摘要
呼吸吸入是再生水利用过程中病原微生物的主要暴露途径之一.本研究提出了呼吸途径病原微生物暴露剂量的计算方法.首先根据再生水中病原微生物的浓度、喷洒强度和再生水雾化效率因子(雾化效率因子取值一般在0.003～0.01之间),确定再生水喷洒过程中病原微生物的排放强度.然后参考大气污染物扩散模型计算微生物气溶胶的分布,并考虑病原微生物在环境中的衰减,得出空气中病原微生物浓度.病原微生物的衰减计算与其自身衰减因子和环境影响因子有关.根据微生物种类的不同,其在空气中的衰减因子在-0.23～0 s-1之间,而环境对微生物的影响因子在0.016～73之间.最后结合呼吸速率和暴露时间求得呼吸途径的暴露剂量.根据易感人群年龄、性别和活动强度的不同,日平均呼吸速率在4.5～17 m3.d-1之间,小时平均呼吸速率在0.3～3.2 m3.h-1之间.本研究提出的方法可直接用于计算再生水利用于农业灌溉、园林绿化以及水景喷泉过程中因再生水雾化导致的病原微生物暴露剂量.
Inhalation is one of the main exposure routes to pathogenic microorganisms during wastewater reuse. An applicable method is introduced to assess the pathogenic microbial exposure from inhalation. Firstly, emission intensity of pathogenic microorganisms during reclaimed water spraying is determined by the concentration of pathogenic microorganisms in reclaimed water, spraying intensity and aerosolizing efficiency factor. The value of the aerosolizing efficiency factor is usually between 0.003 and 0.01. Then the concentration of pathogenic microorganisms in air is calculated by referring to the model of air pollutant dispersion and considering the microorganisms decay. The value of the microbial viability decay factor is between -0. 23 s^- 1 and 0 s ^-1 , and that of the environmental impact factor is between 0.016 and 73, varied by different kinds of microorganisms. And then the exposure from inhalation route can be finally attained by multiplying inhalation rate and exposure time. The daily average inhalation rate is 4.5-17 m^3·d^-1 , and the hourly average inhalation rate is 0.3-3.2 m^3·d^-1 , differentiated by age, gender, and activity of susceptible population. The method proposed in this study can be directly used to assess the pathogenic microbial exoosure caused bv reclaimed water used for agriculture irri^ation, gardening, or fountain snraving.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第1期70-74,共5页
Environmental Science
基金
国家杰出青年科学基金项目(50825801)
关键词
污水再生利用
呼吸途径
暴露剂量
微生物气溶胶
风险评价
wastewater reuse
inhalation route
exposure assessment
microbial aerosol
risk assessment
