Geolithological and anthropogenic controls on the hydrochemistry of the Volturno river (Southern Italy)

Abstract

The present work aims to study the main chemical and physical water parameters in the upper and middle Volturno river catchment (southern Italy), between the Capo Volturno springs and the confluence with the Calore river. This study makes use of morphology, geolithology, tectonic, land use, and physico‐chemical (pH, electrical conductivity, redox potential, temperature, major ions, and 222Rn) data for the identification of the main sources of surface and groundwaters in the Volturno catchment and of their evolution and mixing both in base flow and peak flow conditions. The study was also performed to assess whether the alteration due to potential anthropogenic contamination may hamper the identification of natural “primitive” sources of surface waters, especially in the populated and farmed plains far from the river headwaters. Our data suggest that water chemistry of this stretch of the Volturno river is dominated mainly by lithology and, only marginally, by the intense exogenous activities and that this trend is appreciable in both base flow and peak flow conditions. The proposed simple geochemical approach based on easy‐to‐sample matrices and on cost‐effective standard methods is a valuable tool to address catchment functionality especially in upland areas, where complex geologic and structural settings, heterogeneous groundwater flow, and logistical issues are the rule rather than the exception. Because the upper and middle Volturno catchment is comparable with numerous valleys of the Mediterranean area, this study could be a reference for analogous applications.

Deciphering Interannual Temperature Variations in Springs of the Campania Region (Italy)

“…Figure 5 shows that the mean EC variation with altitude in the monitored springs is reasonably well represented by a power law, if we exclude the most mineralized springs (Paestum and Castellamare di Stabia), which cluster together around the EC value of 10,000 µS/cm. This confirms that, at the regional scale, the residence times in the Campania aquifers decrease with the spring's elevation [36], although, the large EC variability and the narrow bands of 95% confidence intervals of Figure 4 denote that, at the local scale, aquifer heterogeneities might lead to very different flow paths. Like spring water EC mean values, the spring water temperatures highlight some differences with respect to the mean air-altitude gradient of −0.64 • C/100 m calculated for the Campania region [41].…”

“…It should be noted that a few springs near the coast are characterized by elevated EC and Cl − concentrations, these are the famous mineral springs of Paestum and Castellamare di Stabia. These springs are not affected by seawater intrusion, but their elevated salinity derives from the deep circulation in karst systems along faults [35,36]. Figure 3 highlights that the Cl − spatial distribution in spring water mimics the EC spatial distribution, while the F − spatial distribution in spring water mimics the springs' temperature spatial distribution.…”

“…The springs with elevated temperatures (20 • C < temperatures < 24 • C) are located in areas characterized by elevated geothermal gradients induced by volcanic activity or regional faults [35,36]. Only few springs are characterized by elevated EC values (EC > 1000 µS/cm) and thus highly mineralized, all the others are in the range of oligomineral or mineral freshwaters typical for karst aquifers.…”

Comparison of the Mineral Element Content of Public Drinking Fountains and Bottled Water: A Case Study of Ferrara City

“…The major and most common ions present in natural water were analysed using Dionex ® ICS 1000 ion chromatography systems. Detailed descriptions of analytical methods are reported in Cuoco et al [23]. All samples were filtered through 0.45-µm Minisart ® NML cellulose acetate syringe filters and then stored in 5-mL plastic Dionex ® ion chromatography vials.…”

“…A 10 mg/L anion and cation Fluka spike (Sigma-Aldrich, St. Louis, MO, USA) was analysed along with the samples, standards, and blanks. Internal and external calibrations using a minimum of five standards for both cations and anions were carried out for each analysis [23]. Total salts was determined using gravimetric methods and expressed as the substance content in grams, obtained after evaporation of 1 L of water at 180 • C. HCO 3 − was determined using a Hanna…”