Removal of Cd(II) and Cu(II) from Aqueous Solution by Na⁺-Modified Pisha Sandstone

Table 1

Thermodynamic parameters of Cd(II) and Cu(II) adsorption on PS.

Metal	ΔG (kJ·mol^−1)			ΔH (kJ mol^−1)	ΔS (J·mol^−1·K^−1)
	293 K	303 K	313 K
Cd	−429	−526	−548	−0.14	1.36
Cu	−391	−492	−617	−0.32	1.00

Note: PS means Pisha sandstone.