The presence of perfluorinated compounds(PFCs)in seven major wastewater treatment plants(WWTPs)in Beijing was investigated in the current study.We detected nine PFCs in all the wastewater and sludge samples.Perfluorooctane acid(PFOA)is the dominant PFCs in influents and effluents,while perfluorooctane sulfonate(PFOS)is the major contaminant in sludge.The highest PFC concentration was found in plants at Qinghe and Jiuxianqiao WWTP,while the lowest was found at Fangzhuang WWTP.The total values of PFC range from 2.88 to 176 ng/L in influents,from 5.48 to 498 ng/L in effluents,and from 1.21 to 32.0 ng/g(dry wt)in sludge.The fact that effluents usually contain higher levels of PFCs than influents suggests that additional PFCs are produced during the wastewater treatment processes.However,PFOS decreases in effluents than in influents in 62%of the water samples.This may be due to the adsorption and removal of the sludge during the active process.Perfluoroalkyl carboxylates(PFCAs)were found significantly correlated with each other in the effluents,which may indicate their similar sources or the existence of their potential precursors in the wastewater or treatment processes.The mass flows of PFC discharges into WWTPs are 0.4–51.4 mg/day,and the mass flows of PFCs in effluents exceed those in influents by 127%.Domestic and commercial wastewaters are suggested to be the major sources of PFC pollution in WWTPs in Beijing.
Eleven perfluorinated compounds(PFCs) were determined in tissue samples from farmed pigs and chickens(n=143) that were purchased in Beijing in March 2009.The total PFCs mean concentration was the highest in pig liver(3.438 ng g-1 wet weight(ww)),followed by pig kidney(0.508 ng g-1(ww)),pig heart(0.167 ng g-1(ww)),chicken liver(0.098 ng g-1(ww)),chicken heart(0.050 ng g-1(ww)),pork loin(0.018 ng g-1(ww)),and chicken breast(0.012 ng g-1(ww)).Among the PFCs analyzed,perfluorooctane sulfonate(PFOS) was the predominant compound in viscera and muscle of farmed pigs and chickens.In addition,a strong linear correlation(r = 0.932) was observed between the concentrations of PFOS and perfluoroundecanoic acid(PFUnDA) in pig liver.Our preliminary conclusion is that there is little potential risk of exposure to PFCs via the consumption of these products in Beijing.
