Sustainable Management of Agro-Food Wastes Derived from the Olive Mill and Sugar Industry and Clinoptilolite to Produce Novel Adsorptive Materials

Novel sorbents were produced using sustainable and eco-friendly methods, aimed at minimizing environmental impact while utilizing industrial by-products and natural minerals. Olive stones and molasses derived from olive mill and sugar industries, respectively, and an abundant, natural and low-cost mineral, clinoptilolite, were combined in the following proportions: 80/20 clinoptilolite/stone, 80/10/10 clinoptilolite/stone/molasses, 50/50 stone/molasses, w / w . Then, physical carbonization (CL80OL20C, CL80OL10M10C, OL50M50C) or chemical activation (CL80OL20A, CL80OL10M10A, OL50M50A) took place. The adsorbents were characterized through Raman, FT-IR, BET and SEM-EDS analysis. The CL80OL20A material presents the highest ratio of C/O in EDS analysis and the lowest I D /I G in Raman spectroscopy. The increase in the specific surface area is as follows: OL50M50C < OL50M50A < CL80OL10M10C < CL80OL20C < CL80OL20A < CL80OL10M10A. Three applications were conducted: two with dyes (methylene blue and methyl red) in aqueous means and one in olive mill wastewaters for the removal of total phenols and their addition to rice, increasing the total phenolic content and producing novel foods. The well-fitted application of the pseudo-second order kinetic model to the experimental data has shown that chemisorption is the prevailing mechanism. The adsorbed amount of the recovered phenols to rice ranges from 0.14 to 0.93 mg/g. Consequently, olive and sugar by-products can be used as filters either to adsorb dangerous organic compounds or to recover bioactive compounds from wastewater, preventing their disposal in the environment, which could otherwise lead to severe negative effects on the ecosystems.