Study of the Equilibrium, Kinetics, and Thermodynamics of Boron Removal from Waters with Commercial Magnesium Oxide

Table 5

Thermodynamic parameters for the adsorption of boron with MgO at 25°C, 40°C, and 50°C.

Temperature		(kJ·mol-1)	H° (kJ·mol^−^1·K^−^1)	(kJ·mol^−^1)
25°C	5.36	−4.16	21.75	87.33
40°C	9.61	−5.88	−	−
50°C	10.29	−6.26	−	−

Concentration of boron = 350 mg·L−1, pH = 10, concentration of MgO = 40 g·L−1, stirring speed = 150 rpm, and time = 240 min. The positive value of the standard enthalpy ∆H° = 21.75 kJ·mol⁻¹·K⁻¹ for boron adsorption onto MgO shows the endothermic feature.