Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, People's Republic of China.
Chinese Research Academy of Environmental Sciences, Beijing, 100012, People's Republic of China.
Environ Sci Pollut Res Int. 2023 Apr;30(19):55756-55767. doi: 10.1007/s11356-023-26393-8. Epub 2023 Mar 11.
Light non-aqueous phase liquids (LNAPL) are considered to be a composition-based risk, containing multiple chemical ingredients that release dissolved- and vapor-phase plumes. In dissolved form, there is a saturation-based risk as the water source expands, affecting groundwater aquifers on a larger scale in the aquifer. As a typical pollutant found in petrochemical contaminated sites, the migration and transformation of benzene, toluene, ethylbenzene, and o-xylene (BTEX) between gas, aqueous, and NAPL phases are distinctly affected by groundwater table fluctuation (GTF). BTEX multiphase migration and transformation pattern in a petrochemical factory at the riverside was simulated based on the TMVOC model in differentiating pollution distribution and interphase transformation under stable or fluctuating groundwater tables conditions. TMVOC model performed an excellent simulation effect on the migration and transformation of BTEX in GTF circumstances. In comparison with the stable groundwater table condition, the BTEX pollution depth under GTF increased by 0.5 m, the pollution area increased by 25%, and the total mass increased by 0.12 × 10 kg. In both cases, the mass reduction of NAPL-phase pollutants was more significant than the total mass reduction of pollutants, and GTF further promoted the mass conversion of NAPL-phase pollutants to water pollutants. Prominently, as the groundwater table rises, the GTF can correct for evacuation, and the transport flux of gaseous pollutants at the atmospheric boundary decreases with increasing transport distance. Furthermore, descended groundwater table will intensify the transmission flux of gaseous pollutants at the atmospheric boundary with the transmission range expanding, which can be harmful to human health on the surface due to gaseous pollutants entering into the air.
轻质非水相液体（LNAPL）被认为是一种基于成分的风险，包含多种释放溶解相和气相羽流的化学物质。在溶解状态下，由于水源的扩大，存在基于饱和度的风险，从而在含水层中以更大的规模影响地下水含水层。作为石化污染场地中常见的污染物，苯、甲苯、乙苯和二甲苯（BTEX）在气相、水相和 NAPL 相之间的迁移和转化明显受到地下水位波动（GTF）的影响。基于 TMVOC 模型，在区分稳定或波动地下水位条件下的污染分布和相间转化，模拟了河边石化厂 BTEX 在多相迁移和转化模式。TMVOC 模型在 GTF 情况下对 BTEX 的迁移和转化具有出色的模拟效果。与稳定的地下水位条件相比，GTF 下 BTEX 污染深度增加了 0.5m，污染面积增加了 25%，总质量增加了 0.12×10kg。在这两种情况下，NAPL 相污染物的质量减少比污染物的总质量减少更为显著，并且 GTF 进一步促进了 NAPL 相污染物向水污染物的质量转化。突出的是，随着地下水位上升，GTF 可以进行排空校正，并且随着传输距离的增加，大气边界处气态污染物的传输通量减少。此外，下降的地下水位会随着传输范围的扩大而加剧大气边界处气态污染物的传输通量，由于气态污染物进入空气，这可能对地表的人类健康造成危害。
