交替好氧/缺氧运行模式对生物脱氮效能及活性污泥胞外聚合物的影响

以实际生活废水为处理对象,考察了SBR工艺好氧/缺氧(O/A)和缺氧/好氧(A/O)运行模式对生物脱氮性能、胞外聚合物(extracellular polymeric substance,EPS)及其组分(蛋白质PN、多糖PS和核酸DNA)的影响.结果表明,O/A和A/O运行模式下,SBR工艺均获得了高效稳定的NH_4~+-N去除,去除率分别为97.5%和98.0%,且硝化速率与NH_4~+-N负荷呈现较好正相关性.交替缺氧/好氧运行模式对于EPS影响,A/O模式下EPS产量略高于O/A模式下,且运行模式对TB-EPS及其组分(PN、PS和DNA)产量无显著影响,但A/O模式下LB-EPS及其组分(PN和PS)产量均高于O/A模式下,倍数介于1.38~1.56之间.2种模式条件下,PS是TB-EPS和EPS的主要组分,而PN是LB-EPS的主要成分.EPS含量与污泥沉降性能具有良好的线性正相关.

Influence of Operating Modes for the Alternating Anoxic/Oxic Process on Biological Nitrogen Removal and Extracellular Polymeric Substances of Activated Sludge

Nitrogen removal, extracellular polymeric substances (EPS), and the chemical composition (protein (PN), polysaccharide (PS), and DNA) by the aerobic/anoxic (O/A) and the anoxic/aerobic (A/O) modes were studied in a sequencing batch reactor (SBR) fed with domestic wastewater. The results showed that the removal rates of NH₄⁺-N were 97.5% and 98.0% in the two operating modes, respectively, and a removal efficiency of NH₄⁺-N with high efficiency and stability was obtained. The nitrification rate was positively correlated with the nitrogen loading ratio. The influence of operating modes for the alternating anoxic/oxic mode on extracellular polymeric substances of activated sludge was evaluated. The EPS constituent in the A/O mode was slightly higher than the O/A mode. The operating mode had no effect on the contents of PN, PS, and DNA in tightly bound EPS (TB-EPS) and TB-EPS. However, PN and PS in loosely bound EPS (LB-EPS) and LB-EPS in the A/O mode were 1.38 to 1.56 times those of the O/A mode. In the two operating modes, PSs were the main constituents in the TB-EPS and EPS, while PNs were the main constituents in LB-EPS. The EPS content had a good linear correlation with the sludge settling performance.