<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0379-3982</journal-id>
<journal-title><![CDATA[Revista Tecnología en Marcha]]></journal-title>
<abbrev-journal-title><![CDATA[Tecnología en Marcha]]></abbrev-journal-title>
<issn>0379-3982</issn>
<publisher>
<publisher-name><![CDATA[Instituto Tecnológico de Costa Rica]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0379-39822020000400103</article-id>
<article-id pub-id-type="doi">10.18845/tm.v33i4.4586</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Fraccionamiento de metales pesados en un suelo contaminado del Valle de Mexicali]]></article-title>
<article-title xml:lang="en"><![CDATA[Heavy metals fractionation in Mexicali Valley contaminated soil]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gómez-Puentes]]></surname>
<given-names><![CDATA[Francisco Javier]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Reyes-López]]></surname>
<given-names><![CDATA[Jaime Alonso]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Amado-Moreno]]></surname>
<given-names><![CDATA[María Guadalupe]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,TecNM Campus Mexicali  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>México</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Instituto de Ingeniería de la Universidad Autónoma de Baja California  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,TecNM Campus Mexicali  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>México</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>12</month>
<year>2020</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>12</month>
<year>2020</year>
</pub-date>
<volume>33</volume>
<numero>4</numero>
<fpage>103</fpage>
<lpage>113</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_arttext&amp;pid=S0379-39822020000400103&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_abstract&amp;pid=S0379-39822020000400103&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_pdf&amp;pid=S0379-39822020000400103&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen La contaminación provocada por metales pesados constituye uno de los grandes retos relacionados con la calidad del ambiente y la salud humana. La introducción de estos elementos en los sistemas naturales puede deberse a diversas actividades humanas entre ellas la agricultura y la disposición de residuos sólidos. En el Valle de Mexicali, la agricultura representa la actividad económica más importante, sin embargo, el uso de agroquímicos, así como la disposición clandestina de residuos sólidos urbanos (RSU) han generado problemas de contaminación severos afectando la fertilidad de suelos y la calidad de las aguas subterráneas. El propósito de esta investigación consistió en evaluar el contenido de metales pesados en diferentes fracciones de suelo a través de la zona vadosa (ZV) en un sitio ubicado en el Valle de Mexicali e influenciado por la agricultura y la disposición de residuos. Las muestras de suelo se sometieron al procedimiento de extracción secuencial y fueron analizadas mediante espectrometría de absorción atómica. Los resultados obtenidos revelan una marcada acumulación de metales desde la superficie hasta los primeros 50 cm de profundidad. Las variaciones estacionales del nivel freático, así como el riego agrícola favorecen el transporte de solutos observándose concentraciones de metales en el agua subterránea superiores a los estándares para agua potable. Los elementos Cd, Cr y Ni se distribuyen preferentemente en la fracción residual del suelo limitando así su movilidad. El Cu presentó una fuerte asociación con la materia orgánica en tanto que el Zn y Pb presentaron la mayor asociación con fracción intercambiable.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract Heavy metals contamination is one of the greatest challenges related to the environment quality and human health. The introduction of these elements into natural systems may be due to various types of human activities such as agriculture and solid wastes disposal. In Mexicali Valley, agriculture represents the most important economic activity, however, the use of agrochemicals as well as the clandestine disposition of urban solid wastes have generated severe pollution problems affecting soil fertility and groundwater quality. The purpose of this research was to evaluate the heavy metals content in the different fractions of soil through the vadose zone (ZV) in a site located in Mexicali Valley, B.C. influenced by agriculture and solid wastes disposal. Soil samples were subjected to the sequential extraction procedure and then analyzed by atomic absorption spectrometry. The results obtained reveal a marked accumulation of metals from the surface until 50 cm depth. Seasonal variations in the water table, as well as agricultural irrigation, favors the solutes transport with heavy metals concentrations in groundwater higher than the standards for drinking water. The elements Cd, Cr y Ni are preferably distributed in the residual fraction of soil, limiting their mobility. Cu presented a strong association with organic matter, while Zn and Pb presented the greatest association with the exchangeable fraction.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Partición química]]></kwd>
<kwd lng="es"><![CDATA[metales pesados]]></kwd>
<kwd lng="es"><![CDATA[zona vadosa]]></kwd>
<kwd lng="es"><![CDATA[agua subterránea]]></kwd>
<kwd lng="en"><![CDATA[Chemical partitioning]]></kwd>
<kwd lng="en"><![CDATA[heavy metals]]></kwd>
<kwd lng="en"><![CDATA[vadose zone]]></kwd>
<kwd lng="en"><![CDATA[groundwater]]></kwd>
</kwd-group>
</article-meta>
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