Development of a novel in-situ aluminum/carbon composite from olive mill wastewater for the selective adsorption and separation of malachite green and acid yellow 61

Abstract

In this study, an aluminum/carbon composite was developed from olive mill wastewater (OMWW) and successfully applied in the removal/separation of malachite green (MG) and acid yellow 61 (AY61) and in the treatment of a real discharge from a denim dye bath. The optimized composite (0.5% Al) is microporous, has a specific surface area of 1269 m2.g−1, rich in anionic sites, has an adsorption capacity of 1063 mg.g−1 and exhibited efficient separation of AY61/MG. Thermodynamic results showed physical, endothermic and disordered adsorption. The substrates were attached to the surface by electrostatic, hydrogen and π- π interactions through the contribution of multiple sites in parallel and non-parallel orientations. The composite can be used repeatedly without significantly losing its performance. This study, presents an exploitation of agricultural liquid waste to develop carbon composites for industrial dye removal and separation, creating new economic opportunities for farmers and rural communities.