Sediment and Suspended Matter Lead Contamination in the Gulf of Kavala, Greece

Sediment and suspended particulate matter samples from 24 stations in the Gulf of Kavala have been examined for lead contamination. Grain size analysis and organic matter content were also performed. Total – anthropogenic sediment lead concentrations and enrichment factors at stations close to harbors and chemical industries were found higher (up to 209–135μg/g and 4.12 respectively), in relation to concentrations from the rest of the coastal zone. In the above areas, increased suspended particulate lead in the bottom of the water column was also recorded (up to 109μg/g). Total sediment lead concentrations composed of high natural Pb background increased with decreasing grain size, suggesting their association with the fine fractions of the sediments (31.1–66.0% mud presence) and the organic matter content (6–9% higher values). Overall, higher total lead concentrations in the sediments, determined by this work, appear to be significantly different from those reported for the Gulf of Kavala in previous studies and similar to those detected in other highly contaminated eastern Mediterranean coastal areas.     

Temperature Effect on Migration of Zn and Cd Through Natural Clay

To investigate the effect of temperature on effective diffusion coefficients and retardation factors for Zn and Cd, combined diffusion and sequential extraction analyses were conducted at 15 ^˚C and 55 ^˚C. The effective diffusion coefficients of the metals increased up to ten times according to the increased temperature. On the other hand, the effect of temperature on the retardation factor depended on the retention mechanisms of the metals. The distribution coefficient for Zn, which was mainly partitioned in the carbonate phase, increased up to two times with the increase in temperature. On the other hand, the distribution coefficient for Cd, which was mainly partitioned in the exchangeable phase, was hardly affected by the temperature change. Results of combined diffusion and sequential extraction analysis showed that the effect of temperature on the heavy metals’ (Zn and Cd) migration through the compacted natural clay was influenced by the combined effects of the diffusion coefficient and the retardation factor. Additionally, we could also observe the change in retention mechanism for the metals with the change in pore water concentration.     

Characterization and Identification of the Sources of Chromium, Zinc, Lead, Cadmium, Nickel, Manganese and Iron in Pm10 Particulates at the Two Sites of Kolkata, India

Monitoring of ambient PM₁₀ (particulate matter which passes through a size selective impactor inlet with a 50% efficiency cut-off at 10 μm aerodynamic diameter) has been done at residential (Kasba) and industrial (Cossipore) sites of an urban region of Kolkata during November 2003 to November 2004. These sites were selected depending on the dominant anthropogenic activities. Metal constituents of atmospheric PM₁₀ deposited on glass fibre filter paper were estimated using Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). Chromium (Cr), zinc (Zn), lead (Pb), cadmium (Cd), nickel (Ni), manganese (Mn) and iron (Fe) are the seven toxic trace metals quantified from the measured PM₁₀ concentrations. The 24 h average concentrations of Cr, Zn, Pb, Cd, Ni, Mn and Fe from ninety PM₁₀ particulate samples of Kolkata were found to be 6.9, 506.1, 79.1, 3.3, 7.4, 2.4 and 103.6 ng/m³, respectively. The 24 h average PM₁₀ concentration exceeded national ambient air quality standard (NAAQS) as specified by central pollution control board, India at both residential (Kasba) and industrial (Cossipore) areas with mean concentration of 140.1 and 196.6 μg/m³, respectively. A simultaneous meteorology study was performed to assess the influence of air masses by wind speed, wind direction, rainfall, relative humidity and temperature. The measured toxic trace metals generally showed inverse relationship with wind speed, relative humidity and temperature. Factor analysis, a receptor modeling technique has been used for identification of the possible sources contributing to the PM₁₀. Varimax rotated factor analysis identified four possible sources of measured trace metals comprising solid waste dumping, vehicular traffic with the influence of road dust, road dust and soil dust at residential site (Kasba), while vehicular traffic with the influence of soil dust, road dust, galvanizing and electroplating industry, and tanning industry at industrial site (Cossipore).     

基于FHWA的兰州市道路交通噪声预测模型的建立

结合美国道路交通噪声污染预测模型(FHWA)和国内学者在该方面的大量研究成果,选择兰州市主、次干道共计52条、142个监测点的建模采样数据,并应用统计学原理分析了影响道路交通噪声的各个因子与道路交通噪声的相关性,最终得出了符合兰州市道路交通特征的噪声污染统计预测模型.随后通过兰州市15个监测点的预测与实测对比验证后发现二者具有较高的一致性,此模型可应用在兰州市道路交通噪声污染的预测评价中.     

松嫩平原西部碱尘气溶胶的时段变化及其气候影响因素分析

利用耦合等离子体发射光谱测试技术(ICP-AES)对松嫩平原西部2003年7月到2004年5月间获得的大气总悬浮颗粒物(TSP)样品进行了元素分析,并结合气象资料和TSP质量浓度,初步确定了碱尘活动年际内的演变规律及其主要控制因素.结果表明,TSP质量浓度的高峰时段是早春,其元素总体浓度亦高于其它时段,其中Na元素浓度具有明显的高值,表明碱尘在该时段为TSP的主要成分;晚春时段区域沙尘影响加强,很难监测本地碱尘活动;夏季,碱尘的3种重要元素(Na、Ca、K)含量增加,表明夏季有碱尘活动,与TSP浓度偏高吻合;秋季,碱尘和区域沙尘的活动均减弱.影响碱尘活动的气候因子主要是风力、降水量、温度、日照和湿度,但不同时段其主导作用不同.     

利用卫星遥感数据估算PM2.5浓度的应用研究进展

近年来,PM_(2.5)已成为中国大气污染的首要污染物,危害人体健康。为弥补地基监测站点在空间分布上的局限性,借助卫星遥感技术估算PM_(2.5)浓度已成为研究热点。文章总结了利用卫星估算PM_(2.5)浓度的各种研究方法,探讨了不同方法的优势和不足,指出不同方法对不同应用目的的选择性差异较大。提出,应针对不同应用目的选择相应的方法,从而取得满足各方面需求的研究成果,为未来PM_(2.5)浓度估算应用工作提供参考。     

施工工地出口附近道路交通扬尘排放特征研究

为了量化施工工地附近社会道路因施工运输车辆带泥及遗撒造成的二次交通扬尘,对4个典型工地出口2个方向社会道路尘负荷进行了采样分析,根据AP-42交通扬尘排放模型,计算和分析了工地出口附近道路交通扬尘排放特征.结果表明,工地出口附近道路尘负荷高于正常道路,随着距离工地出口长度的增加,尘负荷逐渐减小;工地出口2个方向共400 m道路上交通扬尘PM₁₀排放因子为正常道路的2～10倍,因施工增加的排放量相当于422～3?800 m正常道路排放.根据以上结果,结合2002年北京市施工工地时空分布数据,经计算得出,2002年北京市城八区工地出口形成的二次扬尘相当于增加了道路总长度的59%.     

皂素生产废水处理方法比较研究

皂素生产废水为难处理高浓度酸性含硫有机废水,目前常用处理工艺为UASB+SBR,但该工艺运行效果较差。文章对UASB+SBR改进工艺进行了比较研究,结果表明:在UASB中加入适量铁屑和颗粒活性炭解除了SO42-的二次抑制,COD去除率比对照组UASB高2%～3%,出水水质COD一直稳定在1300mg/L左右,去除率在95%以上,出水无异味。UASB中污泥增长速率约为0.0686d-1,是仅加活性炭污泥增长速率(0.0197d-1)的3.48倍,可见加入铁屑后污泥增长速率改变明显。该改进UASB+SBR工艺的COD去除率高于对照组,出水COD维持在200mg/L以下,略带浅黄色(20倍左右),低于GB8978-1996《污水综合排放标准》原料药料二级排放标准值(300mg/L),SBR污泥增长速率为0.3083d-1,略高于对照组。     

北京市铁路站场大气颗粒物的特征与来源分析

利用扫描电镜-X射线能谱(SEM-EDX)技术对北京市铁路站场采集的颗粒物的形貌和化学组分进行分析,并利用富集因子法及元素相关性对颗粒物中的各元素来源进行判别。研究结果表明,铁路站场所采集的主要是2μm以下的球形或椭球形富含S、Br、Zn元素的颗粒,富集因子及元素相关性分析显示,该颗粒物主要来源于铁路机车燃油排放。因此,确定颗粒物的排放源并以此进行控制,对于改善北京铁路站场周围的大气环境具有重要意义。     

蜡烛燃烧产生的亚微米颗粒物的数量排放因子

蜡烛燃烧产生的亚微米颗粒物(在10nm-500nm范围内),稳定燃烧排放的颗粒物呈单峰正态分布,而非稳定燃烧呈近似双峰正态分布.将现场测得的浓度数据通过气溶胶动力方程转化为排放因子.结果表明,蜡烛燃烧产生的颗粒物在经过一段时间历程后,粒径谱会发生较大的变化,纳米级颗粒物逐渐消失,颗粒物的粒径有所增大.蜡烛在稳定燃烧环境下产生的亚微米颗粒物的数量排放因子为4.05×1012±0.73×1012个·g-1,在非稳定燃烧下的排放因子为1.49×1012±0.32×1012个·g-1.