河道底泥中异养硝化-好氧反硝化菌群富集培养及其脱氮性能

采用选择性富集培养基,从河道底泥中成功筛选出具有氮素去除效果的优势微生物菌群:异养硝化-好氧反硝化菌群(H)、异养硝化菌群(Y)和好氧反硝化菌群(F).高通量测序分析结果显示,各混合菌群中脱氮功能菌的相对丰度分别为54.72%、46.26%和91.57%.在此基础上,考察了微量元素对3组混合菌群脱氮性能的影响,结果表明,混合菌群H和F在添加微量元素浓缩液0.5 mL·L~(-1)时脱氮性能最佳,在72 h时混合菌群H对氨氮、硝酸盐氮的去除率分别为69.11%和99.06%,混合菌群F对硝酸盐氮的去除率达99.62%;而混合菌群Y在不添加微量元素时氨氮的去除率最高,为82.60%.采用优化培养的3组混合菌群及其复合菌群(H+Y、Y+F、H+F、H+Y+F)分别对模拟河水进行处理,模拟河水的COD和氮素指标可从地表水V类水质净化至Ⅳ类水质,其中,复合菌群H+Y+F的氮素去除效果最佳,在36 h时氨氮、硝酸盐氮和总氮的浓度分别为0.182、0.000和0.501 mg·L~(-1),说明本研究富集筛选出的混合脱氮菌群在实际河水净化中具有潜在应用价值.

Enrichment and nitrogen removal characteristic of heterotrophic nitrification-aerobic denitrifiers from rive sediment

Three cultures, heterotrophic nitrification-aerobic denitrifiers (H), heterotrophic nitrifiers (Y) and aerobic denitrifiers (F), were successfully enriched from river sediment by selective enrichment medium. High-throughput sequencing revealed that the relative abundance of functional bacteria in each community was identified as 54.72%, 46.26% and 91.57%, respectively. trace element effects on nitrogen removal performance for three denitrifying cultures were investigated. The results show that culture H and F exhibited the best nitrogen removal performance at 0.5 mL·L^-1 of trace elements. The removal efficiencies of ammonia and nitrate by culture H were 69.11% and 99.65% after 72 hour, and the removal efficiencies of nitrate by culture F reached 99.62%. However, the removal efficiency of ammonia was the highest at 82.60% for culture Y when no trace elements were added at the 72 hour. The COD and nitrogen indexes of the simulated river water could be purified from class V of quality standards for surface water to class IV after these three optimized single and their mixed cultures (H+Y, Y+F, H+F, H+Y+F) inoculated respectively. The mixed culture (H+Y+F) had the highest nitrogen removal efficiencies, with 0.182 mg·L^-1 ammonia, 0.000 mg·L^-1 nitrate and 0.501 mg·L^-1 total nitrogen (TN) of the simulated river water at the 36 hour. The selected three denitrifying culture have potential application value in actual river water purification.