排序方式: 共有48条查询结果,搜索用时 15 毫秒
31.
硝化过程清洁生产研究 总被引:5,自引:1,他引:4
探讨了芳香族化合物硝化过程存在的主要环境问题,针对这些问题,提出了在硝化过程采用清洁生产技术减少或消除水污染的各种途径。 相似文献
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中国长三角背景点冬季大气棕碳污染特征及来源解析 总被引:2,自引:2,他引:0
为探究长三角城市群背景点大气棕碳(brown carbon,BrC)的污染特征及来源,本研究采集并分析了长三角城市群下风向地区上海崇明岛2018年12月~2019年1月大气PM2.5样品的化学组成及光学特性.结果表明,甲醇萃取的棕碳在波长365 nm处的吸光系数(absorption coefficients,Abs365,M)平均为(5.39±3.33)M-1·m-1,是水萃取棕碳的1.3倍,且二者均随pH值的增大而显著增加,显示大气颗粒物酸度较弱时有利于棕碳光吸收.冬季Abs365和单位质量吸光效率(mass absorption efficiency,MAE365)均呈现出夜高昼低的变化趋势,且夜间Abs365与左旋葡聚糖呈强线性相关(R2=0.72),说明生物质燃烧排放大量的吸光性物质是导致夜间Abs365较高的一个重要原因.冬季硝基芳香族化合物(nitro-aromatic compounds,NACs)和多环芳烃(polycyclic aromatic hydrocarbons,PAHs)平均浓度分别为(1.5±1.1)ng·m-3和(8.3±4.7)ng·m-3,作为棕碳重要的发色基团,二者在365 nm波长处对BrC的吸光贡献分别为0.1%和0.067%.正交矩阵源解析(positive matrix factorization,PMF)分析表明,生物质和化石燃料等燃烧源的直接排放是冬季崇明岛棕碳的主要来源,贡献达56%,其次是二次生成棕碳,占比为24%,而道路扬尘源仅占6%. 相似文献
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Ferton试剂氧化水中芳香族化合物的机理 总被引:9,自引:1,他引:9
用Fenton试剂法对苯、苯酚、苯胺、甲苯、硝基苯、苯甲基等6种模拟水样进行了氧化处理,并利用紫外光谱考察了氧化前后分子结构的变化,对Fenton试剂氧化芳香族化合物的机理进行了初步的探讨分析。 相似文献
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Hai Hoang Ning Yu Tadashi Toyam Daisuke Inoue Kazunari Sei Michihiko Ike 《环境科学学报(英文版)》2010,22(4):494-499
Removal experiments of phenol,aniline,2,4-dichlorophenol,nonylphenol and bisphenol A(BPA) using Spirodela polyrrhizabacterial associations revealed that all compounds but BPA underwent accelerated removal.The mechanisms differed depending on the substrates.It was found that S.polyrrhiza has a great ability to release phenolic compound-rich root exudates,and the exudates seem to stimulate bacterial degradation of a variety of aromatic compounds. 相似文献
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Wei WEI Shuxiao WANG Jiming HAO Shuiyuan CHENG 《Frontiers of Environmental Science & Engineering》2014,8(1):27-41
This study estimates the detailed chemical profiles of China's anthropogenic volatile organic com- pounds (VOCs) emissions for the period of 2005-2020. The chemical profiles of VOCs for seven activity sectors are calculated, based on which the Photochemical Ozone Creation Potential (POCP) of VOCs for these sectors is evaluated. At the national level, the VOCs species emitted in 2005 include alkanes, alkenes and alkynes, aromatic compounds, alcohols, ketones, aldehydes, esters, ethers and halocarbons, accounting for 26.4wt.%, 29.2wt.%, 21.3 wt.%, 4.7 wt.%, 5.4 wt.%, 1.7 wt.%, 2.1 wt.%, 0.7 wt. % and 2.2wt.% of total emissions, respectively. And during 2005-2020, their mass proportions would respec- tively grow or decrease by - 34.7%, -48.6%, 108.5%, 6.9%, -32.7%, 7.3%, 65.3%, 100.5%, and 55.4%. This change would bring about a 13% reduction of POCP for national VOCs emissions in the future. Thus, although the national VOCs emissions are expected to increase by 33% over the whole period, its ozone formation potential is estimated to rise only by 14%. Large discrepancies are found in VOCs speciation emissions among provinces. Compared to western provinces, the eastern provinces with a more developed economy would emit unsaturated hydrocarbons and benzene with lower mix ratios, and aromatic compounds except benzene, oxidized hydrocar- bons and halocarbons with higher mix ratios. Such differences lead to lower POCP of VOCs emitted in eastern provinces, and higher POCP of VOCs emitted in western provinces. However, due to the large VOCs emissions from Chinese eastern region, the ozone forma- tion potential of VOCs emission in eastern provinces would be much higher than those in western provinces by about 156%-235%. 相似文献
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氯代芳香族化合物高效降解菌的驯化与筛选 总被引:3,自引:0,他引:3
为了筛选除解造纸废水中的氯代芳香族化合物的高效降解菌株,选用了造纸废水SBR处理系统的活性污泥作为菌源,采用平板分离池分离出18种菌株,并从中选出生长势态良好的11种,通过对废水中CODCr,TCl的降解效果试验,确定出以M3+M8为组合的优势混合菌。 相似文献
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第二十二类硝基芳香族化合物 活性特点: 芳香族硝基化合物是指芳环上的氢原子被硝基取代后的化合物,具有ArNO2的结构.硝基是吸电子基团,由于与芳环相共轭,而使芳环钝化;但硝基对其邻对位上的取代基有明显的致活作用;硝基越多,致活作用越强,这就是碱催化致爆的内因. 相似文献
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ZHOU Hong-cang JIN Bao-sheng ZHONG Zhao-ping HUANG Ya-ji XIAO Rui LI Da-ji 《环境科学学报(英文版)》2005,17(1):141-145
The hazardous organic pollutants generated from coal gasification, such as polycyclic aromatic hydrocarbons(PAHs), are highly mutagenic and carcinogenic. More researchers have paid particular attention to them. Using air and steam as gasification medium, the experiments of three kinds of coals were carried out in a bench-scale atmospheric fluidized bed gasifier. The contents of the 16 PAHs specified by US EPA in raw coal, slag, bag house coke, cyclone coke and gas were measured by HPLC to study the contents of PAHs in raw coal and the effects of the inherent characters of coals on the formation and release of PAHs in coal gasification. The experimental results showed that the distributions of PAHs in the gasified products are similar to raw coals and the total-PAHs content in coal gasification is higher than in raw coal(except Coal C). The totaI-PAHs contents increase and then decrease with the rise of fixed carbon and sulfur of coal while there has an opposite variation when volatile matters content increase. The quantities of PAHs reduce with the increase of ash content or the drop of heating value during coal gasification. 相似文献
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运用回归分析与人工神经网络预测含硫芳香族化合物好氧生物降解速率 … 总被引:6,自引:0,他引:6
为了研究人工神经网络预测有机化合物生物降解的性能,运用多元线性回归方法和误差2反向传递人工神经网络模型以基团代码作为结构描述符,分别拟合,预测一批硫芳香族化合物的一级好氧生物降解速率常数。 相似文献