Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China; College of Environment and Ecology, Chongqing University, Chongqing 400045, PR China.
North China Municipal Engineering Design and Research Institute, Tianjin 300381, PR China.
Bioresour Technol. 2021 Dec;342:126002. doi: 10.1016/j.biortech.2021.126002. Epub 2021 Sep 22.
In this study, two denitrification bio-filters adopted polycaprolactone (PCL) and sodium acetate (NaAc) as polymer and water-soluble carbon sources respectively. With the increasing influent nitrate concentrations, NaAc bio-filter always had shorter HRT to achieve complete nitrate removal. Furthermore, the optimal volumetric denitrification rate in NaAc bio-filter was 0.728 g N/(L·d), which was higher than 0.561 g N/(L·d) in PCL bio-filter. For nitrates removal, the costs of bio-filters supported by NaAc and PCL were 24.93 and 120.25 CNY/kg N respectively. Although Proteobacteria in PCL bio-filter was abundant with 83.98%, NaAc bio-filter had better denitrification performance, due to the appropriate ratio of nitrate removal microorganisms and organic matters degradation organisms. The total abundance value of the denitrification genera is NaAc (16.06%) < PCL (41.19%). However, PCL bio-filter had poor denitrification performance, due to the lower adequacy of PCL depolymerization enzymes and the low expression of the key genes for denitrification.
在本研究中，采用聚己内酯（PCL）和乙酸钠（NaAc）分别作为聚合物和水溶性碳源的两种反硝化生物滤池。随着进水硝酸盐浓度的增加，NaAc 生物滤池总是具有更短的水力停留时间（HRT）来实现完全的硝酸盐去除。此外，NaAc 生物滤池的最佳容积反硝化速率为 0.728 g N/（L·d），高于 PCL 生物滤池的 0.561 g N/（L·d）。对于硝酸盐的去除，以 NaAc 和 PCL 为支撑的生物滤池的成本分别为 24.93 和 120.25 CNY/kg N。尽管 PCL 生物滤池中的变形菌门（Proteobacteria）的丰度高达 83.98%，但由于硝酸盐去除微生物和有机物降解微生物的适当比例，NaAc 生物滤池具有更好的反硝化性能。反硝化属的总丰度值 NaAc（16.06%）<PCL（41.19%）。然而，由于 PCL 解聚酶的充足性较低和反硝化关键基因的低表达，PCL 生物滤池的反硝化性能较差。
