聚丙烯酰胺对活性污泥特性的影响研究

高分子混凝剂PAM投加是强化污泥造粒的有效方法,但PAM的投加对活性污泥中微生物群落以及对其生化降解性能的影响尚缺乏系统性研究。为此,通过实验室小型实验,在SBR中连续投加PAM,运用FISH等微生物检测技术,研究了PAM对活性污泥的影响。在PAM投量为3 mg/L的条件下,反应器中活性污泥的生长过程与对照反应器没有根本性差别,且PAM投加后MLSS浓度和单位重量污泥的生物量均有一定增大,污泥的沉降性能也得到改善。FISH检测的结果表明,与对照反应器相比,总细菌、亚硝化菌、硝化菌的个数分别由9.1×105、1.8×105和1.1×105CFU/mL增长到1.0×106、2.0×105和1.2×105CFU/mL,说明PAM没有对各种菌落的生长产生不利影响。连续运行80 d的结果也表明,投加PAM的反应器中COD和氨氮的去除均有所改善。

Study on effect of polyacrylamine on characteristics of activated sludge

The addition of polymer coagulant PAM is an effective way to enhance particle pelletization. However, it is still unclear whether PAM has influence on the characteristics of activated sludge and its biological degradation process. A laboratory experiment was thus conducted to investigate the effect of continuous PAM addition on the activated sludge using a sets of SBR and application of fluorescence in situ hybridization (FISH) and other microbiological techniques. As a result, no significant difference was noticed in the growth of activated sludge between the two SBR, with PAM dosage of 3 mg/L.Moreover, certain increase in both the MLSS density and the amout of microorganism in the weight of sludge per unit was found by PAM addition. The experiment with FISH also indicates that the numbers of total bacteria, ammonia-oxidizing bacteria and nitrifiers were detected as 1.0×10⁶, 2.0×10⁵ and 1.2×10⁵ CFU/mL, respectively, in the SBR with PAM addition, comparing with 9.1×10⁵, 1.8×10⁵ and 1.1×10⁵CFU/mL, respectively in the SBR with no PAM addition,which shows that PAM addition did not impose negative impacts on microbial growth. Slight improvement was also noticed for the removal of COD and NH⁺₄-N in the process of 80 d operation with PAM addition.