Emerging contaminants and their transformation products are widely distributed in the environment. These pollutants carry unknown risks owing to their persistence, migration, and toxicity. The wide variety and complex structures of these substances render them difficult to identify using only target analysis.
View Article and Find Full Text PDFEmerging pollutants occur in the environment, which has become a pressing issue for environmental research. In order to comprehensively screen potential polar organic pollutants in surface water of Wujin and Yixing in the Taihu Lake Basin, nontarget screening was carried out by high performance liquid chromatography(HPLC) and time of flight mass spectrometry(TOF-MS). Screened by accurate mass, isotope distribution, and MS/MS information, 162 organic compounds were identified, including 46 pesticides, 34 drugs, 8 personal care products, and 27 additives; 17 organic synthetic intermediates and 30 metabolites, 45 of which have been verified by reference standards.
View Article and Find Full Text PDFNitro polycyclic aromatic hydrocarbons (NPAHs) are important pollutants with carcinogenic effects present in PM. To analyze the pollution characteristics and sources of NPAHs, 14 samples of PM were collected in Nanjing from November 2017 to March 2018. The results showed that, 2,8-dinitrodibenzothiophene (743 pg·m), 2, 7-dinitrofluorene (331 pg·m), 9-nitroanthracene (326 pg·m), 3-nitrofluoranthene (217 pg·m), and 1,8-dinitropyrene (193 pg·m) were dominant, and the detection concentrations notably varied between seasons; the highest concentrations occurred in winter (3082 pg·m) followed by autumn (1553 pg·m) and spring (1218 pg·m).
View Article and Find Full Text PDFCarbon dots (CDs) are photoluminescent nanomaterials with wide-ranging applications. Despite their photoactivity, it remains unknown whether CDs degrade under illumination and whether such photodegradation poses any cytotoxic effects. Here, we show laboratory-synthesized CDs irradiated with light degrade into molecules that are toxic to both normal (HEK-293) and cancerous (HeLa and HepG2) human cells.
View Article and Find Full Text PDFTo better understand the environmental impact of ubiquitous perfluoroalkyl substances (PFASs) in waters, reliable and robust measurement techniques are needed. As one of the most widely used passive sampling approaches, diffusive gradients in thin-films (DGT) is not only easy to handle but also provides time-weighted analyte concentrations. Based on DGT with XAD18 as a binding agent, we developed a new methodology to measure two frequently detected PFASs in surface waters and wastewaters, i.
View Article and Find Full Text PDFTo better understand phthalate esters (PAEs) pollution in key areas of Taihu Lake, water and sediment samples were collected for content analysis. The concentrations of ∑PAEs in water samples from wet, dry, and normal seasons ranged 1.6-11.
View Article and Find Full Text PDFFood is a major source of human exposure to perfluorooctanoic acid (PFOA), however, PFOA bioavailability in food has not been studied. An in vivo mouse model and three in vitro methods (unified BARGE method, UBM; physiologically based extraction test, PBET; and in vitro digestion method, IVD) were used to determine the relative bioavailability and bioaccessibility of PFOA in the presence of 17 foods. PFOA was mixed with foods of different nutritional compositions and fed to mice over a 7-d period.
View Article and Find Full Text PDFScientificWorldJournal
February 2014
Based on the life cycle cost (LCC) approach, this paper presents an integral mathematical model and particle swarm optimization (PSO) algorithm for the heating system planning (HSP) problem. The proposed mathematical model minimizes the cost of heating system as the objective for a given life cycle time. For the particularity of HSP problem, the general particle swarm optimization algorithm was improved.
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