硫酸盐还原菌促进市政污泥厌氧发酵产乙酸

Improvement of Acetate Production from Anaerobic Fermentation of Sewage Sludge by Sulfate Reducing Bacteria

添加各浓度钼酸盐考察不同抑制水平下硫酸盐还原菌(SRB)对市政污泥发酵产酸的作用.结果表明:在有硫酸盐存在时,未抑制SRB体系中ρ(乙酸)占ρ(总VFAs)的比例可达83%,无丙酸、丁酸积累;而在SRB高抑制水平体系中,ρ(乙酸)只占约40%.随后以未添加硫酸盐体系为对照,研究了硫酸盐投加方式及在发酵中后期抑制SRB对产物中挥发性脂肪酸(VFAs)成分及其浓度的影响;同时,通过对dsrA酶的编码基因含量定量分析发现,随着硫酸盐的加入,SRB数量速增,产物中丙酸、丁酸先后转化为乙酸,且ρ(乙酸)占ρ(总VFAs)的比例可达90%以上.添加SRB可作为实现污泥发酵定向累积乙酸的调控手段.

The role of sulfate-reducing bacteria（SRB） during the anaerobic fermentation of sewage sludge was investigated by adding different concentrations of inhibitors of molybdate.The results showed that the（ρ（acetate）） percentage can reach as high as 83% of the total（ρ（VFAs））（volatile fatty acids） in the anaerobic system without molybdate and in the presence of sulfate.Meanwhile,the propionate and butyrate disappeared.In contrast,in the SRB complete inhibition system,the（ρ（acetate）） percentage was only 40%.Furthermore,sulfate and molybdate were used to adjust the activity of SRB,and a real-time PCR method targeting dissimilar sulfite reductase A gene（dsrA） was established to quantify the SRB in the sludge.The results showed that the SRB increased significantly with the addition of sulfate,and the（ρ（acetate）） accounted for 90% of total（ρ（VFAs））.All the results demonstrated that the SRB improved the acetate accumulation from the propionate and butyrate transformation,and SRB can probably serve as a way to realize acetate accumulation in the sludge anaerobic fermentation process.