National Environmental Research Institute, Aarhus University, PO Box 358, 4000 Roskilde, Denmark.
Environ Sci Technol. 2011 Apr 1;45(7):2932-7. doi: 10.1021/es1033124. Epub 2011 Feb 28.
Bioremediation of contaminated soils often leaves a desorption-resistant pollutant fraction behind in the soil, which in the present study was isolated with a combination of diffusive carrier and infinite diffusive sink. Such a diffusive sink was made by casting a composite of silicone and activated carbon into the bottom of a large glass. Field-contaminated soil samples were then suspended in a cyclodextrin solution and incubated in such glasses for the continuous trapping of PAH molecules during their release from the soil matrix. The PAH concentrations remaining in the soil were determined by exhaustive extraction and compared with a biodegradation experiment. The concentration decline in the first soil was faster in the contaminant trap than in the biodegradation experiment, but the halting of the biodegradation process before reaching the legal threshold level was well indicated by the contaminant trap. The PAH concentrations in the second soil hardly decreased in the traps at all, in good agreement with the biodegradation experiment. The PAHs in this soil appeared to be "stuck" by strong sorption. The contaminant trap proved to be a practical approach to the isolation and quantification of the desorption-resistant PAH fraction.
生物修复往往会在污染土壤中留下解吸抗性污染物残留，本研究采用扩散载体和无限扩散汇的组合方法对其进行分离。通过将硅酮和活性炭复合材料浇铸在一个大玻璃容器的底部，制得一个这样的扩散汇。然后，将现场污染土壤样品悬浮在环糊精溶液中，并在这种玻璃容器中进行孵育，以在 PAH 分子从土壤基质中释放出来时连续捕获它们。通过彻底萃取来确定土壤中残留的 PAH 浓度，并与生物降解实验进行比较。在第一个土壤中，污染物陷阱中的污染物浓度下降速度比生物降解实验更快，但在达到法定阈值水平之前，生物降解过程的停止很好地表明了污染物陷阱的作用。在陷阱中，第二个土壤中的 PAH 浓度几乎没有下降，这与生物降解实验的结果非常吻合。该土壤中的 PAHs 似乎因强烈的吸附而“被困”。污染物陷阱被证明是一种实用的方法，可以分离和定量解吸抗性 PAH 组分。
