Hollow fiber layout matters the denitrification performance and mechanism of H2-based membrane biofilm reactor: A comprehensive study of hydrodynamics, bioecology and biokinetics.

作者：Junjian Zheng, Minmin Jiang, Yuchao Chen, Yuanyuan Zhang, Qiaoyan Wei, Mei Chen, Xingran Zhang, Xuehong Zhang, Haixiang Li · 发表于：Water Research · 年份：2025 · DOI：10.1016/j.watres.2025.123708 · 被引用次数：7 · 研究领域：Medicine

As a promising technology for water treatment, the decontamination performance of membrane-biofilm reactor (MBfR) is largely affected by its flow distribution, which regulates the biofilm structure and activity. Herein, we firstly optimized the hydraulic conditions to ameliorate the denitrification performance of H2-based MBfR through a rational design of hollow fiber membrane (HFM) layout. Two MBfRs, assembled by bundled and dispersed modules (termed as B-MBfR and D-MBfR, respectively), were constructed to investigate their process performance and mechanism, from a multi-perspective analysis of flow characteristics, biofilm ecology and microbial kinetics. The results indicated that as the HFM spacing was enlarged from 0 to 4 mm, the shift of flow distribution from bias flow to homogeneous flow occured, leading to the development of annular biofilm and individual biofilms in B-MBfR and D-MBfR, respectively. The superior denitrification flux was attained by D-MBfR instead of B-MBfR (1.1 vs. 0.58 g N/m2·d) in long-term experiments, and so were the denitrification kinetics rates of the former in short-term tests. The biofilms in D-MBfR exhibited the stronger anti-shear capacity over annular biofilm, due to their more uniform distribution of proteins and polysaccharides. Benefiting from the thinner thicknesses of biofilms and narrowed hydrodynamic boundary layer, D-MBfR enabled the greater abundance and metabolic activity of hydrogenotrophic denitrifying bacteria than B-MBfR, whi...