The influence of dissolved natural organic matter (NOM) on the transport of Cu(II) in saturated media was investigated in controlled batch and column experiments. Six sources of natural organic matter (two in their ambient solution matrices and four isolated humic substances) were chosen to represent different environments and different humic fractions. 5i02 and a-Al203 comprised the mineral surfaces with which the NOM and Cu(II) interacted. The experiments were conducted at a constant ionic strength and buffer concentration and at pH 6.2 (all sources) and pH 7.5 (two sources). Equilibrium Cu(II) concentrations were monitored with an ion specific electrode and atomic absorption spectrophotometer and NOM was measured as UV absorbance at 254 rim. Adsorbate effect on particle surface charge was evaluated using microelectrophoresis and the effect of molecular weight on NOM breakthrough was determined with ultrafiltration of column influent and effluent. Column studies showed significant variation in NOM breakthrough as a function of source on a mixed bed of SiO₂ and a-Al203. Humic acid from the Suwannee River showed greater adsorption than the fulvic acid from the same source. The presence of Cu(II) resulted in greater retardation of all the NOM sources than in the Cu(II) free systems. Cu(II) transport was slightly facilitated at pH 6.2 by the Orange County NOM and Biscayne aquifer NOM, while the other NOM sources inhibited Cu(II) movement. At pH 7.5 the Orange County and Biscayne Aquifer sources greatly facilitated the transport of Cu(II) in a mixed bed column. The results of this research suggest that the following mechanisms can influence trace metal transport in saturated media: 1) competition of the NOM with the mineral surface for metal complexation; 2) formation of mixed ligand complexes (metal-NOM-mineral surface); 3) complexation of Cu(II) by adsorbed NOM; and 4) metal bridging of NOM to a mineral surface. The results also show that cations commonly found in natural waters ,especially Ca(II) and Mg(II), can influence the interaction of trace metals and NOM with mineral surfaces.

No description available.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

A total of 78 sludge samples originating from 69 sewage works of South Africa were used in this investigation. Seven of the sludge samples were liquid and the rest were solid. Moisture content, pH and mineral ion determination using ICP-OES were carried out. The methods used to digest the samples were EPA 3050B and 301OA for solid sludge and effluent (liquid sludge) respectively. The moisture content determination showed that fresh wet sludge was composed of water between 40 to 90 %. The minimum moisture content was found to be 2.70 % while the maximum was 88.50 % with a mean value of41 %. The pH results showed that the majority sludges produced had pH values between 4.8 - 6.5. The ICP-OES results which involved analysis and quantification of 22 mineral ions showed that the order ofabundance that was most common to the majority ofthe samples was P, Ca, Fe, AI, Mg, K, Zn, Na, Si, Mn, Cu, Cr, Ba, Pb, Sr, Se, B, Ni, Co, Mo and Cd. Even though phosphorus was the most abundant, 11 of the samples had calcium as the highest element. Looking at the heavy metals, zinc was the highest with cadmium being the least. The order of abundance in majority of the solid samples (64 in total) was Zn> Pb > Ni> Cd with the relative metal concentrations of Cu, Se, B, Cr, Co & Mo varying among the sewage works. The liquid samples also had phosphorus as one of the most abundant elements but was 102 times smaller comparing to solid sludges. In addition, most of the transition elements were found to be below the detection limit. Beryllium was exceptionally found to be below detection limit in all sludge samples. The results have pointed out that industrial effluent have 3 times the level of pollutants when compared to the domestic effluents. However, the methods of preparing sludge have no influence on the content or quantity of mineral ions. The results have been compared with 1989 data. The outcome shows that concentrations of the major nutrients namely calcium, magnesium and potassium remained relatively constant whereas phosphorus increased by more than 3 fold. On heavy metals, the data shows that the mean concentration level of Zn, Cu, Cr, Pb, Ni and Cd declined whereas that of Se, B and Mo showed an increase in 2002, all to a varying degree. The current results were also compared with the current maximum limits as stipulated in the permissible utilization and disposal of sewage sludge government guideline. The amount of Cu, Se, Pb and Zn were found to be above the limit in more than 90 % of the samples. There was no sewage works that met the required limits for all the elements of interest. When these results are compared with the intenational limits, all the elements fall within the acceptable range. It is therefore clear that the current South African guideline limit is too restrictive. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

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

Chan Pui-Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 169-182). / Text in English; abstracts in English and Chinese. / Chan Pui-Ling. / Acknowledgements --- p.i / Abstracts --- p.ii / Table of Contents --- p.v / List of Plates --- p.ix / List of Figures --- p.xii / List of Tables --- p.xiv / Abbreviations --- p.xviii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Indoor Air Quality (IAQ): An overview --- p.1 / Chapter 1.1.1 --- Importance of indoor air quality --- p.2 / Chapter 1.1.2 --- Common indoor air pollutants --- p.2 / Chapter 1.1.3 --- Airborne bacteria --- p.4 / Chapter 1.1.3.1 --- Possible sources of airborne bacteria --- p.4 / Chapter 1.1.3.2 --- Health effects of the airborne bacteria --- p.5 / Chapter a. --- Sick building syndromes --- p.5 / Chapter b. --- Building-related illness --- p.7 / Chapter 1.1.4 --- Importance of studying airborne bacteria --- p.12 / Chapter 1.2 --- Situation in Hong Kong --- p.13 / Chapter 1.2.1 --- Outdoor air quality --- p.14 / Chapter 1.2.2 --- Indoor air quality --- p.14 / Chapter 1.2.2.1 --- Hong Kong studies --- p.16 / Chapter 1.2.3 --- Air quality objectives in Hong Kong --- p.18 / Chapter 1.3 --- Different sampling methods --- p.18 / Chapter 1.4 --- Identification of bacteria --- p.24 / Chapter 1.5 --- Site selection --- p.26 / Chapter 2 --- Objectives --- p.28 / Chapter 3 --- Materials and methods --- p.29 / Chapter 3.1 --- Samples collection --- p.29 / Chapter 3.1.1 --- Sampling site --- p.29 / Chapter 3.1.2 --- Complete Biosampler System --- p.29 / Chapter 3.1.3 --- Sampling preparation --- p.33 / Chapter 3.1.4 --- Sampling procedures --- p.33 / Chapter 3.2 --- Recovery of the airborne bacteria --- p.36 / Chapter 3.2.1 --- Cultural medium --- p.36 / Chapter 3.2.2 --- Recovery procedures --- p.36 / Chapter 3.2.3 --- Frozen stocks --- p.37 / Chapter 3.3 --- Indentification of bacterial strains --- p.37 / Chapter 3.3.1 --- Gram stain --- p.37 / Chapter 3.3.1.1 --- Chemical reagents --- p.37 / Chapter 3.3.1.2 --- Gram stain procedures --- p.38 / Chapter 3.3.2 --- Oxidase test --- p.38 / Chapter 3.3.2.1 --- Chemical reagents --- p.38 / Chapter 3.3.2.2 --- Oxidase test procedures --- p.41 / Chapter 3.3.3 --- Midi Sherlock® Microbial Identification System (MIDI) --- p.41 / Chapter 3.3.3.1 --- Culture medium --- p.41 / Chapter 3.3.3.2 --- Chemical reagents --- p.41 / Chapter 3.3.3.3 --- MIDI procedures --- p.41 / Chapter 3.3.4 --- Biolog MicroLogTM system (Biolog) --- p.41 / Chapter 3.3.4.1 --- Culture medium --- p.41 / Chapter 3.3.4.2 --- Chemical reagents --- p.44 / Chapter 3.3.4.3 --- Biolog procedures --- p.44 / Chapter 3.3.5 --- DuPont Qualicon RiboPrinter® Microbial Characterization System (RiboPrinter) --- p.46 / Chapter 3.3.5.1 --- Culture medium --- p.46 / Chapter 3.3.5.2 --- Chemical reagents --- p.46 / Chapter 3.3.5.3 --- RiboPrinter procedures --- p.46 / Chapter 4 --- Results --- p.50 / Chapter 4.1 --- Sample naming system --- p.50 / Chapter 4.2 --- Interpretation of results --- p.50 / Chapter 4.2.1 --- Midi Sherlock® Microbial Identification System (MIDI) --- p.51 / Chapter 4.2.2 --- Biolog MicroLog´ёØ System (Biolog) --- p.51 / Chapter 4.2.3 --- DuPont Qualicon RiboPrinter® Microbial Characterization System (RiboPrinter) --- p.52 / Chapter 4.3 --- Sample results --- p.53 / Chapter 4.3.1 --- Sample 1 (Spring) --- p.53 / Chapter 4.3.2 --- Sample 2 (Summer-holiday) --- p.62 / Chapter 4.3.3 --- Sample 3 (Summer-school time) --- p.71 / Chapter 4.3.4 --- Sample 4 (Autumn) --- p.81 / Chapter 4.3.5 --- Sample 5 (Winter) --- p.90 / Chapter 4.4 --- Bacterial profile of the student canteen --- p.100 / Chapter 4.5 --- The cell and colony morphology of the dominant bacteria --- p.100 / Chapter 4.6 --- Comparison between samples --- p.121 / Chapter 4.6.1 --- Spatial variation --- p.121 / Chapter 4.6.1.1 --- Spatial effect on bacterial abundance --- p.121 / Chapter 4.6.1.2 --- Spatial effect on species diversity --- p.121 / Chapter 4.6.2 --- Daily variation --- p.126 / Chapter 4.6.2.1 --- Daily effect on bacterial abundance --- p.126 / Chapter 4.6.2.2 --- Daily effect on species diversity --- p.126 / Chapter 4.6.3 --- Seasonal variation --- p.126 / Chapter 4.6.3.1 --- Seasonal effect on bacterial abundance --- p.126 / Chapter 4.6.3.2 --- Seasonal effect on species diversity --- p.130 / Chapter 4.7 --- Temperature effect on individual airborne bacterial population --- p.130 / Chapter 4.7.1 --- Gram positive bacteria --- p.130 / Chapter 4.7.2 --- Gram negative bacteria --- p.130 / Chapter 4.8 --- Effect of relative humidity on individual airborne bacterial population --- p.137 / Chapter 4.8.1 --- Gram positive bacteria --- p.137 / Chapter 4.8.2 --- Gram negative bacteria --- p.137 / Chapter 5 --- Discussion --- p.143 / Chapter 5.1 --- Bacterial profile --- p.143 / Chapter 5.1.1 --- Bacterial diversity --- p.143 / Chapter 5.1.2 --- Information of the identified bacteria from the student canteen --- p.144 / Chapter 5.1.3 --- Pathogenicity --- p.153 / Chapter 5.1.4 --- Summary on the bacterial profile --- p.153 / Chapter 5.2 --- Comparison between samples --- p.160 / Chapter 5.2.1 --- Spatial variation (Sampling point 1 against Sampling point 2) --- p.160 / Chapter 5.2.2 --- Daily variation (Morning against Afternoon) --- p.161 / Chapter 5.2.3 --- Seasonal variation --- p.162 / Chapter 5.2.4 --- Summer holiday against Summer school time --- p.163 / Chapter 5.2.5 --- Summary on the factors affecting the bacterial content --- p.164 / Chapter 5.3 --- Summary on indoor air quality of the student canteen in terms of bacterial level. --- p.166 / Chapter 6 --- Conclusions --- p.168 / Chapter 7 --- References --- p.169 / Appendix 1 --- p.183 / Appendix 2 --- p.187

Indiana University-Purdue University Indianapolis (IUPUI) / Mercury (Hg) has proven to be a risk to the public, mainly through the consumption of fish. Because of this, many fish consumption advisories have been issued in Indiana. Although much is known about the global cycle of mercury, little is known about how local and regional emission sources of mercury impact local and regional mercury cycling. This study’s objective was to determine the scope of mercury concentration in central Indiana by using a broad grid of soil mercury measurements. Sampling was designed to capture the net retained mercury content in soils, and to determine whether spatial patterns in exist in soil mercury contents that could be related to emission sources of mercury and post-emission transport patterns from wind. Results from this study revealed significant differences in mercury concentrations for soils in central Indiana. The core of the study area, concentrated in the urban area of Indianapolis, exhibited soil mercury contents that were 20 times higher than values in the outskirts of the study area. The spatial pattern resembled a bulls-eye shape centered on Indianapolis, and with comparison to the reported Hg emission from local sources, including a coal-fired power plant, indicates a strong regional deposition signal linked to those emission sources but marked by wind-driven transport to the northeast. This effect of local emission sources resulting in local deposition indicates that limiting mercury emissions will have a net beneficial impact on local environmental quality and human health.

No description available.