College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
Bioresour Technol. 2021 Apr;325:124667. doi: 10.1016/j.biortech.2021.124667. Epub 2021 Jan 7.
Core nitrogen cycle within biofoulant in full-scale anoxic & oxic biofilm-membrane bioreactor (bMBR) treating textile wastewater was investigated. Wastewater filtered through membrane with biofoulant had elevated NH-N and NO-N concentrations corresponding to decreased NO-N concentrations. Nevertheless, total nitrogen concentrations did not change significantly, indicating negligible nitrogen removal activities within biofoulant. Metagenomic analysis revealed a lack of genes, such as AmoCAB and Hao in biofoulant, indicating absence of nitrification or anammox populations. However, genes encoding complete pathway for dissimilatory nitrate reduction to ammonium (DNRA) were discovered in 15 species that also carry genes encoding both nitrate reductase and nitrite reductase. No specie contained all genes for complete denitrification pathway. High temperature, high C:N ratio, and anoxic conditions of textile wastewater could favorite microbes growth with DNRA pathway over those with canonical denitrification pathway. High dissolved oxygen concentrations could effectively inhibit DNRA to minimize ammonia concentration in the effluent.
研究了全规模缺氧-好氧生物膜-膜生物反应器（bMBR）处理纺织废水过程中生物污垢内的核心氮循环。通过膜过滤的废水带有生物污垢，NH-N 和 NO-N 浓度升高，而 NO-N 浓度降低。然而，总氮浓度没有显著变化，表明生物污垢内几乎没有脱氮活性。宏基因组分析显示，生物污垢中缺乏 AmoCAB 和 Hao 等基因，表明不存在硝化或厌氧氨氧化种群。然而，在 15 个物种中发现了编码异化硝酸盐还原为铵（DNRA）完整途径的基因，这些物种还携带编码硝酸盐还原酶和亚硝酸盐还原酶的基因。没有一个物种包含完整的反硝化途径基因。纺织废水的高温、高 C:N 比和缺氧条件有利于具有 DNRA 途径的微生物生长，而不利于具有经典反硝化途径的微生物生长。高溶解氧浓度可有效抑制 DNRA，最大限度减少出水中的氨浓度。
