Bleaching performance of a nigerian (Yola) bentonite

The bleaching performance of raw and acid activated Yola montmorillonite clay was studied. The bleaching performance was enhanced upon activation. The predominant active sites on the raw clay are Lewis acid sites, those on the improved clay are Bronsted acid sites. The best bleaching performance was obtained with clay sample activated with 5M H2SO4 at acid/clay ratio 0.7, bleaching temperature of 120°C and at 10 minute stirring time. At these conditions the improved clay compares favorably well in terms of bleaching performance with the imported industrial standard sample. Thus, it could be a local substitute for the industrial standard. © 2009 Universidad Nacional del Sur.