Books and Chapters by Jürgen Mahlknecht
Water, energy, and food are essential for human well-being and for sustainable development. Water... more Water, energy, and food are essential for human well-being and for sustainable development. Water is required in almost all types of electricity generation and it is highly consumed in food production. Cities, industry, and crop production have increased their needs for water, energy and land resources, and at the same time, they are facing problems associated with the environmental degradation and, in some regions, resource scarcity. This paper proposes a multiobjective optimization model for the design of a water distribution network from a water− energy−food nexus point of view. Additionally, crop production and cost relationships are integrated to account for the water and energy requirements in the agricultural sector. The economic objective is the maximization of annual gross profit, which accounts for the water, energy and food production; the environmental objective establishes the minimization of overall greenhouse gas emissions, and the social objective is the maximization of the number of jobs. In this paper, because the objectives are opposites, a multistakeholder assessment is proposed in order to analyze and quantify the relationship of the water−energy−food nexus to assess synergies that improve the decision-making process. The mathematical model was applied to a case study located in the Sonoran Desert in Mexico, in which, a series of scenarios were solved to illustrate the capabilities of the proposed optimization approach. The results show strong trade-offs between the considered objectives as well as the quantification of the water−energy−food nexus.
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Environmental Monitoring and Assessment, 2017
The Monterrey metropolitan area (MMA) is the third greatest urban area and the second largest eco... more The Monterrey metropolitan area (MMA) is the third greatest urban area and the second largest economic city of Mexico. More than four million people living in this megacity use groundwater for drinking, industrial and household purposes. Thus, major ion and trace element content were assessed in order to investigate the main hydrochemical properties of groundwater and determine if groundwater of the area poses a threat to the MMA population. Hierarchical cluster analysis using all the groundwater chemical data showed five groups of water. The first two groups were classified as recharge waters (Ca-HCO3) coming from the foothills of mountain belts. The third group was also of Ca-HCO3 water type flowing through lutites and limestones. Transition zone waters of group four (Ca-HCO3-SO4) flow through the valley of Monterrey, whereas discharge waters of group 5 (Ca-SO4) were found toward the north and northeast of the MMA. Principal component analysis performed in groundwater data indicates four principal components (PCs). PC1 included major ions Si, Co, Se, and Zn, suggesting that these are derived by rock weathering. Other trace elements such as As, Mo, Mn, and U are coupled in PC2 because they show redoxsensitive properties. PC3 indicates that Pb and Cu could be the less mobile elements in groundwater. Although groundwater supplied to MMA showed a high-quality, high mineralized waters of group 5 have NO3− concentrations higher than the maximum value proposed by international guidelines and SO42−, NO3−, and total dissolved solid concentrations higher than the maximum levels allowed by the Mexican normative.
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Approximately 80 per cent of the population of Latin America is concentrated in urban centres. Pr... more Approximately 80 per cent of the population of Latin America is concentrated in urban centres. Pressure on water resources and water management in cities therefore provide major challenges. Despite the importance of the issues, there has been little systematic coverage of the topic in book form.
This work fills a gap in the literature by providing both thematic overviews and case study chapters. It reviews key aspects of why water matters in cities and presents case studies on topics such as groundwater management, green growth and water services, inequalities in water supply, the financing of water services and flood management. Detailed examples are described from Argentina, Brazil, Colombia, Ecuador, Mexico and Peru, and there is also a chapter comparing lessons which might be learnt from US cities. Contributing authors are drawn from both within and outside the region, including from the Inter-American Development Bank, OECD and World Bank to set the issues in a global context.
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El agua, como en todo el mundo, juega un papel primordial en la subsistencia y desarrollo de los ... more El agua, como en todo el mundo, juega un papel primordial en la subsistencia y desarrollo de los países latinoamericanos y caribeños. Es importante conocer el estado actual que guarda este recurso en la región como la condición de los cuerpos de agua, la infraestructura hidráulica, la demanda, disponibilidad, gestión, etc. Esta información es primordial ya que contribuye a la correcta planeación y gestión sostenible del recurso hídrico. Por lo tanto, la difusión de este conocimiento es esencial para el progreso de la región y del sector. La presente obra se basa en los objetivos del Centro del Agua para América Latina y el Caribe. Bajo este fundamento, recientemente el centro convocó a expertos en la materia de diferentes países de América Latina y el Caribe para realizar un diagnóstico de la situación hídrica de la región. A su vez, a otro grupo de expertos le fue encomendada la tarea de revisar los documentos a nivel editorial. Fue así que a cada país se le asignó un experto para desarrollar su diagnóstico con la intención de identifi car los principales datos de relevancia hídrica, incluyendo una descripción general y un directorio de los actores principales del sector. Los diagnósticos se estructuraron de acuerdo a ocho secciones generales:
1. Introducción: incluye datos básicos del país como sus aspectos geográficos y demográficos, indicadores económicos, grado de marginación, actividades económicas y huella hídrica.
2. Descripción general: comprende información general del país como su clima, precipitación, cuencas, corrientes principales, acuíferos y la distribución de sus actividades económicas dentro de su territorio.
3. Aguas superfi ciales: abarca la hidrografía del país, así como su infraestructura hidráulica, disponibilidad, red de monitoreo superfi cial y volúmenes superficiales utilizados.
4. Aguas subterráneas: engloba información acerca del nivel de explotación de los acuíferos del país, los volúmenes de agua subterránea utilizados, además de la disponibilidad y red de monitoreo del agua subterránea.
5. Calidad del agua y salud: contiene datos sobre la red de monitoreo superficial y subterránea de la calidad del agua, los resultados del monitoreo, las principales problemáticas del país en cuanto a la calidad del agua y salud, además de normas relacionadas y enfermedades hídricas que se han presentado.
xviii Prefacio
6. Usos del agua: dentro de esta sección se incluyen tópicos relacionados con los diversos usos del agua. Los usos del agua fueron agrupados en: uso urbano, industrial, agrícola, ecosistemas y otros usos.
7. Gestión: esta sección incluye los planes de desarrollo y programas nacionales, la participación de las organizaciones no gubernamentales, así como el marco legal y jurídico del sector, incluyendo las instituciones, normas, leyes y reglamentos vigentes.
8. Inversiones: comprende los planes de inversión del país, además de sus fuentes de financiamiento y los niveles de inversión del sector.
A partir de esta estructura se generaron diagnósticos de 19 países de la región. Además a modo de introducción, se incorporó un texto inicial en el que a manera general se proporciona un panorama del estado de los recursos hídricos del área. Esperamos que este, producto fi nal del proyecto, represente una importante contribución para difundir el conocimiento acerca del sector hídrico en nuestra región.
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Scientific Papers by Jürgen Mahlknecht
The Sierra Madre Oriental (SMO) is composed of ranges with important regional geological structur... more The Sierra Madre Oriental (SMO) is composed of ranges with important regional geological structures in highly fractured carbonate rocks (Abra Formation), which facilitate the recharge of aquifers. At the regional scale, recharge occurs in the western SMO and locally, in ranges such as Palmillas, La Colmena and Abra, while the regional discharge is to the east in the Huasteca zone. Intermountain valleys, such as El Salto, are located near the regional discharge zone. Three end members were identified in these regions, one related to local flow, another to intermediate and a third to regional flow. These flows define ternary mixing processes in groundwater. In this paper, the evolution of groundwater is studied, which is important for learning the system performance and hydrogeochemical processes through VISHMOD (Virtual Samples in Hydrochemical Modeling) methodology. The mixing model for the intermountain valleys indicates that many recharges occur, for which local flow contributes 68.3%, intermediate flow 12.3% and regional flow 19.4%. The inverse modeling shows that the water-rock interaction, precipitation and/or dissolution of calcite, gypsum and dolomite are the main processes occurring in the aquifer system of the intermountain valleys.
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With the increasing population, urbanization and industry in the arid area of Tecate, there is a ... more With the increasing population, urbanization and industry in the arid area of Tecate, there is a concomitant increase in contaminants being introduced into the Tecate River and its aquifer. This contamination is damaging the usable groundwater supply and making local residents and commercial enterprises increasingly dependent on imported water from the Colorado River basin. In this study we apply a suite of chemical and isotopic tracers in order to evaluate groundwater flow and assess contamination trends. Groundwater recharge occurs through mountain-block and mountain-front recharge at higher elevations of the ranges. Groundwater from the unconfined, alluvial aquifer indicates recent recharge and little evolution. The increase in salinity along the flow
path is due to interaction with weathering rock-forming silicate minerals and anthropogenic sources such as urban wastewater, residual solids and agricultural runoff from fertilizers, livestock manure and/or septic tanks and latrines. A spatial analysis shows local differences and the impact of the infiltration of imported waters from the Colorado River basin. The general trend of impaired water quality has scarcely been documented in the last decades, but it is expected to continue. Since the
groundwater system is highly vulnerable, it is necessary to protect groundwater sources.
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This study addresses the changes in dissolved major and trace element concentrations along the Or... more This study addresses the changes in dissolved major and trace element concentrations along the Orinoco River, including the mixing zone between the Orinoco and Apure Rivers. Water samples from the Apure and Orinoco Rivers were collected monthly in four sectors over a period of 15 months. Auxiliary parameters (pH, dissolved oxygen, conductivity, and temperature), total suspended sediments, dissolved organic carbon (DOC), and major (Na, K, Ca, Mg, and Si) and trace (Al, Fe, Mn, Zn, Cu, and Cr) element concentrations were measured in all sectors. The relative contribution of both rivers after the Apure–Orinoco confluence was determined using Ca as a tracer. Moreover, a mixing model was developed to determine whether dissolved species exhibit a conservative behavior during mixing. The results indicate that DOC is removed from waters during the Apure–Orinoco mixing, probably due to absorption of DOC on mineral phases supplied by the Apure River. Dissolved Na, Ca, and Mg behave conservatively during the mixing processes, and their concentrations are controlled by a dilution process. The anomaly in the temporal pattern of K in the Orinoco is caused by the input of biogenic K originating from the Apure River during the high‐water stage. The loss of dissolved Si during the low‐water stage can be explained by the uptake of Si by diatoms. Dissolved Mn, Zn, Al, and Fe showed a non‐conservative behavior during the Apure–Orinoco mixing. The removal of Mn and Zn from the dissolved phase can be explained by the formation of Mn‐oxyhydroxides and the scavenging of Zn onto Mn oxides. Dissolved Fe is controlled by redox processes, although the removals of Fe and Al due to the preferential adsorp-tion of large organometallic complexes by mineral surfaces after the Apure–Orinoco confluence can affect the mobility of both elements during transport. The conservative behavior shown by Cu and Cr can be related to the tendency of both elements to be complexed with small organic colloids, which are not preferentially adsorbed by clays.
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This study addresses the changes in dissolved major and trace element concentrations along the Or... more This study addresses the changes in dissolved major and trace element concentrations along the Orinoco River, including the mixing zone between the Orinoco and Apure Rivers. Water samples from the Apure and Orinoco Rivers were collected monthly in four sectors over a period of 15 months. Auxiliary parameters (pH, dissolved oxygen, conductivity, and temperature), total suspended sediments, dissolved organic carbon (DOC), and major (Na, K, Ca, Mg, and Si) and trace (Al, Fe, Mn, Zn, Cu, and Cr) element concentrations were measured in all sectors. The relative contribution of both rivers after the Apure–Orinoco confluence was determined using Ca as a tracer. Moreover, a mixing model was developed to determine whether dissolved species exhibit a conservative behavior during mixing. The results indicate that DOC is removed from waters during the Apure–Orinoco mixing, probably due to absorption of DOC on mineral phases supplied by the Apure River. Dissolved Na, Ca, and Mg behave conservatively during the mixing processes, and their concentrations are controlled by a dilution process. The anomaly in the temporal pattern of K in the Orinoco is caused by the input of biogenic K originating from the Apure River during the high‐water stage. The loss of dissolved Si during the low‐water stage can be explained by the uptake of Si by diatoms. Dissolved Mn, Zn, Al, and Fe showed a non‐conservative behavior during the Apure–Orinoco mixing. The removal of Mn and Zn from the dissolved phase can be explained by the formation of Mn‐oxyhydroxides and the scavenging of Zn onto Mn oxides. Dissolved Fe is controlled by redox processes, although the removals of Fe and Al due to the preferential adsorp-tion of large organometallic complexes by mineral surfaces after the Apure–Orinoco confluence can affect the mobility of both elements during transport. The conservative behavior shown by Cu and Cr can be related to the tendency of both elements to be complexed with small organic colloids, which are not preferentially adsorbed by clays.
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Mexico is exposed to droughts and vulnerable to their impacts. Despite a history of serious econo... more Mexico is exposed to droughts and vulnerable to their impacts. Despite a history of serious economic and social consequences from drought, until recently national water policy did not acknowledge this type of natural disaster as a priority issue. This paper analyses how drought policy in Mexico has evolved since the creation of the National Water Commission in 1989 up to 2013, when the most specific initiative in that regard was introduced: the National Drought Program (Programa Nacional Contra la Sequía, PRONACOSE). Over that period of time drought has slowly but steadily gained importance in national water planning and management. Significant initiatives have been implemented, including a national drought early warning and monitoring system. Nevertheless, efforts still focus on compensating economic losses after the fact and little has been achieved in terms of reducing the country's vulnerability to drought. There is a great need to increase public awareness and boost the scientific knowledge necessary for the design of appropriate preventive measures. A long way remains to establish an effective , forward-looking, integrated and preventive drought management model.
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Groundwater from the La Paz arid coastal aquifer in Baja California, Mexico, is essentially the o... more Groundwater from the La Paz arid coastal aquifer in Baja California, Mexico, is essentially the only source of drinking water for the local population and tourists, as well as irrigation water for agricultural needs. The intensive exploitation of the aquifer and water cycling has resulted in groundwater abatement (up to 10 m) and high salinity (up to *5800 mg l-1 ). A study using hydrochemistry, isotopic (deuterium, oxygen-18 and car- bon-14) and gaseous tracers (chlorofluorocarbons CFC-11, CFC-12, CFC-113), as well as multivariate statistics, was developed to elucidate groundwater composition, flow and occurrence. Groundwater is of meteoric origin, and a large proportion is subject to evaporation. The primary natural recharge is generated in the El Novillo and Las Cruces ranges, and groundwater subsequently flows in a SE–NW direction toward the coast. The initial water type is the result of discordant dissolution of silicate minerals and ion exchange on soils. In the lower plain portion, the aquifer system is recharged from irrigation return flow and sea- water intrusion, which significantly affects groundwater chemistry. Nitrate and chloride concentrations indicate that groundwater is highly affected by an overuse of fertilizers in agricultural activities, but there is little effect from urban activities. Seawater intrusion has progressed rapidly during the past decade, and the impact currently extends 13 km inland. Radiocarbon residence time calculations suggest that groundwater is modern, with the exception of Cha- metla and El Centerario sites in the central and western lowlands with ages of up to 5000 years. These waters indicate an additional recharge source for the upconing of fossil groundwater or regional flow.
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Groundwater chemistry and isotopic data from 40 production wells in the Atemajac and Toluquilla v... more Groundwater chemistry and isotopic data from 40 production wells in the Atemajac and Toluquilla valleys, located in and around the Guadalajara metropolitan area, were determined to develop a conceptual model of groundwater flow processes and mixing. Stable water isotopes (δ2H, δ18O) were used to trace hydrological processes and tritium (3H) to evaluate the relative contribution of modern water in samples. Multivariate analysis including cluster analysis and principal component analysis were used to elucidate distribution patterns of constituents and factors controlling groundwater chemistry. Based on this analysis, groundwater was classified into four groups: cold groundwater, hydrothermal groundwater, polluted groundwater and mixed groundwater. Cold groundwater is characterized by low temperature, salinity, and Cl and Na concentrations and is predominantly of Na-HCO3-type. It originates as recharge at "La Primavera" caldera and is found predominantly in wells in the upper Atemajac Valley. Hydrothermal groundwater is characterized by high salinity, temperature, Cl, Na and HCO3, and the presence of minor elements such as Li, Mn and F. It is a mixed-HCO3 type found in wells from Toluquilla Valley and represents regional flow circulation through basaltic and andesitic rocks. Polluted groundwater is characterized by elevated nitrate and sulfate concentrations and is usually derived from urban water cycling and subordinately from agricultural return flow. Mixed groundwaters between cold and hydrothermal components are predominantly found in the lower Atemajac Valley. Twenty-seven groundwater samples contain at least a small fraction of modern water. The application of a multivariate mixing model allowed the mixing proportions of hydrothermal fluids, polluted waters and cold groundwater in sampled water to be evaluated. This study will help local water authorities to identify and dimension groundwater contamination, and act accordingly. It may be broadly applicable to other active volcanic systems on Earth.
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In this work, the biocatalytic ability of laccases from filtered culture supernatant of Pycnoporu... more In this work, the biocatalytic ability of laccases from filtered culture supernatant of Pycnoporus sanguineus was evaluated without mediators and under mild reaction conditions. This 100 U L −1 laccase cocktail removed 50% Diclofenac, 97% β-Naphthol and 71% 2,4 Dichlorophenol within 8 h of reaction and 78% for 5,7-Diiodo-8-hydroxyquinoline within 3.5 h; at initial concentrations of 10 mg L−1 and at 25 °C. Furthermore, this enzyme cocktail also removed in excess of 53% all tested compounds in a real groundwater sample from northwestern Mexico. In comparison with purified laccases, the use of cocktail offers operational advantages since additional purification steps can be avoided.
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The biodegradation of organic compounds present in water at trace concentration has become a crit... more The biodegradation of organic compounds present in water at trace concentration has become a critical environmental problem. In particular, enzymatic oxidation by fungal laccases offers a promising alternative for efficient and sustainable removal of organic pollutants in water. In this work, the biocatalytic ability of laccases from the Pycnoporus sanguineus CS43 fungus was evaluated. A filtered culture supernatant
(laccase cocktail) evidenced an enhanced biotransformation capability to remove common endocrinedisruptor compounds (EDCs), such as bisphenol A, 4-nonylphenol, 17-α ethynylestradiol and triclosan. A biodegradation of around 89–100 % was achieved for all EDCs using synthetic samples (10 mg L−1) and after the enzymatic treatment with 100 U L−1 (50.3 U mg −1). The biodegradation rates obtained were fitted to a first
order reaction. Furthermore, enzymatic biocatalytic activity was also evaluated in groundwater samples coming from northwestern Mexico, reaching biotransformation percentages between 55 and 93 % for all tested compounds. As far as we know this is the first study on real groundwater samples in which the enzymatic degradation of target EDCs by a laccase cocktail from any strain of Pycnoporus sanguineus was evaluated. In comparison with purified laccases, the use of cocktail offers operational advantages since additional purification steps can be avoided.
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Zona Citrícola is an important area for Mexico due to its citriculture activity. Situated in a su... more Zona Citrícola is an important area for Mexico due to its citriculture activity. Situated in a sub-humid to humid climate adjacent to the Sierra Madre Oriental, this valley hosts an aquifer system that represents sequences of shales, marls, conglomerates, and alluvial deposits. Groundwater flows from mountainous recharge areas to the basin-fill deposits and provides base flows to supply drinking water to the adjacent metropolitan area of Monterrey. Recent studies examining the groundwater quality of the study area urge the mitigation of groundwater pollution. The objective of this study was to characterize the physical and chemical properties of the groundwater and to assess the processes controlling the groundwater’s chemistry. Correlation was used to identify associations among various geochemical constituents. Factor analysis was applied to identify the water’s chemical characteristics that were responsible for generating most of he variability within the dataset. Hierarchical cluster analysis was employed in combination with a post-hoc analysis of variance to partition the water samples into hydrochemical water groups: recharge waters (CaHCO3), transition zone waters (Ca-HCO3-SO4 to Ca-SO4-HCO3) and discharge waters (CaSO4). Inverse geochemical models of these groups were developed and constrained using PHREEQC to elucidate the chemical reactions controlling the water’s chemistry between an initial (recharge) and final water. The primary reactions contributing to salinity were the following: (1) water-rock interactions, including the weathering of evaporitic rocks and dedolomitization; (2) dissolution of soil gas carbon dioxide; and (3) input from animal/human wastewater and manure in combination with by denitrification processes. Contributions from silicate weathering to salinity ranged from less important to insignificant. The findings suggest that it may not be cost-effective to regulate manure application to mitigate groundwater pollution.
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Renewable and Sustainable Energy Reviews, Apr 1, 2014
Mexico ranks 9th in the world in crude oil reserves, 4th in natural gas reserves in America and i... more Mexico ranks 9th in the world in crude oil reserves, 4th in natural gas reserves in America and it is also highly rich in renewable energy sources (solar, wind, biomasss, hydropower and geothermal). However, the potential of this type of energy has not been fully exploited. Hydropower is the renewable energy source with the highest installed capacity within the country (11,603 MW), while geothermal power capacity (958 MW) makes Mexico to be ranked 4th in the use of this energy worldwide. Wind energy potential is concentrated in five different zones, mainly in the state of Oaxaca, and solar energy has a high potential due to Mexico's ideal location in the so called Solar Belt. Biomass energy has the highest potential (2635 to 3771 PJ/year) and has been the subject of the highest number of research publications in the country during the last 30 years (1982–2012). Universidad Nacional Autonoma de Mexico has led research publications in hydropower, wind, solar and biomass energy and Instituto de Investigaciones Electricas in geothermal energy during this period. According to the General Law for Climate Change the country has set the goal of generating 35% of its energy needs from renewable sources by 2024. This paper presents an overview of the renewable energy options available in Mexico, current status, main positive results to date and future potential. It also analyses barriers hindering improvements and proposes pertinent solutions.
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Science of the Total Environment, 2014
Nitrate isotopic values are often used as a tool to understand sources of contamination in order ... more Nitrate isotopic values are often used as a tool to understand sources of contamination in order to effectively
manage groundwater quality. However, recent literature describes that biogeochemical reactions may modify
these values. Therefore, data interpretation is difficult and often vague. We provide a discussion on this topic
and complement the study using halides as comparative tracers assessing an aquifer underneath a sub-humid
to humid region in NE Mexico. Hydrogeological information and stable water isotopes indicate that active
groundwater recharge occurs in the 8000km2 study area under present-day climatic and hydrologic conditions.
Nitrate isotopes and halide ratios indicate a diverse mix of nitrate sources and transformations. Nitrate sources
include organic waste and wastewater, synthetic fertilizers and soil processes. Animal manure and sewage
from septic tanks were the causes of groundwater nitrate pollution within orchards and vegetable agriculture.
Dairy activities within a radius of 1000m from a sampling point significantly contributed to nitrate pollution.
Leachates from septic tanks caused nitrate pollution in residential areas. Soil nitrogen and animal waste were
the sources of nitrate in groundwater under shrubland and grassland. Partial denitrification processes helped
to attenuate nitrate concentration underneath agricultural lands and grassland, especially during summer
months.
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Environmental Earth Sciences, 2011
Chemical compositions and stable isotope ratios of water and sulphate were used to characterise s... more Chemical compositions and stable isotope ratios of water and sulphate were used to characterise sources and processes responsible for elevated concentrations of sulphate and other constituents in groundwater from aquifers at Colima State along Mexico’s Pacific Coast. The δ18O and δ2H values of the groundwater were similar to those of precipitation indicating a meteoric origin, and recharge processes are relatively uniform in large parts of the study area with only slight local evaporation effects. δ34Ssulphate and δ18Osulphate analyses indicated that high sulphate concentrations of up to 1,480 mg/l are mainly due to dissolution of evaporites and volcanic exhalations. Chloride is largely related to sources other than seawater. The Marabasco sub basin is affected by anthropogenic contamination through manganese and iron ore mining activities. The obtained knowledge regarding sources and areas of contamination will be essential for the development and design of a water quality monitoring program in the study area.
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National Groundwater Association Summit 2013 Abstracts, Apr 29, 2013
We used environmental tracers (CFCs, 18O, 2H, 3H, 14C, and water chemistry) to analyze the ground... more We used environmental tracers (CFCs, 18O, 2H, 3H, 14C, and water chemistry) to analyze the groundwater quality and flow system underlying and supplying part of the Metropolitan Area of Guadalajara, México. Most of the samples showed isotopic signatures, indicating recharge from local meteoric precipitation. Significant tritium concentrations were interpreted as a clear sign that groundwater was a mixture from water prior to 1952 and post 1960, which indicates that precipitation from the last years contributed significantly to groundwater recharge. CFCs revealed apparent recharge from 1960 to 1980. 14C results indicated groundwater aging approximately between 10,000 and 12,000 for the northern portion (Atemajac), and >20,000 years BP for the southern portion (Toluquilla). Comparison of CFCs, 3H and 14C concentrations proves that the samples are a mixture of waters from different ages. Additionally, zones with aquifer temperatures higher than 30°C were identified, suggesting the presence of chemical elements associated to geothermal sources.
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Books and Chapters by Jürgen Mahlknecht
This work fills a gap in the literature by providing both thematic overviews and case study chapters. It reviews key aspects of why water matters in cities and presents case studies on topics such as groundwater management, green growth and water services, inequalities in water supply, the financing of water services and flood management. Detailed examples are described from Argentina, Brazil, Colombia, Ecuador, Mexico and Peru, and there is also a chapter comparing lessons which might be learnt from US cities. Contributing authors are drawn from both within and outside the region, including from the Inter-American Development Bank, OECD and World Bank to set the issues in a global context.
1. Introducción: incluye datos básicos del país como sus aspectos geográficos y demográficos, indicadores económicos, grado de marginación, actividades económicas y huella hídrica.
2. Descripción general: comprende información general del país como su clima, precipitación, cuencas, corrientes principales, acuíferos y la distribución de sus actividades económicas dentro de su territorio.
3. Aguas superfi ciales: abarca la hidrografía del país, así como su infraestructura hidráulica, disponibilidad, red de monitoreo superfi cial y volúmenes superficiales utilizados.
4. Aguas subterráneas: engloba información acerca del nivel de explotación de los acuíferos del país, los volúmenes de agua subterránea utilizados, además de la disponibilidad y red de monitoreo del agua subterránea.
5. Calidad del agua y salud: contiene datos sobre la red de monitoreo superficial y subterránea de la calidad del agua, los resultados del monitoreo, las principales problemáticas del país en cuanto a la calidad del agua y salud, además de normas relacionadas y enfermedades hídricas que se han presentado.
xviii Prefacio
6. Usos del agua: dentro de esta sección se incluyen tópicos relacionados con los diversos usos del agua. Los usos del agua fueron agrupados en: uso urbano, industrial, agrícola, ecosistemas y otros usos.
7. Gestión: esta sección incluye los planes de desarrollo y programas nacionales, la participación de las organizaciones no gubernamentales, así como el marco legal y jurídico del sector, incluyendo las instituciones, normas, leyes y reglamentos vigentes.
8. Inversiones: comprende los planes de inversión del país, además de sus fuentes de financiamiento y los niveles de inversión del sector.
A partir de esta estructura se generaron diagnósticos de 19 países de la región. Además a modo de introducción, se incorporó un texto inicial en el que a manera general se proporciona un panorama del estado de los recursos hídricos del área. Esperamos que este, producto fi nal del proyecto, represente una importante contribución para difundir el conocimiento acerca del sector hídrico en nuestra región.
Scientific Papers by Jürgen Mahlknecht
path is due to interaction with weathering rock-forming silicate minerals and anthropogenic sources such as urban wastewater, residual solids and agricultural runoff from fertilizers, livestock manure and/or septic tanks and latrines. A spatial analysis shows local differences and the impact of the infiltration of imported waters from the Colorado River basin. The general trend of impaired water quality has scarcely been documented in the last decades, but it is expected to continue. Since the
groundwater system is highly vulnerable, it is necessary to protect groundwater sources.
(laccase cocktail) evidenced an enhanced biotransformation capability to remove common endocrinedisruptor compounds (EDCs), such as bisphenol A, 4-nonylphenol, 17-α ethynylestradiol and triclosan. A biodegradation of around 89–100 % was achieved for all EDCs using synthetic samples (10 mg L−1) and after the enzymatic treatment with 100 U L−1 (50.3 U mg −1). The biodegradation rates obtained were fitted to a first
order reaction. Furthermore, enzymatic biocatalytic activity was also evaluated in groundwater samples coming from northwestern Mexico, reaching biotransformation percentages between 55 and 93 % for all tested compounds. As far as we know this is the first study on real groundwater samples in which the enzymatic degradation of target EDCs by a laccase cocktail from any strain of Pycnoporus sanguineus was evaluated. In comparison with purified laccases, the use of cocktail offers operational advantages since additional purification steps can be avoided.
manage groundwater quality. However, recent literature describes that biogeochemical reactions may modify
these values. Therefore, data interpretation is difficult and often vague. We provide a discussion on this topic
and complement the study using halides as comparative tracers assessing an aquifer underneath a sub-humid
to humid region in NE Mexico. Hydrogeological information and stable water isotopes indicate that active
groundwater recharge occurs in the 8000km2 study area under present-day climatic and hydrologic conditions.
Nitrate isotopes and halide ratios indicate a diverse mix of nitrate sources and transformations. Nitrate sources
include organic waste and wastewater, synthetic fertilizers and soil processes. Animal manure and sewage
from septic tanks were the causes of groundwater nitrate pollution within orchards and vegetable agriculture.
Dairy activities within a radius of 1000m from a sampling point significantly contributed to nitrate pollution.
Leachates from septic tanks caused nitrate pollution in residential areas. Soil nitrogen and animal waste were
the sources of nitrate in groundwater under shrubland and grassland. Partial denitrification processes helped
to attenuate nitrate concentration underneath agricultural lands and grassland, especially during summer
months.
This work fills a gap in the literature by providing both thematic overviews and case study chapters. It reviews key aspects of why water matters in cities and presents case studies on topics such as groundwater management, green growth and water services, inequalities in water supply, the financing of water services and flood management. Detailed examples are described from Argentina, Brazil, Colombia, Ecuador, Mexico and Peru, and there is also a chapter comparing lessons which might be learnt from US cities. Contributing authors are drawn from both within and outside the region, including from the Inter-American Development Bank, OECD and World Bank to set the issues in a global context.
1. Introducción: incluye datos básicos del país como sus aspectos geográficos y demográficos, indicadores económicos, grado de marginación, actividades económicas y huella hídrica.
2. Descripción general: comprende información general del país como su clima, precipitación, cuencas, corrientes principales, acuíferos y la distribución de sus actividades económicas dentro de su territorio.
3. Aguas superfi ciales: abarca la hidrografía del país, así como su infraestructura hidráulica, disponibilidad, red de monitoreo superfi cial y volúmenes superficiales utilizados.
4. Aguas subterráneas: engloba información acerca del nivel de explotación de los acuíferos del país, los volúmenes de agua subterránea utilizados, además de la disponibilidad y red de monitoreo del agua subterránea.
5. Calidad del agua y salud: contiene datos sobre la red de monitoreo superficial y subterránea de la calidad del agua, los resultados del monitoreo, las principales problemáticas del país en cuanto a la calidad del agua y salud, además de normas relacionadas y enfermedades hídricas que se han presentado.
xviii Prefacio
6. Usos del agua: dentro de esta sección se incluyen tópicos relacionados con los diversos usos del agua. Los usos del agua fueron agrupados en: uso urbano, industrial, agrícola, ecosistemas y otros usos.
7. Gestión: esta sección incluye los planes de desarrollo y programas nacionales, la participación de las organizaciones no gubernamentales, así como el marco legal y jurídico del sector, incluyendo las instituciones, normas, leyes y reglamentos vigentes.
8. Inversiones: comprende los planes de inversión del país, además de sus fuentes de financiamiento y los niveles de inversión del sector.
A partir de esta estructura se generaron diagnósticos de 19 países de la región. Además a modo de introducción, se incorporó un texto inicial en el que a manera general se proporciona un panorama del estado de los recursos hídricos del área. Esperamos que este, producto fi nal del proyecto, represente una importante contribución para difundir el conocimiento acerca del sector hídrico en nuestra región.
path is due to interaction with weathering rock-forming silicate minerals and anthropogenic sources such as urban wastewater, residual solids and agricultural runoff from fertilizers, livestock manure and/or septic tanks and latrines. A spatial analysis shows local differences and the impact of the infiltration of imported waters from the Colorado River basin. The general trend of impaired water quality has scarcely been documented in the last decades, but it is expected to continue. Since the
groundwater system is highly vulnerable, it is necessary to protect groundwater sources.
(laccase cocktail) evidenced an enhanced biotransformation capability to remove common endocrinedisruptor compounds (EDCs), such as bisphenol A, 4-nonylphenol, 17-α ethynylestradiol and triclosan. A biodegradation of around 89–100 % was achieved for all EDCs using synthetic samples (10 mg L−1) and after the enzymatic treatment with 100 U L−1 (50.3 U mg −1). The biodegradation rates obtained were fitted to a first
order reaction. Furthermore, enzymatic biocatalytic activity was also evaluated in groundwater samples coming from northwestern Mexico, reaching biotransformation percentages between 55 and 93 % for all tested compounds. As far as we know this is the first study on real groundwater samples in which the enzymatic degradation of target EDCs by a laccase cocktail from any strain of Pycnoporus sanguineus was evaluated. In comparison with purified laccases, the use of cocktail offers operational advantages since additional purification steps can be avoided.
manage groundwater quality. However, recent literature describes that biogeochemical reactions may modify
these values. Therefore, data interpretation is difficult and often vague. We provide a discussion on this topic
and complement the study using halides as comparative tracers assessing an aquifer underneath a sub-humid
to humid region in NE Mexico. Hydrogeological information and stable water isotopes indicate that active
groundwater recharge occurs in the 8000km2 study area under present-day climatic and hydrologic conditions.
Nitrate isotopes and halide ratios indicate a diverse mix of nitrate sources and transformations. Nitrate sources
include organic waste and wastewater, synthetic fertilizers and soil processes. Animal manure and sewage
from septic tanks were the causes of groundwater nitrate pollution within orchards and vegetable agriculture.
Dairy activities within a radius of 1000m from a sampling point significantly contributed to nitrate pollution.
Leachates from septic tanks caused nitrate pollution in residential areas. Soil nitrogen and animal waste were
the sources of nitrate in groundwater under shrubland and grassland. Partial denitrification processes helped
to attenuate nitrate concentration underneath agricultural lands and grassland, especially during summer
months.