自动变光焊接滤光片响应时间快速测试设备

自动变光焊接防护装备已在欧美国家得到广泛应用,其关键部件是自动变光焊接滤光片。响应时间是自动变光焊接滤光片的关键技术指标,目前国内缺乏响应时间快速测试技术。本文介绍了一种响应时间快速测试设备,可以满足符合欧洲标准及我国国家标准中的测试要求。     

啤酒废水同步脱氮除磷工艺启动研究

为了将短程硝化反硝化与A/O法除磷同时应用于SBR工艺处理啤酒废水,通过改变序批式反应器(SBR)工艺运行方式,使活性污泥依次经历厌氧、好氧、缺氧3个阶段,控制ρ(MLSS)=4 700 mg/L、pH=7.5～8.0、DO=0.3～0.5 mg/L(好氧阶段)。反应器内短程硝化反硝化同步除磷效果明显,氨氮去除率大于90%,亚硝酸盐积累率大于85%,磷去除率大于98%。试验结果表明短程硝化反硝化与A/O法除磷可同时应用于SBR工艺处理啤酒废水。     

基于生命周期的产品碳足迹评价与核算分析

近年来,越来越多的企业对其产品进行碳足迹评价,评价方法主要采用产品碳足迹评价标准提供的碳计量方程,如GHG Protocol、ISO14064、PAS 2050、TS Q 0010等。在介绍相关评价标准的基础上,分析了产品碳足迹的评价步骤,最后利用河北盛华化工有限公司生产的PVC产品为例,给出了基于生命周期的B2B模式的产品碳足迹评价的案例。为企业及相关机构开展碳足迹评价提供借鉴作用。     

废弃产品回收处理企业环境绩效评价初探

近年来,废弃产品回收处理行业日益受到政府和社会各界的关注,而回收处理企业是实施回收处理活动的主体,相关法律、法规的出台对回收处理企业提出了更高的要求。本文在概括梳理相关法律、法规的基础上,初步建立了废弃产品回收处理企业环境绩效评价指标体系,为回收处理企业采用先进的技术工艺、降低环境负荷、加强职业健康监护和企业环境管理提供参考,以适应国家政策要求和行业发展的需要。     

城市空气污染影响因素的灰色斜率关联度分析研究

城市空气污染严重影响着城市的发展和人民的健康,为了研究城市空气污染的影响因素对于污染的影响程度和类型,采用了灰色系统理论中灰色关联分析方法的斜率关联度模型.以广州、西安和乌鲁木齐为研究对象,选取了几个具有典型的空气污染因素.结果表明:对于这三个城市而言,燃煤都是空气污染的最主要污染因素,而对于不同的城市,其他污染因素对于不同污染物有着不同的影响,在污染治理的时候要分析城市具体所存在的首要污染物以对症下药.     

毛细管离子色谱法测定空气中的氯化氢

以多孔玻板吸收管采样,用氢氧化钾-碳酸钠溶液吸收空气中的氯化氢(HCl),毛细管离子色谱法测定吸收液中的氯离子含量,根据采气量计算空气中的HCl含量。该方法灵敏度高,检出限低,结果准确,可避免其他阴离子及卤素和含卤酸盐离子的干扰,适用于环境空气中低含量HCl的测定。     

Spatial character of polychlorinated biphenyls from soil and respirable particulate matter in Taiyuan, China

As one of China’s great metropolises, Taiyuan is affected by heavy chemical industry and manufacture of chemical products, and faces pollution from polychlorinated biphenyls (PCBs). Therefore, this study was conducted to determine the PCB concentrations in various environmental media in Taiyuan. We collected 15 soil samples, 34 respirable particulate matter (PM) samples (17 of PM_2.5 and 17 of PM₁₀) from urban areas of Taiyuan, and measured a total of 144 PCB congeners (including some coeluting PCB congeners). The total PCB concentrations were 51–4.7 × 10³ pg g⁻¹ in soil, 27–1.4 × 10² pg m⁻³ in PM_2.5 and 16–1.9 × 10² pg m⁻³ in PM₁₀. Of the PCB homologues, the dominant PCBs detected in the various media were all tri-CBs. Soil was relatively the most polluted media. Furthermore, principal-component analysis revealed that the major PCB source in Taiyuan may be associated with the main commercial PCB through long-range transmission. Toxic equivalency (TEQ) concentrations (based on ten dioxin-like PCBs) ranged from N.D. to 5.9 × 10⁻³ pg-WHO TEQ g⁻¹ in soil, 2.0 × 10⁻⁴–3.4 × 10⁻³ pg-WHO TEQ m⁻³ and 1.0 × 10⁻⁴–1.2 × 10⁻³ pg-WHO TEQ m⁻³ in PM_2.5 and PM₁₀, respectively. In previous studies, PCBs were not a severe component of contaminant in Taiyuan; however, this study suggested there is a potential threat of human exposure to PCBs for residents of Taiyuan.     

A new direct thermal desorption-GC/MS method: Organic speciation of ambient particulate matter collected in Golden, BC

Particulate matter having an aerodynamic diameter less than 2.5 μm (PM2.5) is thought to be implicated in a number of medical conditions, including cancer, rheumatoid arthritis, heart attack, and aging. However, very little chemical speciation data is available for the organic fraction of ambient aerosols. A new direct thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) method was developed for the analysis of the organic fraction of PM2.5. Samples were collected in Golden, British Columbia, over a 15-month period. n-Alkanes constituted 33–98% by mass of the organic compounds identified. PAHs accounted for 1–65% and biomarkers (hopanes and steranes) 1–8% of the organic mass. Annual mean concentrations were: n-alkanes (0.07–1.55 ng m⁻³), 16 PAHs (0.02–1.83 ng m⁻³), and biomarkers (0.02–0.18 ng m⁻³). Daily levels of these organics were 4.89–74.38 ng m⁻³, 0.27–100.24 ng m⁻³, 0.14–4.39 ng m⁻³, respectively. Ratios of organic carbon to elemental carbon (OC/EC) and trends over time were similar to those observed for PM2.5. There was no clear seasonal variation in the distribution of petroleum biomarkers, but elevated levels of other organic species were observed during the winter. Strong correlations between PAHs and EC, and between petroleum biomarkers and EC, suggest a common emission source – most likely motor vehicles and space heating.     

Pollution characterization and diurnal variation of PBDEs in the atmosphere of an E-waste dismantling region

Diurnal air samples were collected from the E-waste dismantling region Guiyu and the underwear industry region Chendian. This was the first report to present the diurnal variation of PBDEs in the atmosphere. The average concentrations of 11 PBDE congeners were 11,742 pg m⁻³ in the daytime, and 4830 pg m⁻³ at night in Guiyu, while the concentrations were lower in Chendian with 376 pg m⁻³ in the daytime, and 237 pg m⁻³ at night. BDE-209 accounted for 22% and 31.3% of the total PBDEs in Guiyu and Chendian, respectively. The diurnal variation trends of BDE-47, -99, -153, -183, and -209 were also analyzed in detail in the two regions.