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Sulin coal-mining district is characterized by rich coal resources, and its shallow groundwater (SG) and mid-layer groundwater (MG) are the main freshwater source for drinking, agriculture, and industrial purpose. However, frequent mining activities had damaged groundwater systems. Therefore, it is necessary to understand the hydrogeochemical characteristics and determine the status of groundwater quality. To achieve a higher degree of accuracy in water quality assessment, this paper proposed a fuzzy analytical hierarchy process (AHP) which combined the fuzzy analysis model and AHP model. The results showed that Na+ and HCO3- were the dominant cation and anion in both SG and MG, respectively. In addition, TDS, SO42-, Cl-, Mn, Na+, and NO3- of SG and TDS, SO42-, Cl-, Mn, Na+ and F- of MG were higher than the grade III limits of Chinese groundwater standards. Analysis with molar ratios of major ions suggested that the geochemical composition of SG and MG were mainly determined by the dissolution of silicates. The fuzzy AHP evaluation results indicated that the samples of SG and MG within the III-type water accounted for 90.64% and 94.44%, respectively, and their water quality was good, which were consistent with the actual natural conditions of the study area. [ABSTRACT FROM AUTHOR]

To manage public health and make better use of groundwater resources, the concentration characteristics and a health risk assessment of eight heavy metals in shallow groundwater were studied. Besides this, this paper introduced triangular fuzzy numbers into the USEPA health risk assessment model to assess the health risk posed to local children and adults through different exposure pathways. The results showed that Mn levels exceeded the WHO's guideline values of 100 mg/L with the proportion of 27.98% and Sr were over the health reference level (HRL) of 1500 µg/L with the proportion of 56.25%, while other heavy metals were below the corresponding standard. The results of the HRA showed that the non-carcinogenic risks from Sr and Mn in the district were relatively higher, while those from the remaining six heavy metals were relatively lower. All hazard index (HI) values did not exceed the safety level of 1 for either age group. The average carcinogenic risk from Cr was slightly higher than the acceptable level of 1 x 10-6 for adults. Sensitivity analyses conducted using Monte Carlo simulation indicated that Sr and Cr concentrations were the most influential variables contributing to the non-carcinogenic and carcinogenic risk values, respectively, while body weight had a minor contribution. [ABSTRACT FROM AUTHOR]

The immobilized N-heterocyclic carbene–Pd complex was readily prepared by reaction of silica gel-supported imidazolium chloride with Pd(OAc)2. The Pd complex exhibited excellent catalytic activity in the coupling reaction of aryl halides with arylboronic acid. The heterogeneous Pd catalyst was reusable as well as air-stable to allow easy use. [ABSTRACT FROM AUTHOR]

In order to master the environmental geochemical characteristics of heavy metals in the sediment of urban scenic areas, in this study the water area of the delta Park in Suzhou City (Anhui Province, China) as an example, the contents of Pb, U, V, Mn, Ni, Cr, Cu and Zn in sediment were tested. On this basis, using the Kriging spatial interpolation, self-organizing map (SOM) and positive matrix factorization model (PMF) to explore the spatial distribution, pollution characteristics and sources of heavy metals in the study area. The results showed that the heavy metal content of the sampling points in the estuary area was higher than that in the park; the potential ecological risk index and the geoaccumulation index evaluation results showed that the sediment of water area of the delta park was in a light pollution state; three pollution factors, including agricultural, industrial and natural sources, were analyzed by the positive matrix factorizing model, with contribution rates of 42.13%, 35.39% and 22.48% respectively, of which agricultural and industrial sources were the main sources of heavy metals in the sediments of the study area. [ABSTRACT FROM AUTHOR]

Chiral amino thioacetate ligands were prepared from the corresponding amino alcohols and used as catalysts for enantioselective aryl transfer reaction. The amino thioacetates were remarkably superior to the corresponding amino alcohols. Low catalyst loadings of only 1−2.5 mol % were sufficient to achieve excellent enantioselectivity as well as high conversion in short reaction time. The results reveal that the thioacetoxy moiety of the amino thioacetates has a surprisingly beneficial effect in enhancing the asymmetric induction. [ABSTRACT FROM AUTHOR]