<?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>2007-9753</journal-id>
<journal-title><![CDATA[RIIIT. Revista internacional de investigación e innovación tecnológica]]></journal-title>
<abbrev-journal-title><![CDATA[RIIIT. Rev. int. investig. innov. tecnol.]]></abbrev-journal-title>
<issn>2007-9753</issn>
<publisher>
<publisher-name><![CDATA[Universidad Autónoma de Coahuila]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S2007-97532019000500002</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Precipitation of Ag, Hg and Cr for recycling derived from hazardous liquid wastes]]></article-title>
<article-title xml:lang="es"><![CDATA[Precipitación de Ag, Hg y Cr para el reciclaje derivado de residuos líquidos peligrosos]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Pitalúa-Sánchez]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Rosano-Ortega]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Martínez-Tavera]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Sánchez-Ruiz]]></surname>
<given-names><![CDATA[F.J.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Garrido-Hoyos]]></surname>
<given-names><![CDATA[S.E.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Martínez-Gallegos]]></surname>
<given-names><![CDATA[S.M.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Cruz-González]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Popular Autónoma del Estado de Puebla Faculty of Environmental Engineering ]]></institution>
<addr-line><![CDATA[Puebla Puebla]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Instituto Mexicano de Tecnología del Agua  ]]></institution>
<addr-line><![CDATA[Jiutepec Morelos]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Instituto Tecnológico de Toluca  ]]></institution>
<addr-line><![CDATA[Metepec Estado de México]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af4">
<institution><![CDATA[,Benemérita Universidad Autónoma de Puebla Faculty of Chemical Engineering ]]></institution>
<addr-line><![CDATA[Puebla Puebla]]></addr-line>
<country>Mexico</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>10</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>10</month>
<year>2019</year>
</pub-date>
<volume>7</volume>
<numero>40</numero>
<fpage>19</fpage>
<lpage>35</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S2007-97532019000500002&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S2007-97532019000500002&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S2007-97532019000500002&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract Lab tests generate a large amount of waste, including Ag, Hg and Cr, which are the heavy metals from the determination of the Chemical Oxygen Demand (COD). The liquid waste generated by this parameter shows a high initial concentration of 1133 mg/L of Ag, 2252 mg/L of Hg and 950 mg/L of Cr, exceeding what the Official Mexican Standard NOM-002-SEMARNAT-1996 establishes. In this paper, a physicochemical procedure was optimized and applied to reduce the concentration of the heavy metals through laboratory experiments and the evaluation of the operating conditions (temperature, contact time and reagent concentration) using a factorial design 23. The results of the developed technique showed a satisfactory performance obtaining removal efficiencies of 99.99 % for Ag, 99.99 % for Hg and 99.96 % for Cr; the final concentration (0.1 mg/L for Ag, 0.001 mg/L for Hg and 0.36 mg/L for Cr) is below the limits of the Mexican standard. Due to the high removal efficiencies, this technique is adequate and simple to reduce the metals of the COD waste.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen Las pruebas de laboratorio generan una gran cantidad de residuos, entre los que destacan Ag, Hg y Cr, que son los metales pesados provenientes de la determinación de la Demanda Química de Oxígeno (DQO). Los residuos generados por este parámetro muestran una concentración inicial de 1133 mg/L de Ag, 2252 mg/L de Hg y 950 mg/L de Cr, excediendo lo que establece la Norma Oficial Mexicana NOM-002-SEMARNAT-1996. En este trabajo, se optimizó y aplicó un procedimiento físico-químico para reducir la concentración de los metales mediante corridas experimentales y la evaluación de las condiciones de operación (temperatura, tiempo de contacto, concentración de reactante) empleando un diseño factorial 23. Los resultados de la técnica desarrollada mostraron un rendimiento satisfactorio al obtener eficiencias de remoción del 99.99 % para Ag, del 99.99 % para Hg y del 99.96 % para Cr, cuya concentración final (0.1 mg/L para Ag, 0.001 mg/L para Hg y 0.36 mg/L para Cr) está por debajo de los límites de la norma mexicana. Debido a los altos porcentajes de remoción mostrados, esta técnica resultó adecuada y simple para reducir los metales de los residuos de la DQO.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[chromium]]></kwd>
<kwd lng="en"><![CDATA[COD]]></kwd>
<kwd lng="en"><![CDATA[hazardous liquid waste]]></kwd>
<kwd lng="en"><![CDATA[mercury]]></kwd>
<kwd lng="en"><![CDATA[silver]]></kwd>
<kwd lng="es"><![CDATA[cromo]]></kwd>
<kwd lng="es"><![CDATA[DQO]]></kwd>
<kwd lng="es"><![CDATA[mercurio]]></kwd>
<kwd lng="es"><![CDATA[plata]]></kwd>
<kwd lng="es"><![CDATA[residuo líquido peligroso]]></kwd>
</kwd-group>
</article-meta>
</front><back>
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