Study On Performance Of Nitrogen And Phosphorus Removal And Microbial Characteristics In SBR Process Enhanced By Humic Soil

The humic soil has a good effect on the enhancement of nitrogen and phosphorus removal,and improving the properties of activated sludge process.In this paper,the influence of humic soil on nitrogen and phosphorus removal efficiency of SBR process was investigated,and the effect of water temperature and operation mode on the pollutant removal efficiency of humic soil SBR process were studied by setting different water temperature and operation modes,by using the technology of Miseq high-throughput sequencing to study the microbial community changes,to provide a theoretical basis for the further development and application of the technology.The test results of external SBR and conventional SBR under 25 ? water temperature showed that the humic soil had little effect on the removal of COD,but the removal rate of NH4+-N and TP were higher than that of conventional SBR by5.9% and 7.4%,respectively.The test results of external SBR at the temperature of 10 ?,15 ? and 25 ?showed that the water temperature had little effect on the removal of COD.And the increase of water temperature was beneficial to the removal of NH4+-N,but not conducive to the removal of TP.The results of high-throughput sequencing showed that the increase of temperature was beneficial to the enrichment and diversity of microbial community.The relative abundance of Rhodocyclaceae was 20.62%,15.22% and 11.34% respectively,the relative abundance of Aeromonas was 2.12%,0.81%,0.1%,respectively,decreased with the increase of water temperature.The relative abundance of Comamonadaceae was 3.65%,4.16% and 10.42%,respectively,increased with the increase of water temperature.The changes of these functionalbacteria were consistent with the difference of NH4+-N and TP removal efficiency in these reactors.The test results of external SBR and internal SBR under 25 ? water temperature showed that there was no significant difference in the removal of COD between the external and the internal SBR.As to the removal rate of NH4+-N and TP,internal reactor higher than the external reactor by 2.2%,3.8%,respectively.It showed that the internal humic soil is conducive to the removal of ammonia nitrogen and phosphorus.The results of high-throughput sequencing showed that the microbial enrichment of the internal reactor was better than that of the external reactor,but the diversity was not significantly different.The relative abundance of the Rhodocyclaceae,Xanthomonadaceae,Comamonadaceae,Thauera in internal sample were higher than that of the external sample by 4.27%,1.9%,2.82%,4.26%,respectively,which was consistent with that the internal humic soil was help to remove ammonia nitrogen and phosphorus.The test results of internal SBR reactors by the modes of aerobic/anaerobic and anaerobic/aerobic under 10 ? water temperature showed that the order of aerobic and anaerobic had little effect on the removal rate of COD and TP,but the COD and TP degradation rate of aerobic/anaerobic operation were faster than that of anaerobic/aerobic operation.And the removal rate of NH4+-N in aerobic/anaerobic operation was higher than anaerobic/aerobic operation by 4.3% or so.Aerobic/anaerobic operation is conducive to the removal of ammonia nitrogen.The results of high-throughput sequencing showed that the abundance and diversity of microbial community in aerobic/anaerobic reactor were higher than anaerobic/aerobic reactor.Compared with the crude sludge,Aeromonas increased by 5.02% and 1.79%,respectively,and Thauera increased by 3.49% and 2.71%,respectively,Comamonadaceae increased by 4.74% and 2.72%,respectively.This was consistent with the better removal of NH4+-N and TP under aerobic/anaerobic conditions.