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本实验通过建立一套两级串联UASB反应器研究油田集输系统及高含盐量废水中反硝化抑制硫酸盐还原的工艺处理特性,并在工艺稳定运行后对形成的颗粒污泥性状及微生物特性进行研究.结果表明,添加Na NO2可促使反应体系中反硝化细菌(denitrifying bacteria,DNB)数量由7.0×103CFU·(100 m L)~(-1)增加至7.3×105CFU·(100 m L)~(-1)并保持稳定,DNB对硫酸盐还原菌(sulfate-reducing bacteria,SRB)的竞争抑制作用导致SRB数量由8.0×105CFU·(100 m L)~(-1)减少,稳定至7.6×104CFU·(100 m L)~(-1),同时,硫酸盐还原过程被抑制,硫离子的抑制率不断增加,最终稳定至82%.生物量与亚硝酸盐的质量比为1 200时,反应体系对S2-的抑制率最高,达到92%,可实现较好的硫酸盐还原过程抑制效果;该工艺对其抑制率可保持在92%左右,具有较好的稳定性.形成的反硝化颗粒污泥为棕褐色,基本为椭球形和球形,表面光滑且密实.反硝化抑制前,颗粒污泥的粒径多分布于1.0~1.4 mm,平均粒径为1.17 mm,经反硝化抑制后,粒径多分布在1.2~1.6 mm,平均粒径为1.21 mm,反硝化抑制过程促进污泥粒径的小幅增加;形成的反硝化颗粒污泥平均沉速为47.6 m·h~(-1),沉降性能较好.PCR-DGGE分析结果表明,反硝化抑制作用使微生物菌种由18种减少至14种,优势菌种由4种减至3种,多样性降低,反硝化抑制前后微生物种群相似性为62.6%,种群结构发生较大改变,优势菌群由SRB演变为DNB,SRB优势菌种由4种减至2种,同种菌的丰度明显降低;反硝化抑制过程的主要功能菌为Uncultured Sulfurimonas sp.,是一种自养型反硝化细菌,与SRB抢夺电子并占优势,抑制硫酸盐还原过程及SRB生长繁殖,从而抑制硫化物的产生.
In this experiment, we established a two-stage series UASB reactor to study the process characteristics of denitrification inhibition of sulfate reduction in oil gathering and transportation system and high salt content wastewater. After the process was stable, the characteristics of granular sludge and microorganisms The results showed that the addition of NaNO2 promoted the increase of denitrifying bacteria (DNB) from 7.0 × 103CFU · (-1) to -1.3 × 105CFU · (-1) in the reaction system ) -1 and remained stable. The competitive inhibition of DNB on the sulfate-reducing bacteria (SRB) resulted in a decrease of SRB from 8.0 × 105 CFU · (-1) to -1 7.6 × 104CFU · (-100 m L) -1. At the same time, the sulfate reduction process was inhibited and the inhibition rate of sulfur ions increased steadily to reach 82%. The mass ratio of biomass to nitrite was 1 200 , The reaction system has the highest inhibition rate of S2-, reaching 92%, which can achieve better inhibition effect of sulfate reduction process. The inhibition rate of this process can be maintained at about 92% with good stability. Denitrifying granular sludge is tan, basically ellipsoidal and spherical, smooth and dense surface. The particle size of the granular sludge was distributed in the range of 1.0-1.4 mm with an average particle size of 1.17 mm. After denitrification was inhibited, the particle size was distributed in the range of 1.2-1.6 mm with an average particle size of 1.21 mm. The denitrification process The average settling velocity of the formed denitrification granular sludge was 47.6 m · h -1, and the sedimentation performance was better.PCR-DGGE analysis showed that the denitrification inhibited the growth of microbial strains From 18 species to 14 species, the dominant species decreased from 4 species to 3 species, the diversity decreased, the similarity of microbial population before and after denitrification was 62.6%, and the population structure changed greatly. The dominant bacteria changed from SRB to DNB , The dominant bacteria of SRB decreased from 4 to 2, and the abundance of the same species decreased significantly. The main fungus of denitrification inhibition was Uncultured Sulfurimonas sp., A kind of autotrophic denitrifying bacteria, And dominant, inhibit the sulfate reduction process and SRB growth and reproduction, thereby inhibiting the production of sulfide.