SCSC-S/Fe复合系统脱氮除磷途径及微生物群落特性

Way of nitrogen and phosphorus removal and microbial community characteristics for SCSC-S/Fe

为提升再生水品质,以玉米芯耦合硫铁填料构造出固相纤维素碳源+硫铁填料复合脱氮除磷系统(简称SCSC-S/Fe复合系统),基于填料生物膜Miseq高通量测序构建了16S rRNA基因克隆文库,结合系统沉积物的X射线衍射(XRD)分析,探讨了该系统对模拟城市污水处理厂低C/N比尾水深度脱氮同步除磷特性及作用途径.结果表明,随温度升高,TN去除率逐渐增大,TP去除率增加不明显,在温度为30℃和水力停留时间HRT=9h时,NO_3^--N、TN、TP平均去除率分别为99.86%、92.70%和89.15%.固相纤维素碳源反硝化脱氮单元内具有降解纤维素类和反硝化作用类细菌分别占细菌总数的41.37%和54.02%,硫铁复合填料脱氮除磷单元内异养反硝化、硫自养反硝化和氬自养反硝化的细菌占细菌总数的91.53%;XRD结果表明,水中的PO_4^(3-)主要以FeP0_4、Fe_3(P0_4)_2·χH_20和Fe_3(P0_4)_3(0H)_2等物质形式去除.因此,复合系统脱氮以异养反硝化作用为主,协同硫自养反硝化和氢自养反硝化作用;复合系统具有"化学+生物"双重除磷作用,以化学除磷作用为主.SCSC-S/Fe复合系统实现了低C/N比城市污水处理厂尾水深度脱氮同步除磷的目的.

In order to improve the quality of reclaimed water,a coupling process with solid carbon source of corncob cellulose and sulfur/sponge iron composite fillers was integrated for the further deep removal of nitrogen and phosphorus for municipal wastewater treatment plant(WWTP)effluent that usually contains little organic carbon for heterotrophic denitrifying bacteria to utilize.Based on the bacteria16S rRNA gene clone library analysis by adopting the high-throughput sequencing technologies,both the effect and mechanism of the system(abbreviated as SCSC-S/Fe)on nitrogen(N)and phosphorus(P)simultaneous removal from simulated WWTP effluent were investigated.The results indicated that the TN removal efficiency of the system increased gradually with the increase of temperature,but the removal rate of TP did not raised obviously.Under the condition of30℃temperature and9h HRT,the average removal rates of NO3--N,TN and TP were99.86%,92.70%and89.15%,respectively.There were two main classes of bacteriaincluding cellulose degradation and denitrification bacteria with the total bacteria of41.37%and54.02%separately in the solid carbon source of corncob cellulose unit.And there were simultaneous existence of heterotrophic,hydrogen and sulfur autotrophic denitrifying bacteria accounted for91.53%of the total number of bacteria in the sulfur/sponge iron composite fillers unit.X-ray diffraction(XRD)analysis showed that PO43-was removed mainly by the form of FePO4,Fe3(PO4)2·χH2O and Fe3(PO4)3(OH)2.In the system,the nitrogen was removed mainly by heterotrophic denitrification with auxiliary hydrogen and sulfur autotrophic denitrification,and the phosphorus was removed by main chemical reaction and a little biological uptake of phosphate.SCSC-S/Fe system represents a promising method for simultaneous and improved N and P removal from WWTP effluent.