浅谈压力容器制造过程中的材料监检

加强制造过程中对材料的质量控制与监督检验,确保材料选用得当、材料质量过关,是保证压力容器产品质量的前提条件。本文以钢制压力容器为例,结合相关规范、标准,从材料质量证明书、材料标准、熔炼方法、化学分析、材料复验、材料代用等角度阐述了压力容器制造监检过程中的些许案例与经验。     

Environmental disaster education at the university level: an integrative approach

Because of the highly complex nature of chemical and nuclear accidents, efforts aimed at prevention, preparedness and response require the melding of many types of knowledge and the close collaboration of a wide range of professions. Nevertheless, the need for such integration and cooperation is not always strongly emphasized in university-level curricula. As a result, developing professionals have few opportunities to learn and practise unified models of environmental accident management. In an effort to foster a more integrative approach, the University of Alabama at Birmingham, USA, has launched the “Environmental Disasters” project. The project crosses disciplinary boundaries with respect to both curriculum and enrollment. In terms of curriculum, the project examines chemical and nuclear accidents from a multi-dimensional perspective, considering not only regulatory, scientific and policy issues, but also the public health, social, and psychological implications. In terms of enrollment, the project brings together students from the full range of fields that are involved with environmental accidents, including engineering, public health, public administration, social work, psychology, nursing, communications, medicine, and environmental studies. Emphasizing the need for a collaborative approach, students work in multi-disciplinary teams as they explore theory, case studies and current research. In addition, the student teams develop detailed plans for addressing the effects of a chemical or nuclear disaster. With environmental accidents representing an on-going threat to health and safety, the approach discussed in this article may provide a useful model for environmental disaster education at the university level.     

砷渣和铬渣的药剂稳定化研究

研究了施加药剂稳定砷渣和铬渣的工艺流程和有关的基本技术参数。经稳定化处理后的废渣毒性大有降低,溶出液中砷、铬含量在容许范围。      

TIE技术在某化工厂废水毒性原因鉴别中的应用

运用美国水生生物毒性鉴别评价技术对组分相对复杂的某化工厂废水进行毒性原因鉴别。结果表明：导致该厂废水毒性的关键污染物是二萘酚,对硝基氯苯和间硝硝基氯苯。对ＴＩＥ技术在中国推广的实用性,可行性以及应用前景等进行了讨论。     

Effects of sulfur on variations in the chemical speciation of heavy metals from fly ash glass

● A higher sulfur content reduced the curing rate of Cr in glass. ● Depolymerization increased the amounts of heavy metals in the carbonate bound state. ● Reducing the CaO/SiO₂ ratio increased the proportion of stable heavy metals. This work designed a new CaO-Al₂O₃-SiO₂-SO₃ glass for the immobilization of multiple heavy metals found in dechlorinated fly ash having high amounts of calcium and sulfur. Increasing the (CaO + SO₃)/SiO₂ mass ratio (M(CS/S)) from 0.28 to 0.85 was found to lower the proportions of Mn, Ni and Zn in an unstable state, while an M(CS/S) ratio of 0.51 gave the lowest proportions of unstable Cr and Pb. Decreasing the degree of polymerization of the glassy network increased the proportions of Mn, Cr, Ni, Pb and Zn in the carbonate bound state. The leaching out of metals in this state was the primary cause of degradation of Q³ structural units in the glassy network. The amount of Mn in the iron-manganese oxide bound state was increased by increasing the number of Q² units in the silicate network. Decreasing the CaO/SiO₂ mass ratio (M(C/S)) raised the proportions of Mn, Ni and Zn in the unstable state. An M(C/S) value of 0.43 lowered the proportions of unstable Cr and Pb. A principal components analysis determined that the leaching of toxic heavy metals from the glass was primarily related to the proportions of these metals in the unstable state while there were no evident correlations between leaching and the proportions in stable states.     

Characteristics of PM2.5 pollution in Beijing after the improvement of air quality

Following the implementation of the strictest clean air policies to date in Beijing, the physicochemical characteristics and sources of PM_2.5 have changed over the past few years. To improve pollution reduction policies and subsequent air quality further, it is necessary to explore the changes in PM_2.5 over time. In this study, over one year (2017–2018) field study based on filter sampling (TH-150C; Wuhan Tianhong, China) was conducted in Fengtai District, Beijing, revealed that the annual average PM_2.5 concentration (64.8 ± 43.1 μg/m³) was significantly lower than in previous years and the highest PM_2.5 concentration occurred in spring (84.4 ± 59.9 μg/m³). Secondary nitrate was the largest source and accounted for 25.7% of the measured PM_2.5. Vehicular emission, the second largest source (17.6%), deserves more attention when considering the increase in the number of motor vehicles and its contribution to gaseous pollutants. In addition, the contribution from coal combustion to PM_2.5 decreased significantly. During weekends, the contribution from EC and NO₃^? increased whereas the contributions from SO₄^2?, OM, and trace elements decreased, compared with weekdays. During the period of residential heating, PM_2.5 mass decreased by 23.1%, compared with non-heating period, while the contributions from coal combustion and vehicular emission, and related species increased. With the aggravation of pollution, the contribution of vehicular emission and secondary sulfate increased and then decreased, while the contribution of NO₃^? and secondary nitrate continued to increase, and accounted for 34.0% and 57.5% of the PM_2.5 during the heavily polluted days, respectively.     

我国合成洗涤剂生产废水治理技术研究

综述了近年来我国合成洗涤剂生产废水的特性;化学混凝法、泡沫分离法和生物接触氧化法处理合成洗涤剂生产废水的最佳工艺条件及其处理效果;工程应用实例及经济分析等。生产运行结果表明,处理后出水水质全面达到国家排放标准。化学混凝法,泡沫分离一混凝法其设备、流程简单、去除效率高、占地少,但运行费用较高。生物接触氧化－臭氧氧化法其出水可以回用、工艺先进、可靠、运行费用低、无二次污染。     

城市富营养湖泊沉积物中磷负荷及其释放对水质的影响

以南京玄武湖为研究对象,探讨了城市富营养湖泊沉积物中磷的分布、化学形态和负荷量:通过模拟实验深入研究了溶解氧、pH值、温度、扰动等环境因子对沉积物中磷的释放影响．进而得出磷释放速率．并对pH值影响作出校正,计算出沉积物中磷对湖水释放量,为玄武湖富营养化防治提供科学依据。      

模糊最大矩阵元鉴别海面溢油

建立了模糊最大矩阵元的海面溢油鉴别模式,提出了油种鉴别的置信水平λ_i的模糊区概念,给出了常见的14种油、两种风化油和海面溢油的模糊动态聚类图。油种鉴别的置信水平λ_i主要受风化的影响,风化30天,任丘原油和30~#重柴油同其它13种油可分类的置信水平范围分别为:0.99939>λ_i>0.99725和0.99791>λ_i>0.99026。海面溢油鉴别结果表明,本法较指纹谱图辨识法的准确度高。     

复合絮凝剂Al2(SO4)3+PAM处理生活污水中CODCr和浊度的实验研究

研究絮凝剂硫酸铝Al2(SO4)3与助凝剂聚丙烯酰胺(PAM)联合处理生活污水的效果。研究表明:Al2(SO4)3与PAM联用比单独用Al2(SO4)3处理生活污水效果更好;Al2(SO4)3 PAM对生活污水CODCr和浊度具有良好的去除能力;当投加1:1的50mg/L的Al2(SO4)3 0.5mg/L的PAM,调节水体pH=7时,处理效果最理想,CODCr去除率可达95.8%,浊度去除率可达97.5%。为复合絮凝剂Al2(SO4)3 PAM处理生活污水的应用提供了有价值的参考依据。