Size, composition, and mixing state of individual aerosol particles in a South China coastal city

Aerosol samples were collected in summer in Macao,a coastal city of the Pearl River Delta Region in China.Morphology,size,elemental composition,and mixing state of individual aerosol particles were determined by scanning electron microscopy coupled energy dispersive X-ray(SEM/EDX) and transmission electron microscopy(TEM).Based on the morphologies of 5711 aerosol particles,they consist of soot(32%),mineral(17%),secondary(22%),and unknown fine particles(29%).The sizes of these particles were mostly distributed between 0.1 and 0.4 μm.Compositions of 202 mineral particles were obtained by SEM/EDX.Mineral particles were mainly classified into three types:Si-rich,Ca-rich,and Na-rich.The compositions of typical mineral particles can indicate their sources in sampling location.For example,mineral particles,collected along the main street,were associated with trace amounts of heavy metals,such as Zn,Ti,Mn,Ba,Pb,and As.TEM observations indicate that most Na-rich particles were aged sea salt particles(e.g.,Na2SO4 and NaNO3) which formed through heterogeneous chemical reactions between sea salt and acidic gases.Additionally,aging time of soot was short in Macao due to high humidity,high temperature,and high levels of sunlight in Macao.Most of soot and fine mineral dust particles were internally mixed with secondary particles.     

垃圾堆体固有渗透与孔隙度协同演化特征实验研究

为探讨上覆载荷作用下垃圾堆体渗透特性的变化规律,采用自制的生活垃圾渗透率/孔隙度测试实验装置,研究了不同载荷、不同压实密度及不同含水率对垃圾堆体固有渗透率和孔隙度变化规律的影响,并构建了固有渗透率与孔隙度之间的协同表征模型。结果表明,压实密度与上覆载荷呈指数递增的变化形式;随着含水率的增大,垃圾固有渗透率显著降低;垃圾固有渗透率随孔隙度的减小呈现指数递减,传统K-C模型无法描述这一变化规律,而幂函数形式(κ=AnB)和线性形式(lg(κ)=a+blg(n))2种协同表征模型均与实验结果达到了良好的拟合效果,验证了2种模型的可靠性;随着模型尺度的增大,固有渗透率从10-15m2量级增加至10-12m2量级,孔隙度从0.378增加至0.685。     

灾难性的海洋石油污染

较详细地分析了海洋石油污染的概况、重大溢油事件及其对海洋生态环境的严重破坏。除了油船海难事故所造成的海洋石油污染之外,海上油田开发是另一个重要的污染源。最大的一次油船事故直接经济损失可达100万美元,而海洋石油泛滥对海洋生态环境的破坏所造成的（间接）经济损失,还远远超过其直接经济损失。文章从海洋生态系统保护的角度出发,对目前石油污染物的净化方法作了简要的讨论。     

气相色谱法测定废水中的7种低分子量醛,酮和醇

用液上空间气相色谱ＦＩＤ检测器,同时测定了废水中的甲醇、乙醛、乙醇、丙酮、异丙醇、甲醛和正丁醇等７种低分子量挥发性有机物,色谱柱为ＧＤＸ－１０１与ＰＥＧ－２０Ｍ串联填充柱,能较好地分离上述７种化合物,方法的精密度和准确度均可达到环境监测质量要求,最低检出质量浓度均低于０．０６０ｍｇ／Ｌ。     

淮安清江浦区 “四清”工作法助力安全生产

淮安清江浦区以“底数清、保障清、流程清、责任清”为工作抓手,探索总结了安全生产管理提质增效“四清”工作法。监管底数清。清江浦区共有私营企业13050户,个体工商户55817户,规上企业333家,其中涉及化工品的企业6家,区应急管理局作为安全生产综合监管部门,要求每一名工作人员做到对规上企业名称、地址、法人姓名、经营情况熟记于心。