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Integration of substance flow analysis, transport and fate of materials in the environment, and environmental risk assessment for provision of information for regional environmental management: cadmium as a case study in AustraliaKwonpongsagoon, Suphaphat, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Extraction, production, utilization and disposal of material resources have been undertaken continuously for much of human histories. Unavoidably, all of these activities have disturbed our environment, and subsequently have been harmful to humans and ecosystems in this and future generations. Due to time lag associated with both environment impact and the effects of measures taken to reduce this impact, existing approaches (i.e. monitoring and reacting) do not give sufficiently rapid feedback for effective environmental management. With regard to the complexity and concern related to environment-health chain effects, there is currently no environmental tool or approach that can provide comprehensive information and indicators covering all major environment and health themes, to enable decision makers to make informed judgements about regional policies and plans, relating to the sustainable use and disposal of material resources. Consequently, there is a need for developing a new approach by taking account of a multidisciplinary concept used in this thesis. Substance Flow Analysis (SFA) has been mainly applied in order to provide input information for Health Risk Assessment (HRA). The SFA approach provides the quantity of the substance that is transported (flows) and stored in the system (stock), and of which sub-system, flow, and process is the greatest concern. The HRA approach provides estimates of human health risk associated with site, activity and facility. An environmental fate and transport model is another key knowledge area incorporated into the HRA process. An integrating method of SFA, environmental fate and transport, and HRA is developed and illustrated by a case study of cadmium in Australia. This thesis shows that this new integration of existing stand-alone methods can provide holistic information and useful indicators covering all significant economic activities, environment, flows, and health risk assessment for selected substances. This enables better decision making on the use and disposal of substances at a range of levels in the economy, from corporations to regions and nations.
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Electrokinetic remediation of cadmium-contaminated natural clay of high buffer capacityGu, Yingying, 顾莹莹 January 2011 (has links)
published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy
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Integration of substance flow analysis, transport and fate of materials in the environment, and environmental risk assessment for provision of information for regional environmental management: cadmium as a case study in AustraliaKwonpongsagoon, Suphaphat, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Extraction, production, utilization and disposal of material resources have been undertaken continuously for much of human histories. Unavoidably, all of these activities have disturbed our environment, and subsequently have been harmful to humans and ecosystems in this and future generations. Due to time lag associated with both environment impact and the effects of measures taken to reduce this impact, existing approaches (i.e. monitoring and reacting) do not give sufficiently rapid feedback for effective environmental management. With regard to the complexity and concern related to environment-health chain effects, there is currently no environmental tool or approach that can provide comprehensive information and indicators covering all major environment and health themes, to enable decision makers to make informed judgements about regional policies and plans, relating to the sustainable use and disposal of material resources. Consequently, there is a need for developing a new approach by taking account of a multidisciplinary concept used in this thesis. Substance Flow Analysis (SFA) has been mainly applied in order to provide input information for Health Risk Assessment (HRA). The SFA approach provides the quantity of the substance that is transported (flows) and stored in the system (stock), and of which sub-system, flow, and process is the greatest concern. The HRA approach provides estimates of human health risk associated with site, activity and facility. An environmental fate and transport model is another key knowledge area incorporated into the HRA process. An integrating method of SFA, environmental fate and transport, and HRA is developed and illustrated by a case study of cadmium in Australia. This thesis shows that this new integration of existing stand-alone methods can provide holistic information and useful indicators covering all significant economic activities, environment, flows, and health risk assessment for selected substances. This enables better decision making on the use and disposal of substances at a range of levels in the economy, from corporations to regions and nations.
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Concentrations of Cadmium in Common Moose Browse in MaineMcGee, Chandra J. January 2006 (has links) (PDF)
No description available.
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Flux of cadmium through a laboratory food chain (media-algae-mussel) and its effectsHennig, Helmke F-K O January 1981 (has links)
The increasing pollution of the aquatic environment by cadmium is a potentially severe problem and techniques are needed to document the effect of the metal. To investigate the flux of this metal through a laboratory food chain, algae were grown in various cadmium concentrations for subsequent use as contaminated food for mussels. The results showed that in order to make valid deductions, more information about chemical mechanisms and background ecophysiological data is needed, otherwise accumulation reports may become misleading. It was found that the best growth and accumulation results were achieved by harvesting algae from a zinc deficient media containing 7 μmole dm-3 cadmium and at a particular life cycle phase. Two uptake mechanisms are proposed. These "contaminated" algae were fed to mussels under different accumulation regimes. The metal gain and loss were determined and compared to a "baseline" dry body weight which had been calculated from a shell length-body weight relationship. Cadmium accumulation took place in the mussels and after some initial delay, could be correlated to weight loss. Such a weight loss was due to pathological and biochemical changes in the mussels. It was shown that the toxic effect of cadmium could be determined much earlier by the presence of special proteins. The elutant profiles of the gel chromatography study showed the production of metal binding protein as well as a spill over of cadmium into the enzyme pool, caused by a higher uptake than elimination rate. Cadmium on metal binding protein and in the enzyme pool could be related to the poisoning effect of the metal and a pollution history for the mussels identified. The characteristics of the metal binding protein were found to be very similar to those reported for metallothionein and had an approximate molecular weight of 10 600 daltons.
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The effect of cadmium upon the growth and nitrogen fixation of the cyanobacterium Gloeothece ATCC 27152 /Rodrigues, Kevin J. 01 January 1986 (has links) (PDF)
No description available.
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Interactions of cadmium with Bacillus subtilis and with natural bacterial populations /Titus, Jeffrey Alan, January 1981 (has links)
No description available.
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The effects of long-term exposure to cadmium on the earthworm Eisenia Fetida (Oligochaeta) : an investigation of the development of genetic metal resistanceVoua otomo, Patricks 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: The development of potential genetically based resistance to cadmium (Cd) after long-term
exposure to this metal at a sublethal concentration, was investigated in earthworm specimens
belonging to the genus Eisenia. Adult (clitellate) earthworms from a long-term laboratory Cdexposed
population (> 78 generations) and from other populations having no previous history
of metal exposure were exposed to increasing concentrations (0; 2.5; 5; 10 and 20 mg/l) of Cd
in the form of CdSO4. Different biomarkers and molecular markers were used to determine
whether the specimens from the long-term Cd-exposed population had acclimatized or adapted
to the metal contaminated environment.
Acclimation was investigated at different physiological and biochemical levels using the
following three biomarkers: the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide
assay (MTT assay) measuring mitochondrial activity and cell viability; the single cell gel
electrophoresis assay (comet assay) measuring DNA strand breaks and the biosynthesis of
metallothioneins (MTs) that have the function of lowering metal toxicity. Earthworms from the
long-term exposed substrate as well as specimens from populations not exposed to Cd were
used.
Adaptation was investigated by looking at both allozyme polymorphism at seven enzyme
encoding loci and DNA polymorphism using chosen neutral and selectable genetic markers.
The markers used were cytochrome c oxydase subunit I (COI) and metallothionein-2 (mt-2)
respectively. This was done amongst the same pool of populations. Additionally, the DNA
polymorphism study also aimed at genetically identifying the species utilized in this study
thereby determining whether these earthworms belong to the species Eisenia fetida or Eisenia
andrei.
MTs biosynthesis did not generate the expected data mainly due to the fact that a suitable
antibody could not be obtained (discussed in Chapter 5 section 5.3.3.). Similarly, the
assessment of DNA polymorphism at the chosen selectable genetic marker mt-2 did provide
information relevant to understanding the potential development of resistance to Cd in the long-term metal contaminated group. COI sequences generated in this study were compared to
E. fetida and E. andrei COI sequences available on Genbank. Consequently, specimens used in
this study were identified as possibly belonging to the species E. andrei.
Allozyme polymorphism revealed no fixed genetic differences between the long-term Cd
exposed laboratory culture and the rest of the populations. All the populations departed from
Hardy-Weinberg equilibrium (χ2 > 5.9; p < 0.05), and showed a low mean heterozygosity per
locus (Ho ≤ 0.21), probably due to inbreeding.
Cell viability and proliferation as tested by the MTT assay revealed that coelomocytes, isolated
from the long-term Cd-exposed group showed the highest viability (98.42%) compared to
those from other groups (+/- 80%). Kruskal-Wallis ANOVA (H2, 225=109.7165 p < 0.001)
revealed that the long-term Cd-exposed laboratory culture showed a better response to acute
exposure to Cd, thus demonstrating that these worms have developed some kind of tolerance to
Cd.
Similarly, the comet assay showed that in the long-term Cd-exposed specimens, less DNA
breaks occurred after Cd exposure than in the unexposed groups. Of all the comet parameters
assessed in this study (comet tail length, tail moment and tail DNA percentage), tail DNA
percentage seemed to be more sensitive although all three parameters indicated that long-term
Cd-exposed specimens were more resistant than unexposed specimens as shown by the number
of single strand DNA breaks induced by exposure to higher concentrations of Cd (p < 0.001).
The comet and the MTT assays indicated that the earthworms with a previous history of Cd
exposure have developed increased fitness towards higher doses of Cd, compared to previously
unexposed groups. These findings mainly proved that several mechanisms could come into
play at the physiological and biochemical level to allow the Cd exposed population to
acclimatize to its chemically stressful environment. Clear genetic support for the differences
found between the tested populations was not obtained, but needs to be investigated further
using Cd selectable markers such as the mt-2 gene, in order to come to a more conclusive
deduction. / AFRIKAANSE OPSOMMING: Die moontlike ontwikkeling van geneties gebaseerde weerstand teen kadmium (Cd) by
erdwurms van die genus Eisenia, na langtermyn blootstelling aan die metaal by 'n subletale
konsentrasie, is ondersoek. Volwasse (klitellate) erdwurms van 'n langtermyn laboratorium Cdblootgestelde
bevolking (< 78 generasies) asook van ander bevolkings met geen
voorgeskiedenis van metaal blootstelling nie, is blootgestel aan 'n reeks van Cd konsentrasies
(0; 2.5; 5; 10; en 20 mg/l) in die vorm van CdSO4. Verskillende biomerkers en molekulêre
merkers is gebruik om vas te stel of die erdwurms geakklimeer of aangepas het by die metaal
in die gekontamineerde omgewing.
Akklimasie is op verskillende fisiologiese en biochemiese vlakke getoets deur die volgende
drie biomerkers te gebruik: Die 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromied
toets (MTT toets), wat mitochondriale aktiwiteit en sel lewensvatbaarheid meet; die enkel sel
elektroforese toets (Komeettoets) wat DNS string breuke meet; die biosintese van
metallotioniene (MT's) wat metaalvergiftiging verlaag. Erdwurms van die langtermyn
blootstellingsubstraat asook eksemplare van bevolkings wat nie aan kadmium blootgestel was
nie, is gebruik.
Aanpassing is ondersoek deur gebruik te maak van allosiem polimorfisme, waar 7 ensiem
koderende lokusse gebruik is asook van DNS polimorfisme deur neutrale genetiese merkers te
selekteer. Die merkers wat gebruik is, was sitochroom c oksidase, subeenheid I (COI) en
metallotionien-2 (mt-2) respektiwelik. Hierdie toetse is met dieselfde groepe bevolkings
uitgevoer. 'n Bykomende van die studie aspek waar ook van DNS polimorfisme gebruik
gemaak is, was daarop gemik om die spesie wat vir die huidige studie gebruik is, geneties te
identifiseer en om vas te stel of die erdwurms aan die spesie Eisenia fetida of Eisenia andrei
behoort. Die MT biosintese het nie die verwagte data gegenereer nie, hoofsaaklik weens die feit dat
geskikte teenligaampies nie beskikbaar was nie (bespreek in Hoofstuk 5 afdeling 5.3.3).
Soortgelyk, het die waardebepaling van DNS polimorfisme by die geselekteerde genetiese
merker mt-2 nie genoegsame informasie verskaf om die potensiaal van die ontwikkeling van
weerstand teen Cd in die langtermyn blootgestelde groep te verstaan nie. COI geenvolgordes
van E. fetida en E. andrei wat op Genbank beskikbaar was, is gebruik om met die resultate van
die huidige studie te vergelyk. Die spesie wat tydens die huidige studie gebruik is, is op hierdie
wyse geïdentifiseer as E. andrei.
Allosiem polimorfisme het geen vaste genetiese verskille tussen die langtermyn blootgestelde
laboratoriumkulture en die ander bevolkings getoon nie. Al die bevolkings het verskil van die
Hardy-Weinberg ewewigstoestand (χ2 > 5.9; p < 0.05) en het 'n lae heterosigositeit per lokus
getoon (Ho ≤ 0.21), moontlik as gevolg van inteling.
Sellewensvatbaarheid en proliferasie soos getoets met die MTT toets, het getoon dat
selomosiete, geïsoleer vanuit die langtermyn Cd blootgestelde groep, die hoogste
lewensvatbaarheid (98.42%) gehad het in vergelyking met die ander groepe (+/- 80%).
Kruksal-Wallis ANOVA (H2, 225=109.7165 p < 0.001) het getoon dat die langtermyn Cd
blootgestelde laboratoriumkultuur 'n beter respons vir akute blootstelling aan Cd gehad het.
Hierdeur is gedemonstreer dat hierdie wurms 'n soort toleransie teenoor kadmium ontwikkel
het.
Soortgelyk het die komeettoets aangetoon dat daar in die langtermyn blootgestelde eksemplare
minder DNS breuke voorgekom het na verdere blootstelling aan Cd as in die ander groepe.
Van al die komeet parameters wat tydens die studie gemeet is (komeet stertlengte, Olive stert
moment en stert DNS persentasie), het die stert DNS persentasie geblyk om die mees
sensitiefste te wees, alhoewel al drie parameters aangetoon het dat die langtermyn Cd
blootgestelde eksemplare meer weerstandbiedend was teen induksie van DNS enkelstring
breuke weens Cd blootstelling (p < 0.001), as die wat nie voorheen blootgestel was nie. Die komeet en MTT toetse het aangetoon dat erdwurms met 'n voorgeskiedenis van Cd
blootstelling 'n toenemende fiksheid teen hoër dososse van Cd ontwikkel het as die wat nie
voorheen aan kadmium blootgestel was nie. My bevindings kon hoofsaaklik toon dat verskeie
meganismes op die fisiologiese en biochemiese vlak 'n rol sou kon speel om Cd blootgestelde
bevolkings by 'n chemies stresvolle omgewing te laat akklimeer. Duidelike ondersteuning vir
die verskille tussen die getoetsde bevolkings deur van Cd geselekteerde merkers soos die mt-2
geen gebruik te maak om 'n meer finale afleiding te kan maak is nie verkry nie en behoort
verder ondersoek te word.
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The effects of farm management practices on cadmium concentration in wheat grainOliver, Danielle P. (Danielle Peta) January 1994 (has links) (PDF)
Bibliography: leaves 202-223.
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Characterization of metal stabilization effect by X-ray diffraction technique and nano-indentationHe, Yue, 贺悦 January 2011 (has links)
The technological development and application of waste-to-resource strategy is
significantly critical and crucial in both environmental and manufacturing industries, via
which we do not only provide practical treatments to toxic waste materials but also
translate them into usable products. It has been considered as a preferred method which
should be applied in future wastewater treatment strategies.
In this study, we investigated the process of incorporating cadmium oxide and nickel
oxide into ceramic-based materials with the phases of CdAl4O7, and CdFe2O4. Such
products are of less harmful effect to the natural environment and can also be of
beneficial use with their good mechanical properties identified by nano-indentation. We
proved the possibility and provided an opportunity to convert the waste from
wastewater treatment process to a new material resource.
XRD is preferred for characterizing solid mixtures to determine the relative
abundances of crystalline phases during the reaction process. As a result, we can obtain
the relative abundance information on the growth of the crystalline products, such as
CdAl4O7, and CdFe2O4 according to the change of fabrication temperatures. In that case,
the starting reaction temperature and the optimized temperature (at which the completed
reaction could be achieved) could be revealed. In Cd-Al system, the starting temperature
for CdAl4O7 formation is 900 °C, and the optimized formation temperature is around
1020 °C. On the other hand, for Cd-Fe system, such temperatures are of 700 °C and
850 °C correspondingly.
In our research, it is shown that the ceramic-process is an effective strategy to
stabilize the waste hazardous metals (cadmium and nickel) by materials such as
aluminate, ferrite, and kaolin commonly used in ceramic industry. Through this method,
the difficult-to-treat wasted metals would become reusable and applied in building and
infrastructure projects. Products containing CdAl4O7, CdFe2O4 and NiAl2O4 have
shown higher resistance to acidic leaching, comparing to CdO and NiO used as the
starting materials to simulate the waste metal forms discharged from the industrial
stream. Furthermore, similar measurements by alkaline attack on the sintered products
(NiAl2O4 containing samples) were also studied.
Besides the investigation to leaching behavior, the mechanical properties are also
measured by nano-indentation in our work. The incorporation of metal waste into the
fabrication of ceramic products is valuable due to the preferred stabilization
mechanisms of crystal structures and the large volume of ceramic products needed by
the construction industry. Furthermore, because the product safety and functionality
should not be compromised, a fundamental understanding of the surface properties of
metal containing phases should be further established, rather than relying solely on data
from regulatory tests on bulk samples. Therefore, the results of this study demonstrate
the superior mechanical properties of nickel spinel containing products, comparing to
the cristobalite silica matrix, under severe acid attack. / published_or_final_version / Civil Engineering / Master / Master of Philosophy
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