<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>G. R. Aiken</dc:contributor>
  <dc:contributor>J. N. Ryan</dc:contributor>
  <dc:creator>M. Haitzer</dc:creator>
  <dc:date>2003</dc:date>
  <dc:description>&lt;div class="hlFld-Abstract"&gt;&lt;div id="abstractBox"&gt;&lt;p class="articleBody_abstractText"&gt;Conditional distribution coefficients (&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;DOM&lt;/sub&gt;‘) for Hg(II) binding to seven dissolved organic matter (DOM) isolates were measured at environmentally relevant ratios of Hg(II) to DOM. The results show that&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;DOM&lt;/sub&gt;‘ values for different types of samples (humic acids, fulvic acids, hydrophobic acids) isolated from diverse aquatic environments were all within 1 order of magnitude (10&lt;sup&gt;22.5&lt;/sup&gt;&lt;sup&gt;±&lt;/sup&gt;&lt;sup&gt;1.0&lt;/sup&gt;−10&lt;sup&gt;23.5&lt;/sup&gt;&lt;sup&gt;±&lt;/sup&gt;&lt;sup&gt;1.0&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;L kg&lt;sup&gt;-&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;), suggesting similar Hg(II) binding environments, presumably involving thiol groups, for the different isolates.&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;DOM&lt;/sub&gt;‘ values decreased at low pHs (4) compared to values at pH 7, indicating proton competition for the strong Hg(II) binding sites. Chemical modeling of Hg(II)−DOM binding at different pH values was consistent with bidentate binding of Hg(II) by one thiol group (p&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;a&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;= 10.3) and one other group (p&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;a&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;= 6.3) in the DOM, which is in agreement with recent results on the structure of Hg(II)−DOM bonds obtained by extended X-ray absorption fine structure spectroscopy (EXAFS).&lt;/p&gt;&lt;/div&gt;&lt;/div&gt;&lt;div class="hlFld-Fulltext"&gt;&lt;br data-mce-bogus="1"&gt;&lt;/div&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1021/es026291o</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>ACS</dc:publisher>
  <dc:title>Binding of mercury(II) to aquatic humic substances: Influence of pH and source of humic substances</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>