Single walled carbon nanotube reactivity and cytotoxicity following extended aqueous exposure

Globally carbon nanoparticles are increasingly utilized, yet it is not known if these nanoparticles pose a threat to the environment or human health. This investigation examined ‘as-prepared’, and acid cleaned carbon nanoparticle physicochemical characteristics (by FTIR, TEM, FESEM, UV-VIS and X-ray microanalysis), and whether these characteristics changed following 2.5-7 yr exposure to pH neutral saline or fresh water. To determine if these aqueous aged nanotubes were cytotoxic, these nanotubes were incubated with human epithelial monolayers and analyzed for cell viability (vital staining) and ultrastructural nanoparticle binding/localization (TEM, FESEM). The presence of Ni and Y catalyst, was less damaging to cells than CNT lattice surface oxidation. Extended fresh water storage of oxidized CNTs did not reduce surface reactive groups, nor lessen cell membrane destruction or cell death. However storing oxidized CNTs in saline or NOM significantly reduced CNT-induced cell membrane damage and increased cell survival to control levels.     

Emergency response plan for boiler explosion with toxic chemical releases at Nan-Kung industrial park in central Taiwan

A large amount of hazardous materials and equipment has been extensively employed to produce useful chemicals for our daily lives, but many serious accidents, such as fires, explosions, toxic releases, and so on, that harm human beings and impact the environment have occurred during preparation, operation, and transportation of these chemicals. On 17 May 2007, a toxic release from a boiler explosion in a chemical firm triggered a large amount of xylene (7 ton), isopropanol (8 ton), phosphorus trichloride (44.7 ton), and dimethyl formamide (DMF) (1.37 ton) to be released to the atmosphere with total damages of 2000 m² level ground. Through concerted efforts from the Yunlin Emergency Response Information Center (YERIC), sponsored by the Environmental Protection Administration (EPA) of Taiwan and other government sectors, this accident was eventually well controlled after 37 h with 107 people being involved in the rescue action. This study could be applied to lessen the degree of hazard for relevant accidents with an emergency response plan (ERP), and, via Fourier transform infrared (FTIR) spectroscopy and photo ionization detector (PID) the toxic concentrations of airborne chemicals that occurred in the industrial area could be analyzed.     

Photocatalytic degradation of methylbutandioic acid (MBA) in aqueous TiO2 suspension: influences of MBA adsorption on the solid semi-conductor

In the present work we describe the photocatalytic degradation of methylbutandioic acid (MBA), focusing particularly on adsorption of the MBA on TiO₂ surface. We observe a very fast surface carboxylate formation, a decrease of the surface carboxylates during the reaction and an apparent zero order kinetic for the degradation of MBA. We conclude that the main way of MBA degradation is its reaction in the solution, and not on the surface of TiO₂. The influence of the surface carboxylates on the efficiency of the catalyser is under study.     

异戊二烯与O3的大气化学反应研究

研究室温下石英玻璃反应器中异戊二烯与Ｏ３的暗反应,长光路ＦＴＩＲ法得到的实验结果表明,在本模拟反应条件下异戊二烯－Ｏ３反应体系中,主要产物甲基丙烯醛、甲基乙烯基酮和ＨＣＨＯ的产率分别为３７．４％、２０．２％和５５．１％,通过红外谱图的分析可确定反应中的其它产物为ＨＣＯＯＨ、ＣＯ和ＣＯ２等,对异戊二烯与Ｏ３的反应机理进行了探讨。     

絮凝剂PTSS的分子结构研究

以聚硅酸和硫酸钛为原料制得絮凝剂聚硅硫酸钛(PISS),用电子显微镜观察其形貌,发现絮凝剂FISS呈现不同于聚硅酸球形颗粒状的分枝长链状结构,初步推测钛与聚硅酸发生了化学成键作用;通过红外光谱与X-射线衍射研究絮凝剂PTSS结构,证实钛与聚硅酸中的硅通过氧基成键.将该絮凝剂用于处理pH为8的模拟江水,在投加量(以钛离子计)为10 mg/L时,A254的去除率为70.9%,浊度去除率为99.3%,絮凝效果良好.测定不同pH下的Zeta电位,观察所形成絮体的形貌、测定絮体粒度分布以及观测红外光谱图均发现,絮凝剂PISS特殊的长链结构通过络合成键将模拟江水中的腐殖酸官能团带入絮体中,同时也通过吸附、网捕等作用将其余胶体颗粒去除.     

污水中溶解性有机氮类化合物的氯化反应特性及其消毒副产物生成潜能

为探讨城市污水厂二级出水中溶解性有机氮(dissolved organic nitrogen,DON)类化合物的氯化消毒副产物生成潜能及其化学结构变化,首先测定DON、溶解性有机炭(dissolved organic carbon,DOC)、NH4+-N和UV254等指标以及与氯反应前后DON相对分子质量分布,并采用气相色谱测定消毒副产物(disinfection by-products,DBPs)质量浓度,最后应用红外光谱和三维荧光光谱对与氯反应前后的水样进行表征.结果表明,城市污水厂二级出水中DON、DOC、UV254和NH4+-N分别为2.47mg·L-1、14.45 mg·L-1、15.88 m-1和5.42 mg·L-1,DOC与DON比值[m(DOC)/m(DON)]为5.85 mg·mg-1,SUVA为1.09L·(m·mg)-1;与氯反应后,小相对分子质量(Mr<6 000)DON所占比例由70%提高到78%,大相对分子质量(Mr>20 000)DON所占比例从21%降到14%,占较小比例的中等相对分子质量(Mr6 000～20 000)DON基本不变;氯化消毒副产物生成潜能中一氯一溴乙腈(BCAN)质量浓度最大为6.887μg·L-1,三氯乙腈(TCAN)质量浓度最小仅为0.217μg·L-1;与氯反应前,水样的红外光谱出现6个主要吸收区域分别在3 500～3 400、2 260～2 200、1 700～1 640、1 500～1 450、1 150～1 100和850～800 cm-1;与氯反应后水样的红外光谱在1 380～1 350 cm-1和600～550 cm-1增加两个吸收区域;三维荧光光谱证实,与氯反应前后水样中变化与3个主要特征峰有关,分别代表色氨酸类蛋白质、芳香族类蛋白质和富里酸类等物质.     

利用气相色谱——傅里叶红外光谱法联合鉴别溢油污染源

在已有的溢油污染源鉴别研究基础上 ,对油品“指纹”———气相色谱图和傅里叶红外光谱图进行联合识别 ,从而进一步提高了溢油鉴别结果的可能性     

土壤有机质级份的红外和热重特性

用红外分析(FTIR)和热失重分析法对从三种不同利用方式下的黄泥土中提取出的FA,HA及用酸性二甲基亚砜(DMSO)和HF—HCl两种方法提取胡敏素的元素组成及结构特征进行分析,结果表明：胡敏素占腐殖质总碳的60—70％,FA和HA分别占10％和15％左右;不同利用方式下土壤的DMSO-humin,HF-humin 1．HF-humin2在波数2930／1640处的吸收强度比分别为1．18—1．44,0．32—0．43,0．37—0．41;DMSO．humin在78—86℃和264-282℃出现了主要的失重峰,HF-humin1和HF—humin2的主要失重峰在333—338℃和438—458℃之间,FA和HA的主要失重峰分别在300℃和359℃左右,说明用DMSO提取的胡敏素脂肪族类物质较多,缩合程度较低;而用HF—HCl提取的则含较多的芳香族类物质,缩合程度较高．     

The effect of the activation of carboxyl group and hydrogen migration on reaction pathway during the pyrolysis of triglycerides

ABSTRACT

This study investigated the activation of carboxyl group and hydrogen migration on the pyrolysis products of triglycerides. It was found that the activation of carboxylic group determined the efficiency of the decarboxylation reactions. The activation of carboxyl group influenced the pyrolysis products. The glycerol mono-stearate and glycerol mono-oleate were used as the model compounds to analyze the cracking of the ester bond. It was found that the first intermediate formed was RCOO·, but not RCO·. Large amount of ketone was found in the pyrolysis of stearate, while not in that of oleate. In comparison, alcohol was found in pyrolysis products of oleate, while not in stearate. The results indicated that during the pyrolysis process, the carbon-carbon double bond influenced both the cracking of the C-C bond and the transformation of the oxygen-containing functionalities. The activation of carboxyl group and hydrogen migration played essential roles in the determination of the formation of the pyrolysis products. In addition, the mechanism for the evolution of the acid, ester, ketone, aldehyde, alcohol, and other heavy compounds during the pyrolysis was also proposed.     

H3PO4活化法制备互花米草活性炭

利用互花米草茎秆为原料,以H3PO4为活化剂,在不同的活化温度(400℃-700℃)和不同的浸渍比(0.5-3.0)条件下制备活性炭.以高纯氮(N2/77.4K)吸附测定活性炭的比表面积和孔容、孔径分布,以VTIR、零点电荷pHPZC测定活性炭表面官能团的变化,并考察了活化温度及浸渍比对活性炭成品性能的影响.结果表明,...