Zhao Linting, She Zonglian, Jin Chunji, Yang Shiying, Guo Liang, Zhao Yangguo, Gao Mengchun
Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
Bioprocess Biosyst Eng. 2016 Sep;39(9):1375-89. doi: 10.1007/s00449-016-1613-x. Epub 2016 Apr 28.
The composition and distribution of extracellular polymeric substance (EPS) both from suspended sludge and attached biofilm were investigated in a simultaneous nitrification and denitrification (SND) system with the increase of the salinity from 1.0 to 3.0 %. Fourier-transform infrared (FTIR) spectroscopy and three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy were used to examine proteins (PN), polysaccharides (PS) and humic substances (HS) present in EPS. High total nitrogen removal (above 83.9 %) via SND was obtained in the salinity range of 1.0-2.5 %. Total EPS in the sludge increased from 150.2 to 200.6 mg/gVSS with the increase of salinity from 1.0 to 3.0 %, whereas the corresponding values in the biofilm achieved the maximum of 288.6 mg/g VSS at 2.0 % salinity. Dominant composition of EPS was detected as HS in both sludge and biofilm, having the percentages of 50.6-68.6 and 41.1-69.9 % in total EPS, respectively. Both PN and PS contents in soluble EPS (S-EPS), loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) of sludge and biofilm increased with the increased salinity. The FTIR spectrum and 3D-EEM fluorescence spectroscopy of S-EPS, LB-EPS and TB-EPS in the sludge and biofilm showed the changes of functional groups and conformations of the compositions in EPS with the increase of salinity. The results demonstrated that the characteristics of EPS varied from sludge to biofilm. The obtained results could provide a better understanding of the salinity effect on the EPS characteristics in a SND system.
在一个同步硝化反硝化（SND）系统中，研究了随着盐度从1.0%增加到3.0%，悬浮污泥和附着生物膜中胞外聚合物（EPS）的组成和分布。采用傅里叶变换红外（FTIR）光谱和三维激发-发射矩阵（3D-EEM）荧光光谱来检测EPS中存在的蛋白质（PN）、多糖（PS）和腐殖质（HS）。在1.0-2.5%的盐度范围内，通过SND实现了较高的总氮去除率（高于83.9%）。随着盐度从1.0%增加到3.0%，污泥中的总EPS从150.2 mg/gVSS增加到200.6 mg/gVSS，而生物膜中的相应值在盐度为2.0%时达到最大值288.6 mg/g VSS。在污泥和生物膜中，EPS的主要成分均被检测为HS，分别占总EPS的50.6-68.6%和41.1-69.9%。污泥和生物膜中可溶性EPS（S-EPS）、松散结合EPS（LB-EPS）和紧密结合EPS（TB-EPS）中的PN和PS含量均随着盐度的增加而增加。污泥和生物膜中S-EPS、LB-EPS和TB-EPS的FTIR光谱和3D-EEM荧光光谱表明，随着盐度的增加，EPS中成分的官能团和构象发生了变化。结果表明，EPS的特性在污泥和生物膜之间有所不同。所得结果有助于更好地理解盐度对SND系统中EPS特性的影响。
