硫酸盐还原菌对UASB中VFA的转化的促进研究

THE EFFECT OF VOLATILE FATTY ACID TRANSFORMATION BY SULFATE REDUCING BACTERIA IN UASB

厌氧反应器运行过程中,由于产甲烷菌不能及时转化由产酸菌生成的挥发性脂肪酸,容易造成酸的积累产生的酸败问题。实验通过人工模拟挥发性脂肪酸(VFA)积累,添加适量硫酸盐的方法,研究硫酸盐还原菌(SRB)对于挥发性脂肪酸转化的促进作用。结果表明,当UASB容积负荷从8 kg/(m3·d)提升至15 kg/(m3·d)时,反应器会出现酸败现象。当COD/ρ(SO42-)为30时,UASB受酸败的影响最小。COD去除率稳定在70%以上,pH为6.0,VFA浓度为22.65 mmol/L。向某酸性豆制品废水中以COD/ρ(SO42-)=30投加硫酸盐,能快速降低VFA浓度,使反应器快速恢复。

In the operation of anaerobic reactor, volatile fatty acid was generated due to slow hydrogen-acid .production rate, which causes the accumulation of acid rancidity. In a simulative action of VFA accumulation, adding sulfate properly can promote volatile fatty acid transformation by sulfate reducing bacteria. The result shows that in the situation of VFA accumulation, when the volume load increased from 8 kg/（m3·d） to 15 kg/（m3 ·d）, the rancidity phenomenon will appear in the reactor. The reactor is least affected by rancidity when the ratio of carbon to sulfur is 30. The COD removal rate is over 70% while the pH is 6.0 and VFA concentration is 22.65 mmol/L. The addition of sulfate with COD/ρ（SO4^2-）=30 in acidic bean products wastewater could reduce the VFA concentration quickly and restore the system in a short time.