Kinetic Model for pH Variation Resulted from Interaction of Aqueous Solution Contaminated with Nickel Ions and Cement Kiln Dust

Table 1

Kinetic models used to describe the mechanisms governed the interaction of nickel ions and cement kiln dust.

Mechanism	Model	Expression
Sorption	Pseudo-first order
	n ^th order
Precipitation	Avrami

q_t and q_e are the quantities of solute removed from the aqueous solution at time t and at equilibrium, respectively, in (mg/g), k₁ is the pseudo-first order reaction constant (1/min), and k_n is the pseudo-n^th order reaction constant (g/mg min).