Hydrogeochemical Characteristics and Water–Rock Interactions of Coalbed-Produced Water Derived from the Dafosi Biogenic Gas Field in the Southern Margin of Ordos Basin, China

Table 4

Coefficient scores for each principal component in the factor analysis.

Parameter	Principal component
	PC1	PC2	PC3	PC4
pH	0.923	-0.064	0.183	0.031
TDS	0.558	0.331	0.750	0.122
Na^+	0.633	0.267	0.721	0.078
K^+	-0.092	0.266	0.153	0.945
Mg^2+	-0.309	0.924	-0.086	0.180
Ca^2+	-0.392	0.854	-0.256	0.131
Cl^-	0.139	0.930	0.263	0.196
SO4^2-	0.059	-0.408	0.894	0.119
HCO3^-	0.779	-0.515	0.279	-0.180
CO3^2-	0.900	-0.314	0.123	-0.159