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531.
532.
533.
Levels of polybrominated diphenyl ethers and hexabromocyclododecane in the atmosphere and tree bark from Beijing, China 总被引:3,自引:0,他引:3
Air samples in four seasons at one site and tree bark samples from four districts were determined to investigate seasonal variation and regional distribution of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) in Beijing, China. The total concentrations of PBDEs (∑PBDE) and HBCD (∑HBCD) were in the range of 57-470 and 20-1800 pg m−3 in the atmosphere, respectively. The ∑PBDE and ∑HBCD concentrations were significantly influenced by the total suspended particulate matter in atmosphere. The total concentrations of PBDEs and HBCD in tree bark samples were in the range of 99-3700 and 26-3400 ng g−1 lipid weight. It was found that regional distribution of PBDEs and HBCD was related to the function of each district. In addition, the study found that weeping willow bark was an ideal atmospheric PBDEs and HBCD passive sampler. Finally, atmospheric levels of BDE-209 and HBCD at tree bark sampling districts were estimated via applying an established bark/air partitioning model, which had been verified by the measured concentrations in tree bark and atmosphere in Beijing. 相似文献
534.
The presence of Bacillus thuringiensis (Bt) protein in earthworms Eisenia fetida has no deleterious effects on their growth and reproduction 总被引:1,自引:0,他引:1
Earthworms Eisenia fetida, bred in substances with stover of two genetically-engineered Bacillus thuringiensis (Bt) corns (5422Bt1 (Event Bt11) and 5422CBCL (MON810)) expressing Cry1Ab and their near-isogenic non-Bt corn (5422), were used to investigate the non-target effects of Bt corn on soil-dwelling organisms. Cry1Ab concentrations in substances, casts and guts of E. fetida were also investigated by Enzyme-linked immunosorbent assay (ELISA). More than 90% individuals of E. fetida survived over a period of 30 d, irrespective of whether they received Bt corn or non-Bt corn. Compared to 5422 treatments, significantly higher relative growth rate and more number of new offspring and cocoons of E. fetida were found in 5422Bt1 and 5422CBCL treatments. These results were unlikely to be directly caused by Cry1Ab released from Bt corns but rather by differences in other factors of plants such as plant components (soluble sugar, total organic carbon, total protein and available phosphorus of Bt corns were more than 5422). ELISA results indicated immunoreactive Cry1Ab was detectable in substances, and the casts, guts of E. fetida from Bt corns treatments, of which the highest levels were detected in substances under the corresponding experimental conditions. With the increase of treated time, a strong decline was observed in Cry1Ab from substances and casts of E. fetida, whereas Cry1Ab in guts of E. fetida from 5422Bt1 treatments gradually increased and that from 5422CBCL treatments increased between 14 and 30 d. Therefore, the presence of Cry1Ab in E. fetida had no deleterious effects on their growth and reproduction. 相似文献
535.
Szlinder-Richert J Usydus Z Malesa-Ciećwierz M Polak-Juszczak L Ruczyńska W 《Chemosphere》2011,85(11):1725-1733
Chemical analyses were performed in nine fish species that are popular on the Polish market. These included Baltic fish (cod, herring, salmon), fish farmed in Poland (carp, trout), marine fish imported from China (Alaska pollock, sole), and farmed fish imported from Vietnam and China (sutchi catfish, tilapia). The nutritional composition (amino acid, micro- and macronutrients, fat-soluble vitamins - A1, D3, E) and certain contaminants (organochlorine pesticides, OCPs; indicator polychlorinated biphenyl, PCB6; polychlorinated dibenzo-paradioxins and polychlorinated dibenzofurans, PCDD/Fs; dioxin-like polychlorinated biphenyls, dl-PCBs; organotin compounds, OCTs; dyes, malachite green and crystal violet; veterinary drug residues, nitrofurans and chloramphenicol; toxic metals, Cd, Pb, Hg) in the muscle tissues of fish were determined. It was confirmed that the fish species analyzed were excellent sources of amino acids, and were rich in phosphorous and selenium. Baltic Sea fish (salmon, herring), fish farmed in Poland (carp and trout), and tilapia were also rich in vitamin D3.Traces of OCP, PCB6, OCT, dyes, veterinary drug residues, and heavy metals were detected in concentrations which do not pose a threat to consumers at the current rate of fish consumption in Poland. However, the problem might arise from the content of PCDD/Fs and dl-PCBs in fatty Baltic fish. The fish species analyzed, differed in their nutritional values and degrees of contamination. We suggest that for optimum health and safety, it is advisable that consumers include a variety of different fish species in their diets. 相似文献
536.
Jiang HJ Ma Y Qiu GJ Wu FL Chen SL 《Journal of environmental science and health. Part. B》2011,46(8):703-708
The nicotine-degrading bacterium HZN1 was isolated from activated sludge and identified as Shinella sp. based on its physiological characteristics and analysis of 16S rDNA gene. Strain HZN1 is capable of using nicotine as the sole carbon source in the mineral salts medium. The optimum temperature and pH for strain HZN1 growth and nicotine degradation were 30°C and 7.0, respectively. It could degrade approximately 100 % of 0.5 g L(-1) of nicotine within 9 h. Three intermediate metabolites were produced by the strain HZN1 and identified as cotinine, myosmine and nicotyrine using gas chromatography-mass spectrometry. This is the first report of nicotine-degrading strain from the genus of Shinella. The results showed that strain HZN1 could be potentially employed in bioremediation of nicotine. Our findings would provide a new insight into the biodegradation of nicotine. 相似文献
537.
Effects of pH and ionic strength on sulfamethoxazole and ciprofloxacin transport in saturated porous media 总被引:1,自引:0,他引:1
Many antibiotics regarded as emerging contaminants have been frequently detected in soils and groundwater; however, their transport behaviors in soils remain largely unknown. This study examined the transport of two antibiotics, sulfamethoxazole (SMZ) and ciprofloxacin (CIP), in saturated porous media. Laboratory columns packed with quartz sand was used to test the effects of solution pH and ionic strength (IS) on their retention and transport. The results showed that these two antibiotics behaved differently in the saturated sand columns. In general, SMZ manifested a much higher mobility than CIP for all experimental conditions tested. Almost all SMZ transported through the columns within one pore volume in deionized water (i.e., pH=5.6, IS=0), but no CIP was detected in the effluents under the same condition after extended column flushing. Perturbations in solution pH (5.6 and 9.5) and IS (0 and 0.1M) showed no effect on SMZ transport in the saturated columns. When pH increased to 9.5, however, ~93% of CIP was eluted from the sand columns. Increase of IS from 0 to 0.1M also slightly changed the distribution of adsorbed CIP within the sand column at pH 5.6, but still no CIP was detected in the effluents. A mathematical model based on advection-dispersion equation coupled with equilibrium and kinetic reactions successfully simulated the transport of the antibiotics in water-saturated porous media with R(2)=0.99. 相似文献
538.
Ma BL Blackshaw RE Roy J He T 《Journal of environmental science and health. Part. B》2011,46(7):590-599
Knowledge about the prevalence and diversity of antibiotic resistance genes in soil bacteria communities is required to evaluate the possibility and ecological consequences of the transfer of these genes carried by genetically modified (GM) plants to soil bacteria. The neomycin phosphotransferase gene (nptII) conferring resistance to kanamycin and neomycin is one of the antibiotic resistance genes commonly present in GM plants. In this study, we investigated kanamycin-resistant (Km(R)) and neomycin-resistant (Nm(R)) soil bacterial populations in a 3-year field trial using a commercial GM corn (Zea mays L.) carrying the nptII gene and its near isogenic line. The results showed that a portion (2.3 - 15.6 %) of cultivable soil bacteria was naturally resistant to kanamycin or neomycin. However, no significant difference in the population level of Km(R) or Nm(R) soil bacteria was observed between the GM and non-GM corn fields. The nptII gene was not detected in any of the total 3000 Km(R) or Nm(R) isolates screened by PCR. Further, total soil bacterial cells were collected through Nycodenz gradient centrifugation and bacterial community DNA was subjected to PCR. Detection limit was about 500 cells per gram of fresh soil. Our study suggests that the nptII gene was relatively rare in the soil bacterial populations and there was no evidence of gene transfer from a GM corn plant to soil bacteria based on the data from total soil bacterial communities. 相似文献
539.
Ma Jianlong Li Chuanhua Hu Lanyu Kong Wangsheng Lu Qing Zhang Jia 《Journal of Material Cycles and Waste Management》2021,23(2):614-621
Journal of Material Cycles and Waste Management - Electroplating sludge contained multi-metals and organics. In previous reports, electroplating sludges were usually recycled by direct calcination... 相似文献
540.