[Groundwater organic pollution source identification technology system research and application].

Groundwater organic pollutions are found in large amount of locations, and the pollutions are widely spread once onset; which is hard to identify and control. The key process to control and govern groundwater pollution is how to control the sources of pollution and reduce the danger to groundwater. This paper introduced typical contaminated sites as an example; then carried out the source identification studies and established groundwater organic pollution source identification system, finally applied the system to the identification of typical contaminated sites. First, grasp the basis of the contaminated sites of geological and hydrogeological conditions; determine the contaminated sites characteristics of pollutants as carbon tetrachloride, from the large numbers of groundwater analysis and test data; then find the solute transport model of contaminated sites and compound-specific isotope techniques. At last, through groundwater solute transport model and compound-specific isotope technology, determine the distribution of the typical site of organic sources of pollution and pollution status; invest identified potential sources of pollution and sample the soil to analysis. It turns out that the results of two identified historical pollution sources and pollutant concentration distribution are reliable. The results provided the basis for treatment of groundwater pollution.

[Atmospheric deposition of polychlorinated naphthalenes in Dongjiang River basin of Guangdong Province].

Atmospheric deposition of polychlorinated naphthalenes (PCNs) was investigated at 11 sites in Dongjiang River basin of Guangdong Province during the winter (January and February) and summer (July and August) of 2010 to assess the effect of PCNs on those areas. The average daily deposition fluxes of total PCNs was 828 pg x (m2 x d)(-1), and the corresponding TEQ was 0.14 pg x (m2 x d)(-1). Based on these values, the presumed average annual deposition value of sigma PCNs was 8.5 kg for Dongjiang River basin within Guangdong province, while the corresponding TEQ was 1.3 g. Spatially, the average daily deposition fluxes of PCNs in Guangzhou and Dongguan were much higher than that in Huizhou, and the fluxes were higher in urban areas than those in rural areas. Seasonally, the fluxes were generally higher in summer than those in winter. Tri-CNs dominated the deposition fluxes in all samples and contributed to more than 50% of total PCNs. In addition, higher contents of high chlorinated PCNs (penta-CNs to octa-CN) were found in Guangzhou and Dongguan in comparison with Huizhou. Combustion and other sources may both contribute to the PCNs emission in the Dongjiang River basin. Combustion related source may be the main contributor of PCNs in Dongguan; while non-combustion related source may dominate the contribution to the site of Guangzhou.