鼠李糖脂强化生物滴滤塔去除乙苯废气效能及菌群结构研究

对添加表面活性剂鼠李糖脂后生物滴滤塔(BTF)去除乙苯废气的效能及滴滤塔中微生物16S r DNA高通量测序结果进行分析,探讨了鼠李糖脂对生物滴滤塔处理有机废气效能的影响机理.结果发现:鼠李糖脂在浓度为21.6 mg·L~(-1)时对微生物生长的促进作用尤为明显,BTF2(添加鼠李糖脂)和BTF1(对照)在挂膜启动期间生物量都呈现出逐渐增加的趋势,添加鼠李糖脂的BTF2在第35 d时生物量比BTF1增加了39.62 mg·g-1.BTF2的挂膜启动时间比BTF1缩短了5 d,并且系统挂膜稳定后对乙苯废气的去除率提高了12%.BTF1和BTF2的微生物群落组成基本相同,主要优势菌群是变形杆菌门.在BTF1系统中,变形杆菌门占62.3%;在BTF2系统中,变形杆菌门占81.9%.在属水平上,BTF1下层系统的主要优势菌属占45.7%,在BTF2下层系统主要优势菌属占73.4%.研究表明,在BTF系统中添加鼠李糖脂可以促进优势菌的富集生长,缩短系统启动挂膜时间,强化BTF系统对乙苯的降解,并提高BTF的去除效率和稳定性.

Study on the ethylbenzene removal efficiency and microbial community of the rhamnolipid enhanced biotrickling filter

Rhamnolipid was applied to strengthen ethylbenzene removal in biotrickling filter (BTF). The performance of and the associated mechanisms of the rhamnolipid enhanced ethylbenzene gas removal in the BTF were also investigated by using the high-throughput sequencing technology for 16S rDNA analysis. The results showed that the growth of microorganisms was significantly promoted by addition of 21.6 mg·L^-1 rhamnolipid to the cultures. The biomass in the BTF2 (with addition of rhamnolipid) was 39.62 mg·g^-1 higher than the control BTF1 (without addition of rhamnolipid) on day 35 although the biomass of both systems increased gradually with time during the start-up period (the biofilm formation period). In addition, the removal efficiency of ethylbenzene in the BTF2 was 12% higher than that in the BTF1 during the stable operation period. BTF1 and BTF2 had similar microbial community structure and were dominated by the phylum Proteobacteria ssp. However, the proportions of the phylum Proteobacteria ssp within the microbial community in the two systems were different. In the BTF2, Proteobacteria accounted for 81.9% of all the bacteria, while it provided only 62.3% in the BTF1. In the low part of BTF2, the dominant bacteria provided 73.4% of the total microorganism community while it accounted for 45.7% only in the same part of BTF1 at the genus level. The results suggested that the addition of rhamnolipid to the BTF can promote the growth of dominant bacteria which resulted in remarkable reduction in start-up period, enhanced increase the removal of ethylbenzene from waste gas and improvement in system stability in the rhamnolipid enhanced BTF.