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1.
Distinguishing and quantifying anthropogenic trace metals and phosphorus accumulated in sediment is important for the protection of our aquatic ecosystems. Here, anthropogenic proportion and potential sources of trace metals and phosphorus in surface sediments of Chaohu Lake were evaluated based on the exhaustive geochemical data. The analysis shows that concentrations of major and trace metals, and phosphorus, displayed significant spatial diversity and almost all elements were over the pre-industrial background value, which should be related to the variations of sediment composition partially. Therefore, conservative element normalization was introduced and calculated enrichment factors (EFs) of the elements were referenced highlighting the human contamination. EFs of the major and trace metals, except Zn, Pb, and Cu, were all nearly 1.0, indicating the detrital origin. The EFs of Zn, Pb, Cu and phosphorus were 1.0–10.4, 1.0–3.8, 1.0–4.9, and 1.0–7.6, respectively, showing moderate to significant contamination. Higher EFs of Zn, Pb and Cu occurred in the mouth areas of Nanfei River and Zhegao River, and they decreased to the lake center in the northwest and northeast lake areas, respectively. We deduced that anthropogenic Zn, Pb, and Cu were mainly from urban and industrial point sources and the non-point sources of atmospheric deposition contributed little to their contamination. The EFs of phosphorus showed similar spatial degradation with that of Zn, Pb, and Cu. Moreover, higher EFs (>1) of phosphorus also occurred in other areas adjacent to the river mouths besides Nanfei River and Zhegao River. This indicated that the non-point agricultural source may also be responsible for the contamination of phosphorus in Chaohu Lake in addition to the urban sewage sources. Anthropogenic phosphorus was mainly concentrated in the speciation of NaOH-P, which had higher potential biological effects than the detrital proportion. Concentrations of Zn, Pb and Cu surpassed the threshold effect concentrations (TEC) of consensus-based sediment quality guidelines of freshwater ecosystems, especially in the contaminated northwest area of Chaohu Lake. This highlighted the contributions of anthropogenic contamination to the elevated potential biological effects of trace metals. Though there had been no obvious human contamination of Cr and Ni in Chaohu Lake, concentrations were all over the TECs, which may be due to higher background levels in the parent materials of soils and bedrocks in Chaohu Lake catchment.  相似文献
2.
In this study, a survey for the spatial distribution of heavy metals in Chaohu Lake of China was conducted. Sixty-two surface water samples were collected from entire lake including three of its main river entrances. This is the first systematic report concerning the content, distribution, and origin of heavy metals (Cu, Cr, Cd, Hg, Zn, and Ni) in the Chaohu Lake water. The results showed that heavy metals (Cu, Cr, Zn, and Ni) concentrations in the estuary of Nanfei River were relatively higher than those in the other areas, while content of Hg is higher in the southeast lake than northwest lake. Moreover, Cd has locally concentration in the surface water from the entire Chaohu Lake. The heavy metal average concentrations, except Hg, were lower than the cutoff values for the first-grade water quality (China Environment Quality Standard) which was set as the highest standard to protect the social nature reserves. The Hg content is between the grades three and four water quality, and other heavy metals contents are higher than background values. The aquatic environment of Chaohu Lake has apparently been contaminated. Both the cluster analysis (CA) and correlation analysis provide information about the origin of heavy metals in the Lake. Our findings indicated that agricultural activities and adjacent plants chimneys may contribute the most to Cd and Hg contamination of Chaohu Lake, respectively.  相似文献
3.
颗粒物激光雷达在大气复合污染立体监测中的应用   总被引:4,自引:4,他引:0  
针对由于局地污染、沙尘输入、外源性输入与局地污染物相互叠加所导致的3种灰霾污染发生过程,分别选取3个典型案例,采用颗粒物激光雷达对污染物的时空分布特征进行解析。研究发现,在局地污染发生时,污染物从地面开始垂直向上扩散,扩散高度约1 km。重度污染过程中,气溶胶的日均垂直消光系数随高度的变化背离指数衰减特征,800 m高度处出现消光系数的极大值层,极大值超过2.5 km-1,800 m以下消光系数近乎常数,约为0.3 km-1。这说明,重污染过程中,有一层较厚重的颗粒物分布,使近地面污染物在垂直方向的扩散能力减弱,形成积累效应,造成大面积空气混浊。当有外源性沙尘输入时,激光雷达能够清晰地监测到污染团输入的全过程。沙团突然出现在高空2~3 km。污染团退偏振度较大,超过0.3。随着沙尘粒子的重力沉降,沙团的轮廓在垂直方向上不断地增大。沙团的输入,导致近地面粗颗粒质量浓度的增加幅度明显大于细颗粒。在第3个案例中,激光雷达清晰地监测到高空1.8~3 km突然出现含有大量球形细颗粒的污染团,同时还发现此污染团与近地面的污染物有不同的演化特征。近地面污染物随时间垂直向上扩散,12:00左右扩散高度超过1.8 km。而高空的污染团逐渐沉降进入边界层内,与近地面扩散的污染物相互混合,共同导致本地的灰霾天气。综上所述,激光雷达可以清晰地捕获污染物的垂直结构特征,对不同的致霾过程进行立体解析,实现对大气复合污染的监测和机理研判。  相似文献
4.
南京青奥会空气质量保障联合观测分析研究   总被引:3,自引:0,他引:3       下载免费PDF全文
2014年8月,为做好南京青奥会空气质量保障工作,江苏省环境监测中心联合中科院大气物理所、南京大学等36家单位,开展了为期一个月的空气质量保障联合观测,共获取监测数据5万多个,巡航观测里程超9 000 km,编制预报及分析报告87份,空气质量预报准确率达80%。结果表明,强力管控措施的实施,对缓解空气污染效果显著;通过联合团队观测方式,集中了产、学、研、用的技术优势和科研力量,带动了全省空气质量监测与分析能力的整体提升,为青奥会空气质量保障工作提供了强有力的技术支撑。  相似文献
5.
南京及周边区域亚青期间大气监控预警走航观测研究   总被引:2,自引:1,他引:1  
2013年8月,为了解亚青会期间南京及周边地区大气污染物的来源、时空分布和输送规律,江苏省环境监测中心联合中科院大气物理所等15家单位,开展了为期一个月的夏季联合观测,监测区域覆盖江苏沿江8市以及安徽部分地区。该次联合观测,江苏首次利用空气质量数值预报模式指导开展走航观测,实现了动静、水平与垂直相结合的立体式巡航观测,并初步揭示了现阶段江苏省大气污染主要特征,观测结果直接服务于亚青空气质量会商,为保障南京市空气质量提供技术支撑,同时为2014青奥会空气质量保障积累经验。  相似文献
6.
用后向空气轨迹方法对胶州湾主要大气污染物分布的分析   总被引:2,自引:2,他引:0  
采用青岛崂山点位2005-2009年的大气监测数据,利用HYSPLIT4.8模式和象限分析方法,计算出污染物的方位贡献情况,判断出胶州湾大气污染物的传输路径主要为北、西北和西部路径,S02、N02和PM10在北部和西北部象限的5年平均贡献率分别为25.32%和28.21%、21.16%和21.53%以及20.25%和22.83%,这与胶州湾东方和东南方为海洋、北方和西北方为工业城市有关.通过个例分析得出的传输路径与象限分析的结果一致.另一方面,胶州湾地区的主要污染物在过去5年中的年均值浓度变化显示,SD2浓度呈下降趋势,NO2浓度呈上升趋势,PM10浓度变化趋势不明显.为调查青岛市和周边5个省污染物排放水平对胶州湾污染物分布的影响,分析了2005-2009年的相关环境统计数据,SO,的排放量下降,燃料煤消耗量、氮氧化物排放量以及机动车数量逐年升高可能是导致胶州湾地区污染物浓度变化的原因.  相似文献
7.
典型地区农用地污染调查及风险管控标准探讨   总被引:1,自引:0,他引:1  
针对《土壤污染风险管控标准——农用地土壤污染风险管控标准》(GB 15618—2018),提出以土壤中全量浓度筛选值和管控值作为衡量农用地土壤污染风险管控的标准,对湖南省部分稻田农用地土壤及点对点稻米样品中镉、铅、砷、汞的总量和有效态浓度及稻米中含量进行监测,根据重金属总量浓度分为低风险、中风险、高风险3组。结果显示:(1)土壤及稻米中镉含量基本为随着风险级别的升高而增加,铅、砷在土壤和稻米中含量无规律性结果,汞监测结果均为未检出。(2)低风险组稻米镉超标率为12. 0%,高风险组稻米镉达标率为33. 3%,表明利用总量浓度对农用地土壤潜在风险进行分组存在一定的局限性。(3)依据4种重金属在土壤中总量及稻米(早稻)中含量情况,对风险级别进行调整并综合判断:有58个样品为低风险组,占样品总数的68. 2%,超标率为零;有15个样品为中风险组,占样品总数的17. 7%,超标率为80. 0%;有12个样品为高风险组,占样品总数的14. 1%,超标率为100. 0%。调整后评价结果与上述标准的划分目标更接近,能够提高上述标准的准确性和实用性。  相似文献
8.
大气污染光学遥感技术及发展趋势   总被引:1,自引:0,他引:1  
空气质量和气候变化是影响人类生存环境的两大主要因素,它们与大气构成变化密切相关,因此,必须对影响人类生存和决定对流层成分的大气过程进行监测。随着监测技术的发展,大气环境监测方法从常规的监测体系向理化、遥测、应急等多种监测分析方法相结合的综合监测技术方向发展。基于激光/光谱的大气污染监测技术以光学探测和光谱数据解析为核心,探测大气痕量气体和颗粒物的时空分布特征和输送规律,并逐渐运用于球载、无人机、卫星等区域动态遥测,可为中国大气灰霾形成的关键影响因素识别提供技术支持。  相似文献
9.
基于光学遥测技术的合肥市气溶胶参数观测   总被引:1,自引:1,他引:0  
为了解合肥市气溶胶光学特性参数,采用太阳光度计CE318对雾霾期间气溶胶进行监测并分析了气溶胶光学厚度(AOD)、Angstorm波长指数(α)、体积谱函数等气溶胶光学特性参数.同时采用多轴差分吸收光谱技术(MAX-DOAS)反演了雾霾期间二次气溶胶前体物NO2柱浓度并和固定点测量的颗粒物(PM)浓度进行了对比.分析表明,雾霾期间的气溶胶光学厚度比晴天高,且随波长的增加而减少.Angstorm波长指数在雾霾天气时平均值较高,表明合肥雾霾天气期间气溶胶粒子以细粒子为主.气溶胶前体物NO2浓度变化与雾霾天气空气中颗粒物含量(PM10、PM2.5等)变化一致性较好,表明二次气溶胶可能对气溶胶颗粒浓度有一定影响.  相似文献
10.
激光雷达以其高精度的探测能力在大气污染研究中得到了广泛应用。由于生产厂家和反演算法等的差异,激光雷达观测数据的质量参差不齐。笔者利用2013年11月和2014年3月2种不同型号激光雷达(高频激光雷达和微脉冲激光雷达) 532 nm波段的气溶胶消光系数和气溶胶自动观测网(AERONET)光学厚度数据,对2部雷达在不同空气质量下的观测性能进行综合对比。结果表明:2部雷达在不同空气质量条件下探测效果不同,空气质量为优和良时,2部雷达的消光系数比较一致,偏差主要在1 km以下;随着污染加剧,2部雷达在1 km以下的偏差先减小后增大,1 km以上的偏差随高度增大。与AERONET的光学厚度相比,高频激光雷达在轻度污染和严重污染时相对误差较小(3.23%和26.75%);微脉冲激光雷达在良和轻度污染时相对误差较小(40.00%和25.81%)。2部雷达设备的差异和重污染时不利的气象条件是影响雷达表现的重要原因。该研究作为全国激光雷达联网的前期工作,为全国激光雷达数据的综合应用提供了参考。  相似文献
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