调控内生正磷酸盐强化好氧颗粒污泥脱氮除磷

Regulating endogenous orthophosphate to initiate a synchronous short-pass nitrification and denitrification phosphorus removal granular sludge process

采用絮状活性污泥为接种污泥,以人工配水为进水,分别以不同的内生正磷酸盐调节方式运行4组活性污泥序批式反应器(SBR),探究不同内生正磷酸盐调节方式对于富集反硝化聚磷菌(DPAOs)和造粒等方面的影响.结果表明,以内生正磷酸盐排出液回流方式运行的颗粒污泥脱氮除磷效果更好,DPAOs活性更高,并且颗粒沉降性能良好.其中,相较于以微好氧模式运行的颗粒污泥系统,以厌氧/微好氧(AO)模式运行的颗粒污泥系统的污染物处理污染物性能更优,其化学需氧量(COD)、总氮(TN)和总磷(TP)的去除效率可分别达到92.57%、94.7%和97.62%.这主要是由内生正磷酸盐刺激、DPAOs和反硝化聚糖菌(DGAOs)的协同作用等多种因素共同影响的结果,在周期性调控系统中内生正磷酸盐后,系统中污泥的内碳源转化率明显提高,DPAOs和DGAOs的活性得到增强,异养反硝化菌(DOHOs)活性被抑制,这也是在进水水质不变的情况下系统脱氮除磷效果得到明显提高的原因,而在较长的周期运行模式下,氨氧化菌(AOB)与DPAOs形成互生作用的同时也抑制其他异养微生物的生长.本研究结果可为同步短程硝化反硝化除磷(SPNDPR)工艺的实际工程化应用提供理论支持.

Orthophosphate is an intermediate product of the biological denitrification process of phosphorus aggregation,which affects the activity of denitrifying phosphorus aggregating bacteria(DPAOs)in competition with other heterotrophic bacteria for carbon sources.In this study,four groups of sequencing batch reactors(SBRs)were operated with various endogenous orthophosphate regulating techniques utilizing synthetic water as influent after being inoculated with flocculent activated sludge.The study aimed to investigate the effects of different endogenous orthophosphate regulation methods on the enrichment of denitrifying phosphorus accumulating bacteria(DPAOs)and granulation.The results showed that the granular sludge operated with endogenous orthophosphate effluent reflux exhibited better nitrogen and phosphorus removal efficiency,higher DPAO activity,and good particle sedimentation performance.In particular,compared to granular sludge systems operated in microaerobic mode,those operated in anaerobic/microaerobic(AO)mode demonstrated superior pollutant treatment performance,with COD,TN,and TP removal efficiencies reaching 92.57%,94.7%,and 97.62%,respectively.This was attributed to multiple factors,such as endogenous orthophosphate stimulation,the synergistic effect of DPAOs and denitrifying glycans bacteria(DGAOs).Periodic regulation of endogenous orthophosphate in the system resulted in a significant increase in the internal carbon source conversion rate of sludge,enhanced activities of DPAOs and DGAOs,and inhibition of heterotrophic denitrifying bacteria(DOHOs).Under a longer cycle operation mode,ammonia oxidizing bacteria(AOB)and DPAOs interacted,while also inhibiting the growth of other heterotrophic microorganisms.The findings of this study provide theoretical support for the practical engineering application of simultaneous short-range nitritation-denitritation phosphorus removal(SPNDPR)process.