Sökning: "Earth and Related Environmental Sciences Geochemistry"

Visar resultat 6 - 10 av 291 avhandlingar innehållade orden Earth and Related Environmental Sciences Geochemistry.

1. 6. The adsorption of arsenic oxyacids to iron oxyhydroxide columns : including studies of weakly hydrated ions and molecules in aqueous solution

   Författare :Johan Mähler; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The fundamental side of this project includes determination of ionic radii and plausible hydration numbers for the weakly hydrated alkali metal ions in solution, as well as an investigation of the intramolecular bond lengths of arsenic oxyacid species and orthotelluric acid. Experimental methods such as EXAFS, XANES and LAXS have been used for these purposes, as well as thorough screening for relevant structures in crystal structure databases. LÄS MER

3. 7. Metal sorption to ferrihydrite : phosphate effects, X-ray absorption spectroscopy and surface complexation modelling

   Författare :Charlotta Tiberg; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Phosphorus affects the sorption of many metals and arsenate to iron (hydr)oxides. This may influence the mobility and bioavailability of metals and arsenate. Phosphorus therefore plays an important role in, e.g. LÄS MER

4. 8. Hydrogeological and geochemical assessment of aquifer systems with geogenic arsenic in Southeastern Bangladesh : Targeting low arsenic aquifers for safe drinking water supplies in Matlab

   Författare :Mattias von Brömssen; Prosun Bhattacharya; David Polya; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arsenic; Bangladesh; drinking water; groundwater; sustainability; geochemistry; hydrogeology; modelling;

   Sammanfattning : Naturally occurring arsenic (As) in Holocene aquifers in Bangladesh have undermined a long success of supplying the population with safe drinking water. Arsenic is mobilised in reducing environments through reductive dissolution of Fe(III)-oxyhydroxides. LÄS MER

5. 9. Unraveling the importance of thiol compounds on mercury speciation, uptake and transformation by the iron-reducer Geobacter sulfurreducens

   Författare :Mareike Franziska Gutensohn; Erik Björn; Ulf Skyllberg; Jeffra K. Schaefer; Vera Slaveykova; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mercury; low molecular mass thiols; speciation; uptake; methylation; reduction; Hg 0 ; Hg II ; MeHg; Geobacter sulfurreducens; ICP-MS; LC-MS MS; X-ray absorption spectroscopy; cell physiology;

   Sammanfattning : The biogenic methylation of inorganic, divalent mercury (Hg(II)) by methylating microorganisms leads to formation and bioaccumulation of monomethyl mercury (MeHg) in the environment and can cause severe damage to ecosystems and human health. Diverse microorganisms carry the gene sequence hgcAB and are able to methylate Hg(II) intracellularly. LÄS MER

7. 10. Binding of per- and polyfluoroalkyl substances (PFASs) in soil : effects of solution chemistry, soil properties, and PFAS structure

   Författare :Hugo de Campos Pereira; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The large environmental mobility and persistence of per- and polyfluoroalkyl substances (PFASs) along with confirmed or suspected toxicities make the substances one of the great challenges of our time in the fields of chemical management and environmental risk assessment. In order to risk assess PFAS-contaminated sites, improved quantitative and mechanistic understanding of the partitioning and retention in soil is crucial. LÄS MER