Contribution to the Modeling of a Biosorbent Derived from Cocoa Pod Shells on the Methylene Blue Index

Abstract

The objective of this study is to improve the preparation of a biosorbent from the cocoa pod shell by an experimental plan. The shells underwent drying and grinding followed by chemical impregnation with sodium hypochlorite. The process was optimized based on the analysis of the methylene blue index as a function of four factors: the drying temperature, the mass of the material, the mass of the hypochlorite and the agitation temperature of the preparation. This analysis based on the experimental plan reveals that under the preparation conditions the methylene blue index varies from 201.24 to 402.61 mg/g. Statistical analysis of the data shows that the size of the biosorbent is the factor that strongly influences the methylene blue index. Also, the interactions between the drying temperature, the size of the biosorbent and the temperature have a significant influence on the adsorption capacities of the biosorbent. The application of the experimental design shows that the drying temperature, the size of the material, the amount of hypochloride and the stirring temperature have a preponderant effect on the model which is significant and adequate. The optimal values for biosorbent preparation are 00 for drying temperature (X1), -0.6519 for biosorbent size (X2), -1.0 for mass of hypochloride (X3) and -1.0 for agitation temperature (X4).