[Contamination Characteristics and Risk Assessment of Polycyclic Aromatic Compounds in Surface Dust of Suntuan Mining Area in Huaibei].

The Suntuan mining area of Huaibei is a typical coal resource mining base in the Huainan-Huaibei areas in North China. Previous environmental studies related to surface dust in coal mining areas mainly focused on heavy metals and water-soluble ions, with little research on polycyclic aromatic compounds (PACs). In this study, gas chromatography-triple tandem quadrupole mass spectrometry (GC-MS/MS) was used to determine the contents of 16 parent polycyclic aromatic hydrocarbons (16PAHs), alkyl polycyclic aromatic hydrocarbons (aPAHs), and some oxygenated polycyclic aromatic hydrocarbons (OPAHs) in surface dust from the Suntuan mining area and surrounding environment. The results showed that the ΣPACs concentration range of surface dust in the Suntuan mining area was 283.8-36852.5 µg·kg-1 (mean:4114.2 µg·kg-1). ΣaPAHs (mean:2593.8 µg·kg-1) was 2.4 times higher than Σ16PAHs (mean:1074.9 µg·kg-1), which was the main contributor to PAC pollution. The composition of 16PAHs and aPAHs in surface dust was dominated by low molecular polycyclic aromatic hydrocarbons. The average OPAH content was 445.6 µg·kg-1. At the same time, PAC pollution was mainly concentrated around the mining area and near the road of a coal gangue landfill. Based on the positive matrix factor (PMF) analysis, it was inferred that the study area was mainly affected by petroleum sources, followed by coal and biomass combustion, and traffic sources and petroleum product leakage accounted for a relatively small proportion. Based on the ratio and distribution pattern of 16PAHs and aPAHs, it was inferred that when Σ16PAHs/ΣPACs<0.25, it was mainly polluted by the coal mining area. The results of PMF combined with lifetime carcinogenic risk (ILCR) showed that there were potential carcinogenic risks for children near the study area, mainly from coal and biomass burning and coal mining. There are many coal mining areas in Huaihe River Basin in China. The results of this study can provide reference for pollution prevention and control of PACs in these coal mining areas.

[Treatment of high-concentration butyl-acrylate-production wastewater by A three-phase biological fluidized bed reactor].

The butyl-acrylate-production wastewater was treated by a three-phase biological fluidized bed reactor. The influences of acrylic acid concentrations, p-toluenesulfonic acid concentrations, volumic load and hydraulic retention time on pollutants removal efficiencies were investigated. It was indicated that the reactor was suitable for the treatment of butyl-acrylate-production wastewater at a high loading rate. Acrylic acid of 100 mg/L or p-toluenesulfonic acid of 50 mg/L in the influent can inhibit the unacclimated microorganisms in the fluidized bed reactor. The inhibition effects were eliminated after an acclimation of two weeks. Acrylic acid and p-toluenesulfonic acid could be removed completely at COD loading rates up to 11.56-13.56 kg/(m3 x d). The effluent COD could satisfy the demand of Class II in Chinese Integrated Wastewater Discharge Standard (GB 8978-1996) at COD loading rates up to 8.86 kg/(m3 x d) when influent COD concentration is below 2000 mg/L. When the influent COD concentration was increased to 9550-11,800 mg/L(acrylic acid of 6244 mg/L and p-toluenesulfonic acid of 1000 mg/L), the effluent COD was 271-360 mg/L, which satisfied the demand of Class III in Chinese Integrated Wastewater Discharge Standard (GB 8978-1996) at COD loading rates of 7.96-9.83 kg/(m3 x d).

[Sequential extraction experiments applied to study chemical mobility of fluorine in rocks].

Sequential extraction experiments were used to study the chemical mobility of fluorine in rocks. The results show that there are quite big differences in chemical mobility of fluorine in rocks of different types. Fluorine in carbonate rock is very active, in which the proportion of leachable fluorine is generally more than 75%. Fluorine in black rocks of Lower Cambrian is closely related to their different metamorphosed grades, in which fluorine in black carbonaceous slate with higher metamorphosed grade mostly has lower leachability than black shale and black siliceous rock. Generally speaking, the leachable percentage of fluorine is high in phosphorite rocks and low in phyllite. The leachable fluorine in diabase is in direct proportion to its fluorine concentration. There are some differences in chemical mobility of fluorine in stone coal of different ages. Fluorine in stone coal of Silurian has higher leachability than stone coal of Cambrian.