膜-生物反应器污泥缺氧反硝化过程中SMP的形成

在不同C/N比下,研究了膜-生物反应器在缺氧状态下溶解性微生物产物(SMP)的形成规律.结果表明,不同C/N比的反硝化过程,随着底物的降解,SMP都呈现不同程度的累积,且高C/N比下的合成量(9~10mgCOD/gVSS)高于低C/N比下的合成量(3~4mgCOD/gVSS).从SMP的组分来看,不同C/N比下糖类的代谢规律相似,蛋白质则随着C/N比的升高其含量占SMP总量的比例增加,成为膜污染潜在的主要贡献者.随着反硝化过程的进行,体系中亚硝酸盐的累积对SMP的形成没有影响.

Formation of SMP during denitrification under anoxic conditions in a membrane bioreactor

The formation of soluble microbial products (SMP) with various C/N ratios under anoxic condition in membrane bioreactors was analyzed. In the process of denitrification at different C/N ratio, SMP concentration increased gradually due to the substrate utilization. The SMP concentration accumulated in the batch tests at high C/N ratio (9~10mgCOD/gVSS), which was higher than that at low C/N ratio (3~4mgCOD/gVSS). The analysis of SMP components showed the polysaccharide metabolism was similar at different C/N ratios, whereas the concentration of protein in total SMP increased with the increase of C/N ratio, and became the major potential contributor to membrane fouling. The results also demonstrated that nitrite accumulation under anoxic conditions had no obvious effects on the formation of SMP in the denitrification process.