Tartrazine Removal from Aqueous Solution by HDTMA-Br-Modified Colombian Bentonite

Table 1

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

Test	pH	Ionic strength (NaCl, M)	Agitation speed (rpm)	Adsorbent mass (mg)	Contact time (min)
1	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11	0	300	25	60
2	6	0, 0.01, 0.05, 0.1	300	25	60
3	6	0	100, 150, 200, 250, 300	25	60
4	6	0	300	10, 25, 50, 75, 125	60
5	6	0	300	25	15, 30, 60, 90, 120, 180, 240