Mn2+对A/O-BAF系统处理效能和细菌群落多样性的影响

Effects of Mn2+ on the removal efficiency and microbial community diversity of A/O-BAF

摘要:

【目的】通过考察Mn²⁺对A/O-BAF系统处理效能及微生物群落多样性的影响，研究了15℃下不同浓度Mn²⁺对A/O-BAF系统处理效能的影响，并通过高通量测序考察了细菌群落多样性的变化情况。【方法】在温度15℃、水力负荷0.50 m³/（m²·h）、气水比10：1的条件下，在进水中投加Mn²⁺，考察反应器处理效能的变化情况，并通过高通量测序对BAF生物膜样品进行分析。【结果】2.0 mg/L Mn²⁺作用下A/O-BAF系统的COD、NH₄⁺-N、TN、TP去除率分别提高3.51%、2.21%、6.26%和12.13%；4.0 mg/L Mn²⁺作用下COD、NH₄⁺-N、TN、TP去除率分别提高了4.24%、1.92%、7.75%和10.73%；Mn²⁺作用下A/O-BAF系统内反硝化细菌和亚硝酸菌的数量明显增加，硝酸菌数量有所减少，生物膜量和生物膜活性提高。高通量测序结果可知：2.0 mg/L和4.0 mg/L Mn²⁺作用下，微生物群落多样性大幅增加，样本OTU数量从4 430分别提高到5 659和5 556；BAF柱内变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）、黄色单胞菌科（Xanthomonas）、红环菌科（Rhodocyclaceae）、丛毛单胞菌科（Comamonadacea）、丛毛单胞菌属（Comamonas）、陶厄式菌属（Thauera）、Denitratisoma、Sulfuritalea和热单胞菌属（Thermomonas）的相对丰度增加。部分微生物丰度[例如Denitratisoma、Sulfuritalea、红环菌科（Rhodocyclaceae）和丛毛单胞菌科（Comamonadacea）]的增加幅度随着Mn²⁺浓度的提高有所减少；Mn²⁺作用下硝化螺旋菌门（Nitrospirae）和硝化螺菌属（Nitrosospira）的相对丰度减少。【结论】一定浓度下Mn²⁺主要是通过促进A/O-BAF系统的亚硝化和反硝化作用和除磷微生物的生长提高A/O-BAF系统污染物去除效果，但对硝化的促进效果并不明显，且硝酸菌更易被Mn²⁺的抑制和毒害作用所影响。

Abstract:

[Objective] In order to investigate the influence of Mn²⁺ on the removal efficiency and microbial community diversity of A/O-BAF system, the removal efficiency of Anoxic and Aerobic Biological Aerated Filter were analyzed under different concentration of Mn²⁺ at 15.[Methods] Manganese ions were added into the influent water to investigate the change of reactor treatment efficiency under the temperature of 15, hydraulic load 0.50 m³/(m²·h), gas water conditions than 10:1. The BAF biofilm samples were analyzed by high-throughput sequencing.[Results] The results showed that the removal efficiency of COD, NH₄⁺-N, TN and TP in Anoxic and Aerobic Biological Aerated Filter under concentration of 2.0 mg/L Mn²⁺ were increased by 3.51%, 2.21%, 6.26% and 12.13%. Under the concentration of 4.0 mg/L Mn²⁺, the removal efficiency of COD, NH₄⁺-N, TN and TP were increased by 4.24%, 1.92%, 7.75% and 10.73%, respectively. The number of denitrifying bacteria and Nitrobacteria increased significantly, and the number of Nitrosomonas decreased. The number and activity of biofilms also increased. The results of high-throughput sequencing showed that the community diversity increased significantly under 2.0 mg/L and 4.0 mg/L Mn²⁺, and the number of OTU samples increased from 4 430 to 5 659 and 5 556. The relative abundance of Proteobacteria, Firmicutes, Xanthomonas, Rhodocyclaceae, Comamonadacea, Comamonas, Aedonia, Denitratisoma, Sulfuritalea and Thermomonas increased in BAF. The relative abundance of some microorganisms, such as Denitratisoma, Sulfuritalea, and Thermomonas, decreases with higher concentrations of manganese ions. The relative abundance of Nitrosospira and Nitrospirae decreased under the action of manganese ions.[Conclusion] Manganese ion can improve the removal effect of pollutants in the Anoxic and Aerobic Biological Aerated Filter mainly by promoting the nitrification and denitrification and the growth of phosphorus removing microorganisms at 15, but the promotion effect on nitrification is not obvious. Nitrosomonas are more susceptible to the toxic effects of manganese ions.