Recovery and reuse of activated carbon and diatomaceous earth used in purification processes of syrups

Abstract

The correct disposal and reuse of solid waste has been the subject of several studies in recent years. A solid residue composed of activated carbon and diatomaceous earth generated by the candies industry in the purification of syrups was characterized and recovered by washing and heat treatment. The washing process was optimized using an experimental design, varying the concentration of the solvent, time and temperature. The planning indicated a strong influence of the initial dosis of solvent (ethanol 95 %) in the recovery of the surface area of the residue. After washing, heat treatment at 800 °C during 15 minutes has proved more effective. The recovered residue was applied to filter natural water to reduce COD, having an efficiency of 60 % reduction in that parameter.