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硅胶对冷原子吸收法测汞的干扰 总被引:1,自引:0,他引:1
冷原子吸收法是测定样品中微量、痕量汞的特异方法.由于水蒸汽与汞蒸汽一样对253.7nm的紫外光有较强的选择性吸收作用,在测试中表现为正干扰,因而在汞蒸汽进入测汞仪前需去除水蒸汽.文献采用变色硅胶作为干燥剂.笔者在长期的分析测定中发现,硅胶对方法的灵敏度和检测下限影响很大,为此作了深入地探讨. 相似文献
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马生柏 《环境监测管理与技术》1999,11(5):33-34
试验了几种常用的干燥剂在冷原子吸疋地测定水中汞是,对蒸气的干燥性能及对测定灵敏度的影响。结果表明,以无水氯化钙和无水高氯酸镁效果最好。 相似文献
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氢化物发生-原子荧光光度法测定水中砷和汞的比对 总被引:1,自引:0,他引:1
通过水样中砷和汞测定的比对实验,研究了氢化物发生-原子荧光光度法测定砷和汞的优越性,并分别对方法检出限、精密度和准确度进行了测定,结果满意。 相似文献
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水样品中汞砷联合测定的研究--氢化物发生原子荧光光谱法 总被引:10,自引:0,他引:10
利用氢化物发生-原子荧光分析技术(HG-AFS)对水样品中汞、砷联合测定方法进行了有益的探索.通过一系列条件实验,设定出了合理有效的水样前处理方法、仪器测定条件以及主要试剂的浓度.并对其最低检出下限、精密度和准确度进行了评估,结果表明该方法用于环境水样品中汞、砷元素的同时测定具有很好的可行性和适用性. 相似文献
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实验部分 一、原理及方法:汞蒸气对波长253.7nm的光有选择性吸收,在一定温度范围内,吸光度与汞蒸气浓度成正比。 水样经消化后,将各种形态的汞全部转化为二价汞离子,过量的氧化剂用盐酸羟胺还原,然后用氯化亚锡将汞离子还原为单质汞。在室温下,由载气将单质汞蒸气导入吸收管,在波长253.7nm处测定其吸光度,根据吸光度与浓度关系进行定量。用已知不同浓度的Hg离子标 相似文献
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针对近年来燃煤烟气汞污染控制技术的进步,概述烟气汞分析方法,综述烟气汞在线设备及技术的发展现状。通过将电厂排放废气中汞的手工检测和在线监测结果比对,对国内外汞在线仪器进行性能评估。 相似文献
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介绍了世界上一些发达国家的空气污染预报的做法和采取的措施,阐述了我国开展空气质量预报的方针和方法,指出了周报是预报的基础工作。叙述了我国空气质量周报的污染参数的选取、污染指数的分级及其浓度限值和污染指数计算及确定,分析并总结了开展城市空气质量周报所发挥的效用是提高公众的环保意识,加大了治理污染的力度,转变了环境监测的职能,促进了环境监测事业的发展 相似文献
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锅炉烟尘测试中锅炉负荷率的计算方法探讨 总被引:1,自引:1,他引:0
GB5468 -91规定 ,锅炉烟尘测试时 ,必须对锅炉的运行负荷进行测试 ,而实际监测过程中 ,许多锅炉房不具备测试的计量条件 ,为了解决这一问题 ,文章提出利用烟气量和空气过剩系数计算锅炉负荷率。在实际监测工作中 ,该方法方便、易于操作 ,所得结果和标准规定方法所得结果有很好的一致性 相似文献
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实验室质量管理体系内部审核的实施 总被引:3,自引:0,他引:3
在实施GB/T15481-2000 idt ISO/IEC17025:1999标准《检测和校准实验室能力的通用要求》的过程中,通过实验室质量管理体系内部审核的实践与系统分析,识别出内部审核实施阶段的关键环节,提出召开首次会议、收集审核证据、确定审核发现和召开末次会议的技术方法,对提高内部审核的质量和有效性、获得可靠的审核结论具有重要意义。 相似文献
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This study assesses the efficiency of various physico-chemical, biological and other tertiary methods for treating leachate.
An evaluation study on the treatability of the leachate from methane phase bed (MPB) reactor indicated that at an optimum
hydraulic retention time of 6 days, the efficiency of the reactor in terms of biological oxygen demand (BOD) and chemical
oxygen demand (COD) removal was 91.29 and 82.69%, respectively. Recycling of the treated leachate through the municipal solid
waste layers in the leachate recycling unit (LRU) resulted in a significant increase in the biodegradation of organics present
in the leachate. Optimum BOD and COD removal efficiencies were achieved at the third recycle; additional recycling of the
leachate did not produce any significant improvement. Physico-chemical treatment of the leachate demonstrated that alum and
lime (Option 2) were more economical than coagulants lime and MgCO3. A cost analysis of the economics of the various treatments revealed that the alternative treatment consisting of a MPB bed
followed by a LRU and aerated lagoon is the most cost-effective treatment. However, the alternative consisting of a MPB followed
by the LRU and a soil column, which is slightly more costly, would be the most appropriate treatment when adequate land is
readily available. 相似文献
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Alexis Lugo-fernández Pasquale F. Roscigno 《Environmental monitoring and assessment》1999,55(2):319-346
Substantial amounts of NOx (146 000 t/y) and total hydrocarbons (294 000 t/y) are released to the marine atmosphere by the large number of oil and gas operations over Federal waters of the Gulf of Mexico (GOM). Under appropriate meteorological conditions these emissions react to form ozone (0–54 g/m3 over-water) which can affect the marine environment. Using a dry deposition model, this work examines the amount of ozone derived from oil and gas offshore operations and deposited in the sea surface of the Gulf of Mexico, and assesses its impact on the neuston of the sea-surface microlayer. Surface integrated estimates of ozone deposited from oil and gas operations over the sea surface ranges from 400 kg to 1800 kg which results in sea surface concentrations of 15 g/m3. This estimate and the actual toxic ozone levels suggest no acute, toxic impacts to the neuston. However, indirect effects may occur through changes to the pelagic foodwebs and organic carbon pathways. Another potential pathway for ozone impacting the environment is through the production of bromate. Based on the concentrations and time scales (11–139 days) only sublethal effects appear to occur, but uncertainties associated with this assessment need to be further studied. From an ecological perspective, the environmental impacts and risks of NOx and VOC discharges from offshore platforms need to be assessed for neuston and other components of the marine ecosystem. 相似文献
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实验室质量管理体系内部审核的策划 总被引:2,自引:0,他引:2
在实施GBT15481-2000(idtISOIEC17025:1999)标准《检测和校准实验室能力的通用要求》的过程中,通过实验室质量管理体系内部审核的实践与系统分析,识别出内部审核策划阶段的关键环节,提出审核范围确定、审核计划和抽样方案制订的技术方法,为有序高效地实施内部审核提供了行动指南。 相似文献
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用简单合成了二乙氨基二硫代甲酸银试剂,并比较了自制和市售的二乙氨基二硫人 银对测砷的影响。结果表明,采用自制的二乙氨基二硫代甲酸银能大大降低试剂空白,提高方法的灵敏度和降低检出限,试剂质量明显优于市售产品。 相似文献
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液氯泄漏事件的环境安全防护距离与监测布点方法 总被引:1,自引:0,他引:1
以大气湍流扩散模型为基础,结合大气环境基本资料和氯气的性质,提出了氯气泄漏突发事件的应急防护范围,为发生类似事件时的人群撤离范围和布点监测、监控范围,提出了一种思路,供大家参考. 相似文献