Institute of Agricultural Bio-Environmental Engineering, College of Biosystem Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
College of Forestry, Northeast Forestry University, Harbin 150040, China.
J Environ Manage. 2019 Oct 15;248:109267. doi: 10.1016/j.jenvman.2019.109267. Epub 2019 Jul 17.
Moving bed biofilm reactor (MBBR) is widely used for ammonia removal in saline recirculating aquaculture systems but often faces a slow start-up problem. The aim of this study was to develop a strategy for the rapid start-up of MBBR treating synthetic mariculture wastewater. Changes in nitrification performance, biofilm characteristics and bacterial community were assessed in response to various start-up strategies: R1 as the control; R2 with step-decrease of inlet NH-N; R3 with step-increase of inlet salinity; R4 added with particulate organic matter (POM) and R5 inoculated with nitrifying bacteria. Results show that nitrification was completed on day 63 for R3, 16-18 days faster than the other strategies. The highest protein (28.2 ± 5.1 mg/g·VS) and polysaccharide (59.4 ± 0.4 mg/g·VS) contents were observed in R3, likely linked to the faster biofilm formation. Fourier Transform infrared spectroscopy (FTIR) analysis confirmed the typical constituents of carbohydrates, proteins, lipids and DNA in biofilms. Moreover, along with the biofilm development in R3, the intensity of the peak at 1400 cm (assigned to specific amides) decreased. Pyrosequencing of 16s rRNA revealed that Gammaproteobacteria was the predominating microbial community at class level (35.6%) in R3. qPCR analysis further verified the significantly higher gene copies of amoA (1.57 × 10 copies/μL) and nxrB (5.51 × 10 copies/μL) in R3. Results obtained make the elevated salinity strategy a promising alternative for the rapid nitrification start-up of saline wastewater.
移动床生物膜反应器（MBBR）广泛应用于含盐循环水产养殖系统中的氨氮去除，但通常面临启动缓慢的问题。本研究旨在开发一种策略，使 MBBR 快速启动处理合成海水养殖废水。通过评估各种启动策略（R1 为对照；R2 进水 NH-N 逐步降低；R3 进水盐度逐步增加；R4 添加颗粒有机物（POM）；R5 接种硝化细菌）对硝化性能、生物膜特性和细菌群落的变化，研究了快速启动 MBBR 处理海水养殖废水的方法。结果表明，R3 组在第 63 天完成硝化，比其他策略快 16-18 天。R3 组中观察到最高的蛋白质（28.2±5.1 mg/g·VS）和多糖（59.4±0.4 mg/g·VS）含量，可能与更快的生物膜形成有关。傅里叶变换红外光谱（FTIR）分析证实了生物膜中碳水化合物、蛋白质、脂类和 DNA 的典型成分。此外，随着 R3 中生物膜的发展，在 1400 cm 处的峰（分配给特定酰胺）的强度降低。16s rRNA 的焦磷酸测序表明，在 R3 中，γ变形菌门是优势微生物群落（35.6%）。qPCR 分析进一步证实了 R3 中 amoA（1.57×10 拷贝/μL）和 nxrB（5.51×10 拷贝/μL）基因的拷贝数显著更高。研究结果表明，提高盐度的策略是海水废水快速硝化启动的一种很有前景的替代方法。
