Ca^(2+)强化短程硝化颗粒污泥培养

Strengthening cultivation of nitritation granular sludge by adding Ca^(2+)

利用SBR,以普通活性污泥为种泥,在好氧条件下(DO>2 mg/L)研究了Ca2+强化短程硝化颗粒污泥培养的特性。结果表明,通过将进水氨氮浓度由110 mg/L升高至300 mg/L后30 d,出水亚硝酸盐累积率稳定在80%~85%,成功实现了短程硝化。通过添加50 mg/L Ca Cl2,污泥表面Zeta电位由-21.4 m V升高至-13.6 m V,胞外蛋白质的含量由26.82 mg/g升至51.99 mg/g,90 d后,粒径大于300μm的污泥体积分数约占68%,培养了短程硝化颗粒污泥。Zeta电位的升高减小了污泥间的静电斥力,增多的胞外蛋白在Ca2+架桥作用下可相互结合形成高分子生物聚合体,二者的共同作用是Ca2+强化短程硝化颗粒污泥形成的原因。

The cultivation of nitritation granular sludge by adding Ca2 ＋was investigated in a sequencing batch reactor（ SBR） under aerobic conditions（ DO 2 mg/L） by seeding conventional activated sludge. The nitrite accumulation in effluent reached 80% - 85% by increasing influent ammonia concentration（ from 110 to300 mg N/L） after 30 days,indicating the realization of nitritation. The Zeta potential of the sludge surface increased from-21. 4 m V to-13. 6 m V and the amount of extracellular proteins increased from 26. 82 mg/g to51. 99 mg/g by adding 50 mg/L Ca Cl2. Granules with diameters larger than 300 μm accounted for around 68%after 90 days＇ continuous operation.On one hand,the electrostatic repulsion among the flocs were reduced with the increment of the Zeta potential,on the other hand,the increased extracellular proteins can be combined to form biological polymers under the bridging effect of Ca2 ＋. The collaboration of both accelerated the formation of nitritation granular sludge.