Table 1.

Chemical characteristics of the different bio-adsorbents, with average values (n = 3) and coefficients of variation always <5%. EC: electrical conductivity (in dS m⁻¹); (H%): Moisture content (in percentage); DM: Dry matter content (%): P: Porosity (in percentage); As: Ash content (%); VM: Volatile matter content (%); BD: Bulk density (in g cm⁻³); RD: Real density (in g cm⁻³); SI: Swelling Index (in percentage); OM: organic matter content (%); OC%: Organic carbon content (in percentage); X_e: exchangeable cations (Al, Ca, K, Mg, and Na, expressed in cmol_c kg⁻¹); eCEC: effective cation exchange capacity (expressed in cmol_c kg⁻¹).

	Alfa Fiber	Cactus Fiber	Palm Fiber	Acacia Bark	Eucalyptus Bark	Zean Oak Bark
pHw	5.1	7.4	5.5	4.9	5.4	5.7
pHKCl	4.7	7.6	6.9	4.2	5.1	4.8
pHPZC	6.6	6.2	4.3	7.1	7.4	5.8
EC	21	204	818	19.7	4.2	5.9
H%	9.3	6.2	5.4	10.7	11.5	7.0
DM	90.7	93.8	94.6	89.3	88.5	93.0
P	86.6	48.0	41.6	62.8	65.7	57.5
As	2.45	3.34	4.36	1.22	1.42	1.91
VM	97.55	96.66	95.64	98.58	98.58	98.09
BD	1.28	0.96	0.81	1.42	1.53	1.1
RD	1.65	1.23	1.14	1.86	1.97	1.43
SI	2.56	1.43	1.08	2.82	2.96	1.84
OM	40.72	21.76	18.84	49.21	50.25	29.85
OC%	19.54	10.44	9.04	23.62	24.12	14.32
Ale	0.11	0.05	0.05	0.18	0.11	0.09
Cae	6.74	2.04	1.97	7.44	7.98	4.22
Ke	2.22	3.04	2.96	2.02	2.07	2.79
Mge	1.57	3.06	2.99	1.03	0.86	2.81
Nae	2.32	1.05	0.96	3.77	4.04	1.12
eCEC	13.97	9.26	8.55	14.45	15.08	11.04
Paricle size (%)
0.075–0.1 mm	86.17	52.28	66.71	26.14	31.30	39.70
0.05–0.075 mm	11.68	30.61	15.77	68.43	65.45	53.40
0.05–0.02 mm	2.15	10.73	13.47	4.16	3.25	6.78
<0.02 mm	--	6.38	4.05	1.27	--	1.20