适用于猪场沼液处理的好氧反硝化菌筛选及其脱氮特性评价

试验旨在筛选适合于猪场沼液处理的好氧反硝化菌。从活性污泥中分离获得 16 株好氧反硝化菌,其中菌株 ZH-14 的总氮(TN)和硝酸盐氮的去除效果最好,分别达到 50.73%和 99.99%。该菌株经过平板形态观察、功能基因和 16S rDNA 基因分析,鉴定为施氏假单胞菌(Pseudomonas stutzeri)。结果表明:菌株 ZH-14 在硝酸钾为唯一氮源培养基中生长时,48 h 后硝酸盐氮与 TN 的降解率分别为 100%和41.76%;以亚硝酸钠为唯一氮源培养时,亚硝酸盐氮降解率为 99.24%;以氨氮为唯一氮源培养时,氨氮的降解率达 94.1%;使用菌株 ZH-14 处理畜禽沼液,当其接种终浓度为 107 CFU/mL 时,经过 48 h 处理,氨氮、硝酸盐氮和化学需氧量的去除率分别为 54.4%、97.7%和 77.9%。综上表明,菌株 ZH-14 具有较强的反硝化和处理猪场沼液的能力,具有良好的应用开发前景。

Isolation of Aerobic Denitrifying Strain for Piggery Biogas Liquid Treatment and Its Denitrification Characteristics

The aim of the present study is to screen aerobic denitrifying bacteria for the treatment of piggery biogas liquid.Sixteen aerobic denitrifying strains were selected from actived sludge. Among them, stain ZH-14 had the best removal rate of total nitrogen(TN) and nitrate nitrogen, reaching 50.73% and 99.99%, respectively. The strain was identified as Pseudomonas stutzeri by plate morphology, functional genes and 16 S rDNA sequence analysis. The results showed that the maximum degradation rates of nitrate nitrogen and TN reached 100% and 41.76%, respectively, when it grew in the medium with potassium nitrate as the sole nitrogen source after 48 h's cultivation. When sodium nitrite was used as the sole nitrogen source for culturing strain ZH-14, the maximum degradation rate of nitrite nitrogen was 99.24% within 24 h. When strain ZH-14 was cultured with ammonia nitrogen as the sole nitrogen source, the degradation rate of ammonia nitrogen was 94.1% after 24 h. For the treatment of piggery biogas liquid, the removal rate of ammonia nitrogen, nitrate nitrogen and chemical oxygen demand were 54.4%, 97.7%, and 77.9%, respectively, after 48-h treatment of strain ZH-14 at a final inoculation concentration of 10`7 CFU/mL. The result indicates that strain ZH-14 has a good application prospect in biological denitrification and the treatment of piggery biogas liquid.