<?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>1405-7743</journal-id>
<journal-title><![CDATA[Ingeniería, investigación y tecnología]]></journal-title>
<abbrev-journal-title><![CDATA[Ing. invest. y tecnol.]]></abbrev-journal-title>
<issn>1405-7743</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional Autónoma de México, Facultad de Ingeniería]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1405-77432023000300003</article-id>
<article-id pub-id-type="doi">10.22201/fi.25940732e.2023.24.3.019</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Caracterización de lodos activados procedentes, dos Plantas de Tratamiento de Aguas Residuales (PTAR) ubicadas en Costa Rica]]></article-title>
<article-title xml:lang="en"><![CDATA[Characterization of activated sludge from two Wastewater Treatment Plants (WWTP) in Costa Rica]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Alfaro-Arrieta]]></surname>
<given-names><![CDATA[Ernesto]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Instituto Costarricense de Acueductos y Alcantarillados Departamento de Aguas Residuales Laboratorio Nacional de Aguas]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Costa Rica</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>09</month>
<year>2023</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>09</month>
<year>2023</year>
</pub-date>
<volume>24</volume>
<numero>3</numero>
<fpage>0</fpage>
<lpage>0</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S1405-77432023000300003&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S1405-77432023000300003&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S1405-77432023000300003&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen Las descargas de agua residual representan un gran problema de contaminación para el ambiente, ya que en muchos casos no se llegan a tratar de manera correcta y son depositados en los ríos y quebradas. Existen distintos tipos de tratamiento de agua residual entre los cuales resalta, debido a su eficacia, el tratamiento aerobio de lodos activados. Sin embargo, actualmente no existen muchos análisis en Costa Rica que sean específicos para estos lodos, de manera que se pueda dar un criterio de la calidad de estos, y por lo tanto del buen funcionamiento de la planta de tratamiento. Países como España han generado un Índice de Calidad de Lodos Activados utilizando el estudio de sus componentes, que ha permitido la caracterización de estos avanzando enormemente en temas de tratamiento de agua residual. Con el objetivo de realizar una caracterización para la aplicación de dicho Índice de Calidad de Lodos Activados en Costa Rica, se realizaron cuatro muestreos de lodos y de los efluentes de dos distintas Plantas de Tratamiento de Agua Residual, los cuales se analizaron tanto microbiológicamente como fisicoquímicamente, y se les aplicó el índice de lodos activados mencionado anteriormente. Se obtuvieron resultados positivos del índice categorizando los lodos activados como Buenos, coincidiendo con los análisis de calidad de los efluentes y demostrando que dicho índice es aplicable en las plantas de tratamiento aerobias de Costa Rica. Es necesario que el índice de lodos activados se realice como análisis de rutina para dar una caracterización completa de calidad a todas las PTAR de lodos activados.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract Wastewater discharges represent a major pollution problem for the environment, since in many cases it is not treated correctly and is deposited in rivers and streams. There are different types of wastewater treatment among which, due to its effectiveness, the aerobic treatment of activated sludge stands out. However, currently, there are not many analyzes in Costa Rica that are specific to these sludge so that a criterion of their quality can be given, and therefore the proper functioning of the wastewater treatment plant. Countries like Spain have generated an activated sludge Quality Index using the study of its components, which has allowed the characterization of these, making enormous progress in wastewater treatment issues. In order to carry out a characterization for the application of said Activated Sludge Quality Index in Costa Rica, four samplings of sludge and effluents from two different Wastewater Treatment Plants were carried out, which were analyzed, both microbiologically and physicochemically, and the activated sludge index mentioned above was applied to them. Positive results of the index were obtained by categorizing the activated sludge as Good, coinciding with the effluent quality analyzes and showing that said index is applicable in the aerobic treatment plants of Costa Rica. It is necessary that the activated sludge index be performed as a routine analysis to give a complete quality characterization of all activated sludge WWTPs.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Lodos activados]]></kwd>
<kwd lng="es"><![CDATA[agua residual]]></kwd>
<kwd lng="es"><![CDATA[índice]]></kwd>
<kwd lng="es"><![CDATA[tratamiento]]></kwd>
<kwd lng="es"><![CDATA[protozoos]]></kwd>
<kwd lng="en"><![CDATA[Activated sludge]]></kwd>
<kwd lng="en"><![CDATA[wastewater]]></kwd>
<kwd lng="en"><![CDATA[index]]></kwd>
<kwd lng="en"><![CDATA[treatment]]></kwd>
<kwd lng="en"><![CDATA[protozoa]]></kwd>
</kwd-group>
</article-meta>
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