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<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>Jonathan D. Istok</dc:contributor>
  <dc:contributor>Joseph M. Suflita</dc:contributor>
  <dc:creator>Steve H. Harris Jr.</dc:creator>
  <dc:date>2006</dc:date>
  <dc:description>&lt;p&gt;&lt;i class="EmphasisTypeItalic "&gt;In situ&lt;/i&gt;&lt;span&gt; experiments were conducted to measure sulfate reduction rates and identify rate-limiting factors in a shallow, alluvial aquifer contaminated with municipal landfill leachate. Single-well, push–pull tests conducted in a well adjacent to the landfill with &amp;gt;8&amp;nbsp;mM dissolved organic carbon (DOC) exhibited a sulfate reduction rate of 3.2&amp;nbsp;μmol SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;−2&lt;/sup&gt;&lt;span&gt; (L sediment)&lt;/span&gt;&lt;sup&gt;−1&lt;/sup&gt;&lt;span&gt; day&lt;/span&gt;&lt;sup&gt;−1&lt;/sup&gt;&lt;span&gt;, a value in close agreement with laboratory-derived estimates. Identical tests conducted in wells located 90&amp;nbsp;m downgradient where DOC levels remained high (&amp;gt;3&amp;nbsp;mM) showed no detectable sulfate consumption, and laboratory assays confirmed this observation. However, the rates of sulfate reduction in sediment samples obtained from this site were three times larger when they were amended with filter-sterilized groundwater from the upgradient location. The effect of various amendments on sulfate reduction rates was further examined in laboratory incubations using sediment collected from the downgradient site amended with &lt;/span&gt;&lt;sup&gt;35&lt;/sup&gt;&lt;span&gt;S sulfate. Unamended sediments showed only weak conversion of the tracer to &lt;/span&gt;&lt;sup&gt;35&lt;/sup&gt;&lt;span&gt;S sulfide (5 to 7&amp;nbsp;cpm/cm&lt;/span&gt;&lt;sup&gt;2&lt;/sup&gt;&lt;span&gt;), whereas the addition of &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Desulfovibrio&lt;/i&gt;&lt;span&gt; cells increased &lt;/span&gt;&lt;sup&gt;35&lt;/sup&gt;&lt;span&gt;S sulfide production to 44&amp;nbsp;cpm/cm&lt;/span&gt;&lt;sup&gt;2&lt;/sup&gt;&lt;span&gt;. However, the application of heat-killed &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Desulfovibrio&lt;/i&gt;&lt;span&gt; had a similar stimulatory effect, as did a lactate amendment. Collectively, these findings indicate that the lack of measurable sulfate reduction at the downgradient site was not due to the absence of the necessary metabolic potential, the presence of lower sulfate concentration, or the quantity of electron donor, but by its biodegradability. The findings also indicate that field bioaugmentation attempts should be interpreted with caution.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1007/s00248-006-9043-y</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Springer Science+Business Media, Inc.</dc:publisher>
  <dc:title>Changes in organic matter biodegradatility influencing sulfate reduction in an aquifer contaminated by landfill leachate</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>