Adsorption of Cr(VI) in Aqueous Solution Using a Surfactant-Modified Bentonite

Table 1

Experimental conditions for the initial adsorption tests of Cr(VI) in aqueous solution.

Test	pH	Stirring rate (rpm)	Adsorbent amount (g)	Contact time (min)	Ionic strength (added NaCl, mM)
1	1–9	200	0.2	60	Not controlled
2	3	100–300	0.2	60	Not controlled
3	3	200	0.05–0.40	60	Not controlled
4	3	200	0.2	30–240	Not controlled
5	3	200	0.2	60	0.1–2.0