Han Zhiying, Chen Shixia, Lin Xiaochang, Yu Hongjun, Duan Li'an, Ye Zhangying, Jia Yanbo, Zhu Songming, Liu Dezhao
a College of Biosystems Engineering and Food Science , Zhejiang University , Hangzhou , Zhejiang , China.
b Agricultural Engineering Consulting Center , Beijing , China.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2018 Jan 2;53(1):65-72. doi: 10.1080/10934529.2017.1368302. Epub 2017 Oct 16.
To identify the performance of step-fed submerged membrane sequencing batch reactor (SMSBR) treating swine biogas digestion slurry and to explore the correlation between microbial metabolites and membrane fouling within this novel reactor, a lab-scale step-fed SMSBR was operated under nitrogen loading rate of 0.026, 0.052 and 0.062 g NH-N (gVSS·d). Results show that the total removal efficiencies for NH-N, total nitrogen and chemical oxygen demand in the reactor (>94%, >89% and >97%, respectively) were high during the whole experiment. However, the cycle removal efficiency of NH-N decreased significantly when the nitrogen loading rate was increased to 0.062 g NH-N (gVSS·d). The total removal efficiency of total phosphorus in the step-fed SMSBR was generally higher than 75%, though large fluctuations were observed during the experiments. In addition, the concentrations of microbial metabolites, i.e., soluble microbial products (SMP) and extracellular polymeric substances (EPS) from activated sludge increased as nitrogen loading rate increased, both showing quadratic equation correlations with viscosity of the mixed liquid in the step-fed SMSBR (both R > 0.90). EPS content was higher than SMP content, while protein (PN) was detected as the main component in both SMP and EPS. EPS PN was found to be well correlated with transmembrane pressure, membrane flux and the total membrane fouling resistance. Furthermore, the three-dimensional excitation-emission matrix fluorescence spectroscopy results suggested the tryptophan-like protein as one of the main contributors to the membrane fouling. Overall, this study showed that the step-fed SMSBR could be used to treat swine digestion slurry at nitrogen loading rate of 0.052 g NH-N (gVSS·d), and the control strategy of membrane fouling should be developed based on reducing the tryptophan-like PN in EPS.
为了确定分步进水淹没式膜序批式反应器（SMSBR）处理猪沼液的性能，并探索这种新型反应器内微生物代谢产物与膜污染之间的相关性，在氮负荷率为0.026、0.052和0.062 g NH-N/（gVSS·d）的条件下运行了一个实验室规模的分步进水SMSBR。结果表明，在整个实验过程中，反应器中NH-N、总氮和化学需氧量的总去除效率较高（分别>94%、>89%和>97%）。然而，当氮负荷率增加到0.062 g NH-N/（gVSS·d）时，NH-N的周期去除效率显著下降。分步进水SMSBR中总磷的总去除效率一般高于75%，尽管在实验过程中观察到较大波动。此外，随着氮负荷率的增加，活性污泥中微生物代谢产物的浓度，即可溶性微生物产物（SMP）和胞外聚合物（EPS）增加，两者均与分步进水SMSBR中混合液的粘度呈二次方程相关性（两者R>0.90）。EPS含量高于SMP含量，而蛋白质（PN）是SMP和EPS中的主要成分。发现EPS PN与跨膜压力、膜通量和总膜污染阻力密切相关。此外，三维激发-发射矩阵荧光光谱结果表明，类色氨酸蛋白是膜污染的主要贡献者之一。总体而言，本研究表明，分步进水SMSBR可用于处理氮负荷率为0.052 g NH-N/（gVSS·d）的猪沼液，应基于减少EPS中类色氨酸PN来制定膜污染控制策略。
