事故经济损失计算方法的比较分析

本论文分析了我国对事故经济损失计算的比较有代表性的三种方法:事故经济损失的理论计算方法、事故经济损失构成计算方法述评和事故损失性安全成本的计算方法,通过对三种计算方法的比较分析,认为直接损失和间接损失都包含着可确认、可计算的准确的损失,又包括不好计算的隐含损失,所以计算直间比不科学,意义不大.而事故损失性安全成本法把事故损失分为可确认经济损失和隐含经济损失,可确认经济损失包括那些可确认、可计算的准确的损失,隐含经济损失包括不好计算的隐含损失,因此确认-隐含系数比,比直间比系数更有意义.提出事故损失性安全成本法的计算更容易、可控、科学和实用.因而认为我国应该统一采用事故损失性安全成本法计算事故损失.     

Application of the AERMOD modeling system for environmental impact assessment of NO2 emissions from a cement complex

We applied the model of American Meteorological Society-Environmental Protection Agency Regulatory Model (AERMOD) as a tool for the analysis of nitrogen dioxide (NO2) emissions from a cement complex as a part of the environmental impact assessment. The dispersion of NO2 from four cement plants within the selected cement complex were investigated both by measurement and AERMOD simulation in dry and wet seasons. Simulated values of NO2 emissions were compared with those obtained during a 7-day continuous measurement campaign at 12 receptors. It was predicted that NO2 concentration peaks were found more within 1 to 5 km, where the measurement and simulation were in good agreement, than at the receptors 5 km further away from the reference point. The Quantile- Quantile plots of NO2 concentrations in dry season were mostly fitted to the middle line compared to those in wet season. This can be attributed to high NO2 wet deposition. The results show that for both the measurement and the simulation using the AERMOD, NO2 concentrations do not exceed the NO2 concentration limit set by the National Ambient Air Quality Standards (NAAQS) of Thailand. This indicates that NO2 emissions from the cement complex have no significant impact on nearby communities. It can be concluded that the AERMOD can provide useful information to identify high pollution impact areas for the EIA guidelines.     

Emissions of C2 – C12 hydrocarbons in the Hsuehshan tunnel, Taiwan

The concentrations of 56 hydrocarbons from C2 to C12 were measured simultaneously in the southbound bore, the northbound bore and the exhaust air shafts of the Hsuehshan tunnel near Yilan, Taiwan for 12 days during 2007 and 2008. A total of 60 integrated air samples were collected using stainless steel canisters and analyzed using GC/FID and GC/MS. The five most abundant species in all samples were ethylene, acetylene, isopentane, propylene and toluene. The exit/entrance ratios of total non-methane hydrocarbons (NMHC) concentration were 7.8 and 4.8 for the southbound and northbound bores, respectively. Furthermore, the exhaust from the vertical shafts affects air quality in the neighborhood. The most abundant species of emission rate (ER) was toluene (21.93–42.89 mg/sec), followed by isopentane, ethylene, propylene and 1-butene, with ER ranging from 2.50 to 9.31 mg/sec. The species in the three exhaust air shafts showed that the reactivities of these emissions are similar to those of vehicle emissions. Notably, the control of emissions in the vertical shafts of the vehicle tunnel will be important in the future.     

Multivariate analysis of surface water quality in the Three Gorges area of China and implications for water management

Multivariate statistical techniques, cluster analysis, non-parametric tests, and factor analysis were applied to analyze a water quality dataset including 13 parameters at 37 sites of the Three Gorges area, China, from 2003–2008 to investigate spatio-temporal variations and identify potential pollution sources. Using cluster analysis, the twelve months of the year were classified into three periods of lowflow (LF), normal-flow (NF), and high-flow (HF); and the 37 monitoring sites were divided into low pollution (LP), moderate pollution (MP), and high pollution (HP). Dissolved oxygen (DO), potassium permanganate index (CODMn), and ammonia-nitrogen (NH4 +-N) were identified as significant variables affecting temporal and spatial variations by non-parametric tests. Factor analysis identified that the major pollutants in the HP region were organic matters and nutrients during NF, heavy metals during LF, and petroleum during HF. In the MP region, the identified pollutants primarily included organic matter and heavy metals year-around, while in the LP region, organic pollution was significant during both NF and HF, and nutrient and heavy metal levels were high during both LF and HF. The main sources of pollution came from domestic wastewater and agricultural activities and runoff; however, they contributed differently to each region in regards to pollution levels. For the HP region, inputs from wastewater treatment plants were significant; but for MP and LP regions, water pollution was more likely from the combined effects of agriculture, domestic wastewater, and chemical industry. These results provide fundamental information for developing better water pollution control strategies for the Three Gorges area.     

全自动阵列离子迁移谱仪连续监测挥发性有机化合物

为了拓宽离子迁移谱仪的检测范围、提高化合物的识别准确度,研制了一套阵列离子迁移谱仪,该仪器基于63 Ni源正离子模式、63Ni源负离子模式和真空紫外灯光电离模式的组合电离源,可以连续监测空气中挥发性有机化合物.仪器采用全自动的采样进样系统,同时检测了二甲基亚砜的正离子和二氯甲烷的负离子,实现了正负离子的同时检测.通过对阵列离子迁移谱图的综合解析,识别了63Ni源正离子模式下难以鉴别的丙烯腈、间二甲苯和丙酮.连续4 d定量测定丙酮样品,结果表明仪器对丙酮的线性检测范围为2个数量级,线性相关系数R优于0.995,相对标准偏差控制在4.0%～18.3%.采用动态跟踪法,连续24 h在线监测了模拟泄漏的丙烯酸甲酯,监测结果直接反映了其泄漏的时间和浓度.     

高速铁路声屏障对居民环境影响的试验研究

以三种结构的高速铁路声屏障为研究对象,测量了高速列车通过有声、无声屏障两种状态下8个测点的声压值,并计算各测点等效连续A计权声压和声屏障的隔声量,结合GB3096-2008中规定的环境噪声限值进行声屏障结构对高速铁路周边居民的声环境影响评价。试验分析结果表明:声屏障不同程度改善了居民的声环境;由于试验所用的三种结构的声屏障隔声量离一般设计要求(20~25dB(A))相差太远,使得高速铁路周边环境噪声高于国家标准规定限值;声屏障结构改进应着力提高中低频噪声的隔声量。     

地下水LNAPL层的原位曝气模拟研究

曝气法(Air sparging,AS)已经成为修复地下水、土壤有机污染的重要技术,与数值模拟技术相结合可优化修复条件。文章利用TMVOC多相流模型研究了地下水位处LNAPL层的迁移转化,并通过情景模拟比较曝气法对污染修复的贡献率。只考虑地下水水流的对流-弥散作用时,目标污染物苯并没有得到彻底去除,只是通过下边界流出。60 d苯的质量损失率仅为1.79%;而连续曝气30 d后苯的去除率就可达到31.4%,最终脉冲曝气苯的损失率为44.8%。增大曝气量能提高气相渗透率及气相-液相接触面积,扩大污染物修复范围;当超过某一值(12 m3/h),其增量对污染物修复影响甚微。当曝气点位于低渗透岩层下方时,低渗透岩层会阻碍气流的垂向迁移,位于低渗透岩层上方的污染物很难得到除去。曝气法适用于溶解、挥发性较好的污染物。     

深圳市室内空气的健康风险评价

文章利用美国环保局的环境健康风险评价模型,评价了不同人群在满足《室内空气质量标准》(GB/T 18883-2002)的3组室内空气中的暴露风险。结果表明,在这3组室内空气中生活的所有人群都存在非致癌风险和致癌风险,其中儿童(0.5~10岁)的非致癌和致癌风险在所有人群中最小。室内空气质量即使在国家标准范围之内,也可能会对人体产生严重的健康风险。     

天津市烟气排放连续监测系统现状分析及应用经验探讨

CEMS,即烟气连续排放监测系统,通过对固定污染源颗粒物浓度和气态污染物浓度以及污染物排放总量进行连续自动监测,并将监测数据和信息传送到环保主管部门,以确保排污企业污染物浓度和排放总量达标。本文分析了目前天津使用的烟气在线连续监测系统的三种主要技术方法,通过三种方法的比较,结合现场监测的实际经验,提出了今后CEMS运营管理的相关建议。     

我国典型非木浆造纸二噁英排放研究

根据《中国履行〈关于持久性有机污染物的斯德哥尔摩公约〉国家实施计划》,制浆造纸行业是我国开展二英履约减排的六大重点行业之一,需要在规定的时间内达到减排要求.非木浆在我国原生纸浆生产和消费中一直占有重要比例,其生产过程中广泛使用的元素氯漂白工艺被认为是造成制浆造纸行业二噁英产生的重要来源.非木纤维制浆将在我国长期存在,摸清该领域二噁英排放情况,对于我国履约和实施二噁英的减排措施有重要意义.通过对竹子、麦草、芦苇和蔗渣这4种非木纤维的典型制浆企业的漂白全过程开展二噁英排放情况的检测,并结合各企业的浆水平衡数据,得到我国应用氯化碱处理次氯酸盐(CEH)三段漂白典型工艺的草浆、苇浆、竹浆及蔗渣浆生产的外排水所含二噁英的浓度(以I-TEQ计,下同)分别为:41.8、72.7、7.46和19.7 pg.L-1,尽管都在国家规定的新排放标准附近(30 pg.L-1),但随着我国对制浆造纸行业吨耗水要求的日益严格和以上新标准的实施,相关浓度很容易超标.为了实现国内、国际环境管理的要求,认为我国有必要尽快推动该行业研究并应用二噁英减排的最佳可行技术和最佳环境实践(best available techniques/best environmental practices,BAT/BEP).同时,结合监测数据,还初步估算了非木浆元素氯漂白相关的二噁英排放因子,可为联合国环境署补充相关因子提供有意义的参考.