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The bioaccumulation and trophic transfer of 12 Quinolones (QNs) have been studied in a macrophyte dominated lake-Baiyangdian Lake, China. QNs concentrations were detected in surface water, sediments, and 25 biological samples. The average concentrations of QNs varied from 3.01 ng/L for Oxolinic Acid (OXO) to 174 ng/L for Flumequine (FLU) in water, 3.28 ng/g (dry weight, dw) for OXO to 97.0 ng/g (dw) for FLU in sediments, and from 2.88 ng/g (dw) for Pipemidic Acid (PIP) to 37.7 ng/g (dw) for FLU in biological samples. The values of bioconcentration factors (BCFs) or bioaccumulation factors (BAFs) (in the range of 98.0–723 L/kg) and biota sediment accumulation factor (BSAFs) (in the range of 0.000300–0.124) were indicated that low bioaccumulation ability of target QNs in biological species. Due to the detected frequencies of FLU, Enrofloxacin (ENR), Norfloxacin (NOR), and Ofloxacin (OFL) were higher than 50%, the trophic magnification factors (TMFs) values for those QNs were calculated from three different habitats. The TMFs for those QNs were ranged from 0.840 to 1.10. Thereinto, ENR and NOR were appeared trophic magnification, while FLU and OFL were appeared trophic dilution in the food web of Baiyangdian Lake. Although the TMFs values of QNs were not showed significantly difference among three habitats, the TMFs values of those QNs showed significantly difference between the foodweb with macrophyte species and without macrophyte species. Except FLU, the other TMFs values of these QNs without macrophyte species (in the range of 0.700–1.01) were lower than the TMFs for QNs with macrophyte species. Finally, the results of human health risk for QNs suggested that consumption of fish from Baiyangdian Lake with a considerable risk, thus more standard and residue limits of QNs should be set to decrease the human health risk around this region. The spatial variation of bioaccumulation, trophic transfer, and human health risk for 12 QNs has been studied in the benthic foodweb from a macrophyte-dominated shallow lake. Unlabelled Image • The bioaccumulation and trophic transfer of QNs in benthic foodweb was studied. • The BAFs/BSAFs values showed low bioaccumulation ability of QNs. • The TMFs values of QNs were not showed significantly spatial different. • Macrophyte species plays an important role in calculation of the TMFs values. • The human health risk for QNs was a considerable risk level in this region. [ABSTRACT FROM AUTHOR]

PM 2.5 samples were collected inside and outside a primary school classroom in Beijing in 2015 and analysed for 11 polycyclic aromatic hydrocarbons (PAHs) and 10 nitro-PAHs (NPAHs). In the sampling period in the heating season (namely, the heating period), the median concentrations of indoor and outdoor PAHs were 223 ng/m3 and 264 ng/m3, respectively, and those of indoor and outdoor NPAHs were 3.61 ng/m3 and 5.12 ng/m3, respectively. The concentrations of PAHs and NPAHs were consistently higher in the heating period than those (indoor PAHs: 8.75 ng/m3, outdoor PAHs: 8.95 ng/m3, indoor NPAHs: 0.25 ng/m3, outdoor NPAHs: 0.40 ng/m3) in the sampling period in the non-heating season (namely, the non-heating period). In both periods, total PAHs and total NPAHs in indoor PM 2.5 , as well as most individual PAHs and NPAHs, were positively correlated with the outdoor PAH and NPAH concentrations (p < 0.05). This finding suggests that indoor PAHs and NPAHs are largely dependent on outdoor inputs. It is inferred from the diagnostic ratios that PAHs and NPAHs in indoor and outdoor PM 2.5 were affected jointly by coal combustion and vehicular emission in the heating period and mainly derived from vehicle exhaust in the non-heating period. Both indoor and outdoor PM 2.5 showed considerable benzo[ a ]pyrene equivalent toxicity (BaP eq), especially in the heating period. Benzo[ c ]fluorene (BcFE) had relatively low concentrations but large contributions to BaP eq in both periods. This is the first report of PM 2.5 -bound BcFE inside and outside classrooms in Beijing. This result indicates that neglecting PAHs with low abundance but high toxicity leads to a significant underestimation of the overall PAH toxicity. The inhalation cancer risk (CR) of PAHs and NPAHs in PM 2.5 during the primary school year exceeded the acceptable level as defined by the U.S. EPA, emphasizing its impact on the lifetime CR in schoolchildren. Unlabelled Image • PM 2.5 -bound PAHs and NPAHs inside a classroom mainly came from outside. • PAHs and NPAHs in both indoor and outdoor PM 2.5 pose a threat to children's health. • This is the first report on benzo[ c ]fluorene (BcFE) on a campus in Beijing. • BcFE was the largest contributor to PAH toxicity among the detected congeners. [ABSTRACT FROM AUTHOR]

Abstract The addition of zero-valent iron (ZVI) and ZVI & persulfate (PS) were efficient approaches to enhance the production of volatile fatty acids (VFAs), especially butyric acid, from food wastes (FW) during anaerobic fermentation. The maximal concentration of VFAs was increased from 1256 mg COD/L in the control reactor to 8245 mg COD/L with ZVI addition, and it was further improved to 9800 mg COD/L with the PS/ZVI treatment. An investigation of the mechanisms revealed that both the ZVI and PS/ZVI treatments improved the bioavailable substrates in FW and enhanced the bioconversion efficiency of fermentation substrates, especially proteins and lipids. The provision of a sufficient amount of bioavailable substrates was advantageous to the enrichment of the functional bacteria that are responsible for the production of VFAs. Additionally, the microbial activity and key metabolic enzymes involved in the biological VFAs generation processes were stimulated in the ZVI and PS/ZVI-added reactors, which jointly contributed to high-rate VFAs yields. Graphical abstract Unlabelled Image Highlights • ZVI and PS/ZVI contributed greatly to the VFAs promotion, especially butyric acid. • The bioconversion of complex organics was improved, particularly protein and lipid. • The functional acidogens for VFAs yield were enriched in ZVI and PS/ZVI reactors. • The microbial activity involved in VFAs yield was stimulated by the ZVI and PS/ZVI. [ABSTRACT FROM AUTHOR]