梯度洗脱离子色谱法测定宁波地区降水中的6种阴离子

建立了梯度洗脱离子色谱法同时测定降水样品中的氟离子、乙酸、甲酸、氯离子、硝酸根和硫酸根等6种有机酸和无机酸阴离子的测定方法。利用ICS-3000型离子色谱仪配备的氢氧化钾淋洗液发生器,产生梯度氢氧化钾溶液,结果显示在18min内很好地完成了6种离子的同时分离测定。该方法的回收率在90%～105%之间,测试的相对标准偏差小于3.6%。此方法操作简便、准确、实用,是南方地区降水样品较理想的阴离子检测方法。     

甲醇燃料车尾气净化催化剂的研究(Ⅱ)──多组分催化剂对甲醇的深度氧化

利用色谱－微反联用技术研究多种多元催化剂对甲醇深度氧化的活性,并借助于ＸＲＤＢＥＴ等手段考察焙 烧温度对活性的影响,结果表明,不同的催化剂对甲醇氧化时均有甲醛及甲酸甲酯伴生,其伴生温度区间及最大伴生浓度随不同催化剂而变化;３２－３７号催化剂的活性明显高于双组分催化剂,添加少量稀土金属氧化物ＣｅＯ２和贵金属Ｐｄ对活性均有一定的改善作用,提高焙烧温度,催化剂表面发生烧结,对活性有不良影响。     

甲酰吗啉生产过程中的危险因素与安全措施探讨

吗啉酰化合成甲酰吗啉(NFM)过程存在诸多安全与环保的危险、有害因素。实验室小试、中试和工业试生产研究表明:正确选择反应工艺路线是首要条件。较可取的是以甲酸为酰化剂,吗啉酰化初期强放热反应,该类反应安全操作条件是安全生产的关键。选择适宜的传热介质及时移出反应热,适当加入带水剂,采用滴加的加料方式可减缓放热速度是控制反应温度的关键。先进和规范的安全管理制度,是防止事故的保证。     

催化还原脱除地下水中硝酸盐的研究

采用浸渍法制备催化剂Pd-Cu/γ-Al2O3,用BET、ICP、XRD、TEM和EDX对该催化剂进行了表征.以甲酸钠作为还原剂,对催化还原硝酸盐进行了试验研究.结果表明,100 mg·L-1硝酸盐完全反应时总氮的脱除率可以达到87%.催化反应的活性和选择性受pH值、催化剂投加量、甲酸钠浓度和硝酸盐初始浓度等反应条件影响.甲酸钠作为还原剂时只需控制溶液初始pH值,初始pH值过高或过低都会降低催化剂活性;控制初始pH值为4.5,适当降低催化剂投加量和增加甲酸钠的浓度有利于提高催化活性,但选择性会显著降低.初始pH值为4.5时,不同初始浓度硝酸盐的催化还原反应为一级反应.     

离子色谱法测定空气中的甲酸和氯化氢含量

阐述了离子色谱法测定空气和环境样品中甲酸、氯化氢含量的方法与步骤。测定结果显示,甲酸和氯化氢的检测限分别为0.01mg/L、0.02mg/L,方法的回收率为98%～101%、98%～102%,相对标准误差为1.9%、1.6%,线性范围为0.00～10mg/L、0.00～16mg/L,是一种简单、快速、可靠测定降水、空气、废气、地表水、地下水中甲酸和氯化氢的好方法。     

环境可接受的甲酸盐钻井完井液性能探讨

随着环境保护的要求日益严格,一种新型的钻井完井液 ── 环境可接受的甲酸盐钻井完井液,正在国外现场试验和推广应用,目前已引起国内有关研究人员和技术人员的高度重视。分析了甲酸盐钻井完井液的工艺性能,并着重对甲酸盐钻井完井液在环境保护方面的优越性能进行了探讨。     

Effect of calcium formate as an additive on desulfurization in power plants

SO_2 in flue gas needs to be eliminated to alleviate air pollution. As the quality of coal decreases and environmental standard requirements become more stringent, the highefficiency desulfurization of flue gas faces more and more challenges. As an economical and environmentally friendly solution, the effect of calcium formate as an additive on desulfurization efficiency in the wet flue gas desulfurization(WFGD) process was studied for the first time. Improvement of the desulfurization efficiency was achieved with limited change in p H after calcium formate was added into the reactor, and it was found to work better than other additives tested. The positive effects were further verified in a power plant, which showed that adding calcium formate could promote the dissolution of calcium carbonate, accelerate the growth of gypsum crystals and improve the efficiency of desulfurization. Thus, calcium formate was proved to be an effective additive and can potentially be used to reduce the amount of limestone slurry required, as well as the energy consumption and operating costs in industrial desulfurization.     

Degradation of tert-butyl formate and its intermediates by an ozone/UV process

In this paper, the oxidation of tert-butyl formate (TBF) in aqueous solution by an ozone/UV process was described. The oxidation process was investigated experimentally in a semibatch reactor. The results of the study indicated that the ozone/UV process was very effective in oxidizing TBF. tert-Butyl alcohol (TBA), hydroxy-iso-butyraldehyde (HiBA), acetone, formaldehyde, and formic acid were identified as major primary intermediates during the oxidation of TBF. About 90% organic carbon balance was obtained indicating that most reaction intermediates have been identified and quantified. Some of the primary intermediates were also oxidized in the ozone/UV system. Accordingly, HiBA, acetone, formaldehyde, and formic acid were the primary intermediates of TBA oxidation. The oxidation of acetone in the ozone/UV system generated formaldehyde, pyruvaldehyde, acetic acid, formic acid as primary intermediates. It was also observed that the reaction intermediates formed during the oxidation of TBF react well in the ozone/UV system and complete mineralization could be achieved by the process.     

Biotic and abiotic transformations of methyl tertiary butyl ether (MTBE)

Background Methyl tertiary butyl ether (MTBE) is a fuel additive which is used all over the world. In recent years it has often been found in groundwater, mainly in the USA, but also in Europe. Although MTBE seems to be a minor toxic, it affects the taste and odour of water at concentrations of < 30 μg/L. Although MTBE is often a recalcitrant compound, it is known that many ethers can be degraded by abiotic means. The aim of this study was to examine biotic and abiotic transformations of MTBE with respect to the particular conditions of a contaminated site (former refinery) in Leuna, Germany. Methods Groundwater samples from wells of a contaminated site were used for aerobic and anaerobic degradation experiments. The abiotic degradation experiment (hydrolysis) was conducted employing an ion-exchange resin and MTBE solutions in distilled water. MTBE, tertiary butyl formate (TBF) and tertiary butyl alcohol (TBA) were measured by a gas chromatograph with flame ionisation detector (FID). Aldehydes and organic acids were respectively analysed by a gas chromatograph with electron capture detector (ECD) and high-performance ion chromatography (HPIC). Results and Discussion Under aerobic conditions, MTBE was degraded in laboratory experiments. Only 4 of a total of 30 anaerobic experiments exhibited degradation, and the process was very slow. In no cases were metabolites detected, but a few degradation products (TBF, TBA and formic acid) were found on the site, possibly due to the lower temperatures in groundwater. The abiotic degradation of MTBE with an ion-exchange resin as a catalyst at pH 3.5 was much faster than hydrolysis in diluted hydrochloric acid (pH 1.0). Conclusion Although the aerobic degradation of MTBE in the environment seems to be possible, the specific conditions responsible are widely unknown. Successful aerobic degradation only seems to take place if there is a lack of other utilisable compounds. However, MTBE is often accompanied by other fuel compounds on contaminated sites and anaerobic conditions prevail. MTBE is often recalcitrant under anaerobic conditions, at least in the presence of other carbon sources. The abiotic hydrolysis of MTBE seems to be of secondary importance (on site), but it might be possible to enhance it with catalysts. Recommendation and Outlook MTBE only seems to be recalcitrant under particular conditions. In some cases, the degradation of MTBE on contaminated sites could be supported by oxygen. Enhanced hydrolysis could also be an alternative. - * The basis of this peer-reviewed paper is a presentation at the 9th FECS Conference on 'Chemistry and Environment', 29 August to 1 September 2004, Bordeaux, France.     

梯度洗脱离子色谱法测定降水中六种阴离子及离子平衡的讨论

研究了用KOH淋洗液自动发生一离子色谱法测定降水中无机阴离子F-、C1-、SO42-、NO3-和有机酸根甲酸根、乙酸根的梯度淋洗条件,该方法17rain内可将降水中的6个阴离子全部分离,回归曲线线性良好,检出限在O．011～0．057mg／L,相对标准偏差为0．96％～2．4％,加标回收率在94．4％～104％,是一种较理想的测定降水中阴离子的方法。其中甲酸和乙酸的测定作为常规降水检测的一个补充,可通过离子平衡检验来确定降水中是否加测甲酸和乙酸。