Identification of two low-cost and locally available filter media (pumice and scoria) for removal of hazardous pollutants from tannery wastewater

Environmental Systems Research

Table 4 Kinetic parameters for the adsorption of NO₃–N, PO₄–P and [Cr]_T onto the scoria (pH = 9.1, T°= 21 °C)

Pollutants	Initial conc. (g/L)	Pseudo-first-order kinetic				Pseudo-second-order kinetic
Pollutants	Initial conc. (g/L)	q_e, exp. (g/kg)	q_e, cal. (g/kg)	K₁ (h⁻¹)	R ²	q_e, cal. (g/kg)	K₂ (kg g⁻¹ h⁻¹)	R ²
NO₃–N	0.124	0.250	0.249	0.032	0.9951	0.282	0.19	0.8535
PO₄–P	0.168	0.210	0.149	0.053	0.8769	0.220	0.87	0.9806
[Cr]_T	0.0357	0.051	0.025	0.039	0.4690	0.539	2.61	0.9294