Karst aquifer recharge areas are usually difficult to identify because of the complexity of these aquifers’ characteristics. On the other hand, their identification is very important in the aim of protecting the groundwater resources that these aquifers host. Regarding this topic, this paper presents an approach aimed at identifying karst aquifer recharge areas by the application of oxygen-18 and deuterium isotopes composition of groundwater coupled with hydrological features. Oxygen-18 and deuterium isotope composition of Capodacqua di Spigno Spring, in the South of the Latium Region, has been applied with rainfall and discharge values related to the feeding aquifer of this spring. As δ18O and δ2H values of groundwater samples are natural tracers of the recharge area’s elevation, we propose a model, based on the distribution of the basin surfaces involved as recharge areas, in relation to elevations. The model estimates, for any discharge value, the percentage of the topographic area involved in the aquifer recharge. The setting up of this simulated distribution is supported by a Weibull cumulative probability function. The results show that the measured discharges increase as larger areas with lower elevations are involved in the recharge process.

The increasing occurrence of widespread drought phenomena is a global environmental emergency, especially for the effects of ongoing climate change on groundwater availability. Dry years and extreme temperatures are common drivers of current climate impacts all over the world, including, for example, the freshwater supply for drinking and agriculture purposes, ecosystems, forestry, health, etc. In this frame, to ensure temporal water availability in water-stressed areas, sustainable groundwater management is an increasing challenge. Most groundwater in the South-East Latium Region, Central Italy, as in the whole Apennine Mountains chain, is stored in karst aquifers. In this area important water resources are present, but even here in the last decades they are affected by groundwater depletion as a consequence of occurring drought events, the upward trend in the global average temperature and the increase in groundwater extraction. Due to the lack of flow rate data of springs in many areas of Italy, spring response modeling could be a useful tool for supporting proper water resource management. Several research studies proposed methods based on relationships between spring discharges and rainfall data. The goal of this paper is to propose a simple linear model, based on rainfall-discharge cross correlations, in order to be able to simulate the effects of variation in rainfall on water resource connected Capodacqua di Spigno Spring minimum discharge. The results obtained using the developed model has been compared to an existing method that uses the Standard Precipitation Index (SPI) for the estimation of the minimum annual spring discharge.

The identification of recharge areas in karst aquifers allows us to perform sustainable management of these groundwater resources. Stable isotopes (δ18O and δ2H) have been largely used to provide information about recharge elevation in many mountainous regions. In this paper, an improved version of a recent “isotope-driven model”, for the identification of recharge areas, was applied to Capodacqua di Spigno Spring (south of the Latium region). The model upgrade consists of a preliminary check procedure to estimate the degree of influence of the rainfall’s isotopic variability on the spring water. This additional procedure gives us an indication of the reliability of the model and its applicability conditions. Moreover, the dataset of the spring was updated to analyze the degree of reliability of the isotope-driven model. The purpose of this study was to combine the previously mentioned isotope-driven model with hydrogeological tools. A quantitative study of the basin, based on the estimation of the average monthly infiltration volume, was performed by using the inverse hydrogeological water budget. In this way, the qualitative model for the recharge areas’ estimation was validated by a quantitative hydrogeological tool. Both models show that, for karst mountain basins, the recharge areas decrease as the average recharge elevations increase, including areas at high altitudes.

This paper presents the results of a groundwater quality assessment carried out in the karst coastal region of the West Aurunci Mountains (Central Italy). 55 spring and 18 well water samples, collected from 2016 to 2018, were analysed to study the main processes controlling the hydrogeochemical evolution and groundwater quality properties. In the study area, groundwater samples are mostly characterized by a Ca-HCO3 facies, indicating that the groundwater hydrogeochemical evolution is mainly controlled by the carbonate mineral dissolution/precipitation. The cationic and anionic concentrations confirm that groundwater samples belong to the order of Ca2+>Mg2+>Na+>K+ and HCO3−>Cl−>SO42−, respectively. Well water samples show, over time, an increasing mineralization with respect to the spring water samples. In more detail, the enrichment of Ca2+, Na+, and Cl- in well water samples is mainly due to the dissolution of calcite, dolomite, and halite minerals and secondly to a probable ion exchange related to seawater intrusion. Seawater intrusion, probably affecting the chemical composition of well water samples, was studied using ionic ratios, graphical approaches, and specific indices, such as the BEX index. Results suggest that carbonate weathering, ion exchange, and seawater intrusion in this karst coastal region are the major factors controlling groundwater geochemistry. This study shows that groundwater quality assessment, based on hydrogeochemical investigation techniques, has been a useful tool to characterize and model carbonate aquifers in Central Italy, with the aim of achieving proper management and protection of these important water resources.

Integrated waste management and sustainable use of natural resources are the basis of the Green Economy. In this context, the management of the Municipal Solid Waste Incineration Bottom Ashes (MSWI BA) is one of the current issues worldwide. This paper presents an application of the Life Cycle Assessment (LCA) procedure to the industrial production of ceramic tiles using bottom ashes in the mixture together with feldspathic sands and clays. The comparison between ashes and traditional mixture showed a similar mineralogical and rheological composition. In the reported procedure the MSWI BA, after storage, were treated to separate and recover metals. The residual ashes were added to the mixture and then they followed the traditional industrial production cycle. Samples of the different materials were taken during the experimental industrial activity and leaching tests were carried out to verify the environmental compatibility of MSWI BA use to produce ceramic tiles. The results of the LCA show large environmental and energy benefits related to the proposed reuse of BA. Metal recovery and lower use of clay in traditional mixture avoids emission of substances with a negative potential impact for environment. This study provides a sustainable alternative to the MSWI BA final disposal in landfill as MSWI BA are hazardous wastes that present complicated management and high disposal costs.