Removal of Methylene Blue from Aqueous Solution Using Agricultural Residue Walnut Shell: Equilibrium, Kinetic, and Thermodynamic Studies

Table 2

The zeta potentials of WS at different pH.

pH	2.02	2.98	3.98	4.89	5.80	7.04	7.88	8.97	10.00	11.93
ζ/mV	−4.217	−12.19	−18.51	−22.99	−23.15	−24.96	−25.01	−25.18	−26.68	−33.68