Influences of accumulated mileage and technological changes on emissions of regulated pollutants from gasoline passenger vehicles

In this study, the influences of accumulated mileage(deterioration) and technological changes(emission standards) on emission factors(EFs) of regulated pollutants(CO, HC, and NO_x) from gasoline passenger vehicles were investigated based on Inspection and Maintenance(I/M) data using the chassis dynamometer method. The accumulated mileage of passenger vehicles was significantly linearly correlated with vehicle age. For most cases,the average EFs of CO, HC and NO_x were significantly linearly correlated with accumulated mileage, indicating that emission deterioration had a significant impact on pollutant EFs.Implemented emission standards markedly influenced the EFs of regulated pollutants, and EFs markedly decreased with progressing emission standards. The present study also compared EFs of regulated pollutants between this study and the International vehicle emission(IVE) model, and marked differences in EFs were seen with variations in emission standards, vehicle types and accumulated mileage; NO_x EFs in this study were higher than in the IVE model. The results provide new insight into estimating regulated pollutant emissions using the IVE model.     

The effects of deterioration and technological levels on pollutant emission factors for gasoline light-duty trucks

Vehicle deterioration and technological change influence emission factors (EFs). In this study, the impacts of vehicle deterioration and emission standards on EFs of regulated pollutants (carbon monoxide [CO], hydrocarbon [HC], and nitrogen oxides [NO_x]) for gasoline light-duty trucks (LDTs) were investigated according to the inspection and maintenance (I/M) data using a chassis dynamometer method. Pollutant EFs for LDTs markedly varied with accumulated mileages and emission standards, and the trends of EFs are associated with accumulated mileages. In addition, the study also found that in most cases, the median EFs of CO, HC, and NO_x are higher than those of basic EFs in the International Vehicle Emissions (IVE) model; therefore, the present study provides correction factors for the IVE model relative to the corresponding emission standards and mileages.

Implications: Currently, vehicle emissions are great contributors to air pollution in cities, especially in developing countries. Emission factors play a key role in creating emission inventory and estimating emissions. Deterioration represented by vehicle age and accumulated mileage and changes of emission standards markedly influence emission factors. In addition, the results provide collection factors for implication in the IVE model in the region levels.     

Alterations of protein profile in zebrafish liver cells exposed to methyl parathion: a membrane proteomics approach

Methyl parathion (MP) is an extensively used organophosphorus pesticide, which has been associated with a wide spectrum of toxic effects on environmental organisms. The aim of this study is to investigate the alterations of membrane protein profiles in zebrafish liver (ZFL) cell line exposed to MP for 24 h using proteomic approaches. Two-dimensional gel electrophoresis revealed a total of 13 protein spots, whose expression levels were significantly altered by MP. These differential proteins were subjected to matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry analysis, and nine proteins were identified to be membrane proteins, among which seven were up-regulated, while two were down-regulated. In addition, the mRNA levels corresponding to these differential membrane proteins were further analyzed by quantitative real-time PCR. And the differential expression of arginase-2 was specially validated via Western blotting. Regarding the physiological functions, these proteins are involved in molecular chaperon, cytoskeleton system, cell metabolism, signal transduction, transport and hormone receptor respectively, suggesting the complexity of MP-mediated toxicity to ZFL cell. These data could provide useful insights for better understanding the hepatotoxic mechanisms of MP and develop novel protein biomarkers for effectively monitoring MP contamination level in aquatic environment.     

甲黄隆在有机溶剂中的光解

以中压汞灯为光源,研究了甲黄隆在甲醇和丙酮等有机溶剂中的光解动力学,结果表明均为一级反应。甲黄隆在甲醇中的光解速率与在水中相差不大,而丙酮可明显促进其光解。甲黄隆在甲醇中光解先断裂脲桥,生成磺酰胺和取代三嗪,磺酰胺继续光解生成苯甲酸甲酯和微量的硫酚。     

废水处理生物出水中COD构成的解析——以焦化废水为例

以焦化废水为例,采用连续过滤及化学分析的方法考察了悬浮组分、胶体组分及溶解组分对生物出水残余COD的贡献,并结合紫外-可见光谱和GC/MS图谱定性解析各形态组分的有机构成特征,构建了一种废水生物出水COD构成解析的评价方法.实验结果显示,焦化废水生物处理出水中悬浮态和胶体态组分对残余COD的贡献分别占COD总量的25.9%—46.3%和18.7%—44.4%,建议优先考虑采用混凝沉淀工艺去除约35.0%—45.0%的COD,使处理出水基本能够达标排放;溶解组分的COD占COD总量的24.6%—40.7%,其中4.3%—15.8%的COD由硫化物、硫氰化物等还原性物质贡献,其余部分主要由链状烃类、酯类及醇类等溶解有机组分贡献,建议采用氧化或吸附工艺进行处理,以满足更高的出水水质要求.     

Spatial variation of volatile organic compounds in a "Hot Spot" for air pollution

The spatial variations of volatile organic compounds (VOCs) were characterized in the Village of Waterfront South neighborhood (WFS), a "hot spot" for air toxics in Camden, NJ. This was accomplished by conducting "spatial saturation sampling" for 11 VOCs using 3500 OVM passive samplers at 22 sites in WFS and 16 sites in Copewood/Davis Streets (CDS) neighborhood, an urban reference area located ～1000 m east of the WFS. Sampling durations were 24 and 48 h. For all 3 sampling campaigns (2 in summer and 1 in winter), the spatial variations and median concentrations of toluene, ethylbenzene, and xylenes (TEX) were found significantly higher (p < 0.05) in WFS than in CDS, where the spatial distributions of these compounds were relatively uniform. The highest concentrations of methyl tert-butyl ether (MTBE) (maximum of 159 μg m(-3)) were always found at one site close to a car scrapping facility in WFS during each sampling campaign. The spatial variation of benzene in WFS was found to be marginally higher (p = 0.057) than in CDS during one sampling campaign, but similar in the other two sampling periods. The results obtained from the analyses of correlation among all species and the proximity of sampling site to source indicated that local stationary sources in WFS have significant impact on MTBE and BTEX air pollution in WFS, and both mobile sources and some of the stationary sources in WFS contributed to the ambient levels of these species measured in CDS. The homogenous spatial distributions (%RSD < 24%) and low concentrations of chloroform (0.02-0.23 μg m(-3)) and carbon tetrachloride (0.45-0.51 μg m(-3)) indicated no significant local sources in the study areas. Further, results showed that the sampling at the fixed monitoring site may under- or over-estimate air pollutant levels in a "hot spot" area, suggesting that the "spatial saturation sampling" is necessary for conducting accurate assessment of air pollution and personal exposure in a community with a high density of sources.     

轻烃回收装置大检修动火风险管控措施探讨

针对轻烃回收装置火灾爆炸事故大部分发生在维检修阶段的现象,通过结合生产实际,提出采用动火前施工工序确认制度,严控高风险点位,避免"立体交叉"动火作业等措施,杜绝经验主义和侥幸心理,最大限度避免动火作业着火爆炸事故的发生。文章介绍了轻烃回收装置的介质特点及主要工艺,分析了轻烃回收装置大检修基本流程及动火风险,提出控制动火施工安全风险的管理实践。     

污染源在线监测管理中对营运方的考评

污染源在线监测管理采用第三方营运模式具有很好的优越性,但仍存在一定的问题。本文以上海市嘉定区环境监测站对该区污染源在线监测管理模式为例,对第三方营运过程中出现的问题进行探讨。详细阐述了嘉定区环境监测站对污染源在线监测管理对营运方采用技术考评的依据、考评内容,总结了技术考评的优势及其存在的问题,并提出相应的对策,最后对该考评模式进行了展望。     

污水土地处理试验工程慢速渗滤系统对优先有机污染物的净化

本文通过模拟实验及现场考察,研究了天津污水土地处理试验工程中慢速渗滤系统对优先有机污染物的净化效率以及该系统经处理污水后对土壤及作物的影响进行了探讨.     

Spatial/temporal variations of elemental carbon, organic carbon, and trace elements in PM10 and the impact of land-use patterns on community air pollution in Paterson, NJ

An urban community PM10 (particulate matter < or = 10 microm in aerodynamic diameter) air pollution study was conducted in Paterson, NJ, a mixed land-use community that is interspersed with industrial, commercial, mobile, and residential land-use types. This paper examines (1) the spatial/temporal variation of PM10, elemental carbon (EC), organic carbon (OC), and nine elements; and (2) the impact of land-use type on those variations. Air samples were collected from three community-oriented locations in Paterson that attempted to capture industrial, commercial, and mobile source-dominated emissions. Sampling was conducted for 24 hr every 6 days from November 2005 through December 2006. Samples were concurrently collected at the New Jersey Department of Environmental Protection-designated air toxics background site in Chester, NJ. PM10 mass, EC, OC, and nine elements (Ca, Cu, Fe, Pb, Mn, Ni, S, Ti, and Zn) that had more than 50% of samples above detection and known sources or are toxic were selected for spatial/temporal analysis in this study. The concentrations of PM10, EC, OC, and eight elements (except S) were significantly higher in Paterson than in Chester (P < 0.05). The concentrations of these elements measured in Paterson were also found to be higher during winter than the other three seasons (except S), and higher on weekdays than on weekends (except Pb). The concentrations of EC, Cu, Fe, and Zn at the commercial site in Paterson were significantly higher than the industrial and mobile sites; however, the other eight species were not significantly different within the city (P > 0.05). These results indicated that anthropogenic sources of air pollution were present in Paterson. The source apportionment confirmed the impact of vehicular and industrial emissions on the PM10 ambient air pollution in Paterson. The multiple linear regression analysis showed that categorical land-use type was a significant predictor for all air pollution levels, explaining up to 42% of the variability in concentration by land-use type only.