研究报告

  • 孙佳薇,张焱鑫,席劲瑛.基于静态箱的污染土壤释放挥发性有机物特性研究[J].环境科学学报,2022,42(11):286-292

  • 基于静态箱的污染土壤释放挥发性有机物特性研究
  • Characterization of volatile organic compounds release from contaminated soil in a static chamber
  • 基金项目:国家重点研发计划项目(No.2018YFC1801101,2018YFC1801105)
  • 作者
  • 单位
  • 孙佳薇
  • 清华大学环境学院,北京 100084;清华苏州环境创新研究院,苏州 215163
  • 张焱鑫
  • 清华苏州环境创新研究院,苏州 215163
  • 席劲瑛
  • 清华大学环境学院,北京 100084;清华苏州环境创新研究院,苏州 215163
  • 摘要:静态箱法是测定土壤中气态污染物释放通量的常用方法.为了阐明静态箱内污染土壤释放挥发性有机物(VOC)的特性,本文考察了 土壤中VOC种类、含量、气温和箱体内空气扰动对VOC释放通量的影响.研究发现,静态箱内VOC浓度可在5 min内达到平衡或开始衰减,前30 s的VOC浓度变化可用于计算土壤的VOC释放通量.静态箱内土壤的VOC释放通量与其lgKow值和分子量呈显著负相关.土壤VOC含量越高,其VOC释放通量越大.同时,静态箱内污染土壤的VOC释放通量与室外气温呈正相关,表明在实际测定VOC释放通量时应考虑气温的影响.对比静态箱内设置不同风扇个数时VOC的释放通量,发现设置1个风扇时测得的VOC释放通量最大,表明在该条件下实现静态箱内污染物 混匀是较适宜的.本研究揭示了静态箱内土壤VOC释放通量的主要影响因素,可为科学评价污染土壤的VOC释放能力并进行风险管控提供科学支撑.
  • Abstract:Static chamber is commonly used to detect the release flux of gaseous pollutants from soil. In order to clarify the characteristics of volatile organic compound (VOC) release from contaminated soil in the static chamber, the effects of VOC types, VOC contents in soil, air temperature and air disturbance on VOC release flux were investigated in this study. The results showed that the VOC concentration in the static chamber tended to balance or decrease within 5 min. The VOC concentration profile by first 30s was selected to calculate the VOC release flux. The VOC release flux in the static chamber is significantly negatively correlated to its lgKow value and molecular weight. The VOC release flux will increase by the increment of VOC content in the soil. The VOC release flux was also positively correlated to the air temperature. This demonstrated that air temperature should be accounted when detecting the VOC release flux. The VOC release fluxes in the static chamber with different numbers of fans were compared and the VOC release flux when using one fan was the largest. Therefore, using one fan in the static chamber is suggested to homogenize the VOC in the chamber. This study showed effects of main influencing factors on VOC release flux from the soil in a static chamber, which can provide scientific support for evaluation of the VOC release capacity and its risk control for contaminated soils.

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