Effects of low molecular weight organic acids on sorption and desorption behavior of p-chlorophenol by yellow earth     

Daoyong ZHANG Xiangliang PAN Shuimu LIAO Chenglin HUANG Jingmei ZHANG 《中国地球化学学报》2006,25(B08):133-133

Low molecular weight organic acids （LMWOAs） are important components of root exudates. They play an important role in immobilizing and remobilizing contaminants in rhizospheric soil. Effects of four LMWOAs on the sorption and desorption behavior of p-chlorophenol by yellow earth was studied in batch mode. The results showed that the previous application of LMWOAs to enhanced adsorption capacity of p-chlorophenol of the soil in the order of maleic acid〉malic acid〉oxalic acid〉citric acid. However, when LMWOAs were applied to soil where p-chlorophenol had been previously adsorbed, substantial p-chlorophenol was desorbed from soil by oxalic acid, whereas citric acid, malic acid and maleic acid didn＇t desorb as much p-chlorophenol from soil as deionized water.  相似文献   

Origin and three-dimensional fluorescence spectrum of the chromophoric dissolved organic matter in Yangtze estuary, East China     

Fan YANG Qinghui HUANG Jianhua LI Xiaomin ZHU 《中国地球化学学报》2006,25(B08):262-262

Dissolved organic matter （DOM） is an important chemical component in natural water. Chromophoric dissolved organic matter （CDOM）, a fraction of optical properties, plays art important role in the biogeochemical cycle of nutrients in aquatic environment. People realized that DOM cycle is crucial in the global carbon and nitrogen flux, and also is inherently related to nutrients and trace metal elements. Therefore, CDOM was concerned by scientists in global oceanography and limnology fields. Water samples were collected from three sections （North Channel, South Channel and Zhuyuan） of the Yangtze （Changjiang River） estuary in March 2006 Three-dimensional excitation emission matrix （3-DEEM） fluorescence spectra were analyzed for those filtrates through Whatman GF/F filters. Dissolved organic carbon （DOC） was also measured by TOC analyzer. The tidal variety was also taken into account. The 3-D EEM fluorescence scans suggested the fluorescence characteristics of humic acid （Ex=332-344 nm, Em=439-451 nm） and fulvic acid （Ex=250-254 nm, Em=472-478 nm） were obvious, and the fluorescence group of protein-like and tyrosine （Ex=230 nm, Em=283 nm） was also found. They are mainly composed of CDOM in the Yangtze estuary. Further data analysis, especially the fluorescence index （f 450/500）, showed that terrestrial signal was rather strong （1.41-1.65） in the surface water, however, some terrestrial CDOM signals of bottom water showed excursions （1.28-1.39）. On the other hand, anthropogenic sign was impressed in the waters of Zhuyuan, which is one of the main drain outlets of Shanghai Metropolis. DOC concentrations ranged from 2.2 mg/L to 3.4 mg/L in Zhuyuan and South Channel, and from 2.0 mg/L to 2.4 mg/L in North Channel. The tide effect played a role in the composition of the CDOM measured by 3-D fluorescence scan technology.  相似文献   

紫色丘陵区不同土地利用方式下土壤活性有机碳垂直分布特征     

《山地学报》2006,24(B10):21-26

  相似文献   

Dissolved Trace Metal–Organic Complexes in the Lot–Garonne River System Determined Using the C18 Sep-Pak System     

E. Lemaire  G. Blanc  J. Schäfer  A. Coynel  H. Etcheber 《Aquatic Geochemistry》2006,12(1):21-38

An 11-month observation of dissolved and particulate organic matter, chlorophyll a(Chl a), C18 Sep-Pak extractable hydrophobic dissolved organic matter (hDOM) fraction and associated dissolved trace metals (Cd, Cu, V, Co, Ni, Mo, U) was performed in the Lot–Garonne River system. This system includes the Riou Mort, the Lot River and the downstream reaches of the Garonne River and represents the fluvial transport path of trace metals between the major point source of polymetallic pollution, located in the Riou Mort watershed and the Gironde estuary. Spatial and temporal variations of dissolved and particulate organic carbon and Chl areflect the presence of different types of organic matter and their relation with the hDOM fraction. Maximum Chl a/POC ratios (up to 0.03), indicate intense phytoplankton production from March to May. In the Lot River (Temple), DOC and POC concentrations were clearly higher and mean Chl a concentration (2.8 mg g⁻¹) was about three times higher than those of the other sites. High Chl a/POC ratios suggest high phytoplankton activity with maxima in spring and late summer. In the Riou Mort River, very high POC concentrations of up to 40 (mean: 20) occurred, whereas Chl a concentrations were relatively low indicating low phytoplankton activity. High, strongly variable DOC and POC concentrations suggest important natural (Carboniferous soils, forests) or anthropogenic (e.g., former coal mines, waste areas, agriculture, sewage) carbon sources within the small Riou Mort watershed. Despite high DOC concentrations in the Riou Mort River, hDOM metal fractions were generally lower than those at the other sites. The general order of decreasing binding strength between metals and the organic hydrophobic phase (Cu, U > Co, Ni > V, Mo > Cd) at all four sites was in good agreement with the Irving–William series of transition element affinity towards organic ligands. Accordingly, the role of the hydrophobic phase in dissolved Cd transport appeared to be negligible, whereas the hDOM–Cu fraction strongly contributed to dissolved Cu transport.  相似文献   

中国中新生代咸化湖盆烃源岩沉积的问题及相关进展   总被引：8，自引：0，他引：8  

金强  朱光有 《高校地质学报》2006,12(4):483-492

我国东部断陷湖盆和西部坳陷湖盆第三系均有蒸发岩与烃源岩共生现象。前者水体深、咸化范围小，在氯化盐和碳酸盐沉积环境中形成了优质烃源岩，后者水体浅、咸化范围大，在氯化盐和硫酸盐沉积环境中发育了优质烃源岩，作者认为两种湖盆出现的水体分层是有机质堆积和保存的重要条件。济阳坳陷和柴达木盆地为两类咸化湖盆的典型代表，对它们的研究可以深化蒸发岩-烃源岩共生区油气地质的认识、促进勘探发展。  相似文献   

旧供水井化学处理方法介绍--以加德满都市旧供水井修复为例   总被引：1，自引：0，他引：1  

章伟民 《水文地质工程地质》2005,32(6):100-101,107

本文以加德满都市旧供水井修复项目为例,针对因滤水管缝隙被化学物质堵塞,导致井出水量逐年减少的旧供水井。通过井下电视摄像系统检查,采用六偏磷酸钠、氨基黄酸等有机酸,结合刷洗、高压喷射等机械方法进行处理,使旧供水井出水量得到明显提高。  相似文献   

马朗凹陷马1井储层长石中有机包裹体研究          下载免费PDF全文

张小青  伊海生  危国亮  张小芹 《沉积与特提斯地质》2005,25(4):83-86

根据对马朗凹陷马1井储层长石中有机包裹体的基本特征、均一温度、荧光及荧光光谱分析，得出有机包裹体均一温度为60～90℃．120～140℃，其对应的荧光颜色分别为黄色和蓝绿色。认为储层的油气运移经历了两期，第一期为烃类的主要运移、聚集期，油气为低成熟油；第二期为少量的烃类聚集，并判断出二叠系条湖组该段储层为油气产层。  相似文献   

Soluble organic compounds in fog and cloud droplets: what have we learned over the past few years?     

Sandro Fuzzi  Maria Cristina Facchini  Stefano Decesari  Emanuela Matta  Mihaiela Mircea 《Atmospheric Research》2002,64(1-4)

We have recently set up a new procedure for characterising the water soluble organic compounds (WSOC) in fog water, for which information is still rather limited. Fog samples collected during the 1998–1999 fall–winter season in the Po Valley (Italy) were analysed following this procedure, which allows a quantitative determination of three main classes of organic compounds (neutral species, mono- and di-carboxylic acids, polycarboxylic acids), together accounting for ca. 85% of the total WSOC. This procedure also provides information on the main chemical characteristics of these three classes of compounds (functional groups, aliphatic vs. aromatic character, etc.). The enhanced chemical knowledge on fog/cloud chemical composition opens new scenarios as far as chemical and microphysical processes in clouds and fogs are concerned.  相似文献   

平落坝储层有机包裹体特征与气藏形成过程研究   总被引：4，自引：0，他引：4  

高岗  黄志龙 《沉积学报》2002,20(1):156-159

通过储集层成岩作用与有机包裹体的研究认为,研究区储集层有机包裹体主要通过交代和重结晶作用而形成,有各种相态形式,主要分布在石英颗粒内溶蚀缝或孔隙中,构造裂缝中基本未见有机包裹体。上三叠统储集层包裹体丰度明显高于侏罗系沙溪庙组。香二气藏砂岩有机包裹体均一温度主峰在 10 0～ 110℃;沙溪庙气藏砂岩有机包裹体均一温度主峰在 90～ 10 0℃。香二气藏形成时间早,经历了印支期少量注入到印支期末-喜山早期大量注入,再到喜山晚期调整、部分注入的过程。沙溪庙气藏天然气注入则主要发生于喜山运动期。  相似文献   

加水热模拟中深湖与煤系泥岩地化特征比较   总被引：2，自引：0，他引：2  

梁春秀  魏志平等 《沉积学报》2002,20(1):165-168

通过深湖泥岩和煤系泥岩的加水热模拟研究认为,在热模拟实验过程中,深湖泥岩和煤系泥岩显示不同特征,并且其演化有差别。深湖泥岩利于液态原油的生成,并且转化率高于煤系泥岩。深湖泥岩残余可溶有机质饱和烃含量高于煤系泥岩,非烃含量则低于煤系泥岩。深湖泥岩胶质 /沥青质和饱芳比均随温度升高而降低,而煤系泥岩的胶质 /沥青质随温度升高有增加趋势,其饱芳比的变化则不大或有降低趋势。深湖泥岩的T_max难以指示演化阶段,其干酪根碳同位素值明显轻于煤系泥岩,它们的值均随温度的升高而变重。  相似文献