冷原子吸收法测汞用于燥剂

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。     

烟气汞在线监测现状及仪器性能评估初探

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。     

南京某燃煤电厂汞的排放特点及分布特征

选择南京某燃煤电厂330 MW机组，对煤、炉渣、粉煤灰、烟尘、石灰石、石膏和烟气中的汞取样测量，探讨煤中汞在燃烧过程中的变化情况，并进一步分析汞的排放特点及分布特征。指出，煤经燃煤锅炉炉内高温燃烧后，炉渣中的汞对环境影响不明显；粉煤灰、烟尘中的汞存在富集现象，且随着粒径变细，富集程度加剧；燃煤锅炉燃烧后，随石膏排放的汞占比较大，应采取相应的防治措施。     

微分法测定天然水中的汞

在硝酸－重铬酸钾介质中，二价汞被氯化亚锡还原成金属汞，汞原子蒸气对２５３．７ｎｍ的紫外光具有选择性吸收作用，对该吸收光谱进行一介微分处理，汞微气浓度与微分光谱的峰值在一定浓度范围内成正比，据此可测定水和废水中汞的浓度。     

固定污染源烟气中汞排放连续监测系统

介绍了中美两国法规对汞排放连续监测的要求，分析了烟气中汞排放连续监测的技术难点，指出现有的汞在线监测只能得到气态总汞的浓度。阐述了冷蒸气原子吸收光谱法、塞曼调制原子吸收光谱法、冷蒸气原子荧光法、原子发射光谱法、紫外差分吸收光谱法等气态元素汞的不同分析方法。通过对湿化学法与热转化单元的比较，得出热转化技术更加适合烟气汞的在线监测。分析了造成汞测量误差的相关因素，并提出了减少误差的措施。     

Hg-CEMS系统中元素汞发生器的溯源和质控方法研究

参考借鉴美国IEMGTP元素汞溯源协议中规定的4个溯源传递层级以及4种常用的成熟溯源质控方法，研究了在中国现有技术条件下，各种质控方法针对Hg-CEMS中元素汞发生器User generator进行质控的适用性。通过对不同质控方法的测试，显示通过可吸附元素汞的活性炭吸附管采样分析（美国EPA 30B方法）和通过汞渗透源两种对元素汞发生器进行质控的方法在中国目前是可行且科学、可靠的。同时对建立和完善中国的元素汞溯源协议和元素汞发生器质控方法提出了建议。     

南京燃煤电厂烟气中汞的排放调查

对南京市8家国控污染源13台（套）燃煤锅炉进行监测，结果表明，燃煤电厂烟气中汞主要以气相部分汞形态存在，其排放值均达标，为0．16～15．9μg／m3，均远低于标准限值；煤质中汞含量与电厂烟气中汞浓度变化曲线的趋势是大致相似，相关系数为0．91；燃煤电厂机组容量、发电负荷越大，汞平均排放因子呈变小趋势；静电除尘器、湿法脱硫和选择性催化还原法的净化配置对汞的脱除效率最高，达到95．4％。     

燃煤电厂煤中汞含量对烟气中汞排放水平的影响

对江苏省9家燃煤电厂入炉煤中ω（汞）及烟气中ρ（汞）进行了测试，结果表明，9家燃煤电厂入炉煤中ω（汞）为54．5～297 ng／g，平均值为139 ng／g，低于我国煤中ω（汞）的平均值（220 ng／g）。燃煤电厂排放烟气中ρ（汞）为0．08～16．97μg／m^3，远低于《火电厂大气污染物排放标准》（GB 13223－2011）汞及其化合物标准限值（30μg／m^3）。通过对燃煤电厂入炉煤中ω（汞）与最终排放的烟气中ρ（汞）进行分析，两者之间有一定的相关性。     

两次金汞齐—冷原子吸收光谱法测定大气中的痕量气态总汞

本文作者在已有仪器的基础上进行简单改装，建立了两次金汞齐—冷原子吸收光谱法测定大气中的微量气态总汞的方法。研究表明，这种方法最低检出限为０．０５ｎｇ；１００μｌ饱和汞蒸气连续测定结果表明其相对标准偏差＜１．４１％。在０～２．０ｎｇ汞量范围内标准工作曲线线性关系良好。运用该法，对贵州省万山汞矿、丹寨汞矿、清镇汞污染农田、省农科院和中国科学院地球化学研究所等地大气气态总汞进行了测定。这种分析方法还可以运用到其它环境样品微量汞的测定。     

直接测汞法和原子荧光法测定土壤中总汞的比对研究

采用DMA-80直接测汞技术，与国标方法原子荧光法对土壤中总汞的测定进行了方法比对研究。试验结果表明，直接测汞法的检出限优于原子荧光法，精密度和准确性能够满足土壤实际样品的测定，对30个实际样品分析结果的比对表明，方法间无显著差异，该方法快速、准确、无污染。     

氨法脱硫废气中烟尘测试方法的实验研究

利用重量法测试原理,将氨法脱硫外排废气中烟尘监测滤筒用二次水经过超声波洗涤后过滤,在烘箱内于105℃烘干2 h后称量恒重,除去滤简中的硫酸铵成分,从而准确获得烟尘的含量.     

利用主动土壤干燥-微波消解技术和原子荧光分光光度法分析土壤中砷的研究

研究利用主动土壤干燥技术,配合微波消解、原子荧光分光光度法,在短时间内完成大量不同用途土壤,如湿地、山林、农田耕地、沙石地等样品中砷的测定。采集的新鲜土壤样品经初筛,过滤、筛分等处理后,利用主动烘干技术,模拟自然干燥状态,可以快速烘干不同含水量的大量样品。该方法避免了因自然风干产生的实验室间的交叉污染,可以短时间处理大量样品;利用微波消解法进行前处理,再利用原子荧光分光光度法进行样品测定。该研究对52个土壤样品中的砷进行了测定,砷含量在2.70~27.3mg/kg。方法的最低方法检出限可以达0.001mg/kg。     

On-site Comparison of Canister and Solid-Sorbent Trap Collection of Highly Volatile Hydrocarbons in Ambient Atmospheres

A field experiment for the comparison of the efficiency of canisters and adsorption multibed tubes for sampling atmospheric highly volatile hydrocarbons at ppbv levels is described. The canister was passivated by the Summa process and the adsorption tubes were filled with Carbotrap C, Carbotrap B and Carbosieve S-III. The sampling with the adsorption tubes was performed at ambient temperature and at -10°C. The highest concentrations were generally obtained with canisters but these results are very similar to those obtained with refrigerated multibed adsorption tubes. Both methods appear to be equivalent for most of the highly volatile hydrocarbons encountered in moderately polluted urban areas. In contrast, sampling with ambient temperature tubes provides lower concentrations. This study has also shown that K2CO3 drying efficiently removes humidity from air samples allowing the obtention of reliable concentration data on highly volatile hydrocarbons at ppbv levels. These drying tubes can easily be re-conditioned and tested for blanks and memory effects, which greatly facilitates the control of external contamination and sample cross-contamination.     

运行方式对人工快渗系统水质净化效果的影响

以天然砂作为主要渗滤介质,建立污水处理人工快速渗滤系统(CRI).分别以洗浴污水、生活污水和受污染河水作为研究对象,在相同的水力负荷条件下,用两种不同的运行方式(定期投配一定量的污水、淹水和落干交替运行)对不同水质的污染物去除效果进行了对比研究.结果表明,通过缩短淹水周期,加大系统淹水和落干的频率,可以明显改善CRI系统的污染物去除效果.     

An evaluation of benthic macroinvertebrate biomass methodology

Evaluation of analytical methods employed for wet weight (live or preserved samples) of benthic macroinvertebrates reveals that centrifugation at 140 x gravity for one minute yields constant biomass estimates. Less relative centrifugal force increases chance of incomplete removal of body moisture and results in weighing error, while greater force may rupture fragile macroinvertebrates, such as mayflies. Duration of specimen exposure in ethanol, formalin, and formol (formaling-ethanol combinations) causes significant body weight loss with within 48 hr formalin and formol cause less body weight loss than ethanol. However, as all preservatives tested cause body weight loss, preservation time of samples collected for comparative purposes should be treated uniformly. Dry weight estimates of macroinvertebrates are not significantly affected by kind of preservative or duration of exposure. Constant dry weights are attained by oven drying at 103 °C at a minimum of four hours or vacuum oven drying (15 inches of mercury pressure) at 103 °C for a minimum of one hour. Although requiring more time in preparation than oven drying and inalterably changing specimen body shape, freeze drying (10 microns pressure, -55 °C, 24 hr) provides constant dry weights and is advantageous for long term sample storage by minimizing curatorial attention. Constant ash-free dry weights of macroinvertebrate samples are attained by igniting samples at 500–550 °C for a minimum of one hour with slow cooling to room temperature in desiccators before weighing.     

Modelling Energy Dissipation Due to Soil-Moisture Hysteresis

Cyclic wetting and drying of soils due to changing weather conditions is characterised by a well-documented hysteresis in the relationship between the pressure or matric potential and the water content in the soil. Hysteresis manifests itself through a difference in drying and wetting curves. Its presence suggests that there is dissipation of energy associated with intermittent wetting and drying of the soil, which can be released in the form of heat. In this paper, we discuss a model for evaluation of the energy dissipation rate due to soil-moisture hysteresis. The model has three main ingredients: (a) a hysteresis constitutive relationship between soil-water potential and moisture content in the soil, which is modelled by the Preisach operator; (b) a lumped form of Darcy’s law assuming that the water flux is proportional to the difference of potentials in the soil and on its surface; (c) a rainfall term governing the evolution of the outer potential, which is modelled by a periodic forcing or a Poisson process. We propose a combination of analytic and numerical methods to evaluate the energy dissipation rate and how it is affected by the variation of rain parameters, such as the frequency of arrivals of rain cells and their shape, intensity and duration.     

Priority PAHs in orthodox black tea during manufacturing process

Orthodox black tea is obtained from fresh leaves followed by withering, rolling, fermentation and drying. The presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) was studied in fresh leaves and at various stages of manufacturing. Benzo(a)pyrene (2A: probable human carcinogen) was found in dried tea leaves only whereas, naphthalene (2B: probable human carcinogen) was present during all the stages of manufacturing. Dry tea leaves showed higher content of total 16 PAHs (∑PAHs) about 3 and 211 times than present in withered and dried leaves, respectively. Chrysene, benzo[g,h,i]perylene, indendo[1,2,3-c,d]pyrene, dibenzo[a,h]pyrene and benzo[a]antracene were not found during manufacturing stages of tea.     

烟尘监测时采样滤筒的质量控制

介绍了合格滤筒的筛选方法和采样滤筒在实验室分析中的质量控制,分析了影响滤筒称量恒重的原因,指出空气湿度、冷却时间和烘干时间对滤筒称量恒重都有影响.     

微波技术在环境试样处理中的应用

综述了微波技术在样品消解、干燥以及溶剂萃取和解吸、生色反应、形态分析、微波雾化等方面的应用。比较了微波技术优于传统预处理技术之处。经分析认为该技术具有广阔的推广和应用前景。