Effect of contamination sources on the rate of zinc, copper and nickel release from various soil ecosystems

Bulletin of the National Research Centre

Table 6 Rate constants describing Cu desorption release from the soils

Soil	Kombora				Abo Rawash				Kafr-Elsheikh
Soil	a	b	R²	SE	A	b	R²	SE	a	b	R²	SE
Modified Freundlich equation
UC*	0.20	0.79	0.91**	0.12	0.24	0.52	0.93**	0.24	0.25	0.77	0.98**	0.16
C*	0.18	0.71	0.92**	0.11	0.23	0.67	0.96**	0.18	0.23	0.67	0.95**	0.18
Elovich equation
UC*	2.37	4.58	0.98**	0.98	3.43	3.61	0.97**	1.87	4.27	5.58	0.96**	2.71
C*	2.14	5.55	0.97**	1.71	2.16	4.69	0.97**	1.81	2.34	4.85	0.96**	2.16
Parabolic diffusion equation
UC*	0.29	10.35	0.78*	4.19	0.37	11.89	0.62 ns	5.72	0.27	14.24	0.74*	6.68
C*	0.21	11.83	0.77*	4.65	0.39	13.46	0.62 ns	6.01	0.20	11.28	0.73*	5.05
First-order equation
UC*	− 0.36	− 0.37	0.87**	0.22	− 0.42	− 0.36	0.85**	0.24	− 0.29	− 0.40	0.85**	0.28
C*	− 0.38	− 0.41	0.85**	0.25	− 0.37	− 0.39	0.86**	0.25	− 0.31	− 0.41	0.83**	0.26