Table 1: The methodological design to evaluate the adsorption of tartrazine independently analyzed the effect of each factor.

TestpHIonic strength (NaCl, M)Agitation speed (rpm)Adsorbent mass (mg)Contact time (min)

11, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1103002560
260, 0.01, 0.05, 0.13002560
360100, 150, 200, 250, 3002560
46030010, 25, 50, 75, 12560
5603002515, 30, 60, 90, 120, 180, 240