饮用水中2-甲基异莰醇降解菌的筛选和生物降解能力初探

Biodegradation Bacteria Screening and Initial Biodegradability Evaluation for 2-MIB in Drinking Water

嗅味是饮用水中普遍关注的关键指标之一,其中2-甲基异莰醇(2-MIB)和土臭素(geosmin)导致的土霉味问题最为常见。以2-MIB为目标,探讨从水厂生物活性炭滤池中分离特定降解菌的可行性,并对2-MIB的降解效果进行评估。结果表明,试验筛选得到了三株对2-MIB具有降解能力的降解菌,经16S rRNA系统进化分析,分别为假单胞菌,鞘氨醇单胞菌以及金黄杆菌;初步的降解能力评价表明,三种降解菌对2-MIB的降解效果类似,且均表现出相对较高的降解能力,接种后不经延滞即开始2-MIB的降解;试验期内对2-MIB的降解率可达94%以上,最终可将初始浓度为200 ng/L的2-MIB降解至阈值浓度以下。后续将对于不同环境条件以及实际连续流操作条件下的降解效果和运行方式进行进一步的评价,探讨其用于实际工艺中强化生物降解2-MIB的可行性。

Taste and odor is one key water quality index in drinking. Among this, earthy / musty odor caused by 2 -MIB and geosmin is most encountered. In this study, the biodegradation bacteria for 2-MIB was screened from activated carbon filter, then the initial evaluation for 2-MIB biodegradation was performed. The results showed that three 2-MIB biodegradation bacteria were obtained. By 16S rRNA analysis, the three bacteria belonged to Pseudomonas sp., Sphingomonas sp. and Chryseobacterium sp.respectively, which showed high and similar biodegradability to 2-MIB. During the experimental time, the 2-MIB could be degraded high than 94% at the initial concentration of 200 ng/L. It could finally achieve to lower than the odor threshold concentration (OTC). In the future, the degradation effects at different environment factors and continuous conditions would be further conducted for the possible application in actual water treatment process.