Stable Carbon Isotopic Composition in Soil Organic Carbon and C3/C4 Source Variations at the Haibei Alpine Meadow

Stable carbon isotopes of organic matter originated from different soil layers (0～5 cm, 5～15 cm, 15～25 cm, 25～35 cm, 35～50 cm, 50～65 cm) were investigated in the Haibei Alpine Meadow Ecosystem Research Station of the Chinese Academy of Sciences. The preliminary results indicated that δ13C values of soil organic matter increased with increased soil depth. δ13C of soil organic carbon in 0～5 cm layer showed the lowest value, -25.09‰; while 50～65 cm soil layer possessed the lowerδ13C value, -13.87‰. Based on mass balance model of stable isotopes, it was proposed that the percentage of C4 carbon source tend to increase with increased soil depth. The preliminary study indicated that alpine meadow might have undergone a successive process from C4-dominated community to C3-dominated one. However, changing δ13C values in atmospheric CO2 overtime and different processes of soil organic carbon formation (or eluviation) might somewhat contribute to increasing δ13C values. In this case, mass balance model would underestimate C3 community and overestimate C4 community.

Soil organic carbon storage and soil CO2 flux in the alpine meadow ecosystem

High-resolution sampling, measurements of organic carbon contents and C-14 signatures of selected four soil profiles in the Haibei Station situated on the northeast Tibetan Plateau, and application of C-14 tracing technology were conducted in an attempt to investigate the turnover times of soil organic carbon and the soil-CO2 flux in the alpine meadow ecosystem. The results show that the organic carbon stored in the soils varies from 22.12x10(4) kg C hm(-2) to 30.75x10(4) kg C hm(-2) in the alpine meadow ecosystems, with an average of 26.86x10(4) kg C hm(-2). Turnover times of organic carbon pools increase with depth from 45 a to 73 a in the surface soil horizon to hundreds of years or millennia or even longer at the deep soil horizons in the alpine meadow ecosystems. The soil-CO2 flux ranges from 103.24 g C m(-2) a(-1) to 254.93 gC m(-2) a(-1), with an average of 191.23 g C m(-2) a(-1). The CO2 efflux produced from microbial decomposition of organic matter varies from 73.3 g C m(-2) a(-1) to 181 g C m(-2) a(-1). More than 30% of total soil organic carbon resides in the active carbon pool and 72.8%. 81.23% of total CO2 emitted from organic matter decomposition results from the topsoil horizon (from 0 cm to 10 cm) for the Kobresia meadow. Responding to global warming, the storage, volume of flow and fate of the soil organic carbon in the alpine meadow ecosystem of the Tibetan Plateau will be changed, which needs further research.

渤海湾盆地前第三系构造演化与煤成气成藏研究

The disequilibrium between supply and demand the east part of North China accelerated natural gas exploration in Bohai bay basin. Exploration practice showed that coal-derived gas is important resource. In searching of big to middle scaled coal derived gas field, and realize successive gas supply, the paper carried out integrated study on structural evolution of Pre-Tertiary and evaluation of reservoir forming condition of coal-derived gas. Study work of the paper was based on the following condition: available achievement in this field at present, good understanding of multiphase of tectonic movement. Study work was focused on geological evolution, source rock evaluation and dissection key factors controlling reservoir forming. Based on analysis of seismic data, drilling data, tectonic style of Pre-Tertiary was subdivided, with different tectonic style representing different tectonic process. By means of state of the art, such as analysis of balanced cross section, and erosion restoration, the paper reestablished tectonic history and analyzed basin property during different tectonic phase. Dynamic mechanism for tectonic movement and influence of tectonic evolution on tectonic style were discussed. Study made it clear that tectonic movement is intensive since Mesozoic including 2 phase of compressional movement (at the end of Indo-China movement, and Yanshan movement), 2 phase of extensional movement (middle Yanshan movement, and Himalayan movement), 2 phase of strike slip movement, as well as 2 phase of reversal movement (early Yanshan movement, and early Himalayan movement). As a result, three tectonic provinces with different remnant of strata and different tectonic style took shape. Based on afore mentioned study, the paper pointed out that evolution of Bohai bay basin experienced the following steps: basin of rift valley type (Pt2+3)-craton basin at passive continental margin (∈1－2)-craton basin at active continental margin (∈3- O)-convergent craton basin (C-T1+2)-intracontinental basin (J＋K). Superposition of basins in different stage was discussed. Aimed at tectonic feature of multiple phases, the paper put forward concept model of superposition of tectonic unit, and analyzed its significance on reservoir forming. On basis of the difference among 3 tectonic movements in Mesozoic and Cenozoic, superposition of tectonic unit was classified into the following 3 categories and 6 types: continuous subsidence type (I), subsidence in Mesozoic and uplift for erosion in Cenozoic (II1), repeated subsidence and uplift in Mesozoic and subsidence in Cenozoic (II2), repeated subsidence and uplift in Mesozoic and uplift for erosion in Cenozoic (II3), uplift for erosion in Mesozoic and subsidence in Cenozoic (II4), and continuous uplift (III). Take the organic facies analysis as link, the paper established relationship between sedimentary environment and organic facies, as well as organic facies and organic matter abundance. Combined information of sedimentary environment and logging data, the paper estimated distribution of organic matter abundance. Combined with simulation of secondary hydrocarbon generation, dynamic mechanism of hydrocarbon generation, and thermal history, the paper made static and dynamic evaluation of effective source rock, i.e. Taiyuan formation and Shanxi formation. It is also pointed out that superposition of tectonic unit of type II2, type II4, and type I were the most favorable hydrocarbon generation units. Based on dissection of typical primary coal-derived gas reservoir, including reservoir forming condition and reservoir forming process, the paper pointed out key factors controlling reservoir forming for Carboniferous and Permian System: a. remnant thickness and source rock property were precondition; b. secondary hydrocarbon generation during Himalayan period was key factor; c. tectonic evolution history controlling thermal evolution of source rock was main factor that determine reservoir forming; d. inherited positive structural unit was favorable accumulation direction; e. fault activity and regional caprock determined hydrocarbon accumulation horizon. In the end, the paper established reservoir forming model for different superposition of tectonic units, and pointed out promising exploration belts with 11 of the first class, 5 of the second class and 6 of the third class.

生物－热催化过渡带沉积成岩演化及其成烃作用研究

The biothermocatalytic transitional zone gas is a new type of natural gas genetic theory, and also an clean, effective and high quality energy with shallow burial depth, wide distribution and few investment. Meanwhile, this puts biothermocatalytic transitional zone gas in important position to the energy resource and it is a challenging front study project. This paper introduces the concept, the present situation of study and developmental trend about biothermocatalytic transitional zone gas in detail. Then by using heat simulating of source rocks and catalysis mechanism analysis in the laboratory and studying structural evolution, sedimentation, diagenesis and the conditions of accumulation formation and so on, this paper also discusses catalytic mechanism and evolutionary model of the biothermocatalytic transitional zone gas formation, and establishes the methods of appraisal parameter and resources prediction about the biothermocatalytic transitional zone gas. At last, it shows that geochemical characteristics and differentiated mark of the biothermocatalytic transitional zone gas, and perfect natural gas genetic theory, and points out the conditions of accumulation formation, distribution characteristics and potential distribution region on the biothermocatalytic transitional zone gas m China. The paper mainly focuses on the formation mechanism and the resources potential about the biothermocatalytic transitional zone gas. Based on filed work, it is attached importance to a combination of macroscopic and microcosmic analysis, and the firsthand data are obtained to build up framework and model of the study by applying geologic theory. Based on sedimentary structure, it is expounded that structural actions have an effect on filling space and developmental cource of sediments and evolution of source rocks. Carried out sedimentary environment, sequence stratigraphy, sedimentary system and diagenesis and so on, it is concluded that diagenesis influences developmental evolution of source rocks, and basic geologic conditions of the biothermocatalytic transitional zone gas. Applying experiment simulating and catalytic simulating as well as chemical analysis, catalytic mechanism of clay minerals is discussed. Combined diagenecic dynamics with isotope fractionation dynamics, it is established that basis and method of resource appraisal about the biothermocatalytic transitional zone gas. All these results effectively assess and predict oil&gas resources about the biothermocatalytic transitional zone gas-bearing typical basin in China. I read more than 170 volumes on the biothermocatalytic transitional zone gas and complete the dissertation' summary with some 2.4 ten thousand words, draw up study contents in some detail and set up feasible experimental method and technologic course. 160 pieces of samples are obtained in oilfield such as Liaohe, Shengli, Dagang and Subei and so on, some 86 natural gas samples and more than 30 crude oil samples. Core profiles about 12 wells were observed and some 300 geologic photos were taken. Six papers were published in the center academic journal at home and abroad. Collected samples were analysised more than 1000 times, at last I complete this dissertation with more than 8 ten thousand words, and with 40 figures and 4 plates. According to these studies, it is concluded the following results and understandings. 1. The study indicates structural evolution and action of sedimentary basin influence and control the formation and accumulation the biothermocatalytic transitional zone gas. Then, the structural action can not only control accommodation space of sediments and the origin, migration and accumulation of hydrocarbon matters, but also can supply the origin of energy for hygrocarbon matters foramtion. 2. Sedimentary environments of the biothermocatalytic transitional zone gas are lake, river and swamp delta- alluvial fan sedimentary systems, having a warm, hot and humid climate. Fluctuation of lake level is from low to high., frequency, and piling rate of sedimentary center is high, which reflect a stable depression and rapidly filling sedimentary course, then resulting in source rocks with organic matter. 3. The paper perfects the natural gas genetic theory which is compound and continuous. It expounds the biothermocatalytic transitional zone gas is a special gas formation stage in continuous evolutionary sequence of organic matter, whose exogenic force is temperture and catalysis of clay minerals, at the same time, having decarbxylation, deamination and so on. 4. The methodology is established which is a combination of SEM, TEM and Engery spectrum analysis to identify microstructure of crystal morphology about clay minerals. Using differential thermal-chromatographic analysis, it can understand that hydrocarbon formation potential of different typies kerogens and catalytic method of all kinds of mineral matrix, and improve the surface acidity technology of clay minerals measured by the pyridine analytic method. 5. The experiments confirm catalysis of clay minerals to organic matter hygrocarbon formation. At low temperature (<300 ℃), there is mainly catalysis of montmorillonite, which can improve 2-3 times about produced gas of organic matters and the pyrolyzed temperature decreased 50 ℃; while at the high temperature, there is mainly catalysis of illite which can improve more than 2 times about produced gas of organic matters. 6. It is established the function relationship between organic matter (reactant) concentration and temperature, pressure, time, water and so on, that is C=f (D, t). Using Rali isotope fractionation effect to get methane isotope fractionation formula. According to the relationship between isotope fractionation of diagenesis and depth, and combined with sedimentary rate of the region, it is estimated that relict gas of the biothermocatalytic transitional zone gas in the representative basin. 7. It is revealed that hydrocarbon formation mechanism of the biothermocatalytic transitional zone gas is mainly from montmorillonite to mixed minerals during diagenesis. In interlayer, a lot of Al~(3+) substitute for Si~(4+), resulting in a imbalance between surface charge and interlayer charge of clay minerals and the occurrence of the Lewis and Bronsted acid sites, which promote to form the carbon cation. The cation can form alkene or small carbon cation. 8. It is addressed the comprehensive identification mark of the biothermo - catalytic transitional zone gas. In the temproal-spatial' distribution, its source rocks is mainly Palaeogene, secondly Cretaceous and Jurassic of Mesozoic, Triassic, having mudy rocks and coal-rich, their organic carbon being 0.2% and 0.4% respectively. The vitrinite reflection factor in source rocks Ro is 0.3-0.65%, a few up to 0.2%. The burial depth is 1000-3000m, being characterized by emerge of itself, reservoir of itself, shallow burial depth. In the transitional zone, from shallow to deep, contents of montmorillonites are progressively reduced while contents of illites increasing. Under SEM, it is observed that montmorillonites change into illite.s, firstly being mixed illite/ montmorillonite with burr-like, then itlite with silk-like. Carbon isotope of methane in the biothermocatatytic transitional zone gas , namely δ~(13)C_1-45‰- -60 ‰. 9. From the evolutionary sequence of time, distribution of the biothermocatalytic transitional zone gas is mainly oil&gas bearing basin in the Mesozoic-Neozoic Era. From the distribution region, it is mainly eastern stuctural active region and three large depressions in Bohaiwang basin. But most of them are located in evolutionary stage of the transitional zone, having the better relationship between produced, reservoir and seal layers, which is favorable about forming the biothermocatalytic transitional zone gas reservoir, and finding large gas (oil) field.

富硫流体的成因与硫酸盐还原作用研究

Origins of H_2S, thiols, thiophenes in natural gases and sulphur-enriched oils are complicated and thus some debates exist on them. The post-doctoral research is based upon oil- and gas-field data. Cases for study include Triassic Jianglingjiang Formation natural gases, Wolonghe Field, Sichuan Basin, Paleozoic oils and bitumen, Central Tarim, gases reserviored nearby Carboniferious - Ordovician unconformity, Hetianhe Field, Tarim Basin and sulphur-enriched oils in Tertiary reserviors in Jinxian Sag, Bohai Bay Basin. We have carried out analyses on the oils and gases for chemistry, δ~(13)C, δ~(34)S, and molecular composition of biomarkers, analyzed authigenetic pyrite forδ~(34)S, formation water for chemistry and δD and δ~(18)O along with petroleum system and burial history analyses, The aims are to assess the origins of the H2S and authigenetic pyrite, to discuss the possibility of reduced sulphur incorporation into hydrocarbons and to determine the mechanisms of hydrocarbon secondary alteration in the above four cases by comparison. The research shows that the reduced sulphur in the four cases is the result of thermochemical and biological sulphate reduction., TSR and BSR, respectively. No evidence indicates an origin of decomposition of organic matter or mantle - derived H2S in the cases. Elevated H_2S contents (up to 32%) in the Triassic Jialingjiang Formation are considered to result from TSR while relatively low H_2S (up to 2000ppm) in the Hetianhe Field resulted from BSR. However, it is not the case for the Central Tarim where relatively low H2S but abundant authigenetic pyrite occurr. Part of the H_2S in the Central Tarim reservoirs has reacted with iron released from clay minerals to precipitate pyrite. Thus, reduced sulphur δ~(34)S and reservoir temperatures rather than the H2S amount are reliable parameters to distinguish between TSR and BSR. TSR in Sichuan Basin Triassic Jialingjiang Formation and Central Tarim Paleozoic reservoirs are showed to take place at more than 125℃. the H2S and authigenetic pyrite have δ~(34)S close to parent anhydrite. In contrast, BSR in the reservoirs near the Carboniferous - Ordovician unconformity in the Hetianhe Field and in the Tertiary in the Jinxian Sag took place at temperatures less than 80℃with sulphide δ~(34)S as light as -24.9‰ and -12.5‰, anhydrite δ~(34)S as heavy as +26‰and +3 5-+40‰, respectively. Chemistry and isotopic composition of the natural gases change as the result of sulphate reduction. It has been observed that relative composition of light hydrocarbon gases is changed along with a rise in H_2S and CO_2. TSR in the Triassic Jialingjiang Formation and BSR in the Hetianhe Field result in a greater degree of preferential depletion of methane than larger molecular hydrocarbon gases. As TSR or BSR proceeds, hydrocarbon gases evolved to heavier carbon isotope as the result of kinetic isotopic fractionation, i.e., selective anaerobic oxidation of ~(12)C. Using the model of residual methane (Whiticar, 1999) to describe the relationship among the proportion of methane oxidation, isotopic shift and fraction factor, about 30% methane is calculated to have been oxidized during BSR in the western part of the Hetianhe Field. From the above, it can be concluded that in the area where H_2S is abundant, empiricalδ~(13)C -Ro relationships do not work. Sulphate reduction results in a rise in sulphur content, gravity and viscosity of an oil as well as changes in δ~(13)C and δ~(34)S. On special conditions, the reduced sulphur from sulphates might be incorporated into oils, i.e., the increasing sulphur is derived from secondarily reduced sulphur. A positive correlative relationship exists between sulphur content and δ~(34)S in the oils in Paleozoic reservoirs in Central Tarim, indicating that enhanced sulphur is ~(34)S-enriched, originated from TSR. The Jinxian oil with the highest sulphur content has the lightest δ~(34)S, suggesting part of the sulphur in the oil is ~(34)S-depleted, originated from BSR. In the Jinxian oil with increasing sulphur content, asphaltenes shows higher content and more negative δ~(13)C, and saturates shows evidence of biodegradetion and a decreasing content and a positive δ~(13)C shift. Thus, asphaltenes have δ~(13)C values closer to saturates. All the above indicate that the reduced sulphur has been incorporated into biodegradated saturates to generate new asphaltenes with relatively light δ~(13)C of saturates. Thiols and thiophenes in natural gases in the Triassic Jialingjiang Formation may result from reaction of H_2S with hydrocarbon. In the Jialingjiang Formation hydrocarbon gases are dominated by methane thus have a high dryness coefficient and thiols are showed to be positively related to H_2S content, suggesting that the thiols may result from H_2S reaction with short chain hydrocarbons. In contrast, high thiophenes occur in wet gases in Jurassic reservoirs with their source rock from sulphur - depleted type I kerogen, indicating that thiophenes may be a product of reaction of H2S with longer chain hydrocarbons.

黄土高原22万年来的黑碳记录和古火灾害历史重建

The term black carbon is used to describe a relatively inert and ubiquitous form of carbon, comprising a range of materials from char and charcoal to element or graphite carbon produced by the incomplete combustion of fossil fuels and biomass. Due to its inertness, the BC in soils, lacustrine and marine sediments and ice can persist over a long period of time. So BC signatures in geological deposits can be used as evidence of natural fires happened in their surroundings. To study the temporal and spatial changes in paleofires over the Chinese Loess Plateau, black carbon concentrations were analyzed on the loess-paleosol samples from three sections including Lijiayuan, Lingtai and Weinan along a north-south transect. Using the orbitally-tuned time-scales of the sections, the black carbon sedimentation rates (BCSR) were calculated. Meanwhile, with objective to document fine resolution fire history during late Pleistocene and Holocene periods, we measured BC concentrations of loess-paleosol samples at dense sampling intervals since 28 ka BP. in Lijiayuan section. The BCSR of the samples were also calculated. In addition, we also conducted observation on black carbon morphologies to examine their sources. Based on the results, the following remarks can be concluded: 1. In the last two glacial cycles, the BCSR values in glacial periods are 2-3 times higher than in interglacial periods, and the BCSR variability has a relatively strong precession-associated 23 kyr period, suggesting that the glacial cold-dry climate conditions were apt to induce natural fires over the Loess Plateau, 2. Comparison of the BCSR records among the three loess sections demonstrates that natural fire occurrence was much more intensive and frequent in the northern and interglacial periods. 3. Pollen records and carbon isotope analyses of organic matter have shown that the Loess Plateau was covered by an Artemisia-dominated grassland vegetation both during glacial and interglacial periods, So grassland fires were the dominant fire types in the Plateau, which is also corroborated by the observation of black carbon morphology. In addition, statistics and comparison of BC particle sizes among the sections demonstrated that BC records probably reflected local fires. 4. According to previous studies about the effect of fires on vegetation changes, we considered that the fires might play an important role in the expansion of grassland during glacial periods, besides the control of climate changes. 5. The high resolution black carbon record in Lijiayuan section has shown that the BCSR series well documented Younger dryas (YD) and Heinrich (HI和H2) events, suggesting that natural fires in the northwestern part of Chinese Loess Plateau could regularly respond to the millennial scale climate oscillation.

地球化学新方法在隐状矿床找矿预测中的应用研究

With the progress of prospecting, the need for the discovery of blind ore deposits become more and more urgent. To study and find out the method and technology for the discovery of blind and buried ores is now a priority task. New geochemical methods are key technology to discover blind ores. Information of mobile components related to blind ores were extracted using this new methods. These methods were tested and applied based on element' s mobile components migrating and enriched in geophysical-geochemical process. Several kinds of partial extraction techniques have tested based on element' s occurrence in hypergenic zone. Middle-large scale geochemical methods for exploration in forest and swamp have been tested. A serious of methods were tested and applied effetely about evaluation of regional geochemical anomaly, 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system instead of the normal net. 1. Element related with ores can be mobiled to migrate upwards and be absorpted by surface soil. These abnomal components can be concentrated by natural or artificial methods. These trace metalic ions partially exist in dissovlvable ion forms of active state, and partially have been absorbed by Fe-Mn oxide, soil and organic matter in the soil so that a series of reaction such as complex reaction have take place. Employing various partial extraction techniques, metallic ions related with the phase of the blind ores can be extracted, such as the technique of organic complex extraction, Fe-Mn oxide extraction and the extraction technique of metallic ions of various absorption phases. 2.1:200000 regional geochemical evaluation anomaly methods: Advantageous ore-forming areas were selected firstly. Center, concentration, morphological feature, belt of anomaly were choosed then. Geological and geochemical anomalies were combined. And geological and geochemical background information were restrained. Xilekuduke area in Fuyun sheet , Zhaheba area in Qiakuerte sheet, the west-north part in Ertai sheet and Hongshanzui anomaly in Daqiao sheet were selected as target areas, in Alertai, in the north of Xinjiang. in Xilekuduke area, 1:25000 soil geochemical methods sampling based on the net in dendritic water system was carried out. Cu anomaly and copper mineralization were determined in the center area. Au , Cu anomalies and high polarization anomaly were determined in the south part. Prospecting by primary halo and organic complex extraction were used to prognosis blind ore in widely rang outcrop of bedrock. 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system were used in transported overburden outside of mining area. Shallow seismic method and primary halo found a new blind orebody in mining area. A mineralization site was fou and outside of Puziwan gold mine, in the north of Shanxi province. Developing middle-large scale geochemical exploration method is a key technique based 1:200000 regional geochemical exploration. Some conditions were tested as Sampling density , distribution sites of sample, grain size of sample and occurrence of element for exploration. 1:50000 exploration method was advanced to sample clast sediment supplement clast sediment in valley. 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system was applied to sample residual material in A or C horizon. 1:2000 primary or soil halo methods used to check anomalies and determine mineralization. Daliang gold mineralization in the northern Moerdaoga was found appling these methods. Thermomagnetic method was tested in miniqi copper-polymetallic ore. Process methods such as grain size of sample, heated temperature, magnetic separating technique were tested. A suite of Thermomagnetic geochemical method was formed. This method was applied in Xiangshan Cu~Ni deposit which is cover by clast or Gobi in the eastern Xinjiang. Element's content and contrast of anomaly with Thermomagnetic geochemical method were higher than soil anomaly. Susceptibility after samples were heated could be as a assessment conference for anomaly. In some sectors thermo-magnetic Cu, Ni, Ti anomalious were found outside deposits area. There were strong anomal ies response up ore tested by several kind of partial extraction methods include Thermomagnetic, enzyme leach and other partial extractions in Kalatongke Cu-Ni deposit in hungriness area in the northern of Xinjiang. Element's anomalies of meobile were mainly in Fe-Mn oxide and salt. A Copper mineralization site in Xilekuduke anomaly area had been determined. A blind ore was foung by shallow seismic and geochemical method and a mineralization site was found outside this mining area in Puziwan gold deposit in shanxi province. A Gold mineralization site was found by 1:50000 geochemical exploration in Daliang, Inner Mongolia.

天然溶解有机质和环境污染物的相互作用--以铜、汞离子和卡马西平为例

天然溶解有机质（natural dissolved organic matter，DOM）是由动植物残体经过复杂的物理、化学和生物过程形成的高分子有机混合物，它广泛分布于水体、土壤和沉积物中。DOM的结构十分复杂，分子量从几百到几十万不等，元素组成和化学结构随时空和来源不同而变化。腐殖物质是DOM的主要组成部分，以溶解有机碳计约占DOM总量的50%~80%。腐殖物质可以分为：富里酸（fulvic acid， FA任何pH值条件下都溶于水），腐殖酸（humic acid，HA在pH 1时不溶于水）和胡敏素（humin，任何pH条件下都不溶于水）。 DOM能影响许多生物地球化学过程。例如DOM是一个重要的碳汇，它能影响微生物的食物链和全球碳循环；DOM和营养元素含量、食物链结构等一起决定水生生态系统的属性和发展动态；它还能吸收自然光，从而影响紫外线在水中的穿透能力和浮游植物的光合作用；DOM含有多种弱酸和弱碱官能团，是天然水体pH的调节剂和控制因素；DOM和痕量金属离子或有机污染物发生作用，从而影响它们的形态、毒性、迁移转化和生物有效性；在饮用水消毒过程中，DOM能生成致癌物三卤甲烷和其它消毒副产物。 天然水体中的痕量金属离子（如Cu2+和Hg2+）主要以DOM络合态存在。在海水中DOM控制铜的主要存在形态；在淡水中 90%以上的铜离子与DOM发生配位。通过配位作用DOM能抑制浮游生物对Hg的吸收，增加鱼类对Hg的蓄积。目前，人们对金属离子在环境中的迁移转化机理的理解还不够深入，尤其是对有机质参与下的有毒重金属循环还缺乏必要地认识。条件稳定常数是描述重金属离子与DOM配位能力的基本参数。前人运用多种手段对DOM与金属离子的结合能力进行了研究，主要包括：离子选择性电极法、溶出伏安法、超滤及荧光淬灭滴定法等。紫外吸收滴定法可用于研究单一有机化合物和金属离子的相互作用，在这一领域的应用尚未报道。本文首次将紫外吸收滴定法应用于测定DOM与Cu2+和Hg2+的条件稳定常数。实验表明紫外吸收滴定法迅速、简便、可望成为研究DOM和痕量金属离子相互作用的有力工具。 药品和个人护理品（pharmaceuticals and personal care products，PPCPs）在环境中普遍存在。有证据表明，环境中的有些PPCPs能对生物体产生影响，如改变生物体的性别比例，影响植物生长，动物幼虫的孵化，甚至具有明显的致畸效应。卡马西平（Carbamazepine，CBZ）是一种常用的抗癫痫、止痛药物和抗抑郁药。毒理学实验表明，环境中的CBZ能严重影响鱼、蚌等水生生物的免疫和循环系统。CBZ使用量大，在环境中含量高，在地下水渗透过程和常规污水处理中保持稳定，因此CBZ成为衡量人类活动和污水处理工艺效率的标志物。但是目前人们对CBZ的环境地球化学循环知之甚少。DOM能与许多有机污染物发生相互作用，从而影响它们的生物环境地球化学行为，但DOM对CBZ的影响尚未见报道。本论文利用三维荧光光谱技术和同步荧光光谱技术，研究了DOM与CBZ的结合强度、结合类型、影响因素，并且初步总结了DOM对CBZ环境地球化学循环的影响。为理解其它PPCPs的生物地球化学循环，预测它们的迁移转化、归宿和环境毒性提供参考。 本文运用紫外吸收滴定法和荧光淬灭滴定法研究了不同来源的DOM和金属离子（Cu2+和Hg2+）的相互作用，运用三维荧光光谱法和同步扫描荧光光谱法研究了DOM和卡马西平的相互作用。主要成果简述如下： 1、本文首次将紫外吸收滴定法应用于测定金属离子和DOM的条件稳定常数，结果表明紫外吸收滴定法操作更简便、测定迅速、仪器普及率高，可在DOM含量很低（约10-5 ~ 10-7 mol/L）的情况下也可以直接进行测定，不必进行复杂的预富集。可望成为DOM和痕量有毒重金属离子相互作用的有力工具。 2、重金属离子（Hg2+和Cu2+）与DOM的羧基和酚羟基等基团配位。配位后电子的离域性增加，导致紫外吸收增加。与此同时配位后分子极性的改变和铜离子顺磁性作用，引起DOM荧光淬灭。在Cu2+和Hg2+的滴定过程中，紫外吸光度和荧光强度之间呈极显著线性负相关关系（R2=0.99，P<0.001）。这说明荧光和紫外从不同侧面揭示了DOM和金属离子的配位作用。 3、紫外吸收滴定法和荧光淬灭滴定法测定其条件稳定常数（log K）一致，介于3.5 ~ 5.5之间。强配位作用是DOM影响有毒重金属离子环境地球化学行为的根源。研究还表明配位作用的强弱受DOM来源和体系pH的影响。 4、 CBZ和DOM能发生强烈的相互作用，结合常数（log K）介于3.41 ~ 5.04之间。DOM能明显减少游离态CBZ的浓度，提高CBZ溶解度和迁移转化能力。这对认识CBZ和其它PPCPs的环境地球化学循环及其影响因素具有指导意义。 5、荧光光谱研究表明CBZ对DOM发射的荧光具有明显的猝灭作用，其猝灭机理为静态猝灭。疏水作用是CBZ和DOM之间的主要作用力。DOM-CBZ受pH值的影响不大， Cu2+对CBZ和DOM的结合有一定的影响。

红枫湖、百花湖水中溶解有机物分子量分布特征及环境地球化学意义

溶解有机物（dissolved organio matter， DOM）通常是指能够通过0.45μm滤膜的有机物质。0.45μm的定义是根据传统的过滤滤膜直径来划分的，不是一个绝对的定义。DOM在水环境中起着重要的作用，它是水环境中重要的配位体和吸附载体。DOM在水化学和生态环境中的重要作用，主要表现在它不仅可以和基本的金属离子和有机化合物结合，还可以与毒性金属离子和除草剂、杀虫剂结合（wershow ond Goldberg，1972）。湖泊水中DoM的浓度及物理化学性质能够影响水生态环境的结构及初级生产力。溶解有机物按元素组成来分，主要含有C、O、H、N、P、S以及灰分。按重量计算，其中C占总有机物的50％，其次是O（科O％）、H（一5％）、N（0.5～6.5％）、P（＜1.0％）、S（＜1.0％）和灰分（1.2-5.0％）（Thurman，1985）。DOM一般由多种有机化合物组成，其中腐殖物质是溶解有机质的主要组成部分，一般占有机质总量的50-80％。目前通常可人为地将腐殖物质划分为胡敏素、胡敏酸和富里酸（Aiken et oL，1 985）。其余的非腐殖类物质主要包括碳水化合物、氨基酸、叶绿素、藻类分泌物、酚酮类化合物、脂肪酸和亲水性有机酸等（Thurman，1985）a在水环境中一些金属离子和微量元素通常和DOM相结合，而这些元素的作用和在水中的迁移都受DoM的分子量分布的影响（chiou etal．，1986）。 DOM的分子量及其分布是指示水质量的一个重要参数，同时在水处理过程中对于研究DOM的去处效率有重要作用（vuorio et oL，1998）。具有不同分子量分布的DOM与金属的络合能力也不同，则它们对金属的生物有效性的作用就不同（wuetal．，2002）。分子量变化的程度可以进一步理解DOM的自然形成过程，也可以在弓！用水处理过程中优化腐殖质的去除过程。红枫湖和百花湖是贵州地区两个人工水库，通过对两湖水文条件的测量，探讨了影响DOM分子量及分布变化的环境因素，包括溶解氧的含量、水体温度、pH值、叶绿素。的含量、光照强度、藻类生长情况、生物活动等，以及溶解有机物的来源，人为污染情况等。本文采样高效体积排阻色谱法（High PerformanceSizeExclusion cbromatograP场，HPsEC）测量了红枫湖、百花湖水中的DOM的含量及分子量分布，得出了以下几点认识：1、选择HPsEC实验的最佳条件：0.03M NaCl和0.002的磷酸盐缓冲液作为流动相，pH为6.8，离子强度为0．034mol几，紫外检测波长为254nm。2、红枫湖、百花湖水中DOM主要以分子量小于3500Da的组分为主，占总溶解有机物的90％以上。根据洗脱曲线的峰面积，可以把DOM分为3个不同 分子量的组分，其中大分子量组分（MW＞2000Da）的含量占总DOM的35％一68％；中等分子量组分（Z000Da＞MW>1000Da）的含量为27％-57％；小分子量组分（MW＜1000Da）占总DOM的3％一31％。 3、红枫湖、百花湖水中Doc含量受气候条件的影响。丰水期，水体上部DOC含量较大，下部较小‘平水期和枯水期，上下水体中DOC含量一致。各组分DOc含量变化与总DOC含量变化相似。DOC含量也表现出明显的季节性变化特征。丰水期DOC含量较高，而在平水期和枯水期含量较低。红枫湖和百花湖二者之间DOC含量没有明显的差别。4、红枫湖、百花湖水中DOM平均分子量也受气候条件的影响。丰水期，随深度的增大，DoM平均分子量增大；平水期和枯水期，上下水体DOM平均分子量一致。DO入左的季节性变化与DOC相反，丰水期，DOM平均分子量偏低；而在平水期和枯水期，DOM平均分子量偏高。5、重均分子量和数均分子量虽然变化趋势相似，但是它们的变化幅度不同，所以多分散系数也会发生变化。总的来说，在水体上部多分散系数偏大，水体下部偏小。丰水期多分散系数较大，平水期和枯水期多分散系数较小。6、随着气候条件的变化，各分子量组分的DOM含量及DOC浓度也在发生变化。大分子量组分随深度而增大，而中等和小分子量组分随深度而减小。丰水期，中等和小分子量组分含量较多，而大分子量组分较少；平水期和枯水期，大分子量组分含量较多，中等和小分子量组分含量较少。

水环境中的溶解有机质及其与金属离子的相互作用——荧光光谱学研究

本论文通过选择这一国际前沿科学领域,主要运用三维荧光光谱仪、紫外-可见分光光度仪、溶解有机碳/氮分析仪、高效体积排阻色谱、荧光猝灭滴定等分析化学方法和手段,对云贵高原湖泊红枫湖、百花湖、洱海沉积物孔隙水以及一些河流等当中的DOM及其水化学特征进行了深入细致的研究,并且运用三维激发发射荧光光谱研究DOM中不同组分与Hg的相互作用,在溶解有机质的化学结构及其与金属汞的相互作用机理等方面取得了一些进展.