铁碳自养反硝化高效去除厌氧氨氧化出水硝酸盐氮效能分析

Performance analysis of iron-carbon autotrophic denitrification for efficient removal of nitrate from anammox effluent

通过工艺连续运行研究、铁沉淀形态转化和微生物种群结构分析,考察铁碳自养反硝化工艺对厌氧氨氧化出水硝酸盐氮的去除效能,揭示铁碳载体与生物膜耦合的理论机制.结果表明:铁碳自养反硝化工艺可实现硝酸盐氮的高效去除.在水力停留时间(HRT)为16.6h时,厌氧氨氧化出水的总氮(TN)去除率可达(90.0±4.7)%;在HRT为13.3h时,厌氧氨氧化出水的TN去除率为(82.2±1.4)%.在运行阶段Ⅰ,Fe_(3)O_(4)是生物膜中的主要铁沉淀类型,而在阶段Ⅲ,生物膜中Fe_(3)O_(4)减少,密度更小的FeOOH型铁沉淀有所增加.铁碳自养反硝化工艺运行过程中,在接种污泥中占优势的兼养反硝化菌脱氯单胞菌(Dechloromonas)比例显著降低,而自养反硝化菌和铁转化细菌得到富集,热单胞菌属(Thermomonas)的相对丰度由第43d的0.70%提升至第120d的4.51%.

The investigation of nitrate removal from anammox effluent using the iron-carbon autotrophic denitrification process,involved the examination of continuous operation,iron precipitation transformation,and microbial community structure.The study revealed the coupling mechanism between the iron-carbon carrier and biofilm,demonstrating the efficient removal of nitrate through the iron-carbon autotrophic denitrification process.At HRT of 16.6h,the total nitrogen(TN)removal efficiency of anammox effluent was found to be(90.0±4.7)%.Conversely,the TN removal rate of anammox effluent was(82.2±1.4)%at HRT of 13.3h.During Stage I,Fe_(3)O_(4) was identified as the predominant form of iron precipitation within the biofilm,whereas in Stage III,there was a decrease in Fe_(3)O_(4) and an increase in the density of FeOOH type iron precipitation.Throughout the iron-carbon autotrophic denitrification process,the prevalence of Dechloromonas,the primary denitrifying bacterium in the initial sludge inoculum,experienced a notable decrease.Conversely,there was an enrichment of autotrophic denitrifying bacteria and iron-converting bacteria,exemplified by the rise in relative abundance of Thermomonas from 0.70%on day 43 to 4.51%on day 120.