MIL-101高效吸附测定土壤气中三氯乙烯及健康风险评估

Determination of Trichloroethylene in Soil Gas by MIL-101 Adsorption and Health Risk Assessment

  • 摘要: 为研究基于实测土壤气中ρ(三氯乙烯)计算风险值与Johnson-Ettinger联合Dual-Equilibrium Desorption(JE-DED)模型和J&E模型计算风险值的差异,在MIL-101、UIO-66、ZIF-8和MOF-801金属-有机骨架(MOFs)材料,球形活性炭、膨胀石墨碳吸附材料及HiSiv1000和HiSiv3000分子筛等3类8种吸附剂中筛选出吸附效率较高的MIL-101 MOF材料用以吸附并测定土壤气中ρ(三氯乙烯),并将基于实测土壤气中ρ(三氯乙烯)计算的风险值与J&E模型和JE-DED模型计算的风险值进行比较.结果表明:①对于北京潮土和黑龙江黑土,J&E模型计算的风险值比基于实测土壤气中ρ(三氯乙烯)计算的风险值高2个数量级.②对于w(有机碳)较低的北京潮土,基于JE-DED模型计算的风险值比基于实测土壤气中ρ(三氯乙烯)计算的风险值高1个数量级,但比基于J&E模型计算的风险值低1个数量级,表明JE-DED模型预测结果更接近实际情况,但仍偏保守.③w(有机碳)较高的黑龙江黑土,JE-DED模型计算的风险值与基于实测土壤气中ρ(三氯乙烯)计算的风险值更接近,JE-DED模型可以比较准确地预测三氯乙烯的风险值.研究显示,采用土壤气中ρ(三氯乙烯)实测值和JE-DED模型进行风险评价在一定程度上可以避免J&E计算过于保守的问题,可以更加真实客观地反映场地污染程度而避免过度修复产生资源浪费.

     

    Abstract: To study the differences in calculated risk values based on measured concentrations of trichlorethylene in the soil gas versus the Johnson-Ettinger Dual-Equilibrium Desorption (JE-DED) model and the J&E model. Through studying the effects of 8 adsorbents belonging to 3 categories (MOFs, Carbon materials, and molecular sieve) on the adsorption of trichloroethylene, MIL-101 was selected from UIO-66, ZIF-8, MOF-801, spherical activated carbon, graphic electrode, HiSiv1000 and HiSiv3000 to adsorb and determine the content of trichloroethylene in soil gas. Results of risk assessment based on trichloroethylene concentration measured in soil gas were compared with the results based on the calculation of J&E and JE-DED models. The results showed that for the fluvo-aquic soil from Beijing and Heilongjiang black soil, the risk value calculated by J&E was two orders of magnitude higher than the risk value calculated based on the measured vapor concentration of trichlorethylene in the soil gas. For the fluvo-aquic soil from Beijing with lower organic matter content, the calculated risk value of trichlorethylene in soil gas was one order of magnitude lower than that calculated by JE-DED model. However, for the Heilongjiang black soil with high organic matter content, the calculated risk value of JE-DED model was closer to the risk value calculated based on the measured concentration of trichlorethylene in the soil gas. Therefore, it was concluded that the risks based on the VOCs concentrations in soil gas and that based on the calculation of JE-DED model can avoid the problem of overly conservative in J&E model, and objectively reflect the pollution states of the site and avoid over-remediation, as well as the waste of resources.

     

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