High-value zeolitic material from bagasse fly ash: utilization for dye elimination.

Bagasse fly ash (BFA), a sugar industry waste, was used to prepare zeolitic material (ZFA) by means of alkaline hydrothermal treatment. ZFA showed improved morphology as a result of this treatment. The adsorption of the reactive dyes turquoise blue (TB) and brilliant magenta (BM), on both BFA and ZFA, was investigated in a batch contact system. A series of batch experiments revealed that optimal dye removal occurs at a 200 mg/L to 300 mg/L solute concentration, 60 minutes of agitation time, 5 g/L to 10 g/L adsorbent dose, a pH level of 2 to 4, and a temperature of 298 K. ZFA showed enhanced adsorption capacity as compared to BFA. According to the Langmuir equation, the maximum adsorption capacity was 12.66 mg/g and 45.45 mg/g for turquoise blue and brilliant magenta dyes, respectively, on BFA; and 21.74 mg/g and 100.00 mg/g for turquoise blue and brilliant magenta dyes, respectively, on ZFA. Kinetic studies showed that the correlation coefficients best fit with the pseudo-second-order kinetic model, confirming that the adsorption rate was controlled by a hemisorptions process.