城市污水处理厂恶臭气体和微生物气溶胶污染物的源解析及释放机理研究

The fast development of municipal wastewater treatment plant brought secondary pollution of malodorous gas and bioaerosol which were threats to lives and health of the residents nearby. This research focused on the sources analysis and emission mechanisms of malodorous gas and bioaerosol in municipal wastewater treatment plant. It followed the concentration of malodorous gas in the wastewater (or sludge) as well as in the air above treatment structures, which were produced by the same fluid of wastewater (or sludge) during the wastewater treatment process. The variation of microbial communities of hydrolytic acidification bacteria and sulfate reducing bacteria were also studied in order to analyze the sources as well as inducing mechanism of malodorous gas. The concentration of heterotrophic bacteria bioaerosol and fungus bioaerosol in the air above treatment structures were studied in order to analyze the source of these bioaerosol and their effects on human respiratory system. The effects of the operating parameters of municipal wastewater treatment plant, the characteristics of wastewater and sludge, and the local meteorological conditions on the variations of composition and structure of microbial communities in wastewater and sludge were also studied. Then, the emission mechanisms of malodorous gas and bioaerosol in municipal wastewater treatment plant were discussed. The achievement of this research will become a foundation for overall control and innocent treatment of malodorous gas and bioaerosol in municipal wastewater treatment plant.

我国城市污水处理厂发展迅猛，但其也常常带来恶臭和微生物气溶胶的二次污染，严重危害了周边居民的正常生活和身体健康。本课题将探究城市污水处理厂恶臭气体和微生物气溶胶污染物的来源及释放机理。追踪同一股污水（污泥）在污水处理厂工艺流程中产生的恶臭气体在污水（污泥）自身中和逸散到空气中的浓度含量，并分析污水污泥中水解酸化菌及硫酸盐还原菌微生物群落的组成结构的变化状况，以厘清恶臭气体的来源和生成机理。研究异养细菌和真菌微生物气溶胶在处理构筑物的上方大气中的浓度含量，以明确它们从污水污泥中向大气中逸散的源头和对人体呼吸系统健康的影响。结合处理构筑物的运行参数以及其中污水污泥性质和当地的气象环境状况，分析它们与污水污泥中微生物群落的组成结构之间的内在联系，最终揭示处理构筑物中恶臭气体和微生物气溶胶污染物的释放机制。本课题将为宏观控制和无害化处理恶臭气体及微生物气溶胶污染物提供可靠的理论依据和数据支撑。

我国市政污水处理设施建设发展迅猛，但也带来了恶臭和生物气溶胶的二次污染。特别是市政污水处理厂在运行过程中不可避免的存在着对污水或污泥的扰动作用，则其中的各种生物性物质很容易因为惯性而逸散到周围空气中形成胶体体系，即生物气溶胶污染物。因其粒径和所含生物性物质的特点，污水处理厂生物气溶胶极可能会进入人体的气管、支气管和肺泡，对人体的呼吸系统健康造成严重威胁；或者通过与身体暴露的皮肤接触，造成重大健康风险。. 本项目的主要研究内容和重要结果如下：.1）恶臭H2S和氨气，以及细菌、总大肠杆菌、粪大肠杆菌和肠球菌气溶胶浓度最大值均出现在倒伞曝气池，而真菌气溶胶浓度最大值出现在污泥脱水车间；.2）夏季，倒伞曝气池上方空气中真菌气溶胶浓度和氨气显著高于其它季节，且真菌气溶胶粒径分布主要集中于能进入人体的气管和支气管范围内；.3）倒伞曝气池中真菌的气溶胶化率最高，而当其污水中真菌浓度最高时，其气溶胶化率反而最低；.4）使用β-Poisson剂量响应模型进行定量风险评价分析（QMRA），12岁-18岁男性在居民区的总大肠杆菌、粪大肠杆菌、肠球菌年感染风险，12岁-18岁女性在居民区的总大肠杆菌、粪大肠杆菌、肠球菌年感染风险，均超过WHO最大可接受风险值10-4，故居民区民众的健康危害风险极大；.5）倒伞曝气池的NoV气溶胶和AdV气溶胶浓度均高于微孔曝气池的NoV和AdV气溶胶浓度；.7）夏季高温和强烈的太阳辐射，使得各个曝气池的NoV和AdV气溶胶浓度均较秋季稍低；.8）倒伞曝气池中NoV的气溶胶化率最高时，污水中NoV浓度最低；.9）使用β-Poisson剂量响应模型进行QMRA计算，人体通过皮肤接触和呼吸途径对病毒气溶胶的暴露有较大风险，故应重点关注污泥堆场的工作人员及居民区的老人儿童的健康风险；.本研究对管理污水处理厂的生物气溶胶污染物和恶臭气体的排放，保护污水处理厂工人及周边居民的人体健康，具有重要的实际应用价值。