盐胁迫对厌氧氨氧化污泥脱氮性能及其胞外聚合物特性的影响

探究了低负荷下盐胁迫对ANAMMOX污泥EPS特性的影响。当盐浓度低于10 g·L-1,厌氧氨氧化脱氮性能未受显著影响,NH+4-N和NO-2-N去除率接近100%,NO-3-N浓度略有升高;当盐浓度提升至15 g·L-1后,脱氮效果急速下降,NO-3-N浓度持续升高,TN去除率最低为53.9%。后经较长时间盐浓度10 g·L-1工况下运行恢复,厌氧氨氧化菌耐盐性经驯化后提高,脱氮效果得到提升;而后继续提升盐浓度至15 g·L-1,脱氮效果维持稳定。随盐浓度增加,EPS含量递增,由8.00 mg·g-1VSS增至13.35 mg·g-1VSS,增幅为66.9%;EPS中主要为TB-EPS,平均占比为81.2%。LB-EPS、TB-EPS中均以PN为主,其平均占比分别为77.0%与91.1%,主要组成为芳香族蛋白类物质与色氨酸蛋白类物质。LB-EPS和TB-EPS的三维荧光光谱图和傅里叶红外光谱图分析表明,盐浓度提升引起ANAMMOX污泥中EPS含量、EPS中蛋白质含量构成及官能团组成产生相应的应答,以抵御高盐对功能微生物的不利影响,从而稳定ANAMMOX工艺脱氮性能。

Effects of Salinity on Nitrogen Removal Performance and Extracellular Polymer Substances of ANAMMOX Sludge

The effect of salinity on the EPS characteristics of anaerobic ammonium oxidation(ANAMMOX)sludge under a low nitrogen loading rate was investigated.When the salinity was lower than 10 g·L-1,nitrogen removal performance was not significantly affected.The removal efficiencies of NH+4-N and NO-2-N were nearly 100%,and the effluent NO-3-N concentration were increased slightly.After the salinity increased to 15 g·L-1,the nitrogen removal performance decreased dramatically.The effluent NO-3-N concentration increased continually,and the minimum total nitrogen(TN)removal efficiency was 53.9%.When the salinity decreased to 10 g·L-1 and maintained for a long time,the anaerobic ammonium oxidizing bacteria(AnAOB)tolerated the high salinity,and the nitrogen removal performance was recovered gradually.Afterward,the salinity was increased to 15 g·L-1 again,the nitrogen removal performance was not significantly affected.With the increase in salinity,the EPS concentration correspondingly increased from 8.00 VSS to 13.35 mg·g-1 VSS,which was 66.9%higher.The main content of EPS was TB-EPS with an average content of 81.2%.LB-EPS and TB-EPS were mainly composed of PN,and their average content were 77.0%and 91.1%,respectively.The major components of LB-EPS and TB-EPS were both aromatic protein-like and tryptophan protein-like substances.Three-dimensional fluorescence spectrogram and Fourier infrared spectrogram analysis of LB-EPS and TB-EPS showed that the increase in salinity induced the corresponding response of EPS contents,protein contents and functional group compositions in ANAMMOX sludge,which can offset the adverse effect of high salinity on functional microorganisms and then stabilize the nitrogen removal performance of ANAMMOX.