The present work aims to assess the widespread boron contamination of groundwater in central-Adriatic Italy. This research has been based on hydrochemical and statistical study of a large amount of chemical analyses on groundwater and soil samples, representing different hydrogeological domains (carbonate aquifers, intramontane basins and alluvial plain aquifers). Boron contamination of groundwater has been detected only in the alluvial aquifers of Adriatic plains. In order to define possible origins of contamination, a new chemical survey has been executed on two sampling areas (Saline river and Vomano river alluvial aquifers), where boron and strontium isotopic ratios have also been determinated. As already highlighted by previous analyses, the correlation between B and Cl indicates the link among these two elements and highlights the importance of salinization of groundwater in boron contamination. In particular, the highest boron concentrations are detected in mineralized water with a Na-Cl facies and low or negative Eh values. The ion ratios between Sr and other analytes allow to clearly distinguish samples from different hydrogeological domains. The δ11B distribution show the highest values (40.5‰), related with maximum boron concentration, are due to groundwater salinization, while the lowest (8.8‰) are comparable with the known values for Italian alluvial aquifers. Two-component mixing models indicate δ11B variation is linked with mixing processes between more shallow fresh groundwater and deeper saline groundwater. 87Sr/86Sr isotopic ratio highlights that the values observed in the more mineralized samples are similar with those known in literature for mio-pliocenic salt waters or, at least, older than the actual seawater. In conclusion, the research results show the highest boron concentration in groundwater are referable to natural contamination related with the uprising of Na-Cl connate groundwater, excluding anthropic pollution.
Multisopic (B and Sr) assessment of Boron-rich groundwater in central adriatic italy.
PALMUCCI, WILLIAM;DI CURZIO, DIEGO;RUSI, Sergio
2016-01-01
Abstract
The present work aims to assess the widespread boron contamination of groundwater in central-Adriatic Italy. This research has been based on hydrochemical and statistical study of a large amount of chemical analyses on groundwater and soil samples, representing different hydrogeological domains (carbonate aquifers, intramontane basins and alluvial plain aquifers). Boron contamination of groundwater has been detected only in the alluvial aquifers of Adriatic plains. In order to define possible origins of contamination, a new chemical survey has been executed on two sampling areas (Saline river and Vomano river alluvial aquifers), where boron and strontium isotopic ratios have also been determinated. As already highlighted by previous analyses, the correlation between B and Cl indicates the link among these two elements and highlights the importance of salinization of groundwater in boron contamination. In particular, the highest boron concentrations are detected in mineralized water with a Na-Cl facies and low or negative Eh values. The ion ratios between Sr and other analytes allow to clearly distinguish samples from different hydrogeological domains. The δ11B distribution show the highest values (40.5‰), related with maximum boron concentration, are due to groundwater salinization, while the lowest (8.8‰) are comparable with the known values for Italian alluvial aquifers. Two-component mixing models indicate δ11B variation is linked with mixing processes between more shallow fresh groundwater and deeper saline groundwater. 87Sr/86Sr isotopic ratio highlights that the values observed in the more mineralized samples are similar with those known in literature for mio-pliocenic salt waters or, at least, older than the actual seawater. In conclusion, the research results show the highest boron concentration in groundwater are referable to natural contamination related with the uprising of Na-Cl connate groundwater, excluding anthropic pollution.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
