Metallic Element Composition of Particulate Matter During Day and Night Sampling at a Traffic Site

Day and night period sampling programs were carried out using a versatile air pollutant system to collect fine particulate matter (PM_2.5) and coarse particulate matter (PM_2.5–10) simultaneously at a traffic junction that is only 60 m from HungKuang University located in Central Taiwan. Therefore, HungKuang University is regarded as the traffic sampling site in this study. Similar measurements were carried out in a previous 2013 study by Fang and colleagues during October 2012 to November 2012. Determination of metallic element composition of fine and coarse particulates collected during the day and the night was accomplished with inductively coupled plasma atomic emission spectrometry (ICP-AES). The results indicated that there were no significant differences in composition of metallic elements Zn, Cu, Cr, Mn, Fe, Pb, and Cd in either coarse or fine particles for both day and night sampling periods. The statistical results indicated no significant differences for metallic elements in the PM_2.5–10 particulates for day and night sampling periods. Also, no significant differences were noted for metallic elements in the PM_2.5 particulates for day and night sampling periods at this traffic sampling site. The proposed reason is the limited sampling period employed in this study. Another potential reason is the presence of traffic that runs heavily both day and night being a major contributor to the ambient air metallic pollutants in this region.     

燃煤飞灰颗粒物中元素分布规律的研究

利用ICP-AES光谱仪和TOC总碳分析仪对不同粒级下的飞灰颗粒进行了元素测定,对元素分布规律的形成原因进行了分析.分析结果表明:煤经旋流燃烧器燃烧而未经过除尘设备的飞灰中300目以下小颗粒含量较高.随着燃烧温度的升高,大颗粒的含碳量增加,小颗粒的含碳量减少,元素Al、Mg、Cr在各个粒级中含量变化不大,Ti、Ba、V在大于280目的小颗粒中含量有下降趋势,其他大部分痕量元素在大于300目的小颗粒中得到富集.     

燃煤飞灰中痕量元素的研究

综述了煤中痕量元素的含量分布、煤燃烧过程中痕量元素的分布转化规律,总结了痕量元素在飞灰中的富集规律和赋存状态,以及痕量元素的释放控制方法和技术,并探讨了今后的研究方向.     

Socioeconomic Dimensions of Changes in the Agricultural Landscape of the Mediterranean Basin: A Case Study of the Abandonment of Cultivation Terraces on Nisyros Island,Greece

Agricultural landscapes illustrate the impact of human actions on physical settings, and differential human pressures cause these landscapes to change with time. Our study explored changes in the terraced landscapes of Nisyros Island, Greece, focusing on the socioeconomic aspects during two time periods using field data, cadastral research, local documents, and published literature, as well as surveys of the islanders. Population increases during the late 19^th to early 20^th centuries marked a significant escalation of terrace and dry stone wall construction, which facilitated cultivation on 58.4% of the island. By the mid-20^th century, the economic collapse of agricultural activities and consequent emigration caused the abandonment of cultivated land and traditional management practices, dramatically reducing farm and field numbers. Terrace abandonment continued in recent decades, with increased livestock grazing becoming the main land management tool; as a result, both farm and pasture sizes increased. Neglect and changing land use has led to deterioration and destruction of many terraces on the island. We discuss the socioeconomic and political backgrounds responsible for the land-use change before World War II (annexation of Nisyros Island by the Ottoman Empire, Italy, and Greece; overseas migration opportunities; and world transportation changes) and after the war (social changes in peasant societies; worldwide changes in agricultural production practices). The adverse landscape changes documented for Nisyros Island appear to be inevitable for modern Mediterranean rural societies, including those on other islands in this region. The island’s unique terraced landscapes may qualify Nisyros to become an archive or repository of old agricultural management techniques to be used by future generations and a living resource for sustainable management.     

Cloud point extraction coupled with HPLC-UV for the determination of phthalate esters in environmental water samples

A method based on cloud point extraction was developed to determine phthalate esters including di-ethyl-phthalate （DEP）, di- （2-ethylhexyl）-phthalate （DEHP） and di-cyclohexyl-phthalate （DCP） in environmental water samples using high-performance liquid chromatography separation and ultraviolet detection （HPLC-UV）. The non-ionic surfactant Triton X-114 was chosen as extraction solvent. The parameters affecting extraction efficiency, such as concentrations of Triton X-114 and Na2SO4, equilibration temperature, equilibration time and centrifugation time were evaluated and optimized. Under the optimum conditions, the method can achieve preconcentration factors of 35, 88, 111 and detection of limits of 2.0, 3.8, 1.0 ng/ml for DEP, DEHP and DCP in 10-ml water sample, respectively. The proposed method was successfully applied to the determination of trace amount of phathalate esters in effluent water of the wastewater treatment plant and the lixivium of plastic fragments.     

Application of multiwalled carbon nanotubes treated by potassium permanganate for determination of trace cadmium prior to flame atomic absorption spectrometry

In this study we investigated the enrichment ability of oxidized multiwalled carbon nanotubes (MWCNTs) and established a new method for the determination of trace cadmium in environment with flame atomic absorption spectrometry.The MWCNTs were oxidized by potassium permanganate under appropriate conditions before use as preconcentration packing.Parameters influencing the recoveries of target analytes were optimized.Under optimal conditions,the target analyte exhibited a good linearity (R~2=0.9992) over the concentration range 0.5-50 ng/ml.The detection limit and precision of the proposed method were 0.15 ng/ml and 2.06%, respectively.The proposed method was applied to the determination of cadmium in real-world environmental samples and the recoveries were in the range of 91.3%-108.0%.All these experimental results indicated that this new procedure could be applied to the determination of trace cadmium in environmental waters.     

成都市西南郊区春季大气PM2.5的污染水平及来源解析

为了解成都市西南郊区大气中PM_(2.5)污染特征,于2015年3月1~31日对成都西南郊区大气PM_(2.5)进行膜样品采集,并分析其中的化学组分.结果表明,3月成都市西南郊区大气PM_(2.5)的日均质量浓度为121.21μg·m~(-3),采集的31个有效PM_(2.5)样品中有24个样品日均浓度在75μg·m~(-3)以上,日超标率为77%,该地区3月PM_(2.5)污染严重.在与大气气象要素的关系研究中发现,大气颗粒物PM_(2.5)与大气能见度有着较好的指数关系,与温度、湿度有一定的正相关关系,但相关性并不明显.水溶性阴阳离子中NH~+_4(16.24%)、SO~(2-)_4(12.58%)、NO~-_3(9.91%)占PM_(2.5)的主导地位,NO~-_3/SO~(2-)_4的比值是0.77,表明成都西南郊区固定源的污染要大于移动源的污染,燃煤排放的污染相对于汽车尾气较多.有机碳(OC)/元素碳(EC)比值均大于2.0,表明有二次有机碳(SOC)产生.利用OC/EC比值法估算SOC的质量浓度发现,成都西南郊区3月PM_(2.5)中SOC的平均浓度水平为3.49μg·m~(-3),对OC的贡献率达20.6%,说明成都市西南郊区的OC主要来源于一次排放,且OC与EC的相关性分析显示,其相关系数达0.95,说明OC、EC来源相似且相对稳定,成都市西南郊区春季受局地源排放影响较大,一次排放占主导地位,二次有机碳对OC贡献相对较小,与估算所得的SOC性质一致.利用主成分分析(PCA)方法对成都西南郊区大气中PM_(2.5)进行来源解析,发现成都西南郊区PM_(2.5)的主要污染源为燃煤、生物质的燃烧、二次硝酸盐或硫酸盐、土壤和扬尘源、汽车尾气源、电子生产源以及机械加工源.     

黔西南高砷煤热解过程中微量元素释放规律研究

采用高温箱式电阻炉对黔西南海子地区煤样进行热解,研究了在300~1200℃下慢速热解过程中,热解温度、元素赋存状态和灰分对微量元素释放规律的影响.结果表明,热解温度是影响煤失重和微量元素挥发的主要原因. As、Mo在900℃以上挥发较快; Pb热解前期挥发较快,450℃以上挥发缓慢;Sb随热解温度的升高缓慢增大.微量元素的挥发性还与赋存状态关系密切,有机态最为活泼;硫化物态和碳酸盐态在热解后期由于矿物的分解而逐步释放;硅酸盐态最稳定,基本残留在灰分中.灰分越高微量元素越不易挥发.     

西南涡对四川盆地PM2.5污染的影响研究

利用2015—2016年西南涡个例数据与同期的细颗粒物（PM_2.5）浓度数据进行时空匹配,对比分析西南涡过境前后四川盆地PM_2.5浓度变化,并结合温度、湿度、风等气象要素及逆温特征,深入研究西南涡对PM_2.5污染的影响机理.结果表明：①2015—2016年四川盆地共182个西南涡,其中,干涡72个（多集中在春季）,弱降水涡75个（多集中在春季和冬季）,强降水涡35个（多集中在夏季）.②总体而言,干涡过境使四川盆地PM_2.5浓度增加,降水涡使PM_2.5浓度减小,强降水涡的削减作用强于弱降水涡.全年来看,干涡过境使四川盆地PM_2.5浓度增加10.52%,强、弱降水涡过境分别使PM_2.5浓度减小29.72%、9.71%.③除降水外,3类西南涡对PM_2.5影响的主导气象要素和逆温条件为相对湿度、风速和逆温层底高.而主导季节差异的气象要素和逆温条件各异：干涡的主导因素是温度垂直变化和逆温强度,在温度随高度递减和逆温强度较小的春季和夏季,对PM_2.5浓度的增幅减小（甚至有削减作用）;弱降水涡的主导因素是湿度和风速、逆温强度和逆温层厚度,春季其过境时湿度和风速最小,逆温强度和逆温厚度仅次于冬季,甚至使PM_2.5浓度增加;强降水涡的主导因素是风速、湿度和逆温层底高,夏季其过境时风速和低层湿度最小,逆温层底高最低,对PM_2.5的削减作用远弱于其他季节.     

环境磁学在监测城市河流沉积物污染中的应用

环境磁学因简便、快速、经济等特征而逐渐广泛应用于城市环境污染研究,并得到了大量学者的认可.与此同时,对环境磁学污染响应机理的研究也成为当前环境磁学发展突破点.本文选取流经兰州市不同功能区（绿地区、生活区、商业区、工业区）的典型河流——寺儿沟为研究对象,通过环境磁学、元素、粒度等指标对其4个功能区河段沉积物的磁性特征进行...