Table 1. Linear isotherm data for heavy metals adsorption on DPAC.

Temperature (K)	Linear isotherm models
	Langmuir				Freundlich
	qm (mg/g)	b (L/mg)	RL	R2	Kf (mg/g)(L/mg)1/n	n	R2
Pb(II)
298	129.9	0.2391	0.0137	0.9993	33.2	3.33	0.7748
308	80.0	0.1120	0.0289	0.9982	21.9	3.96	0.9177
318	73.5	0.1027	0.0314	0.9982	19.1	3.84	0.9125
Cd(II)
298	217.4	0.1488	0.0219	0.9805	42.2	2.62	0.9406
308	149.2	0.0668	0.0475	0.9947	26.7	2.96	0.9268
318	128.2	0.0635	0.0499	0.9968	16.4	2.66	0.9381
Cu(II)
298	156.25	0.0407	0.0757	0.9444	16.68	2.34	0.9836
308	121.95	0.0325	0.0930	0.9487	16.12	2.76	0.9822/
318	107.52	0.0276	0.1077	0.9217	13.95	2.80	0.9692
Zn(II)
298	100	0.0532	0.0590	0.9819	20.18	3.39	0.8016
308	84.0	0.0424	0.0729	0.9710	14.62	3.20	0.9853
318	79.4	0.1850	0.0177	0.9382	6.18	2.35	0.9666