Browsing by Autor "Lorenzo Spadini"

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Assessment of the Sulfamethoxazole mobility in natural soils and of the risk of contamination of water resources at the catchment scale
(Elsevier BV, 2019) Denisse Archundia; Céline Duwig; Lorenzo Spadini; Marie‐Christine Morel; B. Prado; Mayra Pérez; Vladimir Orsag; Jean Martins
Sulfamethoxazole (SMX) is one of the antibiotics most commonly detected in aquatic and terrestrial environments and is still widely used, especially in low income countries. SMX is assumed to be highly mobile in soils due to its intrinsic molecular properties. Ten soils with contrasting properties and representative of the catchment soil types and land uses were collected throughout the watershed, which undergoes very rapid urban development. SMX displacement experiments were carried out in repacked columns of the 10 soils to explore SMX reactive transfer (mobility and reactivity) in order to assess the contamination risk of water resources in the context of the Bolivian Altiplano. Relevant sorption processes were identified by modelling (HYDRUS-1D) considering different sorption concepts. SMX mobility was best simulated when considering irreversible sorption as well as instantaneous and rate-limited reversible sorption, depending on the soil type. SMX mobility appeared lower in soils located upstream of the watershed (organic and acidic soils - Regosol) in relation with a higher adsorption capacity compared to the soils located downstream (lower organic carbon content - Cambisol). By combining soil column experiments and soil profiles description, this study suggests that SMX can be classified as a moderately to highly mobile compound in the studied watershed, depending principally on soil properties such as pH and OC. Potential risks of surface and groundwater pollution by SMX were thus identified in the lower part of the studied catchment, threatening Lake Titicaca water quality.
Functionning of the Katari-Lago Menor Basin aquifer, Lake Titicaca-Bolivia, inferred from geophysical, hydrogeological and geochemical data
(2020) Céline Duwig; Gabriela Flores; Marc Descloîtres; Yvan Rossier; Lorenzo Spadini; Anatoly Legtchenko; Álvaro Soruco; Jaime Argollo; Mayra Pérez; Waldo Medinacelli
&lt;p&gt;The population of the semi-arid Bolivian Northern Altiplano depends greatly on groundwater resources, surface water being intermittent and often contaminated by human activities. The aim of this study is to provide a first insight into the hydrogeological structure and groundwater dynamics of the Katari-Lago Menor Basin aquifer located between the Eastern Cordillera and Lake Titicaca, Bolivia. Resistivity profiles combined with geology, borehole lithology, topography as well as additional groundwater level and geochemical measurements, were helpful in resolving the spatial limits of the aquifer, the vertical and lateral continuity of the Quaternary porous geologic media, the shape and position of the bottom of the aquifer (depth to the bedrock, i.e. Tertiary or Devonian Formations), and revealed a general overview of the natural dynamic behaviour of the aquifer at the scale of the Katari and Lago Menor Basin. The quaternary sediments are hydraulically connected and behave as a single regional basin-aquifer. The main groundwater flow system starts in the upper Piedmont (high mountain ranges of the Eastern Cordillera) and follows the topographic Piedmont gradient (NE to SW). Most groundwater recharge results from the infiltration of precipitation and runoff on the high mountain ranges. Indeed, groundwater circulating in the upper and lower Piedmont layers present primarily &amp;#160;facies. In the regions of the lower Piedmont urbanized areas, groundwater presenting &amp;#160;facies, show a noticeable enrichment of sulphate and chloride relating mainly anthropogenic contamination (mining and urban nature). A large portion of the aquifer presents an unconfined behaviour whereas it remains confined below the Ulloma Formation. The thickness of the unconfined portion varies from 50 to 150 meters and that of the confined from 100 to 150 meters. Values of hydraulic conductivity for the unconfined portion range from 1.1&amp;#215;10&lt;sup&gt;-4&lt;/sup&gt; m s&lt;sup&gt;-1&lt;/sup&gt; (alluvial fan deposit), 2.5&amp;#215;10&lt;sup&gt;-6 &lt;/sup&gt;m s&lt;sup&gt;-1&lt;/sup&gt; (fluvioglacial deposits,) to 5.9&amp;#215;10&lt;sup&gt;-8 &lt;/sup&gt;m s&lt;sup&gt;-1&lt;/sup&gt; (glacial deposits), while for the confined part transmissivity values range around 6.0&amp;#215;10&lt;sup&gt;-6&lt;/sup&gt;&amp;#160; m&lt;sup&gt;2&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt; (paleo-lacustrine deposits).&lt;/p&gt;&lt;p&gt;&amp;#160;This multidisciplinary approach proved to be an appropriate method to derive a consistent picture of the hydrogeological functioning of the Katari-Lago Menor Basin aquifer.&lt;/p&gt;
How Uncontrolled Urban Expansion Increases the Contamination of the Titicaca Lake Basin (El Alto, La Paz, Bolivia)
(Springer Science+Business Media, 2016) Denisse Archundia; Céline Duwig; Lorenzo Spadini; Gaëlle Uzu; Stéphane Guédron; Marie‐Christine Morel; R. Cortez; Oswaldo Ramos Ramos; J. Chincheros; Jean Martins
Hydrogeochemical and nitrate isotopic evolution of a semiarid mountainous basin aquifer of glacial-fluvial and paleolacustrine origin (Lake Titicaca, Bolivia): the effects of natural processes and anthropogenic activities
(Springer Science+Business Media, 2022) Gabriela Patricia Flores Avilés; Lorenzo Spadini; Elisa Sacchi; Yvan Rossier; Joël Savarino; Oswaldo Eduardo Ramos Ramos; Céline Duwig
Hydrogeochemical and nitrate isotopic indicators of vulnerability in the Katari-Lago Menor basin-aquifer, Lake Titicaca-Bolivia
(2021) Gabriela Patricia Flores Avilés; Céline Duwig; Elisa Sacchi; Lorenzo Spadini; Joël Savarino; Oswaldo Eduardo Ramos Ramos
&lt;p&gt;In the semi-arid Bolivian Altiplano, the Katari and Lago Menor Basin, ranging between 6000 and 3800 m a.s.l. in altitude, hosts a major aquifer in Quaternary sediments of fluvioglacial and paleolacustrine origin. This basin supports a population of over 1.2 million of inhabitants and the largest city in the Altiplano, El Alto, one of the Latin America&amp;#8217;s fastest growing cities in the 1980s. This rapid urban growth was accompanied by minimal land planning, and lack of basic infrastructure and environmental policies. In addition, the region is greatly affected by climate change, causing the glaciers to shrink. A multi-tracer approach was used to understand the main hydrogeochemical processes taking place along the groundwater flow, and to evaluate the impact of anthropogenic activities on groundwater quality and nitrate concentrations. In the upper part of the aquifer (above 4000m), in the Piedmont subsystem, siliciclastic and evaporitic rocks host groundwater of high quality. Here, groundwater chemistry is dominated by silicate weathering leading to a Ca(Mg)-HCO&lt;sub&gt;3&lt;/sub&gt; facies, low nitrate concentrations (&lt;3.2 mgL&lt;sup&gt;-1&lt;/sup&gt;), and low mineralization. At lower altitude, the anthropogenic impact is revealed by the increase in NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; concentrations, reaching up to 35.6 mg L&lt;sup&gt;-1&lt;/sup&gt;.&amp;#160; Nitrate stable isotopes allowed discriminating three main nitrate contributions: &amp;#160;leaching from areas influenced by manure piles, use of synthetic N fertilizers, and leakage from sewage collection pipes. Natural attenuation of nitrate occurs when fresh groundwater mixes with brackish groundwater of evaporitic origin. On the other hand, in the lacustrine plain (~3860 to 3810 m a.s.l), the groundwater geochemistry is dominated by evaporite dissolution and calcite precipitation, while nitrate originates from nitrification of synthetic fertilizers. This first hydrogeochemical study of one of the major groundwater systems in the Northern Altiplano is an important step towards a better management of this crucial water resource for the sustainable development of this region.&lt;/p&gt;&lt;p&gt;Fundings :&lt;/p&gt;&lt;p&gt;The present study was undertaken with the financial support of the Plurinational State of Bolivia provided through the Program &amp;#8220;100 Scholarships for Postgraduate Education within the Framework of Technological and Scientific Sovereignty&amp;#8221;, Supreme Decree 2100 (1 September 2014), and partly funded by LABEX OSUG@2020, ANR grant no.ANR-10-LABX-56 (financed by the Future Investments programme launched by the French government and implemented by the ANR).&lt;/p&gt;
Impacts of Anthropogenic Activities on the Contamination of a Sub Watershed of Lake Titicaca. Are Antibiotics a Concern in the Bolivian Altiplano?
(Elsevier BV, 2014) Céline Duwig; Denisse Archundia; Frédéric Lehembre; Lorenzo Spadini; Marie‐Christine Morel; Gaëlle Uzu; J. Chincheros; R. Cortez; Jean Martins
The Titicaca Lake is the most important water resource over the Andean plateau and the ecological equilibrium of this region is nowadays perturbed by recent changes in land use and management practices. The Katari watershed encompasses mining area, cities representing over 1.2 million habitants, and agricultural zones before ending in Cohana bay in the Titicaca Lake. Cohana Bay is known to be one of the most eutrophic bay of the Titicaca Lake. The objective of the study was to evaluate the impact of anthropic activities along the watershed on the river quality and on the bacterial diversity. Both mining activities and release of wastewater in river systems impacts greatly the surface water quality, with level of As exceeding limits for drinking water, and phosphate over the European guidelines for bad quality rivers. Antibiotic from the sulfonamide family was detected in the watershed in high concentrations downstream of the two main cities and bacterial resistance occurred in nearly all the sampled water points.
Insight into the Katari-Lago Menor Basin aquifer, Lake Titicaca-Bolivia, inferred from geophysical (TDEM), hydrogeological and geochemical data
(Elsevier BV, 2020) Gabriela Patricia Flores Avilés; Marc Descloîtres; Céline Duwig; Yvan Rossier; Lorenzo Spadini; A. Legchenko; Álvaro Soruco; Jaime Argollo; Mayra Pérez; Waldo Medinaceli
Sulfamethoxazole mobility and risk of contamination of water resources at the catchment scale (Katari - Titicaca Lake, Bolivia)
(2020) Denisse Archundia Peralta; Céline Duwig; Lorenzo Spadini; Marie‐Christine Morel; Blanca Prado; Vladimir Orsac; Jean Martins
&lt;p&gt;Sulfamethoxazole (SMX) is one of the antibiotics most commonly detected in aquatic and terrestrial environments and is still widely used, especially in low income countries. The Katari watershed encompassing the biggest city in the Altiplano and having its outlet in the Titicaca lake was studied: &amp;#160;ten soils having contrasting properties were collected throughout the watershed. SMX displacement experiments were carried out in repacked soil columns to explore SMX reactive transfer and to assess the contamination risk of water resources in the Bolivian Altiplano. Relevant sorption processes were identified by inverse modelling of experimental breakthrough curves. Different processes were identified depending on the soil type: &amp;#160;irreversible sorption, instantaneous and rate-limited reversible sorption. SMX mobility was lower in soils located upstream of the watershed (organic and acidic soils - Regosol) and was related with a higher adsorption capacity compared to the soils located downstream (lower organic carbon content - Cambisol). SMX was be classified as a moderately to highly mobile compound in the studied watershed, linked to soil properties such as pH, OC and soil texture. Sulfamethoxazole can potentially threaten the quality of surface and groundwater pollution in the lower part of the studied catchment, threatening Lake Titicaca water quality.&lt;/p&gt;