Enhanced denitrification and fouling control in hydrogen-based membrane biofilm reactor using novel flat membrane module

Abstract

In hydrogen-based membrane biofilm reactors (H<inf>2</inf>-MBfR), the most critical concerns revolve removal rate and membrane fouling. This study introduces a novel flat membrane module to enhance denitrification efficiency and the operational stability of MBfR. The membrane module featured an additional layer of polyester material on outer side of the membrane. Experimental results demonstrated that membrane fouling occurred after one week, while the flocking layer extended the fouling-free operation to over eight weeks, representing an eightfold improvement at least. Low temperature and high loading were observed to impact the denitrification efficiency, although it maintained around 50 % without nitrite accumulation. Following the removal of operational disturbances, the MBfR rapidly restored with removal efficiencies reaching 93.8 % to 100 %. As the MBfR operated, microbial analysis revealed a decrease in microbial diversity, and differential expression levels of denitrification genes. The novel membrane module contributed to improving fouling control and removal flux.