| Organophosphate esters (OPEs) are extensively utilized as flame retardants and plasticizers in numerous products including building materials, electronic goods, plastics, furniture and textiles. OPEs have drawn growing attention of the environmental scientists due to their sharply increased consumption and potential adverse effects to the environment and human health such as some of them are considered as neurotoxicant and carcinogen. The aim of this dissertation is to develop the method for analysis of various OPEs and investigate their occurrence and distribution in the urban area of Beijing, China.(1) Analytical methods were developed for simultaneous analysis of 14 OPEs in water, soil, sediment, sludge and biota samples by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The spiked recoveries of OPEs in actual samples ranged from 51.2%-126% with the relative standard deviation (RSD) lower than 10%. The methods were sensitive and accurate for the analysis of 14 OPEs in environmental samples.(2) The occurrence and distribution of 14 OPEs were investigated in sludge from eight sewage treatment plants (STPs) in Beijing. Total concentration of OPEs ranged in 204-4101 μg/kg (dry weight), and organophosphate diesters were also detected in sludge samples. The levels of OPEs in sludge varied with the compositions of the sewage and treatment capacity of STPs. During the span time from 2008 to 2014, the total concentration of OPEs in sludge showed an increasing trend. Finally, high environmental risks were obtained for tricresyl phosphate (TCrP) and 2-ethylhexyl diphenyl phosphate (EHDPP) in sludge.(3) The occurrence and environmental impact of OPEs in a landfill in Beijing were studied. Elevated levels of OPEs were detected in landfill leachate and triethyl phosphate (TEP) revealed the highest concentration of 20709 ng/L. After treatment, the concentration decreased for most of OPEs in leachate, while tri(2-chloroethyl) phosphate (TCEP) was poorly eliminated with removal efficiency of 4.71%. The occurrence of OPEs in rivers around the landfill was significantly influenced by the leachate discharge. The hydrophobicity of OPEs played an essential role for their distribution between water and sediment.(4) In order to investigate the impact of traffic on the pollution of OPEs in urban city, the occurrence and distribution of 14 OPEs in road dust and soil in Beijing were studied. Chlorinated OPEs were the predominant compounds in road dust and soil samples. Significantly higher levels of OPEs were detected in road dust than that in soil, suggesting more serious influence of traffic on the road dust. Additionally, the spatial distribution of OPEs in road dust was closely related to the traffic load level and population density.(5) The occurrence, distribution and bioaccumulation of OPEs in the rivers around an airport were investigated. Tri-n-butyl phosphate (TnBP) showed the highest level of 11597 ng/L in the lake which received parking apron wastewater. The airport may be an important source of OPEs in Xiaozhong River, but not the Wenyu River. Additionally, some OPEs were observed to be adsorbed on sediment and showed bioaccumulation effect in fish.(6) Finally, the occurrence, distribution and risks of 14 OPEs were investigated in urban surface water in Beijing. All of 14 OPEs were detected in water samples, and tri(chloropropyl) phosphate (TCPP) and TCEP were the most abundant compounds. Relatively high levels of OPEs were detected in rivers located at the southern and eastern urban of Beijing, which was probably attributed to the sewage discharge. Besides, higher levels of OPEs were observed in the summer, and the wet deposition (rainfall) was confirmed to be an important factor for this observation. Risk assessment showed low risk of OPEs for the organisms (algae, crustacean and fish). |
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