## 3 Results and Discussion
The total loaded amounts of the solutes on the unpaved roads by the treatment solutions could be leached down by the rainstorm and increase the salinity of the groundwater. Therefore, the load of each studied ion by each solution treatment should be determined. The total annual load amount (\(P_{j}\)) (kg m\({}^{-2}\)) of ion \(j\), where \(j\) could be Cl, Na, or Ca+Mg, on 1 m\({}^{2}\) of the surface area of the unpaved road by the application of brine, TWW, or FW, was determined by Equation (2):  
\[P_{j}=\beta\cdot\sum_{i=1}^{i=N}(V_{ji}\cdot C_{ji}) \tag{2}\]  
where \(C_{ji}\) is the concentration (mg L\({}^{-1}\)) of the applied ion \(j\) (Cl, Na, or Ca+Mg), and \(V_{ji}\) is the volume (L m\({}^{-2}\)) of the brine, TWW, or FW solution containing the ion \(j\), which is applied in the application event \(i\) on a specific application day. \(\beta\) is the number of application days in a year. According to the Israeli regulation, for the three treatment solutions (brine, TWW, and FW), the \(V_{ji}\) equals 4 L m\({}^{-2}\); for the FW and TWW treatment solutions, the \(N\) equals 10 and \(\beta\) equals 192; and for the brine solution the N equals 1 and \(\beta\) equals 1. The \(P_{j}\) values of Cl, Na, and Ca+Mg on the unpaved roads by the TWW, brine, and FW applications are presented in Figure 4. It can be seen from this figure that (i) the TWW application loaded the highest annual amounts of Cl, Na, and Ca+Mg on the unpaved roads, and (ii) the brine application loaded higher annual amounts of Cl and Ca+Mg than the FW application, and the lowest annual amount of Na (\(\sim\)0). In addition, different mechanisms were responsible for the dust emission control in the various studied solutions (brine, TWW, and FW). The mechanism of the brine solution controlling dust emission is based on the high hygroscopic properties of the Ca and Mg elements. The concentrations of the Ca and Mg ions in the brine solution are very high, 23.2 and 62.2 g L\({}^{-1}\), respectively (Table 1). The application of the brine solution causes the accumulation of high contents of Ca and Mg on the unpaved road, which absorb large amounts of H\({}_{2}\)O molecules from the air. These H\({}_{2}\)O molecules are adsorbed on the dust particles by adhesion forces, forming big and heavy aggregates which are beyond the lifting capability of the wind. Consequently, the dust emission under the brine application decreases. In contrast, the application of the TWW and FW solutions with relatively low concentrations of Ca and Mg, <127.5 and <59.8 mg L\({}^{-1}\), respectively (Table 2), leads to the lower accumulation of these ions on the unpaved roads. Furthermore, the frequent applications of the TWW and FW on the unpaved roads, 10 times in each day during the dry season, leach down the Ca and Mg ions from the unpaved roads' surfaces, which in turn decreases their accumulations on the unpaved roads. In this case, the hygroscopic mechanism is negligible. Therefore, the mechanism of the WWT and FW application in controlling dust emission is based on the \"active wetting\" mechanism, i.e., repetitive and frequent wetting of the unpaved roads throughout the day to keep the roads wet during the quarries' activities. The effects of the vertical leaching of the solutes, which accumulated on the unpaved roads following the application of the treatment solutions, on the groundwater salinization could be indicated by the Cl\({}^{-}\) concentration increase in the groundwater. The Cl\({}^{-}\) is a conservative ion, very mobile in soil/rock systems, and is the most dominant anion in groundwater. Therefore, the concentration of Cl\({}^{-}\) is used as a parameter of water salinity; the higher the Cl\({}^{-}\) concentration, the higher the water salinity is [16]. Many quarries in Israel are located above the Yarkon-Tanitim a aquifer, where the dominant rocks in this aquifer are cracked limestone. The paths for water and solutes movement in this aquifer are heterogeneous, complicated, and difficult to describe and predict.