Small Scale Field Study of an Ocean CO<Subscript>2</Subscript> Plume

We have carried out a small-scale (∼20 l) CO₂ sequestration experiment off northern California (684 m depth, ∼5°C, background ocean pH ∼7.7) designed as an initial investigation of the effects of physical forcing of the fluid, and the problem of sensing the formation of a low pH plume. The buoyant CO₂ was contained in a square frame 1.2 m high, exposing 0.21 m² to ocean flow. Two pH electrodes attached to the frame recorded the signal; a second frame placed 1.9 m south of the CO₂ pool was also equipped with two recording pH electrodes. An additional pH electrode was held in the ROV robotic arm to probe the fluid interface. Local water velocities of up to 40 cm sec⁻¹ were encountered, creating significant eddies within the CO₂ box, and forcing wavelets at the fluid interface. This resulted in rapid CO₂ dissolution, with all CO₂ being depleted in a little more than 2 days. The pH record from the sensor closest (∼10 cm) to the CO₂ showed many spikes of low pH water, the extreme value being ∼5.9. The sensor 1 m immediately below this showed no detectable response. The electrodes placed 1.9 m distant from the source also recorded very small perturbations. The results provide important clues for the design of future experiments for CO₂ disposal and biogeochemical impact studies. These include the need for dealing with the slow CO₂ hydration kinetics, better understanding of the fluid dynamics of the CO₂-water interface, and non-point source release designs to provide more constant, controlled local CO₂ enrichments within the experimental area. This revised version was published online in July 2006 with corrections to the Cover Date.     

赤道北太平洋海水中的二氧化碳体系

根据2001年10—11月在赤道北太平洋海域(含赤道东太平洋东、西部海区和西太平洋暖池区)的调查资料，分析了该海域水体中二氧化碳体系各组分的含量及其分布状况，并对其与营养盐及碳酸钙饱和度之间的关系进行了初步探讨。结果表明，表层海水总二氧化碳(∑CO2)含量为1.07—2．01mmol．L^-1，自赤道北太平洋东部向西呈逐渐降低趋势；表层海水二氧化碳分压(Pco2)高于大气二氧化碳分压平均值，表明赤道北太平洋可能为大气二氧化碳的海水源区；海水二氧化碳体系的垂直分布主要受生物生命过程和碳酸钙沉淀与溶解过程影响。     

电厂温排水中余氯浓度预测

利用有限元分步杂交方法,对胶州湾海域潮流场进行了数值模拟。考虑余氯在水体中的化学反应,利用前人大量实验成果选取余氯衰减系数,建立胶州湾余氯的二维输运-扩散模型,并将此模型应用于青岛市黄岛发电厂三期温排水工程,预测了温排水中余氯的浓度分布及影响范围,为电厂冷却水排放口邻近水域的生态环境保护提供依据。     

矽卡岩化作用排碳到大气中的途径SCIEI北大核心CSCD

鉴于大陆岩浆弧上盘广泛分布有碳酸盐岩,岩体上升侵位过程使其碳通量明显的高于洋内岛弧,从而有可能影响着地质历史长时间尺度(百万年)的气候变化。陆弧碳的排放可分为两部分,一部分是与喷出岩相关的火山作用,另一部分是与侵入岩相关的脱碳过程。侵入岩的体量一般是喷出岩体量的10倍以上,由此与侵入岩有关的脱碳作用释放的碳通量不可忽视,可能类似与喷出岩有关的火山作用释放的碳通量甚至更大。火山作用能够将气体直接排入大气中,因此在以往的工作中研究较为充分。但与侵入岩相关的脱碳过程如:矽卡岩化,发生在地下,关于地下脱碳过程如何将碳释放到大气中还缺少详细的工作。本文,通过对比研究火山地区和非火山地区与侵入岩相关的深部脱碳过程,发现深部碳可以通过区域断层系统、地下水系统和热泉、火山通道、隐爆角砾岩筒、高频率的岩浆热液事件等途径瞬时地释放进入大气。通过初步估算,发现单个矽卡岩矿化事件所产生的二氧化碳通量(0.02~0.2Mt/yr)能够与目前地球绝大部分的普通单个火山的碳通量(<0.5Mt/yr)类比。因此岩浆深部脱碳过程对大气的影响至少与火山相当,其对气候的影响不可忽视。     

Experimental Research on Supercritical Carbon Dioxide Fracturing of Sedimentary Rock: A Critical Review

Supercritical carbon dioxide(ScCO₂) fracturing has great advantages and prospects in both shale gas exploitation and CO₂ storage. This paper reviews current laboratory experimental methods and results for sedimentary rocks fractured by ScCO₂. The breakdown pressure, fracture parameters, mineral composition, bedding plane angle and permeability are discussed. We also compare the differences between sedimentary rock and granite fractured by ScCO₂, ultima...     

基于社会网络分析方法的二氧化碳地质封存风险传染特征研究

二氧化碳(CO₂)地质封存技术作为深度减排不可或缺的必要手段,对保护生态环境、推动全球中长期应对气候变化的国际合作以及推进社会绿色、循环、低碳发展具有重要意义。文章总结了二氧化碳地质封存项目全生命周期中可能出现的46个风险因素,运用社会网络分析方法构建风险网络关系模型,对二氧化碳地质封存项目风险因素间的传递作用关系进行了研究。通过风险网络整体与局部参数分析确定风险传递过程中的关键起始节点、关键致险节点、关键传递节点等关键因素,识别出三条潜在风险传递链：(1)地质灾害风险→CO₂供应、注入或运输意外中断风险→预期外的建设或操作成本变化风险;(2)操作人员知识不足或无相应资质风险→人为泄漏风险→项目对环境的破坏风险→公众参与风险→预期外的建设或操作成本变化风险;(3)部门协调不当风险→人才招聘和管理风险→操作人员知识不足或无相应资质风险→预期外的建设或操作成本变化风险。研究旨在为二氧化碳地质封存项目风险研究提供理论创新与技术参考,进而促进CO₂捕集、利用与封存项目的健康发展。     

1981–2020 winter ozone trends,Erzgebirge, Central Europe

Tropospheric ozone (O₃) acts as greenhouse gas and air pollutant. Over the last 100 years, tropospheric O₃ levels increased above background by factor 2.5 in the northern hemisphere and by factor 3–4 across Europe. The gas poses a potential risk to forest ecosystems in many mountain areas. There, O₃ concentrations result from long-range transport and are influenced by removal processes (dry deposition, gas phase and cloud removal, reduction on wet aerosols). Most trend studies analyzed annual-mean concentrations. We focus on winter O₃ trends at high altitudes in the German/Czech Erzgebirge (period 1981–2020) to avoid major noise from photochemical reactions and to better explain recent O₃ behavior in Central Europe. Hourly air quality and meteorological data from four stations (Carlsfeld, CAR; Fichtelberg, FIB; Schwartenberg, SWB; Zinnwald, ZIW) were used to analyze O₃ trends. The data can explain the complex O₃ formation and removal behavior.Three distinct periods of O₃-concentration trends can be discerned: i) Until the late 1980s, characterized by relatively low O₃ concentrations. ii) Dramatic transformation in the 1990s with changing air pollution in Central Europe. Strong O₃-concentration increase at FIB is corroborated by data from CAR and ZIW. iii) Stabilization as of 1997/98, when O₃ concentrations remained at the same level for all four stations, despite general regional air pollution decrease. Key results are:a) Winter O₃ trends mainly depend on O₃ concentration of air masses transported to the stations and on the O₃-removal potential (ORP) of clouds, not on local formation processes.b) ORP differs between clouds and fog, depending on droplet chemical composition. Fog from the North Bohemian Basin showed the highest ORP due to reaction with liquid phase S(IV). However, O₃ reactions with O₂⁻ in fog droplets showed high ORP, too, depending on cloud-water pH values and NO_x concentrations.c) So-called “Bohemian fog” decreased, and with it related ORP, while that of clouds from westerly and northwesterly air masses remained nearly unchanged since 1997/98.d) Decreasing ORP in clouds and fog (= higher O₃ concentration) oppose decreasing O₃ concentrations in westerly air masses. Both effects lead to unchanged O₃ levels in the Erzgebirge since 1997/98.     

干热岩热储建造的二氧化碳爆破致裂器优化设计

储层建造是商业化开采干热岩高温地热能的关键技术,二氧化碳爆破致裂技术为此提供了新思路。本文简述了二氧化碳爆破致裂技术,以及爆破过程中二氧化碳充装量、活化器用量、定压片厚度之间的关系。重点完善了用于干热岩储层建造的二氧化碳致裂器相关工作,设计了致裂器内部具体参数,优化了外部结构和系统,最终研发了一种可用于干热岩热储层建造的二氧化碳致裂器,为干热岩储层建造提供有效的技术手段,填补了耐高温高压的井下二氧化碳致裂器领域的空白。     

海水酸化对中华哲水蚤全蛋白表达的影响

运用蛋白质组学相关技术对暴露于酸化海水中的中华哲水蚤全蛋白进行分析,结果表明,对照组、CCO20.08%和CCO20.20%处理组中华哲水蚤的双向电泳图谱上可以分别分辨出1 191、1 117和946个蛋白点,选取其中43个差异蛋白进行MALDI-TOF/TOF质谱鉴定,成功鉴定出23个差异蛋白,这些蛋白主要与蛋白合成和分解、能量代谢、DNA分子修复以及解毒过程有关。     

珠江三角洲地区SO2浓度卫星遥感长时间序列监测

利用卫星OMI(Ozone Monitoring Instrument)数据获得的长时间序列SO₂浓度,分析广州亚运会从申办到成功举办期间珠江三角洲地区近地面SO₂浓度的变化过程,以及亚运会举办期间珠江三角洲SO₂浓度分布状况。结果表明OMI能够反映近地表的SO₂浓度变化趋势,广州亚运会从申办到成功举办期间珠江三角洲地区近地面SO₂浓度表现出明显的季节变化,且亚运会期间该地区近地面SO₂浓度比以往年同期要低,说明珠江三角洲地区联动的空气质量保障措施明显降低了该地区近地面的SO₂浓度。