城市污水处理厂微生物气溶胶污染和粒径分布特征

摘要

Pollution and control of bioaerosols from the municipal wastewater treatment plant have gradually become the focus of people's attention. In order to define the concentration and granularity distribution of airborne heterotrophic bacteria, fungi and actinomycetes and evaluate their pollution characteristics in different function areas, such as the grit chamber, sewage pool, oxidation ditch, secondary sedimentation tank, sludge dewatering room and the gate region, a urban wastewater treatment plant in Erdos were chosen as research objects . Results showed that concentrations of airborne microorganisms were completely different in different units, particularly highest for heterotrophic bacteria and actinomycetes in the secondary sedimentation tank and sludge dewatering room, and highest fungi in the gate region and the secondary sedimentation tank. According to the related bioaerosol pollution evaluation standard, the heterotrophic bacteria concentrations emitted from the sludge dewatering room reached the pollution level, the heterotrophic bacteria concentrations from the secondary sedimentation tank, oxidation ditch and the gate region reached slight pollution level, and only the grit chamber and sewage pool were not contaminated by heterotrophic bacteria. While, all functional areas were not contaminated by the fungi. Particle size analysis showed that the highest proportion of the size distribution for heterotrophic bacteria in different function areas were mainly in stage 1 and stage 4, the fungi in stage 3 and stage 4, and the actinomycetes in stage 1, stage 2 and stage 3 in different function areas. And there were no significant differences between the different function areas for heterotrophic bacteria, fungi and actinomycetes. A certain amount of bioaerosol particles which were emitted from different function areas can be directly inhaled into the respiratory system, and may have a potential risk to human health. The results can provide a scientific basis for controlling the microbial aerosol pollution during the operation of urban wastewater treatment plant.%　　城市污水处理厂微生物气溶胶的污染与控制逐渐成为人们关注的热点问题。为明确城市污水处理厂微生物气溶胶浓度和粒径分布特征，选择鄂尔多斯市某城市污水处理厂的格栅间、配水池、氧化沟、二沉池、污泥脱水间和厂区门口6个功能区为对象，对各功能区产生的异养细菌、真菌和放线菌气溶胶浓度分布、污染特性和微生物粒子粒径分布特性进行研究。结果表明，该污水处理厂不同功能区内异养细菌、真菌和放线菌的浓度分布存在显著性差异，其中二沉池和污泥脱水间产生的异养细菌和放线菌浓度均较高，真菌浓度较高的区域为厂门口和二沉池；根据相关微生物气溶胶污染评价标准，污泥脱水间逸散的异养细菌浓度均达到污染级，二沉池、氧化沟和厂门口逸散的异养细菌浓度达轻微污染级，格栅间和配水池未受污染，而真菌浓度在各个功能区均未受到污染；各功能区产生的异养细菌、真菌和放线菌粒子粒径分布无明显差异，异养细菌、真菌和放线菌粒子粒径分别集中在第1、4级，第3、4级和第1、2、3级，大体上均呈正态分布；各功能区均逸散出一定比例的可以直接吸入人体呼吸道的微生物粒子，可能对人体健康具有一定的潜在风险。研究结果可为城市污水处理厂运行过程中微生物气溶胶的污染控制提供科学依据。