Evaluation of the environmental impact of microbial aerosols generated by wastewater treatment plants utilizing different aeration systems
Evaluation of the environmental impact of microbial aerosols generated by wastewater treatment plants utilizing different aeration systems
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DOI：
10.1046/j.1365-2672.2000.01024.x
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发表时间：
2000-05-01
影响因子：
4
通讯作者：
Amagliani, G
中科院分区：
文献类型：
--
作者：
Brandi, G;Sisti, M;Amagliani, G
采用三种采样装置（SAS、Andersen Six-Stages和All Glass Impinger），对城市污水处理厂采用不同污泥充氧方法所产生的细菌和真菌气溶胶的环境影响进行了评价。最高的微生物浓度回收罐上方（2247 cfu m（-3））和下风向位置（1425 cfu m（-3）），在那里的污水处理量和微生物气溶胶分散的实体之间的线性相关性（P < 0.05）。此外，随着处理次数的增加，从空气中回收的细菌呈指数增加（P < 0.05）。然而，在工厂长期运行后，在工厂周围的几乎所有地点都发现了高细菌和真菌浓度。大肠菌群、肠球菌、大肠埃希菌和葡萄球菌几乎总是在顺风位置回收。相当大部分（20-40%）的采样细菌能够穿透Andersen装置的最后阶段，因此可能能够穿透肺部。相反，使用细气泡扩散空气系统运行的工厂产生的细菌和真菌浓度相当低;此外，几乎不存在葡萄球菌和指示微生物。最后，沙门氏菌，志贺氏菌，铜绿假单胞菌和气单胞菌属，没有检测到的植物。结果表明，空气中的细菌和真菌的显着的分散从坦克中，氧气是通过机械搅拌的污泥，并建议需要将它们转换为扩散曝气系统，对人类健康造成的危害较小。
Using three sampler devices (SAS, Andersen Six-Stages and All Glass Impinger), the environmental impact of bacterial and fungal aerosols generated by municipal wastewater treatment plants operating with different methods of sludge oxygenation were evaluated. The highest microbial concentrations were recovered above the tanks (2247 cfu m(-3)) and in downwind positions (1425 cfu m(-3)), where a linear correlation (P < 0.05) was found between the quantity of sewage treated and the entities of microbial aerosol dispersion. Moreover, an exponential increase (P < 0.05) in the bacteria recovered from the air occurred at increasing times of treatment. However, after long-term plant operation, high bacterial and fungal concentrations were found in almost all of the sites around the plant. Coliforms, enterococci, Escherichia coli and staphylococci were almost always recovered in downwind positions. Considerable fractions (20-40%) of sampled bacteria were able to penetrate the final stages of the Andersen apparatus and thus, are likely to be able to penetrate the lungs. The plant operating with a fine bubble diffused air system instead was found to generate rather low concentrations of bacteria and fungi; moreover, staphylococci and indicator micro-organisms were almost absent. Finally, salmonellae, Shigella, Pseudomonas aeruginosa and Aeromonas spp, were not detected in either of the plants. The results indicate a remarkable dispersion of airborne bacteria and fungi from tanks in which oxygen is supplied via a mechanical agitation of sludge, and suggest the need to convert them to diffused aeration systems which pose a lesser hazard for human health.