手工电弧焊过程危害分析及对策

电焊作业广泛地应用于压力容器、管道、设备的制造、安装、检维修作业以及建筑施工作业中.根据焊接条件的不同,可以将电弧焊分成许多种类,例如手工电弧焊、埋弧焊和气体保护电弧焊等,其中手工电弧焊是常用、简单易行的一种焊接方法.文章重点介绍了手工电弧焊焊接过程中的危害及预防对策.     

化工废渣(磷石膏)代替天然石膏制做水泥添加剂的研究

研制用化工废渣(磷石膏)代替天然石膏做水泥生产过程中的添加剂,其生产出的水泥质量完全可以达到国家规定的有关标准,而生产成本却明显下降,是一种处理废渣的好方法。     

共生细菌SB1降解聚乙烯醇的研究Ⅱ．共生细菌SB1聚乙烯醇氧化酶的产生、纯

共生细菌ＳＢ１接种在０．３％聚乙烯醇培养堪中，３０℃摇床振荡培养或发酵罐通气培养时，ＰＶＡ氧化酶产生的高峰在４８ｈ或４０ｈ。离心收集的上清液采用４０％－５０％饱和度的硫酸铵分级沉淀ＤＥＡＤ－Ｓｅｐｈａｄｅｘ离子交换柱和Ｃｉｂａｃｒｏｎ蓝Ｓ－Ｓｅｐｈａｒｏｓｅ４Ｂ亲和柱层析等纯化步骤。ＰＶＡ氧化酶收得率３０％，比活力提高３０倍。     

环境磁学在环境科学中的应用研究

综述了环境磁学发展进程中与环境问题的相互联系，以及磁学在气候、土壤、湖泊、生物和环境污染领域的广泛应用。分析了环境磁学进一步发展的研究方向。指出环境磁学以解决环境问题为主要目标。环境磁学方法所具有的样品用量少，灵敏度高，简便快速，非破坏性，费用低等特点，为研究环境问题提供了新途径和新方法。随着人类对环境问题的不断重视，利用环境磁学来追踪污染物的起源以及土壤，湖泊沉积物等物源将是环境磁学服务社会的重要内容。     

水中安替比林的紫外光降解研究

以波长为254 nm的紫外杀菌灯为光源，研究了水溶液中消炎镇痛药物安替比林（PZ）的光降解行为；考察了初始pH值及水中其他物质对PZ光降解的影响，探讨了PZ光解机制，并分析其降解产物及光解途径。结果表明，安替比林的光降解遵循拟一级反应动力学规律，pH值变化对光解速率基本没有影响。安替比林直接光降解占主导作用，活性氧类物种（ROS）对安替比林间接光解基本没有贡献。腐殖酸对安替比林光降解有抑制作用，而NO^-₃，HCO^-₃，Cl^-对安替比林光降解没有明显作用。GC-MS分析表明安替比林在紫外辐射下生成甲酰胺，乙酰胺，2-羟基吲哚-3-酮，2，4（1氢，3甲基）-喹唑啉二酮，1-甲基-2-羟基苯并咪唑，2-羟基苯并恶唑等一系列具有安替比林母体苯环结构的化合物，表明安替比林侧链上N—N键断裂导致其最终降解。     

高铁酸盐处理有机废水的研究进展

综述了高铁酸盐去除水中藻类、细菌、烃类衍生物、药品、农药、染料等有机污染物的国内外最新研究进展,并对高铁酸盐的高效利用进行了探讨。高铁酸盐可破坏藻类和细菌细胞的完整性,将大分子芳香烃衍生物氧化为低毒的小分子中间体,将小分子链烃衍生物矿化,破坏药品、农药及染料的不饱和双键。无机矿物在溶液中负载高铁酸盐或将高分子有机物与固体高铁酸盐混合造粒,将是高铁酸盐高效利用领域的研究热点。     

Accumulation and quantitative estimates of airborne lead for a wild plant (Aster subulatus)

Foliar uptake of airborne lead is one of the pathways for Pb accumulation in plant organs. However, the approximate contributions of airborne Pb to plant organs are still unclear. In the present study, aerosols (nine-stage size-segregated aerosols and total suspended particulates), a wild plant species (Aster subulatus) and the corresponding soils were collected and Pb contents and isotopic ratios in these samples were analyzed. Average concentration of Pb was 96.5 ± 63.5 ng m⁻³ in total suspended particulates (TSP) and 20.4 ± 5.5 ng m⁻³ in the fine fractions of size-segregated aerosols (SSA) (<2.1 μm), higher than that in the coarser fractions (>2.1 μm) (6.38 ± 3.71 ng m⁻³). Enrichment factors show that aerosols and soils suffered from anthropogenic inputs and the fine fractions of the size-segregated aerosols enriched more Pb than the coarse fractions. The order of Pb contents in A. subulatus was roots > leaves > stems. The linear relationship of Pb isotope ratios (²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb) among soil, plant and aerosol samples were found. Based on the simple binary Pb isotopic model using the mean ²⁰⁶Pb/²⁰⁷Pb ratios in TSP and in SSA, the approximate contributions of airborne Pb into plant leaves were 72.2% and 65.1%, respectively, suggesting that airborne Pb is the most important source for the Pb accumulation in leaves. So the combination of Pb isotope tracing and the simple binary Pb isotope model can assess the contribution of airborne Pb into plant leaves and may be of interest for risk assessment of the exposure to airborne Pb contamination.     

矿化垃圾床＋三维电极／电Fenton法处理老龄垃圾渗滤液

提出以二级矿化垃圾床为预处理单元，串联三维电极／电Fenton处理老龄垃圾渗滤液的组合工艺。矿化垃圾床处理后渗滤液中COD、氨氮、总磷、色度的去除率分别为80．55％、88．47％、98．32％和87．53％。通过单因素实验和正交实验，确定了三维电极／电Fenton法最佳工艺条件。经该组合工艺后，渗滤液中COD、氨氮、总磷和色度的最高去除率分别可达97．08％、95．24％、99．55％和96．92％，其中COD、总磷、色度这3个指标低于《生活垃圾填埋场污染控制标准》（GB16889．2008）表2规定的排放标准，为该组合工艺在实际中的应用提供重要理论依据。     

关于气溶胶颗粒物沉积率系数平均方法模型的改进研究

气溶胶颗粒物在壁面的沉积率系数模型的研究已经成为现代气溶胶动力学研究的重要课题.本文通过实验腔测量和理论分析相结合,对Koivisto等(2012)提出的平均方法模型(AM)中的关键参数(即时间间隔)的选取和对测量数据量的要求两个问题进行研究.选取目前广泛使用的最小二乘法模型(LSM)和Lai和Nazaroff(2000)提出的理论分析模型进行对比.研究发现,AM模型中的时间间隔这一关键参数,应由目前的50矫正为20;AM模型和LSM模型均要求实验测量数据个数等于或者大于10,但是AM模型在小数据量情况下的预测结果更精确.     

MoS2 quantum dots based MoS2/HKUST-1 composites for the highly efficient catalytic oxidation of elementary mercury

Due to the ever-tightening regulation on mercury emission in recent decades, there is an urgent need to develop novel materials for the removal of elemental mercury at coal-fired power plants. In this study, a series of MoS₂ quantum dots (QDs)-based MoS₂/HKUST-1 composite materials were prepared. It is found that MoS₂ QDs were encapsulated by HKUST-1 and enhanced the crystallinity and specific surface area of HKUST-1. The MoS₂/HKUST-1 showed excellent performance in catalytic oxidation of Hg⁰ as compared with pristine HKUST-1. It is found that surface layer of lattice oxygens is active and participates in Hg⁰ oxidation, while the consumption of surface oxygens then leads to the formation of oxygen vacancies on the surface. These vacancies are effective in the adsorption and dissociation of O₂, which subsequently participates in the oxidation of Hg⁰. Moreover, the study on the influence of commonly seen gas components, such as SO₂, NO, NH₃ and H₂O, etc., on Hg⁰ oxidation demonstrated that synergistic effects exist among these gas species. It is found that the presence of NO promotes the oxidation of Hg⁰ using oxygen as the oxidant.