This study investigated the performance and microbial communities of denitrifying biofilms on polyurethane foam coupled with various solid carbon sources of acid- and alkali-pretreated rice straw and rice husk. Results showed that acid and alkali-pretreated rice straw both had higher TOC release rates (0.041–0.685 mg g⁻¹ day⁻¹) than those of rice husk (0.019–0.160 mg g⁻¹ day⁻¹) over a month, while acid pretreatment of rice husk and rice straw had a much higher organics release rate than that of alkali pretreatment and non-pretreatment, respectively. Acid-pretreated rice straw achieved the most efficient TN removal performance (82.06 ± 3.65%) with the lower occurrences of NH₄⁺-N during denitrification than that of alkali-pretreated rice straw (80.05 ± 4.12%) over more than a month operation. However, alkali pretreatment of rice husk demonstrated much more significantly efficient TN removal efficiency (80.39 ± 2.1%) than did acid pretreatment (69.59 ± 13.43%). MiSeq sequencing analysis showed that the four biofilm samples attached on polyurethane foam with the addition of pretreated rice straw or rice husk had a range of 13–15 differentially abundant phylum and 81–123 differentially abundant genera in comparison with biofilm without extra solid carbon sources, and a higher TN removal efficiency demonstrated more types of differentially abundant genera.

中文翻译：

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聚氨酯泡沫上反硝化生物膜的性能和微生物多样性，再加上各种固体碳源，可净化富含硝酸盐的水。

这项研究调查了聚氨酯泡沫上反硝化生物膜的性能和微生物群落，以及酸和碱预处理的稻草和稻壳的各种固体碳源。结果表明，酸和碱预处理的稻秸都具有较高的TOC释放率（毫克0.041-0.685克^-1 天^-1）比稻壳（0.019-0.160毫克克^-1 天^-1）超过一个月，而稻壳和稻草的酸预处理分别比碱预处理和非预处理有机物释放速率高。酸预处理的稻草获得了最有效的TN去除性能（82.06±3.65％），而NH ₄ ^+的发生率却较低在一个多月的运行中，反硝化过程中的-N值比碱预处理的稻草（80.05±4.12％）高。但是，稻壳的碱预处理显示出比酸预处理（69.59±13.43％）更有效的总氮去除效率（80.39±2.1％）。MiSeq测序分析表明，与不含额外固体碳源的生物膜相比，附着在聚氨酯泡沫上并添加预处理过的稻草或稻壳的四个生物膜样品具有13-15的差异丰富的门脉和81-123的差异丰富的属，更高的总氮去除效率表明更多种类的差异丰富属。