Bio-Engineered Graphene-Based Cage for Efficient Local Enrichment and Biodegradation of Aqueous Organic Wastes

Microorganism immobilization has attracted great attention as a traditional method to overcome aqueous organic wastes containing N, N-dimethylformamide (DMF). In this approach, graphene oxide was modified with functional polymer firstly to obtain micro-composites material (PGO), and then the prepared composites were deposited on the surface of copper mesh (CM) to block the meshes and CM@PGO was achieved. Moreover, cage-shaped model was designed based on CM@PGO and P. denitrificans was packed inside the cage for batch experiments. This strategy could enrich the local concentration of DMF due to the formation of hydrogen bonds with the oxygen-containing groups from PGO and the character of bacteria in captivity could also contribute to the process of degradation. Results showed that the approach could remove DMF more efficiently about 15% compared with free microorganism and presented excellent cycling performance. Meantime, physical adsorption and chemical adsorption were both contributed to the process of PGO adsorption, and the adsorption isotherm fits Langmuir model well, furthermore, the theoretical maximum of adsorption ability calculated through Langmuir model is 95 mg/g. In other words, this cage-shaped CM@PGO provided a facile platform for treating various wastewaters by altering the species of packed microorganisms, which exhibited considerable prospects for wastewater treatment.