of the liver acinus was conducted to establish the levels of trace elements from the portal triad to the central vein. In addition, novel findings of high concentrations of extracellular zinc were discovered. In all, this dissertation has shown that disruption of hepatic micronutrients caused by PCB126 are likely the result of liver degeneration by means of disturbing the spatial trace element gradients and provides appropriate context for therapeutic/preventive strategies against PCBs.