首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 984 毫秒
1.
The configuration of the California Acid Deposition Monitoring Program (CADMP) precipitation network is described and quality assurance results summarized. Comparison of CADMP and the National Acid Deposition Program/National Trends Network (NADP/NTN) data at four parallel sites indicated that mean depth-weighted differences were less than 3 μeq ℓ−1 for all ions, being statistically significant for ammonium, sulfate and hydrogen ion. These apparently small differences were 15–30% of the mean concentrations of ammonium, sulfate and hydrogen ion. Mean depth-weighted concentrations and mass deposition rates for the period 1985–1990 are summarized; the latter were highest either where concentrations or precipitation depths were relatively high.  相似文献   

2.
大型盛事空气质量保障工作初探研究   总被引:2,自引:0,他引:2  
随着经济社会的迅速发展,中国举办的大型盛事越来越多,但同时由于近年来环境空气质量问题日渐突出,大型盛事的空气质量保障工作越来越重要。近些年来,全国各地在大型盛事空气质量保障工作上积累了许多宝贵经验,尤其是大连市在十二运期间环境空气质量保障工作上开创许多先进做法,为大型盛事空气质量保障工作做出了突出贡献。以大连市十二运空气质量保障工作为例,介绍了大连市的典型做法及空气质量保障工作成效,初步探索了中国大型盛事空气质量保障工作机制。  相似文献   

3.
针对如何做好工业企业厂界噪声监测质量保证工作问题,文中介绍了如何做好监测前的质量保证工作,包括监测人员的保证作用、监测方法的保证作用、噪声监测仪的保证作用、噪声校准仪的保证作用,探讨了对现场监测质量测定的影响因素,主要包括对气象要求、测量工况、监测情况调查、测点位置、测量时间、背景噪声值扣除、人为噪声的排除和测量记录对监测质量的影响,并对监测数据进行了处理及分析,这有益于做好工业企业厂界噪声监测质量保证工作。  相似文献   

4.
This paper presents a framework for data quality assessment of annual and seasonal precipitation chemistry data summaries. Consideration has been to (i) using data from regional or national networks with established quality assurance/quality control programs and well documented network operation protocols, (ii) assessing regional representativeness of each sites, (iii) determining quantitative measures to define data completeness levels, and (iv) documenting the calculation procedures used to compute precipitation-weighted mean concentrations and wet deposition amount. The procedures described here are applied to data collected from 1980 to 1986 by five major acid deposition monitoring networks in North America and examples of annual sulfate deposition summaries are reported. It is recommended that the concepts of site representativeness, data completeness and overall data quality levels be adopted by the user community and routinely be reported along with a data summary. Further work on assesing accuracy and precision to accompany the data quality levels is recommended.  相似文献   

5.
自动在线监测设备对排放的污染物进行实时监测,获取真实有效的监测数据。研究自动在线监测设备监测数据质量保证系统是污染源自动在线监控系统科学判断和分析环境问题的前提。软件系统是数据采集、记录和存储、传输、统计分析、自我识别、形成报表和报告的集成,也是监测数据质量保证的有效手段,通过设定“阈值”和“条件”.实现了监测数的自动甄别、纠错和报警。  相似文献   

6.
浅谈水体中硫化物保存、分离和测定方法的选择   总被引:2,自引:0,他引:2  
水体中的硫化物是环境监测和工厂验收监测的一个重要参数.由于水中硫化物的不稳定性和水体中的干扰物质较多,保存常用技术为醋酸锌-氢氧化钠保存技术,但由于测定的手段不同,可根据不同的测定方法选用不同的保存和分离技术.比色法和碘量法时选用锌盐保存技术,分离技术有吹气分离、负压抽气分离或酸性溶液加锌产生氢气分离,选用不同的吸收液后测量;用间接测定技术时,可选用不同的金属盐进行沉淀后测定金属离子;选用电化学方法测定时,可选用使用于电化学的保存技术.为了准确地测定水体中的硫化物,宜选择最好的保存技术、分离技术和测定方法,并且必须使保存技术和测定方法相匹配,获得完善的监测技术和准确的监测结果.  相似文献   

7.
中国降水酸度和离子浓度的时空分布   总被引:136,自引:7,他引:129  
1991~1995年在全国进行了酸雨观测,建立了覆盖全国的具有区域代表性的酸沉降监测网,含271个测站?降水的pH值和电导率在现场采样后立即测量,降水样品的化学分析则在实验室里进行?主要离子SO2-4,NO-3,NH+4,Ca2+浓度的加权均值分别为125.86,19.96,67.89和80.41μeq/L?由离子浓度地理分布图看出,这些离子浓度地理分布状况因离子而异?值得注意的是降水中SO2-4和NO-3浓度,北方非酸雨区甚高于南方酸雨区,这说明降水的酸度并不简单地决定于降水中SO2-4和NO-3的绝对浓度,而决定于这些离子对于Ca2+和NH+4的相对浓度?发现了降水年均pH值低至4的一些地区,此值可能是目前世界年降水酸性最强的地区?文中还对代表性地区1986~1993年降水化学特征进行了分析,结果表明降水的酸度仍在升高?   相似文献   

8.
Rainfall samples were collected from three observation sites in Guilin from 2013 to 2017, and the chemical composition characteristics of precipitation and the contribution made by different ion sources were analyzed when atmospheric pollutants levels were reduced. The results showed that acid gas emissions and atmospheric pollutant concentrations continued to decline during the study period. However, the change in the volume-weighted mean pH at the three sites suggested that acid rain pollution was not alleviated and began to deteriorate after 2015. The continuing downward trend for alkaline neutralizing ions (Ca2+, NH4+) in precipitation indicated that the reduction in alkaline neutralizing substances in the atmosphere was an important factor that led to the deterioration in acid rain across Guilin. The principal component analysis and spearman correlation analysis indicated five sources of ions in precipitation. Quantitative assessment of these five sources indicated that fossil fuel combustion contributed the most ions concentration in precipitation at the three sites, followed by agriculture, terrestrial (crustal) sources, marine sources, and biomass burning. Long-distance airflow might affect the acidity, the electrical conductivity (EC), and ion concentrations in precipitation across Guilin. The airflow trajectory from the west and southeast directions corresponded to higher acidity and ion concentrations. According to the current air pollution control strategy planned by Guilin, reducing atmospheric coarse particles and NH3 at the same time may potentially lead to further deteriorations in acid rain contents. Therefore, Guilin needs to develop more reasonable pollution prevention measures that synergistically control atmospheric pollutants and acid rain pollution.  相似文献   

9.
环境监测的质量保证是监测数据准确性、可比性的重要保障.在区域大气联合观测项目中,完善的质量保证体系应包括管理机制和技术措施两部分,但目前我国对这类项目质量保证尚无统一标准.针对大气重污染成因与治理攻关项目(简称"大气攻关项目")外场观测任务量大、承担单位多、监测项目复杂的特点,为保证观测数据的质量,避免出现由于监测和质控方法不统一造成的数据可比性差、结果矛盾的问题,提出了大气攻关项目质量保证体系和管理机制.其中,质量保证体系包括制定总体要求(技术文件、监测项目及质控要求)、外场观测质量保证(内部质量管理体系、项目外场观测质量保证体系)、实验室分析质量保证(实验室遴选、项目实验室分析多级质量保证体系、实验室比对和飞行检查)和数据质量控制(数据线上审核、项目实验室分析质控报告、项目数据质量评价)4个方面.管理机制为项目管理办公室、质控实验室和承担单位三级主体,两级监督的分级管理模式.通过项目实践,项目质量保证体系达到了保证观测数据准确性、可比性的预期效果,为揭示区域雾霾形成机理、突破污染控制关键技术提供了有力的技术支持,同时为区域大气联合观测项目的数据质量保证提供了借鉴.   相似文献   

10.
大气降水中的离子含量,能够较全面地表征大气质量状况,对环境评价也是重要方面,同时对环境管理也有重要意义。降水基体复杂,降水离子检测方法也较多,离子色谱仪能在降水复杂环境中快速检测出多种阴、阳离子;具有快速、准确、操作性良好的特点。通过具体试验操作过程,分析试验过程及数据结果讨论,可以验证离子色谱在降水离子检测方面的快速、准确。并同时列出了在实际操作过程中遇到的各种问题与情况,同时给出解决问题所需注意事项和经验方法,供一线化验分析人员参考。  相似文献   

11.
对硫酸钡重量法与仪器分析相结合测定溶液中钡含量的不确定度评定,给出了评定步骤。确定了不确定度来源为测量重复性、样品质量、沉淀质量、滤液和洗涤液中Ba2+量、机械损失Ba2+量、沉淀包夹BaCl2量和Na2SO4量、钡和硫酸钡的摩尔质量。采用统计方法得到了A类不确定度量值;利用所获得各种信息,对B类不确定度各个不确定度分量,逐个进行量化。从而获得合成标准不确定度和扩展不确定度。  相似文献   

12.
大连市酸雨污染特征及原因简析   总被引:1,自引:0,他引:1  
2008年大连市酸雨频率为36.9%,酸雨污染以硫酸型污染为主,但硝酸盐对酸雨的贡献相对较高,降水中对酸雨主要起中和作用的离子为钙离子及铵根离子。2003年-2008年来大连市降水酸度和酸雨频率呈逐年上升趋势,从各季节变化看,最高酸雨频率主要发生在夏季,降水中(Ca2^+NH4^+)/(SO4^-2+NO3^-)呈下降趋势,从而说明虽然大连市局地的二氧化硫和氮氧化物污染对降水酸度产生一定影响,但相比而言,空气中碱性颗粒物的减少.对大连市酸雨频率的升高影响更大;大连市酸雨污染受外来源的远距离输送影响的比例很大。  相似文献   

13.
We explored the seasonal characteristics in wet deposition chemistry for two sites located at different elevations along the east slope of the Colorado Front Range in Rocky Mountain National Park. Seasonally separated precipitation was stratified into highly concentrated (high salt), dilute (low salt), or acid-dominated precipitation groups. These groups and unstratified precipitation data were related to mean easterly or westerly zonal winds to determine direction of local transport. Strong acid anion associations were also determined for the stratified and unstratified precipitation data sets. We found that strong acid anions, acidity, ammonium, and high salt concentrations originate to the east of Rocky Mountain National Park, and are transported via up-valley funneling winds or convective instability from differential heating of the mountains and the plains to the east. These influence the composition of precipitation at Beaver Meadows, the low elevation site, throughout the year, while their effect on precipitation at Loch Vale, the high elevation site, is felt most strongly during the summer. During the winter, Loch Vale precipitation is very dilute, and occurs in conjunction with westerly winds resulting from the southerly location of the jet stream.  相似文献   

14.
应用MAGIC模型分析长江支流沱江主要离子含量的变化趋势   总被引:8,自引:2,他引:8  
应用改进的集水区地下水酸化模型(MAGIC)对四川境内长江支流沱江的主要离子含量变化趋势进行模拟.在只考虑酸沉降和土壤化学过程的情况下,模型模拟结果与沱江李家湾站1972—1990年测定的主要离子含量的变化趋势吻合,初步认为酸沉降是导致沱江主要离子含量变化的主要原因.  相似文献   

15.
To study the characteristics of precipitation in eastern China, an automatic sampler was used to collect rainwater samples from 19 precipitation events at Mangdang Mountain, Nanping City, Fujiang Province, in the spring of 2009. We used ion chromatography to analyze the ionic components and concentrations, and inductively coupled plasma mass spectrometry (ICP-MS) to analyze element compositions and contents. The results demonstrated remarkable acidic characteristics: in more than 80% of precipitation events the pH was less than 5.6, with an average of 4.81. Mass concentration results showed SO4 2?? was the main anionic component (36.2% of the total anion mass), while NH4 + was the main cationic component (47.7% of the total cation mass) and main ion for acidity neutralization in the rainwater. Organic acid content accounted for 30.9% of total anion mass. The main trace metals were Ca, K, and Na. The SO4 2??/NO3?? ratio was 1.4, indicating that precipitation in this region was influenced by complex air pollution – the product of individual coal-burning combined with vehicle exhaust pollution. Correlation analysis of the chemical composition of the precipitation indicated that acidity in this region was determined by a combination of all acidic and neutralization ions rather than any single ion component. The results also showed that Na+ and Cl?? contributions were mainly by seawater; Mg2+ by seawater and crustal materials; the NH4 +, K+, Ca2+, NO3?? and SO4 2?? by anthropogenic sources; the trace metals were from the Earth’s crust; and organic acids were potentially from combustion of biomass.  相似文献   

16.
通过对重庆市黔江区"十二五"期间320个降水样品的pH值和化学组成成分等特征进行了研究,结果表明,五年间黔江区降水pH范围为4.71~7.81,电导率范围为21.8~42.5 μS/cm-1,平均值33.4 μS/cm-1.降水pH和电导率的Spearman秩相关系数法检验表明,pH的rs为正值,电导率的rs为负值,五年期间大气降水中总离子当量浓度有所下降,降水酸雨环境得到有效控制.SO2-4是降水中主要阴离子,占阴离子总量的74.3%,Ca2+是降水中主要阳离子,占阳离子总量的31.4%.黔江区酸雨为硫酸型或燃煤型酸雨,SO2-4/NO-3浓度比均值为7.13,SO2-4/NO-3比值在2013年达最大值,之后呈现减小趋势,黔江区汽车尾气和工业排放的NOx对降水的影响在变大.在99.0%的置信水平下,降水离子浓度总和与电导率线性相关显著.相关性研究表明:降水中SO2-4、NH+4、Ca2+、Mg2+、F-主要来自煤燃烧.Mg2+、Na+与Cl-即来源于地壳源又来自于海洋远源传输,人类活动对黔江区降水影响较大.  相似文献   

17.
环境水质监测的质量保证   总被引:1,自引:0,他引:1  
介绍了水质监测采样质量控制,环境监测实验室条件和实验室的质量保证与质量控制,并以实验室内分析COD样品为例,进一步阐述了环境水质监测中COD的控制方法,从而论证了环境水质监测质量保证和质量控制。  相似文献   

18.
餐饮污水处理为中水的试验研究   总被引:2,自引:0,他引:2  
根据餐饮污水的水质特点 ,选择了污水除油沉淀调节预处理、SBR生化处理和混凝过滤消毒的处理工艺。实验结果显示 ,污水的COD、BOD5及SS去除率均达到 90 %以上 ,出水水质达到中水主要水质标准。该实验为餐饮污水的中水回用提供了重要的技术参数。  相似文献   

19.
为探究珠海市降水及湿沉降的长期变化趋势,基于东亚酸沉降监测网(EANET)的湿沉降监测数据,针对2008—2018年珠海市大气降水量、降水电导率、pH、水溶性离子浓度与湿沉降量进行了降水酸化、降水组分及湿沉降分析.结果表明:①珠海市1—12月降水pH均低于5.6,强酸雨及特强酸雨频率较高,降水酸化问题普遍;2008—2018年pH由4.9增至5.2,总体呈改善趋势;降水电导率小于3 mS/m的月份占61.68%.②珠海市降水中Cl-浓度和Na+浓度较高,二者的区域性特征表明海洋源和人为源共同影响珠海市降水;SO42-/NO3-(浓度比)总体呈逐年递减趋势,降水类型为硫酸-硝酸混合型;较低的ΔpH(酸中和能力评估参数)说明缺乏中和能力可能是珠海降水酸化问题严重的主要原因.③珠海市湿沉降量范围为71.98~200.77 kg/(hm2·a),其中SO42-湿沉降量最高;2008—2018年DIN-N(可溶性无机氮湿沉降量)在11 kg/(hm2·a)上下波动,而SO42--S(硫湿沉降量)降幅接近40%;大气氮、硫湿沉降量在春季达到最高.四季NH4+-N/NO3--N(铵态氮湿沉降量与硝态氮湿沉降量的比值)均大于1,说明珠海市活性氮主要来源于农业活动.研究显示,珠海市大气降水酸化问题普遍但总体呈改善趋势,严重的降水酸化问题与缺乏中和能力存在一定关系.   相似文献   

20.
重庆市大气降水污染及其沉降特征   总被引:1,自引:0,他引:1  
基于东亚酸沉降监测网(EANET)的湿沉降观测数据,针对2002~2016年重庆市的降水电导率、pH值和降水中水溶性离子浓度与沉降量进行了研究.结果表明,重庆市郊区站点的降水酸化问题较严重,而城市站点降水污染较严重.降水中水溶性离子平均浓度在城市和郊区站点分别达到627.00 μeq/L和480.14 μeq/L,其中城市站SO42-、NH4+和Ca2+的平均浓度为郊区站的1.21~1.47倍.由SO42-与NO3-占比说明重庆市的降水类型由硫酸型向硫酸-硝酸混合型转变.城市站的主要离子沉降量较高,约为郊区站点的1.14倍.降水中的无机氮平均沉降量在17.59~47.31kg/(hm2·a)范围内浮动,并且主要以NH4+-N为主,其平均沉降量为NO3--N的2倍左右,说明重庆市大气氨/铵污染比较严重.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号