Quantify the Effects of Wind Speed and Temperature on the Breakthrough Levels of Pops on the Flow through Sampler2013-08-30
Quantify the Effects of Wind Speed and Temperature on the Breakthrough
Levels of Pops on the Flow through Sampler
Prof. Hang Xiao
Institute of Urban Environment, Chinese Academy of Sciences
To investigate the sampling performance of flow through sampler (FTS) a under various environmental conditions, a high volume active sampling pump (HiVol) was connected with sampling train of flow through sampler (FTS), which consist of seven porous PUF disks of one inches thickness arranged sequentially within the flow tube. The retention profiles of different persistent organic pollutants (POPs), particularly relatively high volatile and particle-bound substances, on the sampling ensemble were investigated by separate analysis of seven PUF disks. The sampling efficiency under different linear wind speeds after passage through the sampling column was tested by varying the total wind resistance for the HiVol pump. Theoretical plate number analysis of the break-through curves yields a quantitative understanding of the effect of wind speed on FTS sampling efficiency. The other relevant sampling parameters and environmental conditions, such as sampling durations, temperature and relative humidity were recorded and correlated with break-through levels. A poly-parameter linear free energy relationship (pp-LFER) for the theoretical plate number of FTS sampling column, which includes environmental parameters, was established to estimate the break-through levels for volatile POPs under a wide range of environmental conditions. This equation make it possible to quantitatively correct the results of FTS for some volatile POPs congener, which may suffer serious break-through under longer sampling periods during summer or windy seasons.