Study On Residues And Long-range Transport Potential Of Pentachlorophenol In Typical Area Of Poyang Lake

In this study, Nanjishan of Poyang Lake was taking as the object area.Pentachlorophenol (PCP) residues and its potential risk of different land use types ofsediments in this area were analyzed. And the possible ralationship between physicalproperties and the amount of residual contaminants in sediments were studiedpreliminarily. In addition, the long-range transport potential (LRTP) and overallpersistence (Pov) of persisitent organic pollutants (POPs) through air and water inPoyang Lake were estimated by the TaPL3model，it can provide a scientific basis toesplore environmental process and risks of POPs in Poyang Lake. The results showedin the following:（1）pH values in different land use types sediment of Nanjishan ranged from4.71~7.64, the mean value was5.81, organic matter in98.02~176.10g/kg, mean of123.25g/kg, PCP concentration ranged from N.D.~28.38μg/kg, with a median of11.12μg/kg, the detection rate was78.67%. In china’s major rivers sediments thepresence of PCP residues were detected and the residual concentrations substantiallywere higher than those in Western countries;（2）The distribution order of the residual PCP concentrations in dfferent landuse types was: inland beaches soil> Everglades> paddy soil> pond soil> ditches soil>rural road side soil> bare soil. Correlation analysis revealed that the PCP residualamonts had strongly negative correlation with pH value of the sediment; andmoderate positive correlation with the organic matter contents; Very weak or nocorrelation existed between pH value and the organic matter contents;（3）The interannual residues of PCP in Poyang Lake sedimens is on thedecline, the highest annual residue was in1999. The emergence of PCP substitutesand the reduce usage of pesticides containing PCP are the main reasons for thedeclining trend of their residues in environmental media;（4）The results showed that the CTDAirof p, p’-DDT, γ-HCH, HCB, PCP and2,3,7,8-TCDD ranged from432km (2,3,7,8-TCDD) to86479km (HCB), and thevalue of PovAirranged from85.6d (PCP) to2231d (HCB), when POPs were emitted to the atmosphere. Soil phase was the main fate of these typical POPs.Meanwhile, theCTDWaterwas from4207km (PCP) to1.19×105km (γ-HCH), and PovWaterwas from103d (PCP) to2890d (HCB), when POPs were emitted to the water. Sediment phasewas the main fate of these typical POPs. Compared with other similar studies inChina, the CTDAirof related POPs in Poyang Lake is in the middle level. While theCTDWaterwas a little higher than other areas, which was due to the higher water depthand water flow velocity of Poyang Lake. Therefore, the higher water depth and waterflow velocity were two significantly-affected parameters of CTDWater;（5）Half-life in the environment and octanol-water partition coefficientlogarithm of POPs were the two main physical-chemical parameters that effectedCTD and Pov, five kinds of POPs’ CTDWaterlonger than4000km,which may causepollution of the Yangtze River area.