不同氮源下好氧反硝化菌Defluvibacter lusatiensisstr.DN7的脱氮特性

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 不同氮源下好氧反硝化菌Defluvibacter lusatiensis str.DN7的脱氮特性 DOI: 10.5846/stxb201203090318 作者: 作者单位: 浙江农林大学,浙江农林大学环境与资源学院,浙江农林大学环境与资源学院 作者简介: 通讯作者: 中图分类号: 基金项目: 水体污染控制与治理重大科技专项(2008ZX07101-006-08);浙江省重大科技专项(2009C03006-3) Denitrification characteristics of an aerobic denitrifying bacterium Defluvibacter lusatiensis str. DN7 using different sources of nitrogen Author: Affiliation: Zhejiang Agriculture and Forestry University,,Zhejiang Agriculture and Forestry University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:研究了不同氮源下好氧反硝化菌Defluvibacter lusatiensis str.DN7的脱氮特性。结果表明:菌株均能以硝酸盐和亚硝酸盐为唯一氮源进行好氧反硝化作用。反应4 h,NO3--N和NO2--N的去除率分别达83.35%和85.72%。亚硝酸盐完全还原比硝酸盐提前42 h。硝酸盐还原过程中基本无亚硝酸盐积累,而亚硝酸盐还原过程中则检测到明显的硝酸盐积累,反应4 h,NO3--N积累量达到21.83 mg/L。培养液中同时存在硝酸盐和亚硝酸盐时,菌株优先选择硝酸盐作电子受体。亚硝酸盐共存对硝酸盐还原无显著影响,但培养液中残留的NO2--N随亚硝酸盐比例上升而增加,当亚硝酸盐比例从10%升至50%时,NO2--N残留量由3.38 mg/L增至7.60 mg/L。少量硝酸盐的加入对亚硝酸盐的还原产生抑制作用。当硝酸盐比例为10%时,72 h NO2--N的去除率仅为74.79%,远低于以亚硝酸盐为唯一氮源情况(去除率100%)。以氨氮为唯一氮源时,菌株同时进行异养硝化和好氧反硝化反应,72 h,NH4+-N去除率达85.66%,且基本无硝酸盐或亚硝酸盐积累。少量氨氮共存(氨氮比例<30%)有利于促进菌株的好氧反硝化作用,反之亦然。 Abstract:An aerobic denitrifying bacterium DN7 was isolated from the bio-contact oxidation reactor treating bamboo processing wastewater. Cellular morphology demonstrated that strain DN7 was a gram negative bacillus with an average size of 0.5 μm×1.5 μm and the colony was ivory. Based on the homologic analysis of the 16S rDNA sequence and physiochemical properties, the strain was identified as Defluvibacter lusatiensis str.. The denitrification characteristics of strain DN7 with different sources of nitrogen were investigated. Results showed that the strain could use either nitrate or nitrite as the sole source of nitrogen for aerobic denitrification, and the removal efficiencies of nitrate and nitrite were 83.35% and 85.72% in 4 h, respectively. The completely reduction of nitrite was 42 h before the nitrate. Almost no nitrite accumulation was observed in the aerobic denitrification process with nitrate as the sole nitrogen source, whereas nitrate accumulation was detected with nitrite as the sole nitrogen source, in which the maximum amount of nitrate reached 21.83 mg/L in 4 h. The strain preferred nitrate to nitrite in the nitrate-nitrite mixed system. Coexistence of nitrite and nitrate had no significant effect on nitrate reduction, however, the residual concentration of nitrite increased with the ratio of nitrite to nitrate. As the ratio of nitrite to nitrate increased from 1∶9 to 5∶5, the residual nitrite concentration increased from 3.38 mg/L to 7.60 mg/L. Little amount of nitrate would inhibit the nitrite reduction significantly. When the ratio of nitrate to nitrite was 1∶9, the nitrite removal efficiency dropped to 74.79%, much lower than that with nitrite as the sole nitrogen source. The strain was capable of using ammonium nitrogen as the sole nitrogen source, in which both heterotrophic nitrification and aerobic denitrification occurred. Nitrate accumulation was observed in the heterotrophic nitrification and aerobic denitrification process, and the maximum value was 18.92 mg/L. In 72 h, the removal efficiency of ammonium nitrogen reached 85.66%, and neither nitrate nor nitrite accumulation was observed. The aerobic denitrification of the strain could be promoted in the presence of little amount of ammonium nitrogen. When the ammonium to nitrate ratio was 1∶9, nitrate was completely reduced in 48 h, 24 h before that with nitrate as the sole nitrogen source. Coexistence of nitrate and ammonium nitrogen also enhanced the heterotrophic nitrification. When the nitrate to ammonium ratio was 1∶9, removal efficiency of ammonium nitrogen reached 87.50%, 7.05% higher than that with ammonium nitrogen as the sole nitrogen source. 参考文献 相似文献 引证文献