Occurrence And Source Apportionment Of Persistent Organic Pollutants In Aquatic Environment Of Haihe River Estuary

Haihe River estuary is a typical hotspot of POPs in China. Tianjin City, where the main stream of Haihe River is located, was an important host city of several large POPs producers in the history. In the present thesis, Haihe estuary has been selected as the pilot area for POPs investigation study. Multiple advanced methods have been adopted to measure the occurrence and levels of three categories of POPs in water and sediment. The congener profiles and potential sources were further analyzed.A series of analytical methods including GC/μECD, GC/MS, HRGC/HRMS, CAULEX gene bioassay were established for the determination of three categories of POPs (22 organochlorine compounds, 12 polychlorinated biphenyl congeners, and dioxins). Recovery, determination limit and repeatability are good enough to confirm the requirements for environmental analysis.With the developed methods, measurements of POPs were conducted for samples collected from Haihe estuary in 2004, 2005 and 2006. As the results, POPs contamination in main stream of Haihe River is serious, while that in Bohai Bay is relatively lower. The most contaminated stations are closed to the estuary. HCHs and DDTs are mainly of detected organochlorines. Trichlorinated and tetrachlorinated biphenyls are predominant of analyzed PCBs congeners. OCDD, HpCDD and OCDF are key contributors of the dioxins detected are sediment samples. After the local Dagu Chemical Plant stopped the production of POPs products in 2003~2004, the detected HCHs concentration in main stream of Haihe River did not decrease correspondingly, but increased significantly. Potential reason might be the runoff caused by the rainfall, which could carry POPs form the open stockpile of waste caused by dismantle of the historic POPs production facilities in Dagu Chemical PlantT. E Q determined by CALUX is correlated to that determined by HRGC/ HRMS, which show the applicability of CALUX in screening analysis of sediments sample for dioxins. High concentration of dioxins has been found in the station between the Dagu Chemical Plant and the Haihe floodgate. Comparison of congeners profile of the sediment sample with of sludge samples from the discharge port and soil samples near the plant revealed the similarly. The dioxins contamination should come from the production process of PCP-Na using null isomer of HCH in the Dagu Chemical Plant.Principal component analysis followed by multiple linear regression was applied to apportion sources of PCBs and OCPs in surface sediment of Haihe Estuary. The contributions based on multiple linear regression of major OCPs'sources were identified representing historical residue, stack leak of technical HCH and new input of DDT. For PCBs, the two major sources were identified representing: unintentional produce and long-range air transmission.