反硝化抑制油田采出水中SRB的效果研究

Effect of Denitrification on SRB in Oilfield Produced Water

以硫酸去除率及硫酸盐还原菌(sulfate reducing bacteria,SRB)的数量为指标,研究硝酸盐和反硝化细菌(denitrifying bacteria,DNB)对油田采出水中SRB的抑制作用。结果表明:在单独接种DNB(5%,体积分数)或投加硝酸盐浓度为100mg/L条件下,采出水中SRB的生长均受到有效抑制,其数量从104个/mL可降至10个/mL,硫酸盐去除率从25.5%分别降至6.8%和7.8%;当DNB(12.5%,体积分数)和硝酸盐(100mg/L)共同作用于采出水可使SRB的数量降至10个/mL以下,其硫酸盐去除率降至2.4%,两者对SRB的抑制作用具有协同作用。

The inhibitory effects of nitr ate and denitrifying bacteria( DNB) on the growth and metabolism of SRB in oilfield produced water were studied with the number of sulfate reducing bacteria( SRB) and the sulfate removal rate as indicators, respectively. The results showed that the SRB growth and sulfuric acid reduction in produced water were effectively inhibited when DNB(5%, V/V) or the nitrate(100 mg/L) was inoculated in the oilfield produced water separately. The number of SRB could be reduced from 104 per/mL to 10 per/mL, and the sulfate removal rate could be decreased from 25.5% to6.8% or 7.8% after inoculated 3 days, respectively. The inhibitory effect of DNB and nitrate on the growth and metabolism of SRB was synergistic, while the amount of SRB could be reduced to less than 10 per/mL,and its sulfate removal rate was reduced to 2.4% when DNB(12.5%, V/V) and nitrate(100 mg/L)were inoculated together in the oilfield produced water.