X-ray diffraction (XRD) has become one of the most powerful techniques for crystal structure studies and phase composition identifications. In this thesis, using the quantitative XRD (QXRD) technique to assist the development of reliable engineering strategies of stabilizing hazardous lead pollutants into ceramic matrix and resource recovery will be introduced. Metal stabilization strategies have been sought to replace the traditional disposal methods for the management of waste metal sludge. To demonstrate the unique capability of QXRD in monitoring the lead incorporation behavior, different ceramic precursors was used to react with lead oxide to investigating metal transformation mechanisms during the sintering process. When heating with alumina, influences of Pb/Al molar ratio, temperature, and treatment time on lead incorporation efficiency on the formation of PbAl2O4and PbAl12O19phasesweresuccessfully revealed by QXRD. Moreover, the influence of silica on lead stabilization effect was analyzed by blending amorphous SiO2 and quartz with -Al2O3 as the precursors. The results suggest that both silica precursors could crystallochemically incorporate lead into the lead feldspar (PbAl2Si2O8) structure in significant quantities. In addition, by sintering clay-based precursors with lead oxide, a complete lead incorporation into lead feldspar occurred above 950℃. Lead glass-ceramics were produced by thermally treating waterworks sludge with lead oxide, and amorphous contents in the products were quantified using QXRD. When hematite was used as a Fe-rich precursor to treat lead oxide, three types of lead ferrite crystals were observed and quantitatively determined. Furthermore, the mechanism of incorporating lead-zinc tailing with P-rich municipal waste sludge ash was investigated under different thermal conditions. By detailed X-ray diffraction analysis, Pb was crystallochemically incorporated into the Ca5.5Pb4.5(PO4)6(OH)2 crystalline structure and Zn was stabilized into Zn(Al0.5Fe1.5)O4 spinel phase. The stability of lead in all the product phases was evaluated byprolonged acid leaching, and the results indicated the lower intrinsic lead leachability of the product phases. The progress in optimizing experimental parameters in resource recovery suggest an opportunity of using QXRD technique to investigate the feasibility of extracting Pb from CRT and recycling P by struvite precipitation. A novel process of thermal reduction treatment with the addition of metallic iron (Fe(0)) to recover lead from cathode ray tube (CRT) funnel glass was introduced. The optimal operational parameters for the thermal extraction of lead from CRT glass were determined by QXRD technique as 50 wt.% Fe addition, heating at 700 °C for 30 min. Struvite crystallization for phosphorus recovery from wastewaters has gained strong attention. While the aspects of application and modeling have been widely studied, the phase composition of recovered phosphorus products was rarely reported. The obtained high degree of accuracy supports the validity of Rietveld method for the quantification of both amorphous and crystal phases in the products. QXRD results suggest the amount of increase of struvite in the products with the elevated N/P molar ratio from 0.2/1 to 1.2/1. All the results have demonstrated the capability of QXRD in contributing to the advancements of both material and environmental technologies. / published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

No description available.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Environmental Health Faculty of Applied Sciences Cape Peninsula University of Technology / Soil contamination by metals is a serious environmental problem that has significant implications for human health. Roadside soils have been shown to have considerable contamination due to depositions of metals by vehicles. Metal pollution poses significant environmental concerns because most metals are not biodegradable and often have long half-lives, thus predicating far reaching effects on biological systems, including the soil. Unleaded petrol has been available in South Africa since 1996. The conversion from leaded to unleaded petrol has been a slow process. Leaded petrol has been totally phased out since January 2006. The manganese-containing fuel additive methylcyclopentadienyl manganese tricarbonyl (MMT) that was introduced to automobile fuel formulae as an octane boosting and “anti-knock” agent, to replace or reduce the lead content in petrol, was officially approved in some developed countries. Despite the fact that metal contamination of soil has long been known, few studies have been carried out into its vertical distribution in the soil. The objectives of this investigation were: firstly, to assess the accumulation of lead and manganese in soil along the N1 highway; secondly, to determine the vertical distribution of lead and manganese in soil along the N1 highway; and thirdly, to compare the concentrations of lead and manganese in soil along the N1 highway, before and after the banning of leaded petrol in South Africa. Six soil samples were taken at each site approximately two meters from the road verges and at a depth of approximately 0-2cm of surface soil. The sampling period commenced on the 16th of February 2011 and ended on the 28th of December 2011. Once-off soil samples were also collected at sites 1, 5 and 6 at depths of 0-2cm, 30cm and 60cm, respectively. Samples were digested with 10 ml 55% nitric acid. Lead and manganese concentrations were determined by using Inductively Coupled Plasma Mass Spectrophotometer (ICP–MS). The mean concentrations of lead found in the roadside soils of the N1 highway ranged between 7.32mg/kg and 2068.31mg/kg and these were of high concentrations when compared to studies done in other countries. Results from the vertical distribution of lead investigation showed that lead concentrations ranged from 52.72mg/kg to 215.94mg/kg at surface level, from 15.80mg/kg to 164mg/kg at a depth of 30cm and from 14.06mg/kg to 216.07mg/kg at a depth of 60cm from the surface. It was also shown that there is a positive correlation between lead concentration and the amount of organic content (although not statistical), concluding that as the amount of organic content increases lead concentrations also increase. The mean manganese concentrations found in the roadside soils of the N1 ranged between 12.17mg/kg and 221.47mg/kg. The levels of manganese in the soil were found to be relatively low when compared to other studies an indication of mild to low metal contamination of the sampled soils. Results from the vertical distribution of manganese concentrations showed that concentrations in the soil ranged from 39.23 mg/kg to 63.32 mg/kg at surface level, from 14.4mg/kg to 310.86mg/kg for depths of up to 30cm, and from 4.42mg/kg to 343.96mg/kg for depths of up to 60cm. No relationships of manganese levels in the soil were found at any of the sites when sites were compared prior to the banning of lead and after the banning of lead despite the increased traffic volumes and, thus, increased MMT usage over the years, indicating that manganese contribution from MMT is very low and does not significantly increase soil contamination along the N1 highway. However, further investigations are needed into the future to monitor manganese contamination that may possibly occur.

by Lai Yuen Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 41-45). / Abstract --- p.i / Acknowledgement --- p.ii / Contents --- p.iii / List of Figures --- p.vi / List of Tables --- p.vii / Chapter 1. --- INTRODUCTION / Chapter 1.1 --- Air Pollution in Hong Kong --- p.1 / Chapter 1.2 --- Lead in Air and its Harmful Effects on Human --- p.3 / Chapter 1.3 --- Sampling of Air Particulates --- p.6 / Chapter 1.3.1 --- Principles of filter sampling --- p.6 / Chapter 1.3.2 --- Filter media for air sampling --- p.7 / Chapter 1.4 --- Sample Treatment --- p.9 / Chapter 1.4.1 --- Acid digestion - standard method for analysis of metals --- p.9 / Chapter 1.4.2 --- Slurry sampling - direct method for analysis of metals --- p.9 / Chapter 1.4.3 --- Literature survey on slurry sampling --- p.10 / Chapter 1.4.4 --- Comparison between acid digestion and slurry sampling methods --- p.10 / Chapter 1.5 --- Instrumental Analysis --- p.11 / Chapter 1.5.1 --- Graphite furnace atomic absorption spectrometry --- p.11 / Chapter 1.5.2 --- Background correction by the Zeeman effect --- p.12 / Chapter 2. --- EXPERIMENTAL / Chapter 2.1 --- Apparatus --- p.14 / Chapter 2.2 --- Reagents --- p.14 / Chapter 2.3 --- Procedure --- p.15 / Chapter 2.3.1 --- Selection of sample introduction technique --- p.15 / Chapter 2.3.2 --- Recovery study of lead in standard reference material (SRM) in 1-decanol --- p.16 / Chapter 2.3.3 --- Study of suspension behavior of solvents with SRM --- p.16 / Chapter 2.3.4 --- Recovery study of lead in SRM in ethylene glycol --- p.17 / Chapter 2.3.5 --- Determination of lead in SRM by the developed method --- p.17 / Chapter 2.3.6 --- Determination of lead in SRM by the acid digestion method --- p.18 / Chapter 2.3.7 --- Application of the developed method on the analysis of real sample --- p.18 / Chapter 3. --- RESULTS AND DISCUSSION / Chapter 3.1 --- Choice of Solvents for Suspension of Air Particulates --- p.20 / Chapter 3.2 --- Sample Introduction Technique --- p.20 / Chapter 3.3 --- Recovery Study of lead in SRM in 1-Decanol --- p.22 / Chapter 3.3.1 --- Drying stage of the temperature program for analysis --- p.23 / Chapter 3.3.2 --- Effect of 1-decanol on the absorbance signal of the analyte --- p.24 / Chapter 3.3.3 --- Sample injection volume --- p.25 / Chapter 3.3.4 --- Design of temperature program for analysis --- p.25 / Chapter 3.4 --- Study of Suspension Behavior of Solvents --- p.27 / Chapter 3.5 --- Recovery Study of lead in SRM in Ethylene Glycol --- p.32 / Chapter 3.6 --- Evaluation of the Developed Method --- p.33 / Chapter 3.6.1 --- Determination of lead in SRM --- p.33 / Chapter 3.6.2 --- Application of non-linear standard addition method --- p.35 / Chapter 3.6.3 --- precision and accuracy of the developed method --- p.36 / Chapter 3.7 --- Recovery Study with the Acid Digestion Method --- p.36 / Chapter 3.8 --- Analysis of Real Sample by the Developed Method --- p.37 / Chapter 3.8.1 --- Principles of TEOM® on mass measurement --- p.37 / Chapter 3.8.2 --- Selection of filter media for air sampling --- p.37 / Chapter 3.8.3 --- Study of dislodging efficiency of air particulates from Teflon filter --- p.38 / Chapter 3.8.4 --- Comparison with the acid digestion method --- p.39 / Chapter 4. --- CONCLUSION --- p.40 / Chapter 5. --- REFERENCES --- p.41 / Chapter 6. --- APPENDIX --- p.46

Between May 1985 and December 1986, a cohort of 1,502 pregnant women was recruited at two government clinics in Kosovo (formerly a province of Yugoslavia) for a study of the relationship between environmental lead (Pb) exposure and birth outcomes. Subsequently, a representative group of 541 of their children were selected for long-term follow up. The children were followed longitudinally at six-month intervals for 12 years to examine the effects of environmental Pb exposure on a variety of health outcomes including cognitive and motor function, anemia, endocrine function and growth. This work produced numerous landmark publications (Popovac et al, 1982; Graziano et al., 1990, 1991, 2004; Murphy et al., 1990; Factor-Litvak et al, 1993, 1996, 1998, 1999; Wasserman et al,. 1992, 1994, 1997, 1998, 2000) that contributed to the modification of environmental policies to reduce Pb exposure worldwide. The long-term study ultimately linked environmental Pb exposure from the Trepca mining and smelting operations in Mitrovica to adverse effects on intelligence, motor function, blood pressure, renal, endocrine and hematological functioning. Follow up rates over time were excellent in that 70% of the total cohort was evaluated at 6 years of age, and 65% were evaluated at 12 years of age, at which point the study was - until now - concluded. For the present study, we located 101 members of the original study cohort and requested their participation in a follow-up study in which participants were evaluated to assess their current blood lead (BPb) levels and health outcomes as follows: a) blood pressure; b) biomarkers of endothelial cell function that are associated with cardiovascular disease; c) and measurements of erythropoietin, a glycoprotein hormone produced in the kidney that regulates the production of red blood cells in the bone marrow. The participants, whose environmental exposure history is very well documented from 12 weeks of gestation through 12 years of age, were between 25-26 years of age during the follow-up study. We found a statistically significant association between BPb and systolic blood pressure (sBP), and a marginally significant association between BPb and diastolic blood pressure (dBP), which is consistent with a multitude of studies and meta-analyses referenced in this dissertation. These results provide further evidence that recent circulating dose, as estimated by BPb, or as estimated by lifetime cumulative exposure, is associated with slight increase in sBP. Furthermore, we detected a suggestive relationship between BPb and levels of circulating serum intercellular adhesion molecules (sICAM-1) and serum intravascular adhesion molecules (sVCAM-1), possibly a mechanism by which Pb may lead to increased BP. These findings support the hypothesis that the exposure to Pb either prenatally or in early adulthood, may lead to increased BP and increased circulating levels of sICAM-1 and sVCAM-1 later in life. Lastly, the results regarding the serum erythropoietin (EPO) production presented here resemble the findings reported in this cohort at 4.5 and 6.5 years of age and in contrast with the findings in this cohort when the study participants were 9.5 and 12 years of age (Graziano et al., 2004). In addition, they also contrast the findings reported in the anemic mothers of this study cohort (Graziano et al., 1991) where serum-EPO levels were lower in those with higher BPb levels.

published_or_final_version / Chemistry / Master / Master of Philosophy

In Canada, regulations against the use of lead (Pb) shot for waterfowl hunting were first established in the early 1990s with the creation of a few non-toxic shot zones, and culminated with a national ban in 1997. Prior to establishment of the first non-toxic shot zones in Canada, a nation-wide survey of Pb accumulation in wing bones of young-of-the-year (YY) dabbling and diving ducks determined the incidence of elevated Pb exposure in different parts of the country (Scheuhammer & Dickson, 1996). The objective of the present study was to determine the incidence of elevated Pb accumulation in the same species several years after the national ban on Pb shot; to survey waterfowl hunters to determine approximate levels of compliance with the Pb shot ban; and to use stable Pb isotope analysis to help determine the relative importance of different sources of Pb exposure. / Wing bones from 721 YY black, mallard, and ring necked ducks, and 579 YY woodcock from selected zones in Ontario, Quebec, BC, and the Maritimes, Canada were analyzed for Pb using flame atomic absorption spectrometry. (Abstract shortened by UMI.)

Evaluation of heavy metal accumulation in soils and plants is of environmental importance due to their health effects on humans and other biota. Phytoremediation is an emerging technology that can stabilize or remove heavy metals in soil utilizing metal tolerant plant species (metallophytes). The objectives of this study were to: (1) assess a Superfund site, and a lead-acid battery dump for concentrations of soil lead (Pb) and cadmium (Cd); (2) assess the various chemical fractions of Pb and Cd at both sites; (3) identify native herbaceous vegetation surviving in the contaminated soils; and (4) evaluate plant uptake of Pb and Cd. Soil Pb and Cd concentrations at the Superfund site averaged 55,480 and 8.5 mg/kg, respectively. Soil Pb at the Superfund site occurred primarily in the carbonate, sulfide/residual, and organic chemical fractions (41.6, 28.6, and 26.7, respectively). Soil Pb and Cd concentrations at the dump site averaged 29,400 and 3.9 mg/kg, respectively. Soil Pb occurred mostly in the organic and carbonate fractions as 48.5 and 42.5% respectively. Plant uptake of Pb at both sites ranged from non-detectable (Agrostemma githago, Plantago rugeli, Alliaria officinalis shoots), to 1800 mg/kg (Agrostemma githago root). Cd uptake was maximal in Taraxacum officinale at 15.4 mg/kg (Superfund site). In the majority of plants studied, root Pb and Cd content was higher than for shoots (>_65%). Tissue and soil fractions yielded r2 of 0.61 and 0.57 for the soluble and carbonate-Pb fractions, respectively. The plants with the greatest tissue concentrations of Pb and Cd were predominantly herbaceous species, some of which produce sufficient biomass to be practical for phytoremediation technologies. / Department of Natural Resources and Environmental Management

Phytoextraction is an innovative method that can be implemented to remove lead (Pb), cadmium (Cd), and zinc (Zn) from contaminated soil. A two-year field and growth chamber study was conducted to determine the effectiveness of several soil amendments in the phytoextraction or stabilization of Pb, Cd and Zn. Field plots were established at the Memorial Drive Dump site (Muncie, IN). Amendments included composted municipal solid waste (MSW) (25 Mg/ha), dried sewage sludge (SS) (25 Mg/ha), citric acid (2 mmol/kg soil), ethylenediaminetetraacetic acid (EDTA) (2 mmol/kg soil), and a control. A mixed grass crop was capable of survival and growth in the contaminated soil; in contrast, Helianthus annuus (sunflower) and Ambrosia artemisiifolia (ragweed) failed to become established. Soil Pb and Zn occurred primarily in the carbonate, organic-bound and residual forms (23.1%, 31.8%, and 44.4%, Pb, respectively and 11.4%, 26.5%, and 60.2% Zn, respectively). Soil Cd occurred primarily in the soluble, carbonate, and residual forms (21.8%, 21.3%, and 27.4%, respectively). In a growth chamber leaching study, soil Pb was most rapidly leached from the 0.1 M EDTA treatment (51.7 mg Pb over 200 pore volumes); the 0.001M resulted in the lowest leaching. Soil Pb was most rapidly leached using 0.1 M HEDTA (52.1 mg Pb over 200 pore volumes). The 0.001 M HEDTA rate resulted in lowest Pb leaching. Addition of an NPK solution resulted in minimal Pb leached. The MSW and dried sludge treatments resulted in the greatest dry matter production on the plots. Dry matter production was significantly (p >0.05) higher in the MSW (1.09 MT/ha) and SS (95 MT/ha) treatments. Addition of EDTA, citric acid and MSW significantly (p < 0.05) increased the amount of Cd uptake into plant tissue. The study also demonstrated the ability of vegetation to establish and grow on toxic soil and to uptake Pb, Cd, and Zn. / Department of Natural Resources and Environmental Management

M.Sc. (Geography and Environmental Management) / Saldanha forms part of the heart of the Western Cape and is an integral part of the economic and social well being of South Africa. The recent development of the Namakwa Sands Smelter and the proposed Saldanha Steel Project indicate a possible new phase of industrial growth in the Saldanha area. The evolution of man into beings who are more environmentally aware and the proclamation of more environmentally related legislation, should integrate well with this development. These factors should ensure that companies and institutions implement better pollution control and management. In this study lead pollution caused by the handling and storing of lead concentrate for export purposes in Saldanha Bay, is investigated. The Small Bay area was identified as the area likely to be most polluted and this study concentrated on the pollution in this specific area. The lead pollution was measured for a certain period by monitoring lead concentrations in samples of biological material (black mussels), soil, sediment and dust. From the results the following conclusions are made. Lead concentrations in biological material in the Small Bay area remained constant with no real increase or decrease. Lead concentrations in the soil samples on the north easterly side of Small Bay showed a definite decrease during the monitoring period. Lead concentrations in the sediments of the Small Bay area indicate a decrease during the monitoring period. Lead concentrations in dust collected on the eastern side of Small Bay remained constant during the monitoring period. Lead concentrations in dust collected on the north eastern side showed a decrease. In general, based on the above results obtained, it can be concluded that lead pollution in the Small Bay area of Saldanha decreased during the monitoring period. Lead concentrations in the biological material and dust that did not show a decrease, remained constant i.e. did not worsen.