Adsorption of sugarcane vinasse effluent on bagasse fly ash: A parametric and kinetic study.

Sugarcane and bioethanol production produces large amounts of bagasse fly ash and vinasse, which are solid and viscous liquid wastes, respectively. However, these wastes are often disposed into the environment without treatment, thus posing an environmental and public health risk. This study investigated the treatment of vinasse effluent in terms of reduction of chemical oxygen demand (COD) and acidity removal using sugarcane bagasse fly ash. A maximum COD removal efficiency of 72% was obtained using an effluent volume of 100 mL, contact time of 180 min, and shaking speed of 240 rpm. The adsorbent dose and particle sizes were 4.5 g and 90-125 μm, respectively. Furthermore, the potential application of bagasse fly ash as an adsorbent in a sand filtration bed was assessed using a column test. A maximum recovery of 68% was obtained at the 25-min interval. The adsorption data was found to fit the Freundlich model best (Kf = 2.16 mg g-1; R2 = 0.96), and the kinetics fit the pseudo-second order model (R2 = 0.98).