石油炼化废水组成对厌氧氨氧化-反硝化细菌混培物的影响

Influence on composition of oil refining wastewater to mixed culture bacteria of AAOB-DNB

为了探究石油炼化废水中COD和毒性物质对厌氧氨氧化-反硝化细菌混培物的影响,利用已具有高效脱氮性能的细菌混培物建立生物脱氮反应器进行连续驯化实验,实现进水COD和毒性物质比例的增加,并结合MPN-PCR技术对驯化前后两类菌群数量进行检测。结果发现,驯化前后厌氧氨氧化细菌数目由7.549×10^(14)个·g^(-1)减为8.212×10~8个·g^(-1),脱氮生化活性仍保持在40.2%左右;反硝化细菌数目由3.523×10~6个·g^(-1)增为4.693×10^(16)个·g^(-1),脱氮生化活性增加了5.76倍左右。结果表明,厌氧氨氧化细菌和反硝化细菌混培脱氮体系的脱氮生化活性未与细菌数目呈正相关性变化,COD和毒性物质对体系产生了不同程度的影响;厌氧氨氧化细菌比反硝化细菌对石油炼化废水毒性的作用更敏感;混培脱氮体系在一定程度上可以有效地抵抗石油炼化废水高浓度COD、高毒性物质对厌氧氨氧化生理生化脱氮过程的负面影响。

In order to explore the influence of the chemical oxygen demand（ COD） and poisonous substances on mixed cultures of bacteria（ e. g.,anaerobic ammonia oxidation bacteria and denitrifying bacteria） during the treatment of oil refining wastewater,tests were conducted within a biological nitrogen removal reactor system and the efficiency of the removal performance was assessed. This system was established through continuous domestication periods with the bacteria during which proportional increases of influent COD and toxic substances were achieved. The populations of the two types of bacteria in the system were detected by the most probable numberpolymerase chain reaction（ MPN-PCR） technique before and after the domestication periods. After domestication,the number of anaerobic ammonium oxidizing bacteria decreased from 7. 549 × 10-（14） units/g to 8. 212 × 10-8units·g-（-1）,but the corresponding biochemical activity remained at about 40. 2%; in contrast,the number of denitrification bacteria increased by 3. 523 × 10^6units·g^-1to 4. 693 × 10^16units·g^-1and there was a 5. 76-fold increase in the biochemical activity involved with denitrification. These results demonstrate that the performance of the mixed culture nitrogen denitrification system was not linearly related to the changes in the bacteria numbers. The anaerobic ammonia oxidation bacteria were generally more sensitive to the effects of poisonous substances in the oil refining wastewater compared to the denitrification bacteria. Overall,the mixed culture nitrogen removal system was reasonably effective at treating the oil refining wastewater with high concentrations of COD and poisonous substances through the processes of anaerobic ammonia oxidation nitrogen denitrification.