毛细管柱顶空气相色谱法测定水中的甲醇

讨论了毛细管柱分析水和废水中甲醇的顶空气相色谱方法,该方法的相对标准偏差为3.9%,检出限为0.8 mg/L,加标回收率95%-101%。     

顶空气相色谱法测定水源水中的三氯乙醛

主要介绍了采用顶空气相色谱法,测定水中三氯乙醛的检测方法和相应的测定条件,用该方法测定时,方法检测限为0.1μg/L,回收率在93.3%-103.3%之间,相对标准偏差为2.42%-5.42%,检测方法符合卫生部“生活饮用水卫生规范”的要求。     

毛细管柱顶空气相色谱法测定水中的丙酮

研究了利用毛细管柱顶空气相色谱法,分析水和废水中丙酮的方法。该法的相对标准偏差为7.1%,检出限为0.02 mg/L,回收率在86.9%-106%之间。     

顶空气相色谱测试水中苯系混合物在不同材料上的吸附行为

设计了正交实验对5种材料吸附模拟废水中苯系混合物(苯、甲苯、二甲苯)的条件进行优化,CD02硅藻土与X型纳米分子筛以2∶1(质量比)进行复合后,对苯系混合物去除效果最好.采用顶空气相色谱法测定8种不同材料对水中苯系混合物的去除情况,结果表明复合材料对苯系混合物具有良好的去除效果,仅次于活性炭.复合材料在pH为7、搅拌时间为25 min、用量为1.8g/L时,对苯系混合物质量浓度为4.0 mg/L模拟废水的平均去除率为87.56％.经过4次再生后,复合材料的再生率仍高达84.90％,对苯系混合物的平均去除率为91.49％.     

超声波及其联用技术降解废水中的氯苯

研究了在降解含氯苯废水的过程中，超声波分别与H2O2、O2、空气联用对氯苯降解效率的影响。结果表明，超声波分别与H2O2、O2、空气联用比单独使用超声波降解效率分别提高40、30、18个百分点。并且随H2O2用量的增加，降解效率明显升高。对于O2、空气，当气体流量小于0．3754mL／s时，降解效率随O2、空气流量的增大而明显升高。     

某焦化厂PM_(2.5)中多环芳烃的排放特征及其对周边环境影响

为了解焦化厂在装煤过程中产生的PM_(2.5)及其周边区域空气环境PM_(2.5)中多环芳烃(PAHs)的含量,采用微纤维石英滤膜对PM_(2.5)采样,并通过气相色谱-质谱仪分析PM_(2.5)上负载的16种毒性较大PAHs。结果表明:焦炉装煤除尘烟气PM_(2.5)中PAHs的成分主要受到炼焦配煤的影响;布袋除尘器对装煤除尘烟气中高环PAHs的处理效果显著;焦化厂周边空气环境中PM_(2.5)中的PAHs浓度呈明显空间递减趋势。采用特征比值法分析得到该区域空气环境中PAHs主要来源于煤炭燃烧,用毒性当量法分析得到焦化厂区域PM_(2.5)中PAHs的毒性为其他区域的9~90倍,高环PAHs的毒性贡献较大。     

氯代烃类—方法612

1.范围和应用 1.1 本方法适于某些氯代烃的测定。包括下列化合物: 1.2 本法为一气相色谱法,适于城市和工业污水上表中所列化合物的测定。使用本方法分析含上面任何或全部化合物的未知样品时,化合物的定性至少还要有另一个定性技术证实。方法625提供的色谱/质谱条件适用于用本方法萃取的上述全部化合物测定结果的定性和定量的确证。     

酚类—方法604

1.范围和应用 1.1 本法包括酚及其某些取代酚的测定,用于下列物质: 1.2 本法为一气相色谱法(GC),适用工业和城市污水中上述物质的测定。当用于分析不明样品中前述任一或全部物质时,至少需一附加的定性方法对化合物进行确证。方法中的衍、净化及ECD气相色谱分析条件可以确证FID测定的结果;使用本法得到的萃取液,方法625提供的气相色     

1989年度的Kirkpatrick化学工程成就奖

美国碳化物工业气体联合公司获得了1989年度的Kirkpatrick化学工程成就奖。这是因为该公司以氧为基础的技术提高了有毒废物的燃烧率。该项技术的原理是:使用氧气代替空气。因为空气中含有79％的氮,使用空气助燃时,其中的氮将与废物一起加热,并且氮气将减少50％的处理容量。另外,NOx的产生亦是问题。而采用氧气以高速气流喷射入燃烧     

随身自动空气净化处理器的研究

随身自动空气净化器，采用了活性炭、光催化技术相结合的空气过滤装置。空气污染传感器与单片机组成空气质量监测电路，当空气污染超标时，产生语音提示，液晶屏显示空气质量的等级，自动（或手动）控制引风机工作，供给个人清新无污染的空气。     

Development of an Odor Panel for Evaluation of Odor Control Equipment

The odor panel using the syringe dilution technique has been successfully used to judge the effectiveness of control equipment in eliminating industrial odor problems by monitoring stack emissions. Data is presented using this odor panel method for efficiency tests of direct-flame fume incinerators performed in a large variety of industrial process applications, including pulp and paper mills, rubber processing plants, food processing plants, wire enameling plants, glass fiber manufacturing plants, paint bake ovens, brake manufacturing plants, caster manufacturing plants, rendering plants, and chemical plants. Test data shows that this method of measuring odor using the syringe dilution technique is a useful and practical tool in analyzing odor problems and determining the effectiveness of control equipment by monitoring stack emissions.     

铝箔复合膜集气袋对有机废气的适用性研究

通过在不同的时间段,测定存放于铝箔复合膜集气袋和玻璃注射器的丙酮,醋酸乙酯,苯,异丙醇标准气的浓度,气体浓度与贮存时间的关系,本次试验结果表明,丙酮,醋酸乙酯,苯,异丙醇在铝箔气袋中的稳定性明显优于在玻璃注射器中,应尽可能在８－２４ｈ内测定。     

热解析-固相微萃取-气相色谱法测定空气样品中挥发性有机化合物

建立了热解析-固相微萃取-气相色谱法测定空气样品中挥发性有机化合物的分析方法，并对色谱分离条件、玻璃针筒保存样品的稳定性、固相微萃取萃取纤维、萃取时间、色谱进样时间等条件进行了优化，9种挥发性有机化合物的峰面积与其质量浓度在所测范围内有较好的线性关系，相对标准偏差＜8.8%，检出限为0.05～0.75 μg/100 mL，满足实际空气样品测定需要。     

Appraisal of Odor-Measurement Techniques

All odor measurement methods may be conveniently grouped into three categories: (1) threshold; (2) suprathreshold; and (3) analytical. The threshold techniques include such methods as syringe dilution, scentometer, and osmoscope. Suprathreshold techniques include direct comparison methods and dilution methods involving subjective ratings of preference as opposed to intensity. Analytical techniques involve the use of physicochemrcal methods, e.g., for monitoring of process streams or identification of individual odorants. The relative advantages and disadvantages of each method, as presently used, are discussed. Recommended applications for the various methods and suggested modifications are also presented.     

Further Effects of Temperature and Pressure on Photochemical Oxidant Production

A procedure is described for producing a sulfur dioxide (SO₂) contaminated atmosphere within a body plethysmograph, exposing man to this atmosphere while maintaining the SO₂ concentration at a given level, and measuring the concentration with less than a oneminute lag time. A syringe is used to introduce incremental volumes of SO₂ limiting the maximum SO₂ concentration in the chamber and assuring safety of the subject. A Titrilog SO₂ analyzer with its rapid response characteristics provides quick measurement of the SO₂ concentration. The body plethysmograph used in this manner serves simultaneously as a pulmonary function measuring device and as an exposure chamber.     

嗅觉实验配气方法的改进及影响因素研究

配制气体样品是异味测试及相关研究的基础工作，配气稳定性直接影响测试结果准确度。三点比较式臭袋法使用微量进样针量取并转移液体标准物质到3L无臭气袋的传统配气方法。对于异味阈值较小物质或样品浓度处于较低范围时，为了降低取样体积波动对配气精度和稳定性的影响。提出先将标准注入100mL玻璃注射器，充分挥发混匀后再转移部分气体到无臭气袋的两步式配气方法。结果表明，2种配气方法的准确度不存在显著差异，但两步式配气法的配气稳定性明显优于传统方法。此外，研究还发现，常见异味物质在被注人气袋后3min内便能完全挥发并混合均匀。除一些挥发性和吸附性极强的物质外，气袋内的异味物质气体浓度能在配好后20min内基本保持不变。     

Methoxyphenols from burning of Scandinavian forest plant materials

Semivolatile compounds in smoke from gram-scale incomplete burning of plant materials were assessed by gas chromatography and mass spectrometry. Gas syringe sampling was shown to be adequate by comparison with adsorbent sampling. Methoxyphenols as well as 1,6-anhydroglucose were released in amounts as large as 10 mg kg(-1) of dry biomass at 90% combustion efficiency. Wood, twigs, bark and needles from the conifers Norway spruce and Scots pine emitted 12 reported 2-methoxyphenols in similar proportions. Grass, heather and birchwood released the same 2-methoxyphenols but also the corresponding 2,6-dimethoxyphenols which are characteristic of angiosperms. The methoxyphenols are formed from lignin and differ in structure by the group in para position relative to the phenolic OH group. Prominent phenols were those with trans-1-propenyl and ethenyl groups in that position. Vanillin, 4-hydroxy-3-methoxybenzaldehyde, was a prominent carbonyl compound from the conifer materials.     

Novel use of soil moisture samplers for studies on anaerobic ammonium fluxes across lake sediment-water interfaces

Small soil suction samplers have been used for several years to sample soil solution for chemical analysis in laboratory and glasshouse experiments. They are very cheap, effective and convenient. Here we describe for the first time their use in studies on sediment porewater. Bulk sediment from West Lake, a shallow hypereutrophic lake in Hangzhou, Zhejiang Province, China, was placed in laboratory microcosms and incubated in the dark at 25 degrees C for 182 days to evaluate the feasibility of using the samplers to extract sediment porewater and to estimate NH4+ flux across the sediment-water interface under anaerobic conditions. The results show that the samplers were capable of sequentially extracting sediment porewater, 15 ml of which could be readily extracted for analysis within 30-45 min by vacuum applied using a plastic syringe. The NH4+ flux under laboratory conditions was characterized by a fast phase during the initial 18 days of incubation followed by a slower linear phase, with average release rates of 11.6 and 3.6 mg N m(-2) d(-1), respectively.     

Assessment of nitrogen losses through nitrous oxide from abattoir wastewater-irrigated soils

The land disposal of waste and wastewater is a major source of N₂O emission. This is due to the presence of high concentrations of nitrogen (N) and carbon in the waste. Abattoir wastewater contains 186 mg/L of N and 30.4 mg/L of P. The equivalent of 3 kg of abattoir wastewater-irrigated soil was sieved and taken in a 4-L plastic container. Abattoir wastewater was used for irrigating the plants at the rates of 50 and 100 % field capacity (FC). Four crop species were used with no crop serving as a control. Nitrous oxide emission was monitored using a closed chamber technique. The chamber was placed inside the plastic container, and N₂O emission was measured for 7 days after the planting. A syringe and pre-evacuated vial were used for collecting the gas samples; a fresh and clean syringe was used each time to avoid cross-contamination. The collected gas samples were injected into a gas chromatography device immediately after each sampling to analyse the concentration of N₂O from different treatments. The overall N₂O emission was compared for all the crops under two different abattoir wastewater treatment rates (50 and 100 % FC). Under 100 % FC (wastewater irrigation), among the four species grown in the abattoir wastewater-irrigated soil, Medicago sativa (23 mg/pot), Sinapis alba (21 mg/pot), Zea mays (20 mg/pot) and Helianthus annuus (20 mg/pot) showed higher N₂O emission compared to the 50 % treatments—M. sativa (17 mg/pot), S. alba (17 mg/pot), Z. mays (18 mg/pot) and H. annuus (18 mg/pot). Similarly, pots with plants have shown 15 % less emission than the pots without plants. Similar trends of N₂O emission flux were observed between the irrigation period (4-week period) for 50 % FC and 100 % FC. Under the 100 % FC loading rate treatments, the highest N₂O emission was in the following order: week 1 > week 4 > week 3 > week 2. On the other hand, under the 50 % FC loading rate treatments, the highest N₂O emission was recorded in the first few weeks and in the following order: week 1 > week 2 > week 3 > week > 4. Since N₂O is a greenhouse gas with high global warming potential, its emission from wastewater irrigation is likely to impact global climate change. Therefore, it is important to examine the effects of abattoir wastewater irrigation on soil for N₂O emission potential.