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731.
从1951年原政务院颁布《中华人民共和国劳动保险条例》始,我国的工伤保险制度几经变革与发展,然而日趋完善的背后依旧存在着诸多问题,2009年7月24日国务院法制办发布了关于修改《工伤保险 相似文献
732.
本文简迷了皮肤防护器材--化学防护服(衣)化学防护性能试验与评价用标准物质的重要性,系统地概述了外军化学防护服(衣)化学防护性能试验与评价用标准物质的研究现状,并提出了我国化学防护服(衣)防护性能试验与评价用标准物质研制过程中应注意的一些问题. 相似文献
733.
Persulfate can efficiently decolorize azo dyes through oxidizing these compounds, which enabled us to develop a method of rapid spectrophotometric determination of persulfate for monitoring the wastewater treatment on the basis of the oxidation decolorization of azo dyes. Four azo dyes with different molecular structures were investigated as probes, and the influences of operation parameters including reaction time, solution pH, initial dye concentration, and initial concentration of activator Fe(2+) were checked on the determination of persulfate. Under optimum conditions, the decolorization degree of the dyes responded linearly with persulfate concentration for all the four azo dyes, and the linear range and detection limit were found to be 2.0-150 μmol L(-1) and 0.62 μmol L(-1) for rhodamine B, 2.0-100 μmol L(-1) and 0.42 μmol L(-1) for methylene blue, 4.0-150 μmol L(-1) and 0.50 μmol L(-1) for methyl violet, and 20-150 μmol L(-1) and 8.1 μmol L(-1) for orange II. A persulfate treatment of a spiked wastewater sample was satisfactorily monitored with the new method. 相似文献
734.
Characterization of ambient black carbon and wood burning particles in two urban areas 总被引:1,自引:0,他引:1
Previously it has been suggested that certain organic aerosol components of wood smoke have enhanced ultraviolet absorption at 370 nm relative to 880 nm in two-wavelength aethalometer measurements. This enhanced absorption could serve as an indicator of wood burning particles. Two-wavelength (370 nm and 880 nm) aethalometer measurements were made at urban sites in Rochester, New York and Laredo, Texas from August 1 to December 31, 2009 and from December 23, 2007 to January 2, 2008, respectively. In Rochester, Delta-C (UVBC(370 nm)- BC(880 nm)) values were higher by a factor of 3 during the night than during the day in November and December when residential wood burning was common. In Laredo, particularly high Delta-C values were observed on Christmas Eve and New Year's Eve and were attributed to biomass burning and firework emissions. Exponential decay was found to be a good estimator for predicting BC concentrations at different wind speeds regardless of wind directions. 相似文献
735.
736.
The iron and steel industry is not only an important foundation of the national economy, but also the largest source of industrial air pollution. Due to the current status of emissions in the iron and steel industry, ultra-low pollutant emission control technology has been researched and developed. Liquid-phase proportion control technology has been developed for magnesian fluxed pellets, and a blast furnace smelting demonstration project has been established to use a high proportion of fluxed pellets (80%) for the first time in China to realize source emission reduction of SO2 and NOx. Based on the characteristics of high NOx concentrations and the coexistence of multiple pollutants in coke oven flue gas, low-NOx combustion coupled with multi-pollutant cooperative control technology with activated carbon was developed to achieve efficient removal of multiple pollutants and resource utilization of sulfur. Based on the characteristics of co-existing multiple pollutants in pellet flue gas, selective non-catalytic reduction (SNCR) coupled with ozone oxidation and spray drying adsorption (SDA) was developed, which significantly reduces the operating cost of the system. In the light of the high humidity and high alkalinity in flue gas, filter materials with high humidity resistance and corrosion resistance were manufactured, and an integrated pre-charged bag dust collector device was developed, which realized ultra-low emission of fine particles and reduced filtration resistance and energy consumption in the system. Through source emission reduction, process control and end-treatment technologies, five demonstration projects were built, providing a full set of technical solutions for ultra-low emissions of dust, SO2, NOx, SO3, mercury and other pollutants, and offering technical support for the green development of the iron and steel industry. 相似文献
737.
Huanbo Wang Leiming Zhang Irene Cheng Xiaohong Yao Ewa Dabek-Zlotorzynska 《环境科学学报(英文版)》2021,33(5):1-11
To evaluate the effectiveness of emission control regulations designed for reducing air pollution, chemically resolved PM2.5 data have been collected across Canada through the National Air Pollution Surveillance network in the past decade. 24-hr time integrated PM2.5 collected at seven urban and two rural sites during 2010-2016 were analyzed to characterize geographical and seasonal patterns and associated potential causes. Site-specific seven-year mean gravimetric PM2.5 mass concentrations ranged from 5.7 to 9.6 µg/m3. Seven-year mean concentrations of SO42?, NO3?, NH4+, organic carbon (OC), and elemental carbon (EC) were in the range of 0.68 to 1.6, 0.21 to 1.5, 0.27 to 0.71, 1.1 to 1.9, and 0.37 to 0.71 µg /m3, accounting for 10.8%-18.1%, 3.7%-16.7%, 4.7%-7.4%, 18.4%-21.0%, and 6.4%-10.6%, respectively, of gravimetric PM2.5 mass. PM2.5 and its five major chemical components showed higher concentrations in southeastern Canada and lower values in Atlantic Canada, with the seven-year mean ratios between the two regions being on the order of 1.7 for PM2.5 and 1.8-7.1 for its chemical components. When comparing the concentrations between urban and rural sites within the same region, those of SO42? and NH4+ were comparable, while those of NO3?, OC, and EC were around 20%, 40%-50%, and 70%-80%, respectively, higher at urban than rural sites, indicating the regional scale impacts of SO42? and NH4+ and effects of local sources on OC and EC. Monthly variations generally showed summertime peaks for SO42? and wintertime peaks for NO3?, but those of NH4+, OC, and EC exhibited different seasonality at different locations. 相似文献
738.
Co-metabolic and biochar-promoted biodegradation of mixed PAHs by highly efficient microbial consortium QY1 总被引:1,自引:0,他引:1
Polycyclic aromatic hydrocarbons (PAHs), typical representatives of the persistent organic pollutants (POPs), have become ubiquitous in the environment. In this study, a novel microbial consortium QY1 that performed outstanding PAHs-degrading capacity has been enriched. The degradation characteristics of single and mixed PAHs treated with QY1 were studied, and the effect of biochar on biodegradation of mixed PAHs and the potential of biochar in PAHs-heavy metal combined pollution bioremediation were also investigated. Results showed that, in single substrate system, QY1 degraded 94.5% of 500 mg/L phenanthrene (PHE) and 17.8% of 10 mg/L pyrene (PYR) after 7 days, while in PHE-PYR mixture system, the biodegradation efficiencies of PHE (500 mg/L) and PYR (10 mg/L) reached 94.0% and 96.2%, respectively, since PHE served as co-metabolic substrate to have significantly improved PYR biodegradation. Notably, with the cooperation of biochar, the biodegradations of PHE and PYR were greatly accelerated. Further, biochar could reduce the adverse impact of heavy metals (Cd2+, Cu2+, Cr2O72?) on PYR biodegradation remarkably. The sequencing analysis revealed that Methylobacterium, Burkholderia and Stenotrophomonas were the dominant genera of QY1 in almost all treatments, indicating that these genera might play key roles in PAHs biodegradation. Overall, this study provided new insights into the efficient bioremediation of PAHs-contaminated site. 相似文献
739.
Modified clay (MC), an effective material used for the emergency elimination of algal blooms, can rapidly reduce the biomass of harmful algal blooms (HABs) via flocculation. After that, MC can still control bloom population through indirect effects such as oxidative stress, which was initially proposed to be related to programmed cell death (PCD) at molecular level. To further study the MC induced cell death in residual bloom organisms, especially identifying PCD process, we studied the physiological state of the residual Prorocentrum donghaiense. The experimental results showed that flocculation changed the physiological state of the residual cells, as evidenced by growth inhibition and increased reactive oxygen species production. Moreover, this research provides biochemical and ultrastructural evidence showing that MC induces PCD in P. donghaiense. Nuclear changes were observed, and increased caspase-like activity, externalization of phosphatidylserine and DNA fragmentation were detected in MC-treated groups and quantified. And the mitochondrial apoptosis pathway was activated in both MC-treated groups. Besides, the features of MC-induced PCD in a unicellular organism were summarized and its concentration dependent manner was proved. All our preliminary results elucidate the mechanism through which MC can further control HABs by inducing PCD and suggest a promising application of PCD in bloom control. 相似文献
740.
Isolation and characterization of a strain with high microbial attachment in aerobic granular sludge
Tingting Zhao Kai Qiao Lei Wang Wei Zhang Wei Meng Fan Liu Xu Gao Jianrong Zhu 《环境科学学报(英文版)》2021,33(8):194-203
Aerobic granule is a special microbial aggregate associated with biofilm structure. The formation of aerobic granular sludge is primarily depending on its bacterial community and relevant microbiological properties. In this experiment, a strain with high microbial attachment was isolated from aerobic granular sludge, and the detailed characteristics were examined. Its high attachment ability could reach 2.34 (OD600nm), while other low attachment values were only around 0.06-0.32, which indicated a big variation among the different bacteria. The strain exhibited a very special morphology with many fibric fingers under SEM observation. A distinctive behaviour was to form a spherical particle by themselves, which would be very beneficial for the formation and development of granular sludge. The EPS measurement showed that its PN content was higher than low attachment bacteria, and 3D-EEM confirmed that there were some different components. Based on the 16S rRNA analysis, it was identified to mostly belong to Stenotrophomonas. Its augmentation to particle sludge cultivation demonstrated that the strain could significantly promote the formation of aerobic granule. Conclusively, it was strongly suggested that it might be used as a good and potential model strain or chassis organism for the aerobic granular sludge formation and development. 相似文献