Abstract:
The growing demand for adsorbents used in environmental remediation processes has made them increasingly expensive, prompting further research into the manufacture of new, less expensive adsorbent materials from non-conventional materials, specifically from abundant biomaterials.
In this work, we have chosen waste beans as the adsorbent material because of their easy availability and low cost. The aim is to compare the properties of this material in its natural state and after thermal activation. To gain a better understanding, we carried out various analyses to characterize the physico-chemical properties of both materials. On the chemical side, we studied the pH at zero charge point (phpzc) to identify the charge of the biomaterial surfaces, some indices that gave information on the porosity and functional groups on the surface of each biomaterial. The results show that calcination of the biomaterial results in a basic character of the surface, with an improvement in porosity. On the other hand, the polyphenol content of the biomaterial was significantly increased from 4.69mg/g in the natural state to 10.67mg/g in the calcined state.
Finally, an evaluation of the adsorption capacity of methylene blue by the two types of material (raw and activated), using the response surface methodology (RSM) was carried out and was given the adequate model that validates the experimental results as well as the optimal values that favor the maximum removal of the dye where it reaches rates higher than 98%.
