Endevours on the enhancement of nitrate removal efficiency during methane oxidation coupled with denitrification (AME-D) has always overlooked the role of membrane employed. It would be highly beneficial to enrich the biomass content and to manage biofilm on the membrane, in the utilization of methane and denitrification. In this study, an innovative and scalable double-layer membrane (DLM) was designed and prepared for a membrane biofilm reactor (MBfR), to simultaneously enhance nitrate removal flux and methane utilization efficiency during aerobic methane oxidation coupled with the denitrification (AME-D) process. The DLM allowed quick bacterial attachment and biomass accumulation for biofilm growth, which would be then self-regulated for well distribution of functional microbes on/within the DLM. Upon a high biofilm density of over 70 g-VSS m⁻² achieved on the DLM, the methane utilization efficiency of the MBfR was enhanced significantly to over 1.3 times than the control MBfR with conventional polypropylene membrane. The MBfR employed DLM also demonstrated the maximum nitrate removal flux of 740 mg-NO₃⁻-N m⁻² d⁻¹ that was approximately 1.64 times of that in control MBfR at continuous-mode operation. This DLM indeed favored the enrichment of Type II aerobic methanotrophs of Methylocystaceae, and methanol-utilization denitrifiers of Rhodocyclaceae that preferentially utilize methanol as the cross-feeding intermediates to promote the methane utilization efficiency, and thus to enhance the nitrate removal flux. These results raised from new designed DLM confirmed the importance of membrane surface properties on the effectiveness of MBfR, and offered great potential to address challenging problems of MBfRs during engineering application.

关于提高甲烷氧化过程中硝酸盐去除效率以及反硝化作用（AME-D）的研究一直忽略了所用膜的作用。在甲烷的利用和反硝化过程中，丰富生物质含量并控制膜上的生物膜将是非常有益的。在这项研究中，为膜生物膜反应器（MBfR）设计并准备了一种创新且可扩展的双层膜（DLM），以在需氧甲烷氧化与反硝化（AME-D）同时提高硝酸盐去除通量和甲烷利用效率） 过程。DLM允许细菌快速附着和生物质积累，从而促进生物膜的生长，然后对其进行自我调节，以使功能性微生物在DLM上/内部良好分布。超过70 g-VSS m的高生物膜密度时在DLM上达到的^-2值，MBfR的甲烷利用效率比常规聚丙烯膜的对照MBfR显着提高了1.3倍以上。采用DLM的MBfR的最大硝酸盐去除通量为740 mg-NO ₃ ^-- N m ^-2 d ^-1，约为连续模式操作MBfR的1.64倍。这的确DLM青睐的II型有氧甲烷氧化菌的富集Methylocystaceae，和甲醇利用反硝化细菌Rhodocyclaceae优先利用甲醇作为交叉进料的中间体，以提高甲烷的利用效率，从而提高硝酸盐的去除通量。新设计的DLM产生的这些结果证实了膜表面特性对MBfR有效性的重要性，并为解决工程应用过程中MBfR的难题提供了巨大的潜力。