Nanocomposite of graphene oxide decorated Al-waste sludge for removal of rhodamine B from water

The contamination of land and water resources is reaching its breaking point due to increased human activities. This research attempts to provide a smart solution based on the concept of waste to treat waste, in which solid waste from the aluminium anodizing industry is upcycled and used with graphene oxide to engineer a composite material to treat dye contaminated water. Here, highly porous upcycled aluminium waste sludge is combined with less than 1% (w/w) of graphene oxide and then thermally treated to partially reduce the graphene oxide within the nano matrix. Partial reduction enhances π–π interaction with dye molecules while preserving the hydrophilicity and porosity of the overall composite. Studies carried out with rhodamine B, a toxic dye with intense colour, show complete and efficient removal of the dye from water, independent of any pH adjustment. Moreover, the adsorbed material shows no leachate of the dye nor heavy metals back into water over a wide range of pH values. This facilitates alternative product developments such as building materials and eliminates secondary waste generation. Therefore, the composite described herein is sustainable in both material development and in its usage for wastewater treatment and solid waste management.