Table 2.

Values for the constants of the kinetic models used to fit the experimental data on the adsorption of p-nitrophenol on biochar samples prepared at different pyrolysis temperatures.

Sample	PC300	PC400	PC500	PC600	PC700
q* (experimental value)	7.1181	14.0297	18.491	19.8862	19.2583
Pseudo-first order
q	7.6715	13.4334	17.6011	19.2739	18.1302
k1	0.0303	0.0354	0.0531	0.0337	0.0547
SSE	0.2649	0.4601	0.7888	1.8754	1.4942
R2	0.9824	0.9828	0.9603	0.8454	0.8449
Pseudo-second order
qe	7.0871	14.2018	18.6552	21.0357	20.0589
k2	0.0041	0.0027	0.0037	0.0027	0.0039
SSE	0.1945	0.0983	0.1776	0.9609	0.7946
R2	0.9904	0.9992	0.9679	0.9431	0.9562
Elovich
qe	7.1748	14.4387	19.4924	20.3989	19.9607
a	0.6282	1.5846	4.2774	5.0375	5.7226
b	0.5627	0.3186	0.2844	0.2788	0.2939
SSE	0.2025	0.3828	0.6887	0.2762	0.4002
R2	0.9896	0.9881	0.9897	0.9952	0.9889
Intra-particle diffusion
ki1	1.099	1.9063	2.4338	2.022	1.8304
Ci1	0.2229	0.461	1.3107	2.6471	3.4365
R2	0.9804	0.9999	0.993	0.9961	0.9966
ki2	0.4752	0.7414	0.9858	1.0598	1.2466
Ci2	1.897	3.3176	5.5066	7.8012	6.1088
R2	0.9765	0.9533	0.9325	0.9994	0.9931
ki3	0.031	0.2679	0.2521	0.3341	0.2151
Ci3	6.6865	10.1778	14.8832	15.084	16.2268
R2	0.9756	0.9908	0.9641	0.9878	0.9775