包埋硝化填料在稀土矿山废水中的硝化特性及群落结构分析

Nitrification Characteristics and Community Structure Analysis of Embedded Nitrification Fillers in Rare Earth Mine Wastewater

在中试规模的反应器中,研究包埋硝化填料在稀土矿山废水中的硝化特性,考察DO对硝化填料氨氮去除效果的影响,并通过高通量测序技术分析填料内微生物多样性和菌群结构的变化。结果表明,在DO为5.5~6.5 mg·L^(-1)、pH为7.5~8.0、温度为28.1℃、HRT为3.4 h和填料填充率为8%的条件下,包埋硝化填料氨氮去除速率可达0.43 kgN·m^(-3)·d^(-1)。考虑氧气的传质效率和填料的使用寿命,包埋硝化填料的DO水平应控制在4.5~5.5 mg·L^(-1)。高通量分析表明,包埋填料内硝化菌群结构保持较好,氨氧化细菌Nitrosomonas在填料内的丰度显著增长,占比从6.58%上升至21.24%。

In a pilot-scale reactor,the nitrification characteristics of the embedded nitrification filler in rare earth mine wastewater were studied,the effect of different DO levels on the removal of ammonia nitrogen from the nitrification filler was investigated,and the changes of microbial diversity and bacterial community structure in the embedded nitrification filler were analyzed by high-throughput sequencing technology.Results showed that under with DO of 5.5~6.5 mg·L^(-1),pH of 7.5~8.0,temperature of 28.1℃,HRT of 3.4 h and filler volume rate of 8%,the ammonia nitrogen removal rate of the nitritation filler reached 0.43 kgN·m^(-3)·d^(-1).Considering the mass transfer efficiency of oxygen and the service life of the fillers,the DO level of the embedded nitrification fillers should be controlled at 4.5~5.5 mg·L^(-1).High-throughput analysis showed that the structure of nitrifying bacteria in the embedded filler was well maintained,and the abundance of ammonia-oxidizing bacteria Nitrosomonas within the filler increased significantly,and the proportion increased from 6.58%to 21.24%.