Table 1 The concentrations of main ions in the water seepage at different stages
Content | Concentration (mg/l) | ||||||
|---|---|---|---|---|---|---|---|
Rainwater | Water seepage at Qinglin cave | Water seepage at Yanxia cave | |||||
Before intervention | After 1 month | After 12 months | Before intervention | After 1 month | After 12 months | ||
Na+ | 0.73 | 1.77 | 1.56 | 3.44 | 1.38 | 2.74 | 3.44 |
K+ | 4.53 | – | 1.95 | 4.29 | 1.10 | 1.66 | 1.32 |
Mg2+ | 0.55 | 0.33 | 0.40 | 0.43 | 0.43 | 0.41 | 0.42 |
Ca2+ | 6.04 | 39.55 | 63.06 | 83.60 | 31.00 | 60.99 | 64.86 |
Cl− | 3.78 | 4.55 | 18.26 | 10.65 | 3.01 | 16.29 | 7.19 |
SO42− | 3.09 | 18.10 | 33.48 | 25.34 | 13.68 | 24.87 | 16.96 |
pH | 5.91 | 7.12 | 7.26 | 7.43 | 7.32 | 7.46 | 7.63 |