Valorization of Agroindustrial Wastes as Biosorbent for the Removal of Textile Dyes from Aqueous Solutions

Table 2

Chemical and physical characterization of adsorbents.

	Brewer’s spent grains	Orange peel
Point of zero charge	5.3	3.5
pHwater	—	4.98±0.00
pHKCl  1.0 M	4.80±0.08	4.21±0.04
𝐩𝐇𝐂𝐚𝐂𝐥𝟐𝟎.𝟎𝟏𝐌	4.55±0.10	4.67±0.01
Surface acidity (NaOH) mmol g^−1	3.37±0.02	2.58±0.19
Surface basicity (HCl) mmol g^−1	3.16±0.01	0.25±0.07
Methylene Blue Index mg g^−1	64.9	178.7