SBR系统外加磁场对微生物群落多样性和处理效果的影响

Treatment Efficiency and Microbial Community Diversity in a Magnetic Field Enhanced Sequencing Batch Reactor(SBR)

SBR反应器的应用越来越普遍,为进一步提高其处理效率,提出在SBR反应体系再外加一个磁场来提高其运行性能.研究了不同磁感应强度对反应系统污染物降解效率的影响,并采用Mi Seq高通量测序技术解析了磁场条件下活性污泥微生物群落多样性变化.结果表明,磁场的加入在一定程度上提高了SBR系统的运行性能,且当磁感应强度为7×10^(-2)T时效果最明显.其中,外加磁场对SBR反应系统中总氮去除效果的影响显著,在7×10^(-2)T时脱氮率从无磁场的65.69%提高到85.98%.外加磁场显著提高了污泥脱氢酶活性,因而也会对各种污染物的去除产生积极作用.通过对不同磁感应强度下活性污泥微生物群落多样性的比较发现,7×10^(-2)T磁场下活性污泥微生物丰度及多样性最高.实验SBR反应器中的细菌域共鉴定出14个门,主要以变形菌门Proteobacteria(25.3%~61.5%)、拟杆菌门Bacteroidetes(18.6%~46.2%)、放线菌门Actinobacteria(5.3%~47.2%)、酸杆菌门Acidobacteria(0.4%~4.0%)为主.重要的脱氮细菌:如α-Proteobacteria的Rhodoblastus、Paracoccus;β-Proteobacteria的Alicycliphilus、Comamonas、Xenophilus、Acidovorax、Dechloromonas、Thauera;δ-Proteobacteria的Desulfovibrio;Planctomycetes门等,在中等磁感应强度尤其是7×10^(-2)T时,丰度最高,与脱氮效率增加有内在的联系.典型的PAOs如Acinetobacter、Pseudomonas、Propionicimonas等,在中等磁场条件下含量较高,与除磷率变化趋势相同.活性污泥中细菌群落结构变化与污水处理效率存在一定相关性,外加磁场通过改变微生物群落结构影响污水处理效果.

The application of SBR reactors is becoming more common and in order to further improve the efficiency of their treatment it has been proposed to add a magnetic field to SBR systems.The effects of different magnetic fields on the degradation efficiency of conventional pollutants in an SBR was studied.Mi Seq high-throughput sequencing techniques were used to analyze the diversity of microbial communities in activated sludge under magnetic field conditions.These results show that the addition of a magnetic field improves the performance of a SBR system to an extent and magnetic induction effects are most obvious at 7 × 10^-2 T.This is identified through a significant effect on the removal efficiency of total nitrogen and an increase in the denitrification rate from 65.69% to85.98%.It also significantly improves the activity of sludge dehydrogenase and has a positive effect on the removal of various pollutants.The diversity of microbial communities in activated sludge under different magnetic field intensities shows a greater microbial abundance and diversity in the active sludge.The bacterial domain in the experimental SBR includes 14 phyla,which are mainly Proteobacteria（25.3%-61.5%）,Bacteroidetes（18.6%-46.2%）,Actonobacteria（5.3%-47.2%）,and Acidobacteria（0.4%-4.0%）.Important denitrification bacteria such as Rhodoblastus,Paracoccus of α-Proteobacteria,Alicycliphilus,Comamonas,Xenophilus,Acidovorax,Dechloromonas,Thauera of β-Proteobacteria,Desulfovibrio of δ-Proteobacteria and Planctomycetes,etc.at a moderate magnetic induction of 7 × 10^-2 T have a high abundance and there is an internal relationship between this and an increase in denitrification efficiency.Polyphosphate-accumulating organisms（PAOs） such as Acinetobacter,Pseudomonas,Propionicimonas,etc.,are present at higher levels under these conditions and follow the same trends as for the phosphorus removal rates.There is a correlation between bacterial community structure changes and sewage treatment efficiency in activated sludge.Applied magnetic fields have a positive effect on sewage treatment by changing the microbial community structure.