多相芬顿催化剂表面生物膜对去除双酚A的影响及其微生物群落表征

Effects of the surface biofilms of heterogeneous Fenton catalyst on the bisphenol A removal and the characterization of its bacterial community

为了分析经长期运行的多相芬顿催化柱上生物膜的群落结构特征及其对双酚A去除的影响,利用中试实验对多相芬顿催化降解天然有机物(NOM)进行了为期200 d的跟踪检测,并利用小试实验对比研究了在有无生物膜以及催化柱不同位置上的生物膜对多相芬顿反应去除双酚A的影响效果。同时采集了多相芬顿催化柱不同位置的催化剂样品,对样品表面的生物膜群落结构、微生物量、代谢活性以及胞外多聚物(EPS)进行了系统的表征。结果表明:多相芬顿对NOM有很好的去除效果,而且生物膜的形成使得对双酚A的去除率可提高到36%~39%;此外,催化柱生物膜上微生物群落存在相似性,其中层和下层相似度更高;上层生物膜中微生物以赫山单胞菌属(Herminiimonas)和慢生根瘤菌属(Bardyrhizobium)为主,而中层和下层生物膜中微生物以Reyranella菌属和生丝微菌属(Hyphomicrobium)为主;随着微生物群落的变化,中试催化柱由上层到下层生物量有所增加,微生物代谢活性增强,可分泌更多的EPS,这可能是生物膜特别是下层生物膜提高对双酚A去除效果的主要原因。以上研究结果证实,多相芬顿技术是一种很有应用前景的去除微量污染物的实用技术。

In order to investigate the biofilms communities on the surface of heterogeneous Fenton catalyst after long-time running and their effects on the removal of bisphenol A,the heterogeneous Fenton was studied in a pilot scale to test its effect on the removal of natural organic matter(NOM)for 200 d.The effects of biofilms and the biofilms at different places of catalyst column on the removal of bisphenol A were also studied using a bench scale test.Meanwhile,different catalyst samples at the different places of the catalyst column were collected,and the biofilms bacterial community structure,bacterial biomass,bacterial metabolism,and the composition of extracellular polymeric substances(EPS)on the sample surface were analyzed.The results showed that heterogeneous Fenton had a good performance on the removal of NOM,and the formed biofilms improved the removal rate of bisphenol A to 36%~39%.Moreover,the results also indicated that the biofilms showed great similarity,especially for the biofilms in the middle and lower layers.The bacterial genera in upper layers were dominated by Herminiimonas and Bardyrhizobium,while in middle and lower layers,the bacterial genera were dominated by Reyranella Hyphomicrobium.Along with the changes of bacterial community,the biomass increased in the biofilms of catalyst from top to bottom.The function of bacterial metabolism also increased,and the bacteria could produce more EPS.This may be the main reason for the more removal of bisphenol A by biofilms adsorption,especially for the biofilms in the lower layers.The results indicated that the heterogeneous Fenton was a practical technique with promising applications for removing micropollutants.