地表水样品自然沉降时间对总磷测定结果的影响分析

地表水中总磷含量高低是评定水质优劣的一项重要指标,分析数据表明丰水期中总磷主要来源于泥沙中吸附的有机磷和无机磷,而溶解态磷含量较少;水样中总磷含量随着自然沉降时间的延长而逐渐降低.因此样品采集回来后样品的自然沉降时间是影响地表水中总磷测定结果的一个主要原因之一.     

地表水水样自然沉降放置试验与讨论

本文用四种方式对地表水样品的自然沉降在采样环节还是在分析环节进行实验,对BOD5、CODMn、CODcr之类分析时不需对样品进行预处理的项目有一定影响,自然沉降在分析环节的监测结果低于在采样环节的监测结果;对氨氮、总磷之类分析时需对样品进行预处理的项目影响几率基本持平。     

测定水中铁、锰、汞时前处理问题探讨

基于大量实测数据统计,比较了测定水中铁、锰、汞3种重金属时,样品是否过滤、加酸保存等前处理方式对测定结果的影响,提出铁、锰水样需过滤检测,汞水样不能过滤检测,且3种金属的水样均需加酸保存,这样测定的结果才能根据现行水环境质量标准进行评价。     

富含泥沙水样总氮总磷测定的干扰因素探讨

从分析富含泥沙水样的总氮、总磷入手，探讨了样品静置、样品保存时间及消解后样品溶液稳定时间对总氮、总磷测定结果的影响。     

淡水中叶绿素a测定方法的探讨

对分光光度法测定叶绿素a中样品研磨转移损失,离心后750nm处吸光值达不到0.005要求,加酸消除脱镁叶绿素,加酸量及加酸后测定时间等方面进行对比实验研究,提出了对分光光度法测定叶绿素a修改建议.     

地表水中丁基黄原酸的保存条件研究

通过对不同基质地表水样中丁基黄原酸在p H值、温度、光照、保存时间等条件下进行保存研究,确定对其保存效果的影响为:保存时间保存温度样品中丁基黄原酸浓度光照强度p H值。建议地表水样品使用棕色玻璃瓶盛装,于4℃下避光保存原水。高浓度样品,保存时间不超过5 d;低浓度样品,保存时间不超过1 d,最好采样后立即分析。     

装潢居室空气中甲醛采样方法改进

对空气中甲醛测定的采样方法进行了探讨 ,分别用水和稀硫酸作吸收液对空气甲醛进行采样研究。结果表明 ,用 0 .0 0 5mol LH2 SO4 作吸收液的采样方法 ,可有效、稳定地延长样品的保存时间 ,且又符合方法灵敏度和精密度的要求。     

总磷测定过程中的几点体会

地表水总磷测定中 ,样品消解时间通常需保持 3 0 min,通过进行缩短时间的试验 ,确认消解时间由 3 0 min缩短至 1 0 min,总磷测定结果符合要求。水中总磷测定时 ,标准系列需加 4ml5 % ( m/v)过硫酸钾溶液消解 0 .5 h,对校准曲线制备方法进行改进 ,省略了加热氧化操作步骤 ,样品测定结果无显著差异。地表水总磷测定中显色温度对显色时间存在很大影响 ,而且它们之间存在着一定的线性关系 ,经对低浓度水样进行显色试验 :在室温 1 5℃时 ,显色时间需 1 5 min,显色持续时间可达 3 0 min;而在室温 3 0℃时 ,显色时间仅需 5 min,显色持续时间为 2 0 …     

水中苯胺类化合物分析的难点

结合实验研究了水中苯胺类化合物的测定难点和影响因素，包括样品保存和水样中悬浮物的影响。苯胺类化合物易被氧化，样品不易保存且受悬浮物的影响。研究结果表明：样品中未加入抗氧化剂进行保存时，部分苯胺类化合物迅速降解；当样品中加入80 mg/L硫代硫酸钠进行保存时，部分苯胺类化合物的保存时间可以延迟2~3 d后降解。样品中悬浮物对联苯胺萃取影响较大，回收率偏低，可以通过调节样品pH至酸性后过滤，再将滤液调至中性后进行萃取，回收率明显提高。笔者同时讨论了消除与补偿基质干扰的方法，包括色谱分离条件和检测器条件的选择、优化，内标法、空白基质匹配标准校正法和工作曲线法等定量方法的选择。     

直接进样-气相色谱质谱法同时测定固定污染源排气中的含氟温室气体

建立了一种直接进样-气相色谱质谱法同时分离和测定固定污染源排气中三氟甲烷、四氟甲烷、六氟乙烷和六氟化硫等含氟温室气体的方法。使用CP-Sillica PLOT毛细管填充柱可使上述4种目标化合物实现基线分离。分别用全扫描模式和选择离子扫描模式进行定量分析,方法检出限分别为0.12,0.19,0.10,0.08 mg/m~3和2.8,3.4,1.7,3.1μg/m~3。探讨了样品保存容器与保存时间对样品浓度衰减的影响,指出Tedlar采样袋或铝塑复合膜采样袋可以较长时间保存样品,在常温下,样品可保存至少7 d。实际样品测定结果表明方法快速、简便,适用于固定污染源排气中含氟温室气体的测定。     

从履约压力看环境监测发展方向

分析了在当前履约压力下环境监测的薄弱与不足之处,提出了拓展环境空气监测内容,将生态调查和多样性监测纳入常规体系,推进有机监测技术发展,加大多边合作与联合监测的发展思路.     

泰东河疏浚工程对通榆河水质的影响

为了解泰东河疏浚工程对通榆河水质的影响,于2012年6月8日、9月12日、12月6日,对泰东河沿线以及通榆河东台段进行调查取样,分析施工期间河体水质变化。结果表明,施工期间水质参数基本保持在Ⅱ~Ⅲ类。根据江苏省水环境监测中心盐城分中心2011年、2013年监测资料评价分析,泰东河河道疏浚后,清理了河床淤泥,提高了泰东河的行洪、抗洪以及通航能力,其水质的好转有效地改善了下游通榆河的水质,确保了饮水安全。     

Estimating the Ecological Condition of the Estuaries of the Gulf of Mexico

Monitoring of estuaries in the Louisianian Province was performed annually from 1991–1994 to assess ecological conditions on a regional scale. We found over the four years of monitoring, 25±6% of Gulf of Mexico estuarine sediments in the Louisianian Province displayed poor biological conditions, as measured by benthic community structure, and 14±7% of the area was characterized by poor water clarity, the presence of marine debris, and elevated levels of fish tissue contaminants. Using statistical associations to discern relationships between ecological condition and exposure or stressor data has shown that much of this degraded' condition co-occurs with sediment contamination.     

State of the Estuaries in the Mid-Atlantic Region of the United States

The U.S. EPA has prepared a State of the Region Report for Mid-Atlantic Estuaries to increase knowledge of environmental condition for improved environmental management. Sources of information included the National Estuary Programs, the Chesapeake Bay Program, the state monitoring programs in Delaware, Maryland, and Virginia, Federal programs such as National Status & Trends, National Shellfish Register, National Wetlands Inventory, the Environmental Monitoring and Assessment Program, and other primary literature sources. The state of the estuarine environment was summarized using indicators for water and sediment quality, habitat change, condition of living resources, and aesthetic quality. Each indicator was briefly discussed relative to its importance in understanding estuarine condition. Wherever possible, data from multiple programs were used to depict condition. Finally, an overall evaluation of estuarine condition in the region was determined. The usefulness of monitoring programs that collect consistent information with a well-defined sampling design cannot be overemphasized.     

锅炉污染物监测中运行负荷的现场判断

简述了锅炉的风量和烟气量、锅炉燃料的消耗量以及锅炉运行负荷的估算方法。通过实例分析,用现场监测的实际风量与理论值比较,粗略估算出监测时段锅炉运行负荷,比对锅炉污染物监测时段的锅炉运行负荷标准,从而判断监测数据的准确性与有效性。     

An ecosystem report on the Panama Canal: monitoring the status of the forest communities and the watershed

In 1996, the Smithsonian Tropical Research Institute and the Republic of Panama's Environmental Authority, with support fromthe United States Agency for International Development, undertook a comprehensive program to monitor the ecosystem of the Panama Canal watershed. The goals were to establish baselineindicators for the integrity of forest communities and rivers. Based on satellite image classification and ground surveys, the2790 km² watershed had 1570 km² of forest in 1997, 1080 km² of which was in national parks and nature monuments. Most of the 490 km² of forest not currently in protected areas lies along the west bank of the Canal, and its managementstatus after the year 2000 turnover of the Canal from the U.S. to Panama remains uncertain. In forest plots designed to monitorforest diversity and change, a total of 963 woody plant specieswere identified and mapped. We estimate there are a total of 850–1000 woody species in forests of the Canal corridor. Forestsof the wetter upper reaches of the watershed are distinct in species composition from the Canal corridor, and have considerably higher diversity and many unknown species. Theseremote areas are extensively forested, poorly explored, and harbor an estimated 1400–2200 woody species. Vertebrate monitoring programs were also initiated, focusing on species threatened by hunting and forest fragmentation. Large mammals are heavily hunted in most forests of Canal corridor, and therewas clear evidence that mammal density is greatly reduced in hunted areas and that this affects seed predation and dispersal. The human population of the watershed was 113 000 in 1990, and grew by nearly 4% per year from 1980 to 1990. Much of this growth was in a small region of the watershed on the outskirts of Panama City, but even rural areas, including villages near and within national parks, grew by 2% per year. There is no sewage treatment in the watershed, and many towns have no trashcollection, thus streams near large towns are heavily polluted. Analyses of sediment loads in rivers throughout the watershed did not indicate that erosion has been increasing as a result ofdeforestation, rather, erosion seems to be driven largely by total rainfall and heavy rainfall events that cause landslides.Still, models suggest that large-scale deforestation would increase landslide frequency, and failure to detect increases inerosion could be due to the gradual deforestation rate and the short time period over which data are available. A study of runoff showed deforestation increased the amount of water fromrainfall that passed directly into streams. As a result, dry season flow was reduced in a deforested catchment relative to aforested one. Currently, the Panama Canal watershed has extensive forest areasand streams relatively unaffected by humans. But impacts of hunting and pollution near towns are clear, and the burgeoningpopulation will exacerbate these impacts in the next few decades.Changes in policies regarding forest protection and pollution control are necessary.     

空气质量监测中标准状态对测定结果的影响及建议

环境空气质量标准中各种污染物的浓度限值是评价、考核空气质量状况的基本依据。为了保证在不同时空、不同环境状况下监测数据的可比性,各个国家或组织在制定的空气质量标准中对标准状态(温度和压力)进行了定义。但是,由于标准状态定义不同,即使是同一环境状况下的同一实测结果进行标化计算后的污染物浓度也不相同,达不到可比性的基本原则。因此,建议中国在未来修订空气质量标准所采用的标准状态,进一步与国际接轨。     

Monitoring the quality of the marine environment

As part of the monitoring program from Instituto Hidrográfico, since 1981 sediment and water samples have been collected from four different estuarine areas located along the continental coast of Portugal. The concentrations of different parameters were measured in the water and sediment samples. After normalization, the concentrations of chromium, mercury, lead and zinc in the sediments from the different areas were compared.