Enhancement of organic pollutants bio-decontamination from aqueous solution using newly-designed Pseudomonas putida-GA/MIL-100(Fe) bio-nanocomposites

Abstract As a natural adsorption material, graphene has become a hot research topic in water treatment due to its unique framework, large surface area, low cost, and simple preparation. Here, a series of composite material aerogels (GA/MIL-100(Fe)) consisting of Fe metal-organic frameworks (MIL-100 (Fe)) and graphene-based aerogel (GA) were prepared through a hydrothermal and step-by-step strategy and used for the adsorption of an azo dye in wastewater, scilicet acid orange 10 (AO10). The adsorption equilibrium of AO10 solutions with concentrations of 50 and 100 mg/L was reached within 45 min but the dye could not be fully removed. Besides, the synthesized composite material (GA/MIL-100(Fe)) was a good carrier for immobilized Pseudomonas putida cells due to its good biocompatibility and non-toxicity. A new, environmentally friendly adsorption and biodegradation process has been exploited here, which was to immobilize bacterial cells to the surface of GA/MIL-100(Fe) by a covalent bonding method to form a novel biocomposite material. The material could be used to completely remove AO10 dyes in 14 and 26 h from solutions with initial AO10 concentrations of 50 and 100 mg/L, respectively. This way of combining biological and physical adsorption has a higher processing efficiency and shows huge potential for the treatment of industrial wastewater.