Chemical Evolution Process and Quality Assessment of Seepage Groundwater in Tunnel Crossing Gas-Bearing Coal Seams

<div>The ratio of Mg<sup>2+</sup>/Na<sup>+</sup> to Ca<sup>2+</sup>/Na<sup>+</sup> and HCO<sub>3</sub><sup>-</sup>/Na<sup>+</sup> to Ca<sup>2+</sup>/Na<sup>+</sup>.</div>

Geofluids

fig8

Figure 8

Figure 8: Chemical Evolution Process and Quality Assessment of Seepage Groundwater in Tunnel Crossing Gas-Bearing Coal Seams 