ABSTRACT
Ten sampling points were distributed approximately equidistantly in the Dajiuhu lake wetland, and soils from the depths 0-10 cm, 10-20 cm, and 20-30 cm were collected in April 2012. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the remote mountain wetland shallow soils, and 16 kinds of USEPA priority controlled polycyclic aromatic hydrocarbon (PAH) pollutants were identified. The ∑16PAHs content ranges of the shallow soils of this region were 48.55-984.73 ng·g-1, 14.36-806.47 ng·g-1, and 12.84-1191.53 ng·g-1 in the 0-10 cm, 10-20 cm, and 20-30 cm layers, with a mean of 302.94 ng·g-1, 142.98 ng·g-1, and 208.68 ng·g-1 in the three layers, respectively. The concentrations of seven carcinogenic PAHs ranged from 21.20-844.29 ng·g-1, 2.96-592.06 ng·g-1 and 0.66-964.70 ng·g-1 in the three soil layers, with means of 197.25 ng·g-1, 93.16 ng·g-1, and 147.16 ng·g-1 that accounted for 65.12%, 65.13%, and 69.08% of the total PAHs in the three soil layers, respectively. The concentrations of PAHs in the areas with peat were significantly higher than that in the soil. PAHs having 4-6 rings were the dominant ones. The ratios IcdP/(IcdP+BghiP) and Pyr/BaP showed that the PAHs in the shallow soil form the Dajiuhu lake wetland mainly came from burning fossil fuels and wood. In recent years, the entry of tourist vehicles has contributed significantly to the increase in PAHs. The regression analysis on peat surface layer single body PAH and total PAHs showed that Chr, BbF, IcdP, and BaA could be used as a signaling property of mountain wetland PAH pollution.
ABSTRACT
The Langlois reagent was found to be effective for the isothiocyanation of primary amines in the presence of copper iodide and diethyl phosphonate.
ABSTRACT
The concentration, potential source and health risks of 16 polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Dajiuhu, Shennongjia, China, were studied. Polyurethane foam (PUF) Passive air samplers (PAS) were settled. The results indicated that the total concentrations of 16 PAHs in different samples ranged from 6.94 to 184.23 ng·m-3, with the mean of 30.36 ng·m-3. The dominant compounds were low rings PAHs, such as Phe, Nap, Pyr, Fla, Flu and Ant. Compared with other regions, the PAHs pollution of Dajiuhu atmosphere was at a low level. Higher PAHs concentrations were detected in nearby Deer farm, Dajiuhu peat area and Dajiuhu Wetland Authority. Higher PAHs concentrations were detected in autumn and winter, whereas lower concentrations were detected in spring and summer. Potential pollution sources of PAHs were investigated by diagnostic ratios and backward trajectory analysis, which indicated that coal and biofuel combustion, vehicle emissions and petroleum were the main sources. PAHs of Dajiuhu in air not only came from local emission, but also originated from Hubei, Henan and Hunan's atmosphere transport for most part and long range transport from northwest direction for small part. Health risks assessment results showed that the annual average concentration of total Benzo(a)pyrene-equivalent carcinogenic potency (∑BaPeq) was 0.208 ng·m-3, lower than the value recommended by Ambient Air Quality Standard of China(GB 3095-2012, 1 ng·m-3), indicating a low carcinogenic risk for the local residents.
