Facile approach for nanoconfinement of multilayer graphene oxide with polyether polyurethane sponge as biological carrier for the establishment of microalgal-bacterial bioreactor

Abstract

Physically precise and mechanically robust biocarrier is basic and urgent requirement of algal-bacterial wastewater treatment plants for homogenously biofilm growth. Herein, a highly efficient graphene oxide (GO) coordinated polyether polyurethane (PP) sponge was synthesized through GO incorporation into PP sponge to improve the GO coating, followed by UV-light treatment for industrial application. The resulted sponge showed remarkable physiochemical characteristics, excellent thermal (>0.02 Wm−1 K−1) and mechanical (>363.3 KPa) stability. To test the potential of sponge in real world scenarios, the activated sludge from real wastewater treatment plant was utilized. Interestingly, the GO-PP sponge enhanced the electron transfer between microorganisms and promoted the standardized microorganism’s growth and biofilm formation (22.7 mg/d per gram sponge, 172.1 mg/g), providing the feasibility to accomplish a symbiotic system within specifically design upgraded algal-bacterial reactor. Furthermore, the continuous flow process by utilizing GO-PP sponge in algal-bacterial reactor demonstrated the effectiveness in treating low concentration antibiotic wastewater, presenting 86.7 % removal rate and >85 % after 20 cycles. Overall, this work illustrates an applicable strategy to develop a sophisticated modified pathway for the next-generation biological-based applications.