Department of Civil and Environmental Engineering, Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China..
Department of Civil and Environmental Engineering, Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China.
Sci Total Environ. 2020 Sep 15;735:139345. doi: 10.1016/j.scitotenv.2020.139345. Epub 2020 May 11.
Aiming for total nitrogen (TN) pollution control in the urbanized stream, this study proposed and verified a strategy of cultivating and acclimating sulfur-based autotrophic denitrifiers by using river-bottom sediments as seed sludge, and investigated temperature effects on sulfur-based autotrophic denitrification (SAD). With thiosulfate as an electron donor, seven SAD batch reactors were operated and studied at both 15 °C and 30 °C, to compare reactor performance and their microbial community analysis results. In the first batch, three parallel reactors (A1, A2, and A3) were operated at 30 °C for 30 days. The dynamic analysis showed that sequentially decreasing temperature to 20, 15, and 10 °C had significant adverse effects on nitrate-loading rates. In the second batch, two groups of parallel reactors were operated at 30 °C (B1 and B2) and 15 °C (C1 and C2) for 45 days. High TN removal efficiencies (>95%) were achieved in all four reactors, with comparable nitrate loading rates and less nitrite accumulation at 15 °C. High-throughput sequencing revealed that genus Thiobacillus was predominant (66.3-90.0%) in all seven reactors. However, at the operational taxonomic unit level, microbial communities at 15 °C and 30 °C were significantly different, indicating that dissimilar strains were cultivated. Our findings suggested that deliberately cultivating cold-adapted denitrifiers helps SAD to achieve high TN removal at psychrophilic temperatures and thus, is important for future applications in practical TN pollution control in urbanized streams.
针对城市河流的总氮（TN）污染控制，本研究提出并验证了一种利用河底沉积物作为接种污泥培养和驯化硫自养反硝化菌的策略，并研究了温度对硫自养反硝化（SAD）的影响。以硫代硫酸盐作为电子供体，在 15°C 和 30°C 下运行了七个 SAD 批式反应器，并对其进行了研究，以比较反应器性能及其微生物群落分析结果。在第一个批次中，三个平行反应器（A1、A2 和 A3）在 30°C 下运行了 30 天。动态分析表明，依次将温度降低至 20°C、15°C 和 10°C 对硝酸盐负荷率有显著的不利影响。在第二个批次中，两组平行反应器在 30°C（B1 和 B2）和 15°C（C1 和 C2）下运行了 45 天。所有四个反应器均实现了高 TN 去除效率（>95%），在 15°C 下硝酸盐负荷率相当，亚硝酸盐积累较少。高通量测序结果表明，所有七个反应器中优势属均为硫杆菌属（66.3-90.0%）。然而，在操作分类单元水平上，15°C 和 30°C 下的微生物群落存在显著差异，表明培养了不同的菌株。我们的研究结果表明，有目的地培养耐冷脱氮菌有助于 SAD 在低温下实现高 TN 去除，因此对于未来在城市河流实际 TN 污染控制中的应用具有重要意义。
