Development of an ELISA for the detection of bromoxynil in water

For development of an indirect competitive enzyme-linked immunosorbent assay (ELISA) for the nitrile herbicide bromoxynil, the polyclonal antibodies raised against 2,6-dibromo-4-cyano-phenoxyacetic acid (hapten) conjugated to bovine serum albumin (BSA) by the N-hydroxysuccinimide-activated ester method. Antiserum with a sufficiently high titer to provide the determinations of targeted compounds was obtained only 77 days after the primary immunization. Antiserum A2 was applied to the residual analysis of some water samples, under optimized ELISA condition, the quantitative working range was from 10 to 500 ppb with a limit of detection of 5 ppb. Cross-reactivity to structurally similar agrochemicals and related chemicals was determined. The antiserum showed little cross-reactivity with 2,6-dibromophenol and bromoxynil octanoate ester which have a dibromophenol group as common structure, but showed no cross-reactivity with other herbicides. Each water sample (river water, tap water, purified water, and bottled water) had a matrix effect and was investigated by adding Tween20 in the assay buffer. These four kinds of water samples were fortified with bromoxynil at several concentration levels and were directly analyzed with only dilution with an equal volume of antiserum solution, the mean recovery was 102.3%, and the mean coefficient of variation was 5.96%. The proposed ELISA turned out to be a powerful tool for monitoring of residual bromoxynil in water samples at trace level.     

某原油管道储运企业职业健康监护工作体会

原油管道储运行业地域辽阔、点多线长、易燃易爆,职业危害因素种类繁多,人员接触广泛,职业卫生工作难度较大.笔者结合工作实际,就原油管道储运企业职业健康监护谈谈工作体会.     

Anthropogenic nitrogen sources and exports in a village-scale catchment in Southeast China

An experimental village-scale catchment was selected for investigation of nitrogen (N) sources and exports. The mean N application rate over the catchment was 350.2 kg N ha⁻¹, but this rate varied spatially and temporally. The N leaching loss rate varied from 8.1 to 52.7 kg N ha⁻¹ under different land use regimes. The average N leaching loss rate was 13.4 kg N ha⁻¹ over the whole catchment, representing about 3.8% of the total N inputs. The N export rate through stormflows was 28.8 kg N ha⁻¹, about 8.2% of the total N inputs. Seasonal patterns showed that 95% of N exports through stormflows occurred during July to September in 2002. Overall, the maximum riverine N exports were 12.1% of total N inputs and 15.5% of the inorganic fertilizer N applied. Understanding N sources and exports in a village-scale catchment can provide a knowledge base for amelioration of diffuse agricultural pollution.     

TiO2/SiO2催化剂光催化降解罗丹明B的表观动力学

采用多孔硅胶为载体的TiO₂/SiO₂光催化剂,建立了三相内循环流化床光催化氧化体系,并以罗丹明B染料为典型污染物,研究其降解规律.通过对罗丹明B降解过程的表观动力学研究,发现在该体系中罗丹明B的降解并不符合Langmuir-Hinshelwood反应动力学模型.实验表明,其降解反应动力学符合双曲型模式,即降解率的倒数1/X和时间的倒数1/t成线性关系.反应速率常数与反应物初始浓度无关,与光源强度和相对体积能量吸收速率成正比.将不同实验条件下的罗丹明B的降解率实测值与模型计算值相比较,二者能很好吻合,平均相对偏差仅为3.25%.     

Nationwide monitoring of polychlorinated biphenyls and organochlorine pesticides in sediments from coastal environment of Korea

To assess the organochlorine contamination in the Korean marine environment, a nationwide monitoring study was conducted. A total of 138 surface sediments, covering the whole Korean coast, were collected and analyzed. Organochlorine compounds (OCs) were widely distributed in the Korean coastal environment, with PCB and DDT contamination being particularly prevalent. The overall concentrations of PCBs, DDTs, HCHs, CHLs, and HCB in surface sediments were in the range of 0.088-199ngg(-1) (median value: 1.56ngg(-1)), 0.006-135ngg(-1) (0.68ngg(-1)), not detected (ND)-5.46ngg(-1) (0.32ngg(-1)), ND-3.26ngg(-1) (0.14ngg(-1)), and ND-2.59ngg(-1) (0.05ngg(-1)), respectively. The southeastern coast was found to be highly contaminated. Overall contamination status of Korean coastal sediments with regard to OCs is lower than that of USA. With the exception of highly industrialized sites, Korean coastal areas in general showed similar OC concentrations to those of other Asian countries. There was a significant correlation between distributions of most organochlorine contaminants with each other. OC contamination is closely related to shipping and industrial activities. Of the 7 sites categorized as highly polluted, 4 are in a harbor zone. Adverse effects to benthic communities are expected at the levels of OC contamination observed from harbor and industrial areas.     

Emission factors of air toxics from semiconductor manufacturing in Korea

The development of local, accurate emission factors is very important for the estimation of reliable national emissions and air quality management. For that, this study is performed for pollutants released to the atmosphere with source-specific emission tests from the semiconductor manufacturing industry. The semiconductor manufacturing industry is one of the major sources of air toxics or hazardous air pollutants (HAPs); thus, understanding the emission characteristics of the emission source is a very important factor in the development of a control strategy. However, in Korea, there is a general lack of information available on air emissions from the semiconductor industry. The major emission sources of air toxics examined from the semiconductor manufacturing industry were wet chemical stations, coating applications, gaseous operations, photolithography, and miscellaneous devices in the wafer fabrication and semiconductor packaging processes. In this study, analyses of emission characteristics, and the estimations of emission data and factors for air toxics, such as acids, bases, heavy metals, and volatile organic compounds from the semiconductor manufacturing process have been performed. The concentration of hydrogen chloride from the packaging process was the highest among all of the processes. In addition, the emission factor of total volatile organic compounds (TVOCs) for the packaging process was higher than that of the wafer fabrication process. Emission factors estimated in this study were compared with those of Taiwan for evaluation, and they were found to be of similar level in the case of TVOCs and fluorine compounds.     

长江上游泥石流灾害的特征

长江上游地区地质条件复杂、新构造运动强烈、地震活跃、地形起伏巨大、降水丰沛而集中,对泥石流发育极为有利;而长期不合理的人类经济活动(如过度采伐森林、毁林开荒、陡坡耕作、建设和采矿不合理弃渣等)则对生态环境造成强烈破坏,加剧了泥石流灾害的发生,使长江上游成为我国泥石流活动最强烈及灾害最严重的地区。据统计,1753~2002年的200多年中,区内仅一场泥石流致死百人以上的特大灾害点就达17个,累计死亡近6 000人;致死百人以下的灾害点更多,致死十人以下的灾害点不计其数,死亡人数总和远远大于上列数字;有60余个市县政府驻地城镇受泥石流危害或威胁,乡镇则多达上百个。由泥石流造成的人员伤亡每年数十到数百人,经济损失10~15(亿元／a)。其灾害的严重性由此可见一斑。泥石流灾害已成为制约长江上游地区经济发展的重要因素之一。研究泥石流灾害,掌握其特征,是长江上游防灾减灾所必需,对促进长江上游地区社会经济发展和西部大开发具有重要意义。长江上游己查明的泥石流沟6 800余条。其特殊的地理位置和巨大的地形高差及岩性差异,使区内发育的泥石流不仅数量众多,而且类型石相当齐全,除无火山泥石流外,几乎 包含了世界上目前己发现的其他各种类型的泥石流。在青藏高原边缘等岭谷高差变化大的地貌过渡带,泥石流极为发育;沿深大断裂带和强烈地震带泥石流集中分布;泥石流主要出现在流域面积小于10 km\+2的小流域内,分布呈非地带性特征。泥石流活动频率高,每年都有成百上千处发生,导致了泥石流灾害频繁。如云南东川的蒋家沟,从1965~2001年的37年中,共发生泥石流459次,平均12．4次／a;甘肃武都柳弯沟平均每年暴发泥石流11次。此外,泥石流搬运泥沙石块的能力惊人,搬运物以粗粒物质为主,据干流和支流的69个泥石流堆积物样品分析,堆积物中粒径大于20 mm 的石块占43.%~64.8%,平均50．4％;由此,常常造成其汇入的主河被堵塞而形成淹没和溃决后水毁等次生灾害。泥石流冲刷与淤积能力极强,运动中可将基岩下切10余m,金沙江、雅砻江、大渡河、岷江及其支流被泥石流堵塞成湖,形成淹没灾害,溃决后对下游造成严重的水毁灾害,均屡见不鲜。     

浅议保险对企业安全监督管理之作用

通过开展适合于保险和安全监管工作的风险评估体系的研究,充分发挥保险于安全监管的作用,从而为降低职工、企业乃至全社会的风险水平,为经济的可持续发展和社会稳定提供必要的保证。     

Research on 10-year tendency of China coal mine accidents and the characteristics of human factors

The trend of China coal mine accidents in the latest 10 years was studied and the human factors in these accidents were analyzed by multi-dimensional statistic analysis. It shows that the number of major coal mine accidents and the death toll in the accidents were decreasing steadily, while sporadic death accidents still accounted for the largest percentage of deaths. Gas outburst accidents, gas explosion accidents and mine water accidents remained the major part of the whole story and subject to close attention. Among the causes of these accidents, human factors accounted for 94.09%, of which intentional violation, mismanagement and defective design accounted for 35.43%, 55.12%, 3.54% respectively. Improper operational and management practices in which the safety system, procedures and specifications were neglected or broken were still key roots of China coal mine accidents.     

高炉渣制备光催化剂及其催化活性的研究

以废弃的冶金高炉渣为原料,采用混酸酸溶-水热合成法制备了光催化剂,并对其进行了SEM、UV-Vis、XRD、比表面积等物性测试分析;通过处理甲基橙模拟废水,探讨了制备过程中渣酸比、混酸配比、渣用量、溶渣时间等条件对高炉渣制光催化剂活性的影响。将所制光催化剂与P25光催化剂进行对比分析,结果表明,高炉渣制光催化剂不仅具有较高的光催化活性,而且制备成本低廉,仅为P25光催化剂的1/10,这对于冶金高炉渣的循环再利用及光催化氧化技术的工业化应用具有重要的实际意义。