模拟酶蛋白结合物替代HEMIN测定大气过氧化物

在选择最佳测定条件的基础上,对比了模拟酶蛋白结合物和ＨＥＭＩＮ对过氧化物的测定效果。结果表明,ＨＥＭＩＮ－ＢＳＡ效果最好,其对过氧化物的荧光响应信号约是ＨＥＭＩＮ的２倍,该物质在不改变激发和发射光谱的前提下可增强反应活性,提高反应灵敏度,使方法检测限降低至使用ＨＥＭＩＮ时的１／３左右,最低线性值降至原来的１／５左右,同时,精度亦有所提高。     

单甲脒饱和蒸气压的测定和估算

用气体的法测单甲脒在１５,２５,３５和４５℃时的饱和蒸气分别为０．２０２,０．５５４６,１．９５,６．２９Ｐａ;亨利常数计算值分别为６．３０×１０＾－４,１．６７×１０＾－３,５．６８×１０＾０－３和１．７８×１０＆－２,根据Ｃｌａｕｓｉｕｓ Ｃｌａｐｅｙｒｏｎ方程求出单甲脒在常温下气化热为８９．２ｋＪ．ｍｏｌ＾－１。     

Seasonal variation in dissolved gaseous mercury and total mercury concentrations in Juam Reservoir, Korea

Dissolved gaseous mercury (DGM) and total mercury (TM) concentrations were measured in Juam Reservoir, Korea. DGM concentrations were higher in spring (64+/-13pgL(-1)) and summer (109+/-15pgL(-1)), and lower in fall (20+/-2pgL(-1)) and winter (23+/-6pgL(-1)). In contrast, TM concentrations were higher in fall (3.2+/-0.1ngL(-1)) and winter (3.3+/-0.1ngL(-1)) than in spring (2.3+/-0.1ngL(-1)) and summer (2.2+/-0.4ngL(-1)). DGM concentrations were correlated with water temperature (p<0.0001), ORP (p<0.0001), UV intensity (UV-A: p=0.008; UV-B: p=0.003), and DOC concentration (p=0.0107). DGM concentrations varied diurnally with UV intensity. The average summer DGM (109+/-15pgL(-1)) and TM (2.2+/-0.4ngL(-1)) concentrations in Juam Reservoir were higher than the averages for North American lakes (DGM=38+/-16pgL(-1); TM=1.0+/-1.2ngL(-1)), but lower than levels reported for Baihua Reservoir in China.     

In field arsenic removal from natural water by zero-valent iron assisted by solar radiation

An in situ arsenic removal method applicable to highly contaminated water is presented. The method is based in the use of steel wool, lemon juice and solar radiation. The method was evaluated using water from the Camarones River, Atacama Desert in northern Chile, in which the arsenic concentration ranges between 1000 and 1300 μg L⁻¹. Response surface method analysis was used to optimize the amount of zero-valent iron (steel wool) and the citrate concentration (lemon juice) to be used. The optimal conditions when using solar radiation to remove arsenic from natural water from the Camarones river are: 1.3 g L⁻¹ of steel wool and one drop (ca. 0.04 mL) of lemon juice. Under these conditions, removal percentages are higher than 99.5% and the final arsenic concentration is below 10 μg L⁻¹. This highly effective arsenic removal method is easy to use and inexpensive to implement.     

Heavy metal contamination in the vicinity of an industrial area near Bucharest

BACKGROUND, AIMS AND SCOPE: Chromium enters into the aquatic environment as a result of effluent discharge from steel works, electroplating, leather tanning industries and chemical industries. As the Cr(VI) is very harmful to living organisms, it should be quickly removed from the environment when it happens to be contaminated. Therefore, the aim of this laboratory research was to develop a rapid, simple and adaptable solvent extraction system to quantitatively remove Cr(VI) from polluted waters. METHODS: Aqueous salt-solutions containing Cr(VI) as CrO4(2-) at ppm level (4-6 ppm) were prepared. Equal volumes (5 ml) of aqueous and organic (2-PrOH) phases were mixed in a 10 ml centrifuge tube for 15 min, centrifuged and separated. Concentrations of Cr(VI), in both the aqueous and organic phases, were determined by atomic absorption spectrometry. The effects of salt and acid concentrations, and phase-contact time on the extraction of Cr(VI) were investigated. In addition, the extraction of Cr(VI) was assessed in the presence of tetramethylammonium chloride (TMAC) in 2-PrOH phase. Effects of some other metals, (Cd(II), Co(II), Cu(II), Ni(II) and Zn(II)), on the extraction of Cr(VI) were also investigated. RESULTS AND DISCUSSION: The Cr(VI) at ppm level was extracted quantitatively by salting-out the homogeneous system of water and 2-propanol(2-PrOH) using chloride salts, namely CaCl2 or NaCl, under acidic chloride media. The extracted chemical species of Cr(VI) was confirmed to be the CrO3Cl-. The ion-pair complex extracted into the organic phase was rationalized as the solvated ion-pair complex of [2-PrOH2+, CrO3Cl-]. The complex was no longer stable. It implied the reaction between extracted species. Studies revealed that salts and acid directly participated in the formation of the above complex. Use of extracting agents (TMAC) didn't show any significant effect on the extraction of Cr(VI) under high salting-out conditions. There is no significant interference effect on the extraction of Cr(VI) by the presence of other metals. The Cr(VI) in the organic phase was back-extracted using an aqueous ammonia solution (1.6 mol dm(-3)) containing 3 mol dm(-3) NaCl. The extraction mechanism of Cr(VI) is also discussed. CONCLUSIONS: Salting-out of homogeneous mixed solvent of 2-propanol can be employed to extract Cr(VI) quantitatively, as an ion-pair of [2-PrOH2+ * CrO3Cl-] solvated by 2-PrOH molecules. Then, the complex becomes 'solvent-like' and is readily separated into the organic phase. The increase of Cl- ion concentration in the aqueous phase favors the extraction. The 2-PrOH, salts and acid play important roles in the extraction process. There is no need to use an extracting agent at a high salting-out condition. RECOMMENDATIONS AND PERSPECTIVES: Chromium(VI) must be quickly removed before it enters into the natural cycle. As the 2-PrOH is water-miscible in any proportion, ion-pairing between 2-PrOH2+ and CrO3Cl- becomes very fast. As a result, Cr(VI) can easily be extracted. Therefore, the method is recommended as a simple, rapid and adaptable method to quickly separate Cr(VI) from aqueous samples.     

聚硅酸氯化铝处理皂素废水的研究

制备了聚硅酸氯化铝(PASC)絮凝剂,并用其进行了皂素废水处理实验。考察了絮凝剂投加量、pH值、搅拌速度对COD和浊度去除率的影响。结果表明,当絮凝剂投加量为9～13.5 mg/L、pH值5～7、搅拌速度150～250 r/min时,COD和浊度去除效果较好。最佳工艺条件为：絮凝剂投加量11.25 mg/L、pH值6、搅拌速度200 r/min。此时,COD去除率为93.7％,浊度去除率为97.5％。PASC的絮凝性能明显优于PAC。     

液晶显示器液晶处理与铟回收技术

在实验室条件下,对液晶显示器回收的各个重要环节作了初步的探索,提出了一整套回收工艺.其中包括利用丙酮常温浸取去除偏光片、分离玻璃基板、溶解液晶,还包括利用硫酸溶液和二氧化锰联合浸取玻璃基板,铟的浸取率达89%.得到的铟的酸液经过萃取、置换和电解,可以得到铟的产品,为液晶显示器的资源化和无害化提供实验数据和技术支持.     

超临界水氧化中设备腐蚀的研究现状

超临界水氧化（SCWO）技术是近年发展起来的处理有机难溶废物的安全高效的新技术。在阐述超临界水的物理、化学性质的基础上,介绍了SCWO反应的工作原理和流程,分析总结了世界范围内开展的SCWO环境中设备腐蚀及监测技术等方面的研究动态,提出了我国SCWO技术研究的未来发展方向。     

预腐蚀条件下不同孔数冷挤压强化7075-T6铝合金板件疲劳寿命退化规律

目的 研究腐蚀环境下单孔和多孔冷挤压强化铝合金板件的疲劳寿命退化规律和损伤机理。方法 针对2种不同孔距的三孔冷挤压强化7075-T6铝合金板件,采用模拟热带海洋大气环境的实验室加速腐蚀谱,开展不同腐蚀时间下的预腐蚀疲劳试验。结果 获得了3倍孔距的三孔挤压强化铝板以及单孔挤压强化铝板的C(t)曲线、疲劳S-N曲线和损伤形貌特征,分析了腐蚀后挤压强化试件的腐蚀机理及挤压强化作用。同时,将不同孔数试件的试验结果进行比较,探明了孔数对挤压强化铝板腐蚀和疲劳性能的影响。结论 腐蚀后挤压强化铝合金板件的疲劳性能发生显著退化,腐蚀损伤主要为剥蚀,疲劳裂纹萌生位置由孔边转移至表面。挤压孔数量对挤压强化铝合金板件的疲劳和腐蚀疲劳性能的影响较小。     

矿产资源总体规划对四川省甘孜州资源-环境承载力影响分析研究

本文根据矿区资源环境承载力的内涵,构建了"目标层-准则层-因子层-指标层"资源环境承载力评价体系,并在此基础上通过专家咨询打分的方式,采用层次分析法(AHP法)计算得出甘孜州矿产资源总体规划实施现状年、近景年、远景年3个时间段资源-环境承载力综合指数,为四川省甘孜州矿产资源总体规划环评影响影响评价提供了技术支撑和科学根...