Loofah sponge as an environment-friendly biocarrier for intimately coupled photocatalysis and biodegradation (ICPB)

Intimately coupled photocatalysis and biodegradation (ICPB) provides novel insights into the removal of refractory pollutants. However, the practical application of ICPB was limited by low bacterial loading density and low microbial activity. Herein, an environment-friendly, low-cost and renewable biocarrier was fabricated using natural loofah sponge. In comparison to polyurethane carrier, after employing loofah sponge in ICPB, the tetracycline hydrochloride (TCH) removal rate was increased by ∼6.6 %, the mineralization was increased by ∼9.2 %, and almost all photocatalytic products were degraded. Compared with conventional catalyst coating strategies, our powder spraying method enables the exterior surface of biocarrier to be firmly coated by the photocatalyst, while the inside of biocarrier was extremely clean to accumulate bacteria. The biocarrier provided a higher loading density and a higher microbial activity of bacteria than that of polyurethane carrier. Besides, it can regulate the bacterial community to have more favorable members to biodegrade the photocatalysis intermediates. In summary, using loofah sponge as biocarrier could be an effective approach for enhancing the biodegradation performance of ICPB.