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Research & development
FIGURE 6 Monitoring procedures on a site
of chemical and physical parameters was carried out
on the surface through portable meters equipped with
sensors and electrodes (Figure 6).
FIGURE 5 Measuring the DGPS position and elevation Operating procedures
• Measuring the water table depth (static level) by
respectively at the end of the colder and
wetter season (end of April), and at the end inserting a phreatimeter in the well down to the
of summer (end of September), to collect the water.
data representative of the richer and the poorer • Purging the well and cleaning the water: a
conditions of groundwater. preliminary, brief discharge of the water from the
The measurements and analyses described below well is necessary, in order to remove the upper
have been followed as a routine procedure for all the stagnant water layer and clean up the remaining to
17 wells directly accessible; in the other 4, due to the be analyzed.
reduced diameter of the wells, it was not possible to • Measuring the physico-chemical water parameters
insert the probe; in one case, due to the sealed well, the by inserting the probe into the well. The data are
sample was collected from a hose. For all those wells taken in three steps, during a second purging. On the
not directly accessible for the probe, the measurement wells of Favignana a low-flow pumping was used, for
no longer than 10 minutes, due to the scarcity of the
water in the wells. As the values of pH and electrical
conductivity became stable, water samples were
finally collected.
• Collecting the samples of water: for the analyses of
hydrogencarbonate, a water sample was taken in a
250 mL polyethylene bottle, previously rinsed with
the same water.Water samples for analysis of cations
and anions: each water sample was filtered with a
0.45 µm mixed esters of cellulose filter and divided
into two parts. The first part was acidified to pH <
2 with HNO3 (BDH-Aristar grade) and saved for the
23EAI Energia, Ambiente e Innovazione 4/2015
