Fig. 15. Duasyn Direct Red color removal with time, using cellulose-based flocculation agents from different sources in dual system with bentonite at pH 2.0. Procedure A: 0.25 wt% of bentonite followed by 1.33 mg L⁻¹ of flocculant. Procedure B: 0.25 wt% of bentonite and 2.67 mg L⁻¹ of flocculant. Cationic synthetic PAM in dual system with bentonite was used as reference.