Study On Partitioning And Affecting Mechanism Of POPs In Multi-media

With the increasing worsening of the global oceanic and coastal environment, the chemical behaviors of the POPs in the coastal environment have attracted much attention in the relevant domestic academic fields. Certain studies were also carried out in some typical urban coastal and estuarine areas in terms of the spacial distribution and accumulative laws. Some information has already been obtained through the previous studies. But there is still a big gap in terms of the scopes and depths of the researches compared to the some subject overseas. More efforts are needed to be engaged in the studies of POPs' accumulation and transportation process and mechanisms in different medium especially in their microstudies as well as the factors which can exert certain effects on them in such an ecological environment which is heavily disturbed by humanbeing. The target study area of this paper is the urbanized estuary in a environment which is heavily disturbed by humanbeing. The main tasks of this paper are to enrich and improve the seasonal variation theories of POPs in the sediments-SPMs-animals-plants and the other medium in the estuarine, discuss the accumulative mechanism of POPs in the estuarine environment and further enrich the studies in the estuarine environmental science. Meanwhile this paper also involves the studies of the model in which the POPs flux in sediment-water interface and its decisive factors are studied. PCBs and OCPs were determined by GC-ECD, while PAHS were determined by GC-MS.Studies on the POPs in the SPMs in the Yangtze estuary showed that the composing of HCHs are basically the same in the samples from different sampling sites and the ratios of each homologous compounds are also nearly the same. However, the spacial distribution of DDTs varied in different sampling sites, but the concentration of different components in DDTs are basically the same. Compared to concentration of the OCPs in SS, there is no strong correlation between them, which indicates that the concentration of OCPs and its composings are nearly the same due to the movement of the seawater which makes an even mixture of the SPMs in different areas. Generally, there are no obvious differences among the concentrations of the DDTs and HCHs at different sampling sites and their spatial distributions are also of the same trend. All these have indicated that although the particulate sediments are not even, the sources of the pollutants are similar. The potential environmentalimpacts analysis also showed that the concentration of POPs is lower than ER-M.The analysis of the concentration of PCBs find that the concentration of PCBs is generally higher in the sediments than in the top layer, but this has not demonstrated the law of regional distribution related to the pollution discharge. The PCBs with low chlorine are the main components in the suspended matter in the water. This is different from that of the top layer sediment in which 2CB has comparative advantages. The concentration of PCBs is not strongly correlated with the diameter of the particles and the concentration of the organic matter, it may be affected comprehensively by the sources of the organic matter and mineral composition. Compared to study on the other estuaries in the world, the pollutions of PCBs in SS in the coastal areas of the Yangtze estuary are at a moderate level. As for PAHs which is in a higher concentration, the largest concentration appeared at the discharging point and the concentrations are lower in the areas far away from the draining points. This proves sewage discharge has important contribution to the transportation of PAHs in the tidal flat. The source analysis found that the main sources of PAHs in SPMs are the burning of fossil fuel (coal, etc.). Combined with abundance conjecture of the rings of the aromatic hydrocarbons, PAHs in the SS are mainly from suspended particulate PAHs in atmosphere, petroleum leaking in the water and sewage discharge. The pollution of PAHs in the target area is at low- medium level but the concentrations of phenanthre...