Removal of chromium by micelle-clays complex as total-Cr determined by AAS (■) and as Cr(VI) determined by UV-vis method (♦). Percent of Cr(VI) reduction to Cr(III) (●) is calculated as the difference between total-Cr and Cr(VI) percentages. pH = 6, contact time = 3 h, temperature = 25.0 ± 0.2°C, and adsorbent dosage = 5.0 g L−1. Data represent averages of triplicates ± SE.