RESUMEN: Se usaron técnicas de análisis estadístico multivariado, para determinar la variación temporal y espacial de la calidad del agua en la zona costera de Santa Marta, donde se ubica un emisario submarino que descarga 1 m3/s de aguas residuales domésticas. La ANOVA de dos vías, los análisis de clúster y de componentes principales mas la interpolación de krigging, fueron considerados para este análisis. En la variación temporal se encontraron diferencias que marcan en el año dos periodos de tiempos heterogéneos, de diciembre a abril la concentración de los parámetros de calidad del agua es más alta. El resto del año (mayo, junio, agosto, noviembre, exceptuando el mes de julio donde se presentaron concentraciones altas), se registran concentraciones sensiblemente inferiores. En la variación espacial se reportan dos grupos de áreas en las cuales la calidad del agua es diferente, dicha diferencia está relacionada con la cercanía a la descarga del emisario submarino. | ABSTARCT: Multivariate statistical techniques were used to investigate the temporal and spatial variations of water quality at the Santa Marta coastal area where a submarine outfall that discharges 1 m3/s of domestic wastewater is located. Two-way analysis of variance (ANOVA), cluster and principal component analysis and Krigging interpolation were considered for this report. Temporal variation showed two heterogeneous periods. From December to April, and July, where the concentration of the water quality parameters is higher; the rest of the year (May, June, August-November) were significantly lower. The spatial variation reported two areas where the water quality is different, this difference is related to the proximity to the submarine outfall discharge.

El río Magdalena (RM) constituye una de las principales fuentes fluviales del país, la cual se articula con múltiples procesos de carácter económico, ecológico y social, que inciden en aproximadamente 21 millones de habitantes. En consecuencia, este sistema hídrico se ve expuesto a perturbaciones de carácter antrópico, que afectan considerablemente la disponibilidad del agua para diversos fines. Con el objetivo de valorar la calidad del agua del RM, el presente estudio realizó la comparación de Índices de Calidad del Agua (ICA) nacionales, internacionales y de elaboración propia, a partir de un análisis espacio- temporal, considerando 12 estaciones de monitoreo (identificadas dentro de la red nacional de monitoreo del recurso hídrico), para el periodo comprendido entre 2009 y 2018. Para ello, se desarrolló una metodología basada en un enfoque cuantitativo, considerando datos suministrados por autoridades ambientales, y empleando métodos descritos en literatura y análisis de correlación de variables fisicoquímicas. Los ICA calculados permitieron establecer diferentes criterios de calidad en cada una de las estaciones, destacándose principalmente la incidencia de una calidad Regular y Mala en las estaciones de “Bolívar Calamar” y “Bolívar Magangué” y una calidad Aceptable y Admisible para la estación “Puente de Santander”. El análisis de correlación permitió identificar variables no contempladas en los ICA consultados en literatura, tales como relación N-NH3/NO3 y concentración de Fe-Biodisponible, determinado a partir de sedimentos. Se concluye que el uso y comparación de diferentes metodologías para el cálculo del ICA es una herramienta útil para la valoración espacio-temporal de la calidad del agua del RM, la cual puede ser empleada como estrategia para la estimación de la calidad del agua en otros sistemas hídricos superficiales del país. | Ingeniero Ambiental | Pregrado | The Magdalena River (MR) constitutes one of the main riverine sources of the country, which is articulated with multiple processes of an economic, ecological and social nature that affect approximately 21 million inhabitants. Consequently, this water system is exposed to disturbances of an anthropic nature, which considerably ponder the availability of water for various purposes. In order to assess the water quality of the MR, this study made a comparison of national, international and own-made Water Quality Indices (WQI), based on a temporal space analysis, considering 12 monitoring stations (identified within the national water resource monitoring network), for the period between 2009 and 2018. For this, a methodology based on a quantitative approach was developed, considering data provided by environmental authorities, and using methods described in literature and analysis correlation of physicochemical variables. The calculated WQI allowed to establish different quality criteria in each of the stations, mainly highlighting the incidence of a Regular and Bad quality in the stations of “Bolívar Calamar” and “Bolívar Magangué” and an Acceptable and Admissible quality for the station “Puente of Santander”. The correlation analysis will identify variables not considered in the WQI consulted in the literature, such as the N-NH3 / NO3 ratio and the concentration of Fe-Bioavailable, determined from sediments. It is concluded that the use and comparison of different methodologies for the calculation of the WQI is a useful tool for the temporal space assessment of the water quality of the MR, which can be used as a strategy for the estimation of the water quality in other areas. surface water systems of the country.

A divergência funcional associada à partição de biomassa, ganho de carbono e uso da água foi estudada em 10 clones de Coffea canephora. Mudas com quatro pares de folhas, provenientes do enraizamento de estacas de ramos ortotrópicos, foram cultivadas a pleno sol, em vasos de 24 dm3. Quando atingiram oito meses, as plantas foram submetidas a regimes hídricos diferenciais: um grupo de plantas foi irrigado continuamente (plantas-controle), enquanto o segundo grupo (10 plantas de cada clone) foi submetido à desidratação, imposta pela supressão da irrigação, até que a umidade do solo atingisse 66% da água disponível na capacidade de campo, permanecendo nessa condição durante 90 dias (déficit hídrico moderado). Metade das 10 plantas de cada clone foi então analisadas; à outra metade, permitiu-se que a água disponível decrescesse para 33% em relação à disponibilidade hídrica na capacidade de campo, mantendo-se as plantas nessa condição por mais 30 dias, quando foram, pois, avaliadas (déficit hídrico severo). Análises multivariadas com decomposição em componentes principais foram feitas, com o intuito de se avaliar a divergência funcional entre os clones e as possíveis estratégias desenvolvidas, em resposta à disponibilidade de água. De maneira geral, o déficit hídrico acarretou reduções significativas na biomassa acumulada, com incrementos na razão de massa radicular e redução na razão de massa foliar, enquanto a razão de massa caulinar pouco variou, a despeito do aumento expressivo de densidade de caule na grande maioria dos clones avaliados. Nas plantas-controle, maiores taxas fotossintéticas estiveram associadas com maior condutância estomática e maior razão entre as concentrações interna e externa de CO2, mas não se observou correlação significativa entre trocas gasosas com a composição isotópica do carbono. Independentemente do regime hídrico, a composição isotópica do nitrogênio não variou consistentemente, em resposta aos tratamentos aplicados. De modo geral, clones com maior eficiência hidráulica (menor densidade de caule, maior razão de massa radicular, maior taxa de transpiração, maior condutância hidráulica aparente e potenciais hídricos mais negativos) exibiram maior ganho de carbono. Esses mesmos clones tenderam a manter maiores taxas de fotossíntese líquida sob deficiência hídrica moderada, às expensas de maiores taxas do uso da água. Sob déficit hídrico severo, a manutenção parcial das trocas gasosas foi, em grande extensão, dependente de um status hídrico mais favorável associado a características mais conservativas em termos de uso da água. Ressalta-se que, sob seca severa, as reduções nas taxas fotossintéticas ocorreram em paralelo com reduções na condutância estomática, resultando numa correlação negativa entre taxas de fotossíntese e a razão entre as concentrações interna e externa de CO2; como conseqüência, houve uma correlação negativa entre trocas gasosas e a composição isotópica do carbono. Variáveis associadas ao uso da água, como densidade do caule, potencial hídrico ao meio-dia e taxa de transpiração, além da composição isotópica do carbono (sob déficit hídrico), podem ser ferramentas úteis na identificação de clones promissores, em resposta à disponibilidade hídrica, especialmente porque são de fácil medição e exibiram uma amplitude substancial entre os clones. | The functional divergence associated with biomass partitioning, carbon gain and water use was studied in 10 clones of Coffea canephora. Seedlings, raised as rooted stem cuttings, with four leaf pairs were grown under full sunlight in 24 dm3 pots. When 8 months old, the plants were submitted to varying irrigation treatments: a group of plants was watered regularly as needed (control plants); a second group was maintained at 66% field capacity for 90 days (mild water deficit). Half of the plants of each clone were then analyzed, the other half were kept at 33% field condition for more 30 days (severe water deficit). Multivariate analysis was performed in order to evaluate the functional divergence among clones and possible strategies to cope with water deficit. In general, the total biomass was dramatically decreased in droughted plants; this was accompanied by increases in the root mass ratio and decreases in the leaf biomass ratio, whereas only minor, if any, changes in the stem biomass ratio was found, although the stem density having increased significantly in most clones under drought conditions. In control plants, higher photosynthetic rates were associated with higher stomatal conductance and increased internal-to-atmospheric CO2 concentration ratio; however, gas exchange parameters and carbon isotopic composition did not correlate significantly. Regardless of water deficit, nitrogen isotopic composition did not change consistently among the treatments. In general, clones displaying higher hydraulic efficiency (lower stem density, higher root biomass ratio, transpiration rates, apparent hydraulic conductance, and more negative water potentials) showed improved carbon gain. These clones were able to keep higher net photosynthetic rates under mild water deficit at the expense of higher water use. Under severe water deficit, partial maintenance of photosynthetic rates was, to a great extent, dependent on a more favorable leaf water status associated with more conservative traits linked to water use. It should be emphasized that decreases in photosynthesis rates were accompanied by reductions in stomatal conductance under severe drought, resulting in negative correlation between photosynthesis rates and internal-to-atmospheric CO2 concentration ratio; as a result, negative correlation between gas exchange parameters and carbon isotopic composition was observed. Traits associated with water use, such as stem density, midday water potential and transpiration rate, in addition to carbon isotopic composition (under water deficit), could be useful tools for screening promising clones in response to water availability, specially because these traits are easily obtained and showed substantial amplitude among the clones. | Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

El estado de Oaxaca, México, tiene zonas productoras de 'chile de agua' (Capsicum annuum L.) que se diferencian por sus características fisiográficas y agroecológicas. Con el objetivo de generar conocimiento que contribuya a la conservación y mejoramiento genético del potencial productivo de esta especie, en ocho zonas se colectó germoplasma y caracterizó in situ durante 2006 y 2007 bajo un esquema de muestreo completamente aleatorio, con dos localidades por zona y diez plantas por localidad, para lo cual se empleó la guía del Instituto Internacional de Recursos Fitogenéticos. Durante 2008, para disminuir el efecto ambiental, se llevó a cabo una caracterización morfológica ex situ en condiciones de invernadero; para ello las ocho colectas (360 plantas) fueron cultivadas bajo un sistema intensivo en hidroponía, en un diseño experimental completamente al azar; la información se obtuvo de ocho muestreos efectuados cada quince días, en los cuales se identificaron descriptores de raíz, tallo, flor, fruto y semilla, que permitieron diferenciar (selección de variables) las colectas e identificarlas en tres grupos (análisis de agrupamiento de mínima varianza de Ward) y describir las características responsables de la agrupación (análisis de componentes principales). El germoplasma de la zona de Ocotlán, Oaxaca, resultó promisorio para un proceso de mejoramiento genético por presentar los frutos con los caracteres más deseables para el mercado. | Oaxaca state of Mexico has a number of zones with 'water chilli' pepper, (Capsicum annuum L.) which differ in their physiographic and agro-ecological characteristics. With the objective of to generate knowledge that contributes to the conservation and genetic improvement of the productive potential of this species of chilli, in eight zones, germplasm was collected and characterized in situ during 2006 and 2007 under a completely random sampling using two locations and ten plants per location, which used the guide to the International Plant Genetic Resources Institute. To decrease the environmental effect of the collection sites, was carried out ex situ morphological characterization, during 2008, under greenhouse conditions, therefore the eight collections (360 plants) were grown under an intensive system in hydroponics, in a design completely randomized. The information was extracted from eight samples taken every fifteen days. From analysis of variance and covariance were identified descriptors root, stem, flower, fruit and seed, to distinguish collections. In the cluster analysis of cluster (Ward minimum variance) and describe the characteristics of the grouping responsible (principal components analysis) were identified three groups and Ocotlán germplasm as promising for a process of genetic improvement by to present the fruits with the characteristics most desirable for the market.

RESUMO O objetivo deste estudo foi avaliar a qualidade da água e identificar os grupos de poluição presentes no médio Rio Pomba, por meio de técnica estatística multivariada. Duas campanhas no período de out/2008 a jan/2009 foram realizadas em nove pontos georreferenciados, localizados ao longo do médio Rio Pomba, compreendendo a análise de 18 variáveis de qualidade de água. A técnica estatística multivariada por meio da aplicação da análise fatorial/análise de componentes principais promoveu a redução no número de variáveis de qualidade de água, uma vez que o melhor comportamento das variáveis ocorreu com a inclusão de 15 das 18 variáveis analisadas. Pelo emprego da análise fatorial/análise de componentes principais identificou-se que o melhor comportamento das variáveis de qualidade das águas do médio Rio Pomba foi aquele composto por três fatores, explicando 74,30% da variância total. As variações na qualidade da água no médio Rio Pomba foram definidas por um grupo de nutrientes associado ao esgoto doméstico e à poluição difusa; por um grupo orgânico, causado pelo lançamento de esgoto doméstico no curso de água e por um grupo de sólidos em suspensão, expressando o processo de erosão hídrica na bacia. | ABSTRACT The aim of this study was to evaluate the water quality and identify groups of pollution in the Middle Pomba River through multivariate statistical technique. There were two campaigns from Oct/2008 to Jan/2009 in nine geo-referenced points along the Middle Pomba River including the analysis of 18 variables of water quality. The multivariate statistical technique, through the application of factor analysis/principal component analysis, caused a decrease in the number of variables of water quality, since the best performance of the variables occurred with the inclusion of 15 of the 18 variables. By the use of factor analysis/principal components analysis, it was found that the best behavior of the variables of the water quality of the Middle Pomba River waters was the one composed of three factors, explaining 74.30% of the total variance. Changes in water quality of the Middle Pomba River were defined by a group of nutrients associated with sewage and diffused pollution; for an organic group, caused by untreated sewage in the water stream, and by a group of suspended solids, expressing the process of water erosion in the basin.

El valle de Rioverde geográficamente se puede dividir en dos zonas: a) Norte, de aguas sulfatadas cálcicas, clases de agua C4S1 y C5S1 e impotables, se utilizan en la producción de cosechas; b) Sur, de aguas bicarbonatadas cálcicas, clases de agua C1S1, C2S2 y C3S1 y potables, con diferentes posibilidades de uso. Debido a la excelente calidad del agua en la zona sur, se espera que los efectos de un mayor aprovechamiento sean más intensos en esta zona. Considerando lo anterior, el objetivo del trabajo fue reconocer y jerarquizar los factores que influyen en el aprovechamiento del agua subterránea para uso agrícola y sus implicaciones en el abatimiento del nivel freático en la porción sur del valle de Rioverde. El procedimiento de trabajo fue: a) recopilar y analizar información censal y de archivos sobre el aprovechamiento del agua subterránea del valle de Rioverde; b) realizar una encuesta entre agricultores propietarios de pozos. La temática comprendió infraestructura hidráulica, organización, sistemas de cultivo, producción, rentabilidad y comercialización agrícola, crédito y apoyo oficial. La información censal y de archivos se sintetizó en cuadros. La información de la encuesta se analizó mediante análisis multivariable (componentes principales y TWISPAN). Los resultados indican que el aprovechamiento del agua subterránea se puede caracterizar con las variables aplicación del agua y patrón de cultivos. Asimismo, los agricultores se pueden agrupar con base en la aceptación de medidores que regulan la extracción, en la adopción de tecnologías de extracción y aplicación del agua, y en los patrones de cultivos. | The Rioverde valley can be geographically divided in two areas: North, with calcium sulfate water, C4S1 and C5S1 water classes, and undrinkable water, used for crop production, and South, with calcium bicarbonate, C1S1, C2S2 and C3S1 water classes, and drinking water for different possible uses. Due to the excellent water quality in the south, the effects of greater use are expected to be more intense in this area. Considering the above, the objective was to recognize and prioritize the factors influencing the utilization of groundwater for agricultural use and its implications in the depletion of the phreatic level in the south portion of the Rioverde valley. The working procedure was: to collect and analyze census data and files on the use of groundwater at the Rioverde valley, and to do a survey among farmers who own wells. The topics were hydraulic infrastructure, organization, crop systems, production, profitability and agricultural marketing, credit, and government support. Census information and archive data were synthesized in tables. Information from the survey was analyzed using multivariate analysis (principal components and TWISPAN). The results indicate that the use of groundwater can be characterized with the application of water and crop pattern variables. Also, farmers can be grouped based on the acceptance of water meters governing the extraction, on the adoption of technologies for the extraction and application of water, and on crops patterns.

Resumen: El gran deterioro de la calidad del agua causada por la contaminación constituye un importante factor en la pérdida de fuentes de agua en Michoacán. La Ciénega de Chapala es una zona especialmente vulnerable a los procesos de contaminación hídrica, lo que hace necesario evaluar la calidad del agua para proponer soluciones al problema. El objetivo del trabajo fue evaluar la composición química del agua superficial, el origen de los contaminantes y el grado de contaminación de las corrientes y cuerpos de agua en la zona. Para analizar la composición química y bacteriológica del agua, se seleccionaron 16 sitios y se muestreó en tres fechas en ríos, presas, canales y Lago de Chapala. Se usó análisis estadístico multivariado y se calculó un índice de calidad de agua (ICA) para cada sitio y fecha de muestreo. Los resultados mostraron que la concentración de los contaminantes en las aguas superficiales de la Ciénega de Chapala se incrementó aguas abajo. El mayor aumento fue para la conductividad eléctrica (CE), coliformes fecales (CF) y P total. El cambio en las relaciones iónicas Na/Ca y Cl/SO4 aguas abajo indicó una tendencia hacia la composición Na-SO4 de estas aguas. De acuerdo con los valores del ICA calculados, el 44 y 53% de los sitios bajo estudio presentaron buena y moderada calidad de agua, respectivamente. La mejor calidad de agua fue en la zona de ríos y presas con poca influencia de actividades antropogénicas, mientras que la más baja calidad correspondió al Lago de Chapala. Las variables químicas y bacteriológicas que se asociaron significativamente con el ICA fueron la CE, Pb, Cd, B, P y CF; la CE fue la que principalmente se correlacionó con el deterioro de la calidad del agua. En orden de importancia, los drenajes agrícolas y las aguas residuales son las principales fuentes de contaminantes en la zona. | Abstract: The serious deterioration of water quality caused by pollution is an important factor in the loss of water sources in Michoacán. The “Cienega de Chapala” is an especially vulnerable zone in terms of processes of water pollution. The objective of this study was to evaluate the chemical composition of surface water, the causes of pollution, and the degree of contamination that exist in rivers and water bodies of the area. In order to analyze the chemical and bacteriological composition of water, sixteen sampling sites at three different dates were established for testing on rivers, dams, channels network and Lake Chapala. Multivariate statistical analysis was used, and a water quality index (WQI) was calculated for each site and sampling date. The results revealed that the concentration of contaminants of the surface water increased downstream as the sampling sites of rivers, water bodies and channels network neared Lake Chapala; the highest values found were for electrical conductivity (EC), fecal coliforms (FC), and total P. The change in Na/Ca and Cl/SO4 ionic relationships indicates an increasing trend in Na-SO4 composition. According to the WQI calculated values of sites studied, 44 and 53% presented good or moderately good water quality, respectively. The best water quality was in the rivers and dams where the influence of anthropogenic activities is less, while the lowest quality was found in water of Lake Chapala. The chemical and bacteriological parameters that were significantly associated with the WQI were EC, Pb, Cd, B, P and FC; EC was identified as the principal parameter correlated with the deterioration of water quality. In order of importance, agricultural drainage and residual waters are the main sources of pollution in the zone.

La cuenca hidrográfica del Río Bogotá cumple un importante papel en el eje de desarrollo local, como fuente de recursos ecosistémicos y de abastecimiento de la población. Por tanto, el desarrollo de herramientas de evaluación de la calidad del agua en este sistema hídrico constituye un aspecto relevante. El objetivo del presente estudio fue formular un índice de calidad del agua (ICA) mediante análisis de parámetros fisicoquímicos del río Bogotá (Periodo 2010-2020). Para ello, inicialmente fue depurada la base de datos establecida por la red de monitoreo nacional. Posteriormente, se realizó la comparación del ICA establecido por el IDEAM frente a un referente internacional. Finalmente, fue formulada una estrategia para la estimación de la calidad del agua en la cuenca (ICA-Bta), mediante análisis multivariado e indicadores establecidos en los objetivos de calidad del agua (OCA). El análisis de los índices permitió establecer una categoría “Regular” con tendencia a “Mala” para la mayoría de las estaciones, lo cual supone una alta descarga de diversos contaminantes provenientes de vertimientos industriales, domésticos y agropecuarios, que exceden los límites permisibles para aguas superficiales, alterando su comportamiento y dinámica natural. El ICA-Bta integró cuatro parámetros fisicoquímicos adicionales a los comúnmente empleados a nivel nacional, los cuales fueron: cloruros, hierro, coliformes fecales y demanda bioquímica de oxígeno. Este trabajo constituye un aporte al estudio de la variación espacio-temporal de la calidad del agua del río Bogotá, y a la generación de estrategias para facilitar la interpretación de variables monitoreadas por entidades gubernamentales. | Ingeniero Ambiental | Pregrado | The hydrographic basin of the Bogotá River plays an important role in the axis of local development, as a source of ecosystem resources and supply of the population. Therefore, the development of water quality assessment tools in this water system is a relevant aspect. The objective of this study was to formulate a water quality index (ACI) through analysis of physicochemical parameters of the Bogotá River (Period 2010-2020). To this end, the database established by the national monitoring network was initially purged. Subsequently, the ICA established by the IDEAM was compared to an international reference. Finally, a strategy was formulated for the estimation of water quality in the basin (ICA-Bta), through multivariate analysis and indicators established in the water quality objectives (OCA). The analysis of the indices allowed to establish a "Regular" category with a tendency to "Bad" for most seasons, which implies a high discharge of various pollutants from industrial, domestic and agricultural discharges, which exceed the permissible limits for surface waters, altering their behavior and natural dynamics. The ICA-Bta integrated four additional physicochemical parameters to those commonly used at the national level, which were: chlorides, iron, fecal coliforms and biochemical oxygen demand. This work constitutes a contribution to the study of the space-time variation of the water quality of the Bogotá River, and to the generation of strategies to facilitate the interpretation of variables monitored by government entities.

Introduction. The use of biopolymers in effluents treatment allows to control the environmental impact associated with agroindustrial wastewater discharge. Objective. To evaluate the effectiveness of chitosan as a natural coagulant in the treatment of palm oil production effluents. Materials and methods. The following parameters were determined: Chemical Oxygen Demand (COD), total suspended solids (TSS) and volatile solids (TVS), turbidity and fats and oils (GYA) in wastewater associated with palm oil production from the municipality of Agustín Codazzi in the department of Cesar (Colombia), by the jar test assay. Chitosan was applied in doses of: 100, 200, 300, 400, and 0 mg L-1 at three pH levels 4, 5, and 6 of the water. A completely randomized, two-way, fixed effects experimental was implemented. A multivariate analysis of the physical-chemical parameters of industrial effluent was used for data analysis. The study was conducted in 2012. Results. Chitosan allowed a reduction of more than 87 % turbidity, COD, TSS, TVS and fats and oils in all coagulant doses. While the control (0 mg L-1) was statistically different (p<0.05) to all the treatments. In the multivariate analysis of the data, the principal component 1 (PC1) explained 79.3 % of the total variance of the variables. Conclusion. Doses of 100, 200, 300, and 400 mg L-1 of chitosan evaluated as a natural coagulant in water treatment, decreased the concentration of pollutants in effluents associated with palm oil production. | Introducción. El uso de biopolímeros en el tratamiento de efluentes permite controlar el impacto ambiental asociado a la descarga de aguas residuales agroindustriales. Objetivo. Evaluar la efectividad del quitosano como coagulante natural en el tratamiento de efluentes de producción de aceite de palma. Materiales y métodos. Se determinaron los parámetros: demanda química de oxígeno (DQO), los sólidos suspendidos totales (SST) y volátiles (SSV), turbidez y grasas y aceites (GYA) sobre en el agua residual asociada a la producción de aceite de palma proveniente del municipio de Agustín Codazzi en el departamento del Cesar (Colombia), por el ensayo de pruebas de jarras. Se aplicó quitosano en dosis de: 100, 200, 300, 400 y 0 mg L-1 a tres niveles de pH 4, 5 y 6 del agua. Se implementó un diseño experimental completamente aleatorizado, de dos vías, con efectos fijos. Para el análisis de datos se utilizó un análisis multivariado de los parámetros fisicoquímicos del efluente industrial. El estudio se realizó en el año 2012. Resultados. El quitosano permitió reducir más del 87 % de turbidez, DQO, SST, SSV y grasas y aceites en todas las dosis del coagulante, mientras que el control (0 mg L-1) fue diferente estadísticamente (p<0,05) a todos los tratamientos. En el análisis multivariado de los datos, el componente principal 1 (PC1) explicó el 79,3 % de la varianza total de las variables. Conclusión. Dosis de 100, 200, 300 y 400 mg L-1 de quitosano evaluado como coagulante natural en el tratamiento de aguas, disminuyeron la concentración de contaminantes en efluentes asociados a la producción de aceite de palma.

As part of a province-wide groundwater characterization program, a detailed groundwater geochemistry survey was undertaken in the Outaouais Region (Québec, Canada) in order to identify the primary processes responsible for groundwater quality and to develop a conceptual model for groundwater flow and geochemical evolution. During the summers of 2011 and 2012, 139 samples were collected from municipal and private wells which were analysed for major ions, nutrients, trace elements and sulphides. About 70 % of the samples were obtained from bedrock wells, mainly in the silicate rocks of the Canadian Shield and the remainder from wells screened in Quaternary deposit aquifers. Hydrogeochemical facies distributions were determined from 127 of these samples which had anion-cation charge balance errors within ±10 %. The classification by facies was also supported by a multivariate statistical analysis, namely factor analysis combined with hierarchical cluster analysis. The study identified Champlain Sea invasion, cation exchange and freshwater recharge as the main geochemical processes affecting groundwater chemistry in this region. Secondary processes, related to the bedrock geology, are responsible for exceedances of Canadian drinking-water standards, namely for fluoride, uranium, iron and manganese.