A novel graphene oxide-molecularly imprinted polymers (GO-MIPs) was prepared and applied for selective extraction and preconcentration of bis(2-ethylhexyl) phthalate (DEHP) in environmental water samples by using the dispersive solid-phase microextraction (DSPME) method. The GO-MIPs was synthesized via precipitation polymerization using GO, DEHP, methacrylic acid, and ethylene dimethacrylate as supporting materials, template molecules, functional monomer, and cross-linker, respectively. The prepared GO-MIPs were characterized by scanning electron microscope and Fourier transform infrared spectroscopy. The GO-MIPs-DSPME conditions including type and volume of elution solvents, adsorbents amount, initial concentration of DEHP, pH and ionic strength of water samples were investigated. Under optimized conditions, the DEHP was selectively and effectively extracted in real water samples and enrichment factors of over 100-fold were achieved. Good linearity was obtained with correlation coefficients (R) over 0.999 and the detection limit (S/N=3) was 0.92ngmL. The average recoveries of the spiked samples at three concentration levels of DEHP ranged from 82% to 92% with the relative standard deviations less than 6.7%. The results indicated that the proposed GO-MIPs-DSPME extraction protocol combined with HPLC-UV determination could be applied for selective and sensitive analysis of trace DEHP phthalate in environmental water samples.

The photodegradation of dibutyl phthalate (DBP) over two-dimensional black phosphorene (2D-BP) nanosheets, which were prepared by an environmental friendly solution exfoliation process, in water was investigated under simulated-sunlight. When coexist with water, oxygen, and light, 2D-BP nanosheets can generate the ROS species of 1 O 2 and O 2 •by energy transfer or charge transfer from excited P* to ground state of oxygen, respectively. The ROS species generation is oxygen dependent and positive related with the amount of 2D-BP added. Results from this study demonstrated that the photodegradation of DBP effectively accelerated via 1 O 2 oxidation reaction and effects of O 2 •were negligable due to its relative low oxidative reactivity. The present study provides an excellent method for the removal of DBP phthalate from aqueous solution, which might also be applicable to other photodegradable and water soluble organic pollutants.

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The spatial distribution and seasonal variations of methylmercury (MeHg) in Wen-Rui-Tang (WRT) River network were investigated by monitoring the MeHg concentrations in surface water samples collected from 30 sites across the river network over four seasons. Detection frequencies and concentrations of MeHg were generally higher in January, indicating that low sunlight irradiation, wind speed, and temperature conditions might enhance the persistence of MeHg in surface water. The MeHg levels varied with sampling locations, with the highest concentrations being observed in the industrial area especially around wastewater outfall, revealing that the mercury contamination in WRT River mainly comes from the industrial wastewater. Photodegradation of MeHg in WRT River surface water and the effects of natural constituents such as fulvic acid (FA), ferric ions (Fe), nitrate (NO), and dissolved oxygen on the MeHg photodegradation in aqueous solutions were studied under the simulated sunlight. The experimental data indicated that the indirect photodecomposition of MeHg occurred in WRT River surface water. Photodegradation of MeHg in FA solution was initiated by triplet FA* or MeHg-FA* via electron transfer interaction under light irradiations. The Fe and NO can absorb light energy to produce ·OH and enhance the photochemical degradation of MeHg. The MeHg photodecompositions in FA, nitrate, and Fe solutions were markedly accelerated after removing the dissolved oxygen.