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1.
多环芳烃是一类普遍存在的环境污染物,微生物的降解是PAHs去除的主要途径。介绍了多环芳烃性质及目前国内外研究状况,以及降解多环芳烃的微生物,阐述了三大因素:微生物活性、基质和环境因予等对微生物降解多环芳烃的影响,微生物降解多环芳烃的机理;并对今后的几个研究发展方向进行了展望。  相似文献   

2.
应用植物油淋洗可去除土壤中高浓度多环芳烃,为进一步去除多环芳烃,采用高级氧化(臭氧氧化、过氧化氢和紫外线联合氧化)对两种含多环芳烃植物油进行处理,并考察了运行参数对多环芳烃去除效果的影响.结果表明臭氧具有氧化植物油中多环芳烃的能力,对蒽和荧蒽的氧化能力强于菲.用紫外线、10%过氧化氢,在pH=3的条件下处理MO植物油,总多环芳烃的去除率最高,为81%;按此条件对含高浓度多环芳烃EO植物油处理8 h,总多环芳烃去除率为76.5%,达到良好效果.  相似文献   

3.
多环芳烃是一类可致癌、致畸、致突变的持久性有机污染物,对人体和环境存在着危害.文章主要针对水环境中多环芳烃的来源与危害、水中光降解多环芳烃的一些影响因素、多环芳烃的光降解产物的鉴定进行了简单的阐述.  相似文献   

4.
多环芳烃是一类广泛分布在环境中的有机污染物。由于其致癌性及在环境中长期稳定存在,受到人们广泛的关注。本文介绍了近年来多环芳烃的前处理技术,分析方法的发展,并对去除方法进行了总结,以及对环境样品中多环芳烃的分析方法的发展进行了展望。  相似文献   

5.
多环芳烃是我国环境中的主要污染物之一,对生态系统和人体健康具有严重危害。对中国水生生态系统中多环芳烃的生态毒性与生态风险研究进展进行了综述。从基因、细胞、个体、种群和群落等不同层次概括了多环芳烃的水生态毒性研究进展,介绍了水生生态系统多环芳烃生态风险的主要评价方法,综述了这些评价方法在中国的应用情况,分析了中国水生生态系统中多环芳烃的生态毒性与生态风险研究的存在问题与发展方向。多环芳烃的水生态毒性研究主要集中在水生生物种群与群落水平,基因与细胞水平的研究较少,而生态系统水平的研究基本为空白。在多环芳烃的水生生态风险方面,主要利用国外提出的一些评价方法,缺少自主创新的评价方法,探讨系统水平生态风险评价方法是中国研究人员可能的突破方向。  相似文献   

6.
多环芳烃(PAHs)是一类广泛存在于环境中的持久性有机污染物,具有毒性大、难降解的特点.综述了生物质吸附去除水环境中PAHs的国内外研究现状,着重介绍了常用生物质吸附剂如菌类、藻类、淀粉类、纤维素类和木质素类生物质及其燃烧产生的生物质炭在吸附去除水环境中PAHs的研究进展.对生物质吸附材料的选择、吸附过程的影响因素等进行了分析,并展望了生物质吸附PAHs可能的发展方向.  相似文献   

7.
环境中多环芳烃(PAHs)去除方法的研究   总被引:2,自引:0,他引:2  
多环芳烃是一类广泛分布于环境中的有毒有害污染物,由于其较强的致癌性及在环境中的稳定性而一直受到研究者的关注.介绍了近年来多环芳烃污染物去除方法的研究现状,包括自然降解法、生物修复法、UV光解法、吸附法、高级氧化法及超声分解法等.并对未来多环芳烃去除技术的发展方向进行了展望.  相似文献   

8.
化学改性去除煤沥青中的多环芳烃   总被引:1,自引:0,他引:1  
本文中研究聚合物对煤沥青中多环芳烃的脱除效果,着重从聚合物、催化剂添加量,反应时间和温度等因素对多环芳烃脱除率的影响,同时研究采用复合改性剂对煤沥青中多环芳烃的脱除效果.通过红外光谱分析,初步了解聚乙二醇与多环芳烃反应属于O-烷基化反应,三聚甲醛与多环芳烃反应属于C-烷基化反应.  相似文献   

9.
PAHs在炼油废水处理过程中的变化规律研究   总被引:1,自引:0,他引:1  
张厚勇 《科学技术与工程》2011,11(24):5875-5879,5889
采用二氯甲烷萃取、硅胶柱净化和气相色谱-质谱联用仪的分析方法,对炼油厂废水处理工艺过程中多环芳烃的种类和含量进行了测定,并对各处理工艺单元的多环芳烃的分布和水平进行了分析评价.结果表明,各处理单元16种多环芳烃全部检出,其中二环和三环多环芳烃浓度较高,占总量的90%以上,四环到六环多环芳烃浓度相对较低.整个废水处理过程对多环芳烃的去除率为65%—99%,16种多环芳烃总量去除率为95.6%,其浓度由7 097.46μg/L降低到309.2μg/L,去除效果显著。  相似文献   

10.
用荧光法研究了不同甲壳胺及大孔树脂对香烟烟气中多环芳烃的去除作用.通过有机溶剂萃取不同香烟烟气焦油中有机物,同时以多环芳烃芘作为参比,定量分析了各种品牌香烟在保留过滤嘴条件下使用不同的大孔树脂对烤烟中焦油多环芳烃的吸附率,从而测量烟气在溶剂中多环芳烃的去除率.实验得出D-3520对五种不同品牌的烤烟烟气中焦油多环芳烃的去除率为:46.3%~94.4%,壳聚糖(医药)为:91.9%~99.1%,为卷烟烟气中有害物质的去除提供了一种新方法.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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