SBR工艺城市污水处理厂微生物气溶胶逸散特征

在采用SBR工艺的某污水处理厂设置采样点,研究各污水处理工艺段微生物气溶胶的逸散特征.结果表明,各工艺段均有细菌气溶胶逸散,浓度为82～1 525 CFU·m~(-3),粗格栅、生化池和污泥脱水间为主要逸散源.各工艺段检测到的细菌气溶胶主要菌属为Cyanobacteria,其它丰度较高的菌属有Aeromonas、Peptostreptococcaceae、Moraxellaceae、Chroococcidiopsis、Sphingomonas、Arcobacter及Acinetobacter等,其中Aeromonas、Arcobacter、Acinetobacter及Sphingomonas为潜在致病菌.微生物气溶胶的浓度和丰度沿垂直方向和水平方向减少.适宜的温度和相对湿度利于微生物气溶胶在空气中保持活性(P 0. 01),风速则与微生物气溶胶的逸散呈负相关(P 0. 05).污水处理过程产生的微生物气溶胶的暴露风险较小(HQ 1),但是污染物的累积会增加人体的暴露风险.生物除臭反应器在处理臭味气体的同时还可以有效削减微生物气溶胶.

Characteristics of Bioaerosols Emitted from WWTP with SBR Treatment Process

Sampling sites were located in a wastewater treatment plant (WWTP) with a sequencing batch reactor activated sludge process to investigate the characteristics of bioaerosol emissions. The results indicated that bioaerosols were detected from each treatment section of the WWTP, and concentrations of bioaerosols were in the range of 82-1525 CFU·m^-3. The coarse screen, aeration tank, and sludge dewatering house were the main sources of bioaerosols. The dominant species in each treatment section was Cyanobacteria, and the other main bacterial taxa were Aeromonas, Peptostreptococcaceae, Moraxellaceae, Chroococcidiopsis, Sphingomonas, Arcobacter, and Acinetobacter. Among the identified bacterial genera, Aeromonas, Arcobacter, Acinetobacter, and Sphingomonas were potential pathogens. Bioaerosol concentration and abundance decreased along the vertical and horizontal directions. Appropriate temperature and relative humidity benefited the survival of bioaerosols in the air (P<0.01), whereas a negative relationship between bioaerosol concentration and wind speed was observed (P<0.05). Although exposure risks caused by bioaerosols were negligible in this study, the accumulation of bioaerosols would increase potential health risks. The bioreactor for odor treatment could effectively reduce bioaerosol emissions.