Sökning: "metal speciation"

Visar resultat 1 - 5 av 74 avhandlingar innehållade orden metal speciation.

1. 1. Interactions between metals and bacteria : Importance for metal speciation

   Författare :Lena Brynhildsen; Linköpings universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; INTERDISCIPLINARY RESEARCH AREAS; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN;

   Sammanfattning : The objective of this thesis is to contribute to the understanding of the interactions between metals and microorganisms with respect to* Toxicity of metals (Cd, Cu, Hg, Zn)* Mineralization of metal-organic complexes (citric acid, histidine)* Metal adsorption (Cs, Sr, Eu, Hg, Zn, As)Most of the studies were made on the gram-negative bacterium Klebsiella oxytoca, but the work also involved a Serratia as as well as mixed cultures of microorganisms from soil systems.Most previous studies, reported in the literature, on the toxic effects of metals on microorganisms have been performed at high nutrient levels, despite the fact that microorganisms in nature normally live under energy-limited conditions. LÄS MER

3. 2. Metal Speciation and Toxicity in Sewage Sludge

   Författare :Annika Ekvall; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; partition coefficient; toxicity; speciation; sewage sludge; fractionation; metals;

   Sammanfattning : Increasingly stringent controls on metal concentrations in sewage sludge destined for agricultural application provided a basis for the study of the relevance of metal speciation in sewage sludge. A comprehensive literature review identified difficulties in relating metal speciation through single chemical extractions to plant uptake and soil toxicity. LÄS MER

4. 3. A Passive Sampling System for Monitoring Metals in the Aquatic Environment

   Författare :Lena B Blom; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; metal diffusion; metal monitoring; metal speciation; aquatic systems; passive sampling system;

   Sammanfattning : Water monitoring is undertaken routinely as a requirement of water quality legislation. It is usual that water monitoring is undertaken through spot sampling. A passive sampling system has been developed for the aquatic environment that provides time-averaged (integrated) concentrations for metals. LÄS MER

5. 4. Metal Particles – Hazard or Risk? Elaboration and Implementation of a Research Strategy from a Surface and Corrosion Perspective

   Författare :Klara Midander; Inger Odnevall Wallinder; Sannakaisa Virtanen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ferro-chromium alloy; metal particles; bioaccessibility; chemical speciation; dermal contact; surface oxide; in-vitro testing; chemical speciation; cu; copper; comet assay; intracellular; ultrafine; in vitro; A549; cytotoxicity; DNA damage; nanoparticles; particle characterization; artificial sweat; nickel release; nickel powder particles; particle loadings; release kinetics; surface area; copper release; powder particles; synthetic body fluids; simulation of interstitial lung conditions; skin contact; metal release; stainless steel; particles; test method; Surface and colloid chemistry; Yt- och kolloidkemi; Analytical chemistry; Analytisk kemi; Spectroscopy; Spektroskopi;

   Sammanfattning : Do metal particles (including particles of pure metals, alloys, metal oxides and compounds) pose a hazard or risk to human health? In the light of this question, this thesis summarizes results from research conducted on metal particles, and describes the elaboration and implementation of an in vitro test methodology to study metal release from particles through corrosion and dissolution processes in synthetic biological media relevant for human exposure through inhalation/ingestion and dermal contact. Bioaccessible metals are defined as the pool of released metals from particles that potentially could be made available for absorption by humans or other organisms. LÄS MER

7. 5. Liquid Membrane Techniques for Trace Metal Analysis and Speciation in Environmental and Biological Matrices

   Författare :Kuria Ndung'u; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Pb and Organotin species; MMLLE; SLM; GC MS; PSA; GFAS; FAAS; ICP-MS; Speciation; DEHPA; Aliquat-336; trace metals; Cr III ; Cr VI ; Analytisk kemi;

   Sammanfattning : In this thesis, liquid-membrane-based methods for the analysis of trace metal species in samples of environmental and biological origin were developed. By incorporating extracting reagents in the membrane liquid, trace metal ions were selectively separated from humic-rich natural waters and urine samples, prior to their determination using various instrumental techniques. LÄS MER