China's current perspective for big cities were filled with great population, great number of restaurants, growing gaseous pollutants and great pollution. Volatile organic compounds (VOCs) were main components of catering industry gaseous pollutants. In this study, we collected and analyzed VOCs from Home cooking (HC), Sichuan and Hunan cuisine (S&H), Shandong cuisine (SD), Anhui cuisine (AH), Beijing cuisine (BJ) and Barbecue (BBQ). The result showed that BBQ gave the highest VOCs

For amphoteric ß-lactam antibiotics, the acid dissociation constant (pKa) is a fundamental parameter to characterize physicochemical and biochemical properties of antibiotics and to predict persistence and removal of drugs. pKa of piperacillin (PIP) is determined by potentiometric titration with a glass electrode. Electrospray ionization mass spectrometry (ESI-MS) is creatively applied to verify the reasonable pKa value at every dissociation step. Two microscopic pKa values (3.37 ± 0.06 and 8.96 ± 0.10) are identified and attributed to the direct dissociation of the carboxylic acid functional group and one secondary amide group, respectively. Different from other ß-lactam antibiotics, PIP presents a dissociation pattern where direct dissociation is involved instead of protonation dissociation. Moreover, the degradation tendency of PIP in an alkaline solution may alter the dissociation pattern or dismiss the corresponding pKa of the amphoteric ß-lactam antibiotics. This work offers a reliable determination of the acid dissociation constant of PIP and a clear interpretation of the effect of stability of antibiotics on the dissociation process.

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The violate organic compounds (VOCs) emission from co-processing cement kiln has not been comprehensively investigated and evaluated. In this study, we sampled and determined the VOCs emitted from a typical co-processing cement kiln in Beijing, China. VOCs characteristics, ozone formation potential (OFP), and main odor components for the emitted gas were analyzed. Additionally, a Fuzzy Analytic Hierarchy Process (F-AHP) was innovatively applied to estimate the priority VOCs. The study shows that aromatic (36.6%) and oxygen contained VOCs (O-VOCs) (30.3%) were the most abundant VOCs, with a high average concentration of benzene (1622.0 μg/m3) and acrolein (1105.5 μg/m3). Acrolein, propene, benzene, 1-butane, and 1,3-butadiene were the dominate OFP compounds, with the corresponding average OFP concentration of 8325.6, 3768.2, 1167.9, 1065.9, and 1027.2 μg/m3, respectively. Acrolein was also found to be the dominate main odor component. Eleven VOCs, including one O-VOC, one halohydrocarbon, and nine alkenes, were screened out by F-AHP. Alkene was the priority VOCs category and acrolein was the most important VOC in the stack gas. The results of this study are helpful to systematically understand the VOCs’ characteristics, OFP, main odor components, and priority compounds of VOCs in the stack gas of co-processing cement kiln, and provide a new method for the screening of priority VOCs compounds.

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