绿色化学与环境保护

近年来国际上较普遍提倡和开展的绿色化学与技术的研究,目的是发展环境友好技术、环境无害技术或清洁生产技术,同时强调化学过程的原子经济性,反应的高选择性,不生成或很少生成副产品或废物,实现或接近零排放过程。通过介绍国内外对绿色化学的研究进展,指出国外对绿色化学的研究主要是围绕化学反应、原料、催化剂、溶剂和产品的绿色化展开的。绿色化学的发展能节省资源、减少环境污染,并将成为可持续发展战略的核心内容。     

Selective flotation separation of plastics by chemical conditioning with methyl cellulose

The floatability of seven plastics (POM, PVC, PET, PMMA, PC, PS and ABS) in the presence of methyl cellulose (MC) and separation of plastics mixtures were investigated in this paper. It was found that the seven plastics can be separated into three groups by using the wetting agent MC. Group one includes POM and PVC. They are depressed at very low MC concentrations. Group two, including PET, PMMA and PC, has an intermediate floatability. Group three (ABS and PS) has a high floatability. They are almost not depressed within the given MC concentration range. In order to understand the mechanism of selective flotation of plastics and the chemical conditioning process, surface chemical factors, such as wettability of plastics and surface tension of flotation medium, and gravity factors, such as particle density and shape, were studied. It was found that the depressing effect of MC on plastics is ascribed mainly to its adsorption on the plastics surfaces. The MC molecules absorbed on plastics expose some of their polar groups oriented towards the aqueous phase, hence making the plastics surfaces hydrophilic. In addition, flotation selectivity for the plastics is dominated not only by wettability of plastics, but also by particle size, density and shape.     

原油指纹识别技术

为使毛细管色谱“指纹”特征应用于污染事故的鉴定,采用分辨效能高的毛细管色谱柱及原油指纹识别技术,对江苏油田９个不同地区和来源的原油进行了分析考察,测定了油品中正构烷烃及姥鲛烷、植烷的含量。实验进一步论证了：以正构烷烃轮廓特征和姥鲛烷、植烷特征峰面积比值相结合的原油鉴别方法不受进样和色谱条件的影响,具有一定的准确性和可靠性。     

Use of remote sensing for the characterization of the Mediterranean coastal environment—the case ofPosidonia oceanica

The beds ofPosidonia oceanica, a marine vascular plant species endemic to the Mediterranean, form a major Mediterranean marine ecosystem. These beds are well-developed along the sandy east coast of Corsica, where the continental shelf is wide and extends for ca. 100 km. The upper limit of this ecosystem has been mapped by means of a computer image processing technique using 1/20 000 colour photographs. One of the major problems for image processing in the marine environment is the impact of the water layer (of variable thickness and quality), which can result in variations of the spectral signature for a particular vegetation or bottom type. In an attempt to reduce the impact of this artefact, a processing technique that takes into account bathymetric factors has been tested. Cartographical data obtained for an area extending from Bastia to Solenzara are presented. In the vicinity of the mouths of coastal rivers, a systematic indentation of the upper limit of the seagrass beds has been revealed. On the basis of these results, local variations in the quality of the marine environment can be detected, in particular with regard to salinity, turbidity and/or the impact of sedimentation. The overall surface area of thePosidonia oceanica beds has also been calculated.     

典型喀斯特城区土地利用变化对地表温度的影响分析

利用TM遥感影像数据,运用ENVI及GIS技术,提取典型喀斯特城区(白云区)2002~2013年的土地利用覆盖类型,并反演出地表温度,从而进一步分析探讨土地利用变化对地表温度的影响。贵阳市白云区是贵阳市重点工业区和新2型工业集中分布区,在2002~2013年土地利用变化明显,特别是城区建设用地增加显著,从35.11增加到71.81 km,并占用了大量耕地和灌疏林。白云区土地利用类型的变化引起地表温度的改变,尤其是建设用地的扩张对地表温度影响较大。对地表温度与NDVI关系进行分析,结果表明不同土地类型的地表温度与NDVI相关程度不同。     

Variations in surface functional groups, carbon chemical state and graphitization degree during thermal deactivation of diesel soot particles

The thermal deactivation of diesel soot particles exerts a significant influence on the control strategy for the regeneration of diesel particulate filters (DPFs). This work focused on the changes in the surface functional groups, carbon chemical state, and graphitization degree during thermal treatment in an inert gas environment at intermediate temperatures of 600°C, 800°C, and 1000°C and explore the chemical species that were desorbed from the diesel soot surface during thermal treatment using a thermogravimetric analyser coupled with a gas-chromatograph mass spectrometer (TGA-GC/MS). The surface functional groups and carbon chemical state were characterized using Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The graphitization degree was evaluated by means of Raman spectroscopy (RS). The concentrations of aliphatic C–H, C–OH, C=O, and O–C=O groups are reduced for diesel soot and carbon black when increasing the thermal treatment temperature, while the sp²/sp³ hybridized ratio and graphitization degree enhance. These results provide comprehensive evidence of the decreased reactivity of soot samples. Among oxygenated functional groups, the percentage reduction during thermal treatment is the largest for the O–C=O groups owing to its worst thermodynamic stability. TGA-GC/MS results show that the aliphatic and aromatic chains and oxygenated species would be desorbed from the soot surface during 1000°C thermal treatment of diesel soot.     

Designing of an environmental assessment algorithm for surface mining projects

This paper depicts the method used to quantify the environmental impact of mining activities in surface mine projects. The affected environment was broken down into thirteen components, such as Human health and immunity, Surface water, Air quality, etc. The effect of twenty impacting factors from the mining and milling activities was then calculated for each Environmental Component. Environmental assessments are often performed by using matrix methods in which one dimension of the matrix is the “Impacting Factor” and the other one is the “Environmental Components”. For the presented matrix method, each Impacting Factor was first given a magnitude between −10 and 10. These factors are used to set up a matrix named Impacting Factor Matrix, whose elements represent the Impacting Factor values. The effects of each Impacting Factor on each Environmental Component were then quantified by multiplying the Impacting Factor Matrix by Weighting Factor Matrix. The elements of the weighting factors matrix reflect the effects of each Impacting Factor on each Environmental Component. The outlined method was originally developed for a mining and milling operation in Iran, but it can successfully be used for mining ventures and more general industrial activities in other countries in accordance to their environmental regulations and laws.     

水质条件对膜-羧基官能团之间微观作用力的影响特征

为了探讨pH值、离子强度及膜材料对膜-污染物间相互作用力的影响特征,利用自制的典型膜污染物羧基官能团胶体探针,结合原子力显微镜定量考察了羧基官能团与PVDF及EVOH超滤膜间的相互作用力随pH值及离子强度的变化特征.结果表明:带有羧基基体的污染物与PVDF及EVOH超滤膜之间的相互作用力皆随着pH值的增大而减小;但是上述作用力随着离子强度的增加呈现特殊的变化趋势:在离子强度为0~10mmol/L时,膜-带有羧基基体的污染物之间相互作用力随着离子强度的增加而增大;在离子强度为10~500mmol/L时,膜-羧基之间相互作用力随着离子强度的增大而减小.在特定的水质条件下,EVOH-羧基间的作用力远小于PVDF-羧基之间的作用力.     

石油化工装置火灾灭火救援力量需求计算模型

消防用水流量的确定是灭火救援力量需求分析的关键,也是准确调集力量到达火灾现场实施灭火救援的前提和基础。针对《石油化工企业设计防火规范》(GB50160-2008)对石油化工装置消防用水流量的规定存在比较宽泛和模糊的问题,借鉴国外的一般做法,通过分析化工工艺装置的火灾危险性,确定石油化工装置的火灾爆炸危险性等级;再根据火灾爆炸危险性等级和装置的规模,分级确定石油化工装置一次灭火的消防用水流量;进而建立了一种基于火灾爆炸危险性分析的石油化工装置灭火救援力量需求计算模型。该模型的建立为科学准确地调集石油化工装置火灾灭火救援力量提供了重要决策依据。     

绝热加速量热仪研究锂离子电池电解液热安全性

利用绝热加速量热仪对商业锂离子电池中常用的3种电解液进行了热分析实验,并根据测试结果评价了其热安全性.3种电解液的初始反应温度均在180～200℃之间;运用绝热理论模型,得到3种电解液热分解反应的活化能Ea分别为(246.202±2.866)kJ·mol、(277.94±7.49)kJ·mol-1和(778.81±34.86)kJ·mol-1;每克样品反应终止时压力分别达到2173.84kPa、2 074.80kPa和2408.65 kPa,压力升高值△P分别为:819.42 kPa、1 619.37 kPa和808.54 kPa.