Abstract:

High concentrations of NH₄ ⁺-N and NO₂ ^--N in seawater shrimp ponds threaten the survival of shrimp. Salt tolerant nitrifying bacteria biofilm is the key to solving this problem. In response to the long formation time of salt tolerant nitrifying bacteria biofilm, a method of drying and dehydrating immobilized salt tolerant nitrifying bacteria to quickly form biofilm was proposed. The experimental results showed that under saline (3.00% salinity) conditions, salt tolerant nitrifying bacteria couls form biofilm after 1 hour of drying and dehydration treatment, and the activity and stability of the biofilm were both high. The specific ammonia oxidation rate was 10.20 mg/(g·h), and the specific nitrate oxidation rate was 9.60 mg/(g·h). The immobilization rate of biofilm under shear force was as high as 92.19%. In contrast, the biofilm activity and immobilization rate formed under freshwater (0 salinity) conditions were lower. The reactor inoculated with salt tolerant nitrifying bacteria biofilm achieved control of NH₄ ⁺-N and NO₂ ^--N within 5 days and successfully started the reactor. Nitrosomonas (abundance ranging from 6.57% to 14.61%) and Nitrospira (abundance ranging from 0.08% to 0.42%) in biofilms were key to achieving nitrogen control in reactors. The high stability of biofilm was the basis for achieving stable nitrogen control in reactors. After 14 days of reactor operation, the sludge shedding amount was only 0.25% of the total reactor volume, and the shedding rate of biofilm under shear force was only 0 to 2.29%.

Key words: salt-tolerant nitrifying bacteria, biofilm, nitrogen control, drying and dehydration

摘要：

海水养虾池中高浓度的NH₄ ⁺-N和NO₂ ^--N严重威胁虾的生存，使用耐盐硝化细菌生物膜反应器可以解决该问题，耐盐硝化菌生物膜是该反应器的核心，但其形成周期长，针对此问题，提出了干燥失水固定化耐盐硝化菌快速形成生物膜的方法。结果表明，在盐水条件（盐度为3.00%）下，耐盐硝化菌经过1 h的干燥失水处理后，能够形成生物膜，且该生物膜的活性和稳定性均较高，比氨氧化速率为10.20 mg/（g·h），比亚硝酸盐氧化速率为9.60 mg/（g·h），且生物膜在剪切力作用下，固定化率高达92.19%。相比之下，在淡水条件（盐度为0）下形成的生物膜活性和固定化率均较低。接种了耐盐硝化菌生物膜的反应器，5 d就实现了NH₄ ⁺-N和NO₂ ^--N的控制并成功启动反应器。生物膜中Nitrosomonas（丰度为6.57%~14.61%）和Nitrospira（丰度为0.08%~0.42%）是实现反应器氮控制的关键。生物膜的高稳定性是反应器实现稳定氮控制的基础。反应器运行14 d后，污泥脱落量仅为反应器中污泥总量的0.25%，且生物膜在剪切力作用下的脱落率只有0~2.29%。

关键词: 耐盐硝化菌, 生物膜, 氮控制, 干燥失水

CLC Number: 

• X703.1