State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academic of Sciences, Guangzhou 510640, China.
Environ Pollut. 2013 Oct;181:144-50. doi: 10.1016/j.envpol.2013.06.020. Epub 2013 Jul 15.
A new passive exchange meter (PEM) to measure inter-compartment fluxes of persistent organic pollutants (POPs) at the interface between soil and the atmosphere is described. The PEM uses labeled reference compounds (RC) added in-situ to vegetation litter deployed in open cylinders designed to trap the vertical downward export of the RCs while allowing free exchange of POPs between litter and air. Fluxes of native compounds (bulk deposition, volatilization and downward export) are quantitatively tracked. One scope of the PEM is to investigate the influence of biogeochemical controls on contaminant re-mobilization. The PEM performance was tested in a subtropical forest by comparing measurements under dense canopy and in a canopy gap; conditions in which deposition and turn-over of organic matter (OM) occur at different rates. Significant differences in fate processes were successfully detected. Surprisingly, mobilization by leaching of more hydrophobic compounds was higher under canopy, possibly as a result of canopy mediated enhancement of OM degradation.
一种新型的被动交换仪（PEM）被开发出来，用于测量土壤-大气界面处持久性有机污染物（POPs）在不同相之间的迁移通量。该 PEM 使用标记的参比化合物（RC）添加到布置在开放圆筒中的植被凋落物中，这些圆筒旨在捕获 RC 的垂直向下输出，同时允许 POPs 在凋落物和空气中自由交换。原生化合物的通量（总沉降、挥发和向下输出）被定量跟踪。PEM 的一个应用范围是研究生物地球化学控制对污染物再迁移的影响。该 PEM 的性能在亚热带森林中进行了测试，比较了在茂密树冠下和树冠空隙中的测量结果；这两种条件下，有机物（OM）的沉积和周转速率不同。成功地检测到了不同的命运过程。令人惊讶的是，由于树冠介导的 OM 降解增强，在树冠下，更疏水化合物的淋洗迁移作用更高。
