Table 2.

Isotherm models for adsorption of diazinon onto pumice*.

Models →	Freundlich		Langmuir		Temkin		Redlich–Peterson		Sips		Toth
Statistical metrics ↓	L	NL	L	NL	L	NL	L	NL	L	NL	L	NL
Parameters →	qe: 20.65 bF: 0.472	KF: 20.27 bF: 0.433	KL: 10.48 bL: 0.159	KL: 10.42 bL: 0.161	BT: 1.412 KT: 2.33	BT: 1.370 KT: 2.43	KR: 1.813 aR: 0.220 α: 0.923	KR: 1.763 aR: 0.191 α: 0.964	Ks: 8.923 bs: 0.1592 ns: 0.814	Ks: 10.54 bs: 0.162 ns: 0.962	Kth: 10.35 bth: 0.159 nth: 0.986	Kth: 10.73 bth: 0.180 nth: 0.947
R2	0.972	0.981	0.993	0.995	0.989	0.994	0.982	0.989	0.978	0.986	0.983	0.989
SAE	1.474	1.258	0.533	0.529	0.882	0.540	0.580	0.584	0.661	0.564	0.989	0.573
SSE	0.458	0.366	0.097	0.095	0.264	0.084	0.104	0.094	0.178	0.096	0.247	0.096
ARE	12.883	12.762	3.917	3.882	6.769	4.342	4.629	4.664	4.725	4.343	6.346	4.489
RMSE	0.338	0.282	0.156	0.149	0.257	0.145	0.161	0.154	0.211	0.155	0.248	0.155

*Linear (L); non-linear (NL).

$q_{e,exp}^i,q_{e,pred}^i$ are q_e values of experimental and predicted values respectively. p is the number of parameters; n is the number of experimental runs.

Units: Langmuir: K_L (mg/g). b_L (L/mg). Freundlich: K_F (mg^1-(1/n) L^(1/n) g^-1) and b_F is dimensionless. Temkin: K_T (L/mg). b_T (J/mol). Redlich – Peterson: K_R (L/g) and a_R(L/mg) ^nP and n_R is dimensionless. Sips: K_S,(mg/g). b_s (L/mg)ⁿ and n_s is dimensionless. Toth: K_th (L/g). b_th (mg/L)ⁿ and n_th is dimensionless exponent.