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Role of Carbonic Anhydrase as an Activator in Carbonate Rock Dissolution and Its Implication for Atmospheric CO_(2)Sink

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Acta Geologica Sinica(English Edition) 2001年第3期75卷 275-278页

作者： liu zaihua Karst Dynamics Laboratory of MLR Institute of Karst Geology Chinese Academy of Geological Sciences50 Qixing RoadGuilin 541004

The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic anhydrase (CA), which is widespread in nature, was used to catalyze the CO2 conversion process in dissolution experiments of limestone and dolomite. It was found that the rate of dissolution increases by a factor of about 10 after the addition of CA at a high CO2 partial pressure (Pco2) for limestone and about 3 at low Pco2 for dolomite. This shows that reappraisal is necessary for the importance of chemical weathering (including carbonate rock dissolution and silicate weathering) in the atmospheric CO2 sink and the mysterious missing sink in carbon cycling. It is doubtless that previous studies of weathering underestimated weathering rates due to the ignorance of CA as an activator in weathering, thus the contribution of weathering to the atmospheric CO2 sink is also underestimated. This finding also shows the need to examine the situ distribution and activity of CA in different waters and to investigate the role of CA in weathering.

关键词： carbonic anhydrase CO_(2)conversion carbonate rock dissolution atmospheric CO_(2)sink

Is pedogenic carbonate an important atmospheric CO_2 sink?

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Chinese Science Bulletin 2011年第35期56卷 3794-3796页

作者： liu zaihua The State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Nearly 18 years after the proposal of the weathering-related carbon sink concept(Berner R ***,plants and the long-term carbon *** Cosmochim Acta,1992,56:3225-3231),it is an appropriate timing to re-evaluate its geological context with the updated *** et al.(Ryskov Ya G,Demkin V A,Oleynik S A,et *** of pedogenic carbonate for the last 5000 years and its role as a buffer reservoir for atmospheric carbon dioxide in soils of *** Planet Change,2008,61:63-69) lately claimed that in the course of soil formation for the last 5000 years the soils of Russia fixed atmospheric carbon dioxide as pedogenic carbonate during the arid periods at a rate of 2.2 kg C/(m2 a) in chernozem,1.13 kg C/(m2 a) in dark-chestnut soil,0.86 kg C/(m2 a) in light-chestnut soil,on the basis of carbon isotopic data;however,their interpretations of the data do not appear straightforward nor persuading,and thus their claim is likely *** interpretations are also contrary to the conclusions drawn by Dart et al.(Dart R C,Barovich K M,Chittleborough D J,et *** in regolith carbonates of central and southern Australia:Its source and implications for the global carbon *** Palaeoclimatol Palaeoecol,2007,249:322-334) who found that Australian regolith carbonates did not capture any additional CO2;instead the carbonate was simply being remobilized from one pool to *** we raise comments to these explanations on the following two issues:(1) origin of pedogenic carbonate:silicate weathering *** weathering,and(2) problems in using carbon isotopic technique to distinguish carbonates formed by silicate weathering and carbonate *** is concluded that pedogenic carbonate may not be an important atmospheric CO2 sink at all,*** weathering-related pedogenic carbonate does not capture any additional CO2,while the CO2 capture in silicate weathering-related pedogenic carbonate is small in short-term time scales

关键词：大气CO2 碳酸盐成土二氧化碳含量土壤形成过程全球碳循环暗栗钙土碳同位素技术

A possible important CO_2 sink by the global water cycle

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Chinese Science Bulletin 2008年第3期53卷 402-407页

作者： liu zaihua Wolfgang DREYBRODT WANG HaiJing The State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Karst Dynamics Laboratory Ministry of Land and Resources Guilin 541004 China Institute of Experimental Physics University of Bremen Bremen 28334 Germany School of Geographical Sciences Southwest University Chongqing 400715 China

The locations,magnitudes,variations and mechanisms responsible for the global CO2 sink are uncer-tain and under ***,we show,based on theoretical calculations and evidences from field monitoring results,that there is a possible important CO2 sink(as DIC-dissolved inorganic carbon)by the global water *** sink constitutes up to 0.8013 Pg C/a(or 10.1% of the total anthropogenic CO2 emission,or 28.6% of the missing CO2 sink),and is formed by the CO2 absorption of water and subsequent enhanced consumption by carbonate dissolution and aquatic plant *** the sink,0.5188 Pg C/a goes to sea via precipitation over sea(0.2748 Pg C/a)and continental rivers(0.244 Pg C/a),0.158 Pg C/a is released to the atmosphere again,and 0.1245 Pg C/a is stored in the continental aquatic ***,the net sink could be 0.6433 Pg C/*** sink may increase with the global-warming-intensified global water cycle,the increase in CO2 and carbonate dust in atmosphere,and reforestation/afforestation,the latter increasing soil CO2,and thus the concentration of the DIC in water.

关键词：二氧化碳全球水循环碳酸盐分解水生植物光合作用

岩溶湖库生产力的溶解无机碳施肥及碳增汇和富营养化缓解效应

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科学通报 2023年第8期68卷 915-926页

作者：刘再华中国科学院地球化学研究所环境地球化学国家重点实验室贵阳550081

内陆水体在全球碳循环中的作用日益受到关注,特别是喀斯特地表水体与水生光合作用有关的生物泵(biological pump,BP)将溶解无机碳(dissolved inorganic carbon,DIC)转化为有机碳沉积,是形成长期稳定碳酸盐风化碳汇的关键.富营养化作为B... 详细信息

内陆水体在全球碳循环中的作用日益受到关注,特别是喀斯特地表水体与水生光合作用有关的生物泵(biological pump,BP)将溶解无机碳(dissolved inorganic carbon,DIC)转化为有机碳沉积,是形成长期稳定碳酸盐风化碳汇的关键.富营养化作为BP的特殊阶段,是地表水环境面临的主要环境问题之一.然而,通常认为富营养化的控制元素是磷(P)和氮(N),而BP的控制元素还包括碳(C),如喀斯特湖库尽管DIC浓度高,但其碱性环境使得水中的CO_(2)很低,因此BP效率受到C限制.同时BP产生的碳酸钙促进了水中P的共沉淀,缓解了水体向蓝藻型富营养化的发展,可能促成水质安全和水体碳增汇的双赢.未来需通过对不同气候(温度、降水差异)、不同土地利用(N-P营养输入差异)和不同岩性(碳酸盐岩-硅酸盐岩风化产生pH和DIC差异)条件下的喀斯特地表水体BP的DIC施肥及其碳增汇和富营养化缓解效应进行系统研究,重点揭示以下关键科学问题:(1)DIC对BP施肥的机制及控制因素;(2)水体C:N:P:Si与浮游-沉水植物群落结构/组成的耦合关系及机制;(3)DIC施肥下BP的碳增汇和富营养化缓解效应.系统研究将为HCO_(3)-Ca型地表水体碳增汇和水质安全调控提供新的理论依据和科学支撑.

关键词：喀斯特地表水体生物泵溶解无机碳施肥碳增汇富营养化缓解

Influence of the biological carbon pump effect on the sources and deposition of organic matter in Fuxian Lake, a deep oligotrophic lake in southwest China

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Acta Geochimica 2019年第5期38卷 613-626页

作者： Haibo He zaihua liu Chongying Chen Yu Wei Qian Bao Hailong Sun Yundi Hu Hao Yan State Key Laboratory of Environmental Geochemistry Institute of GeochemistryCASGuiyang 550081China University of Chinese Academy of Sciences Beijing 100049China CAS Center for Excellence in Quaternary Science and Global Change Guiyang 550081China

Biological carbon pumping(BCP)is a key process in which dissolved inorganic carbon in terrestrial aquatic ecosystems is utilized by aquatic autotrophs for photosynthesis and transformed into autochthonous organic matter(AOC).However,the mechanisms underlying BCP and the amount of generated AOC deposited effectively,are still poorly ***,we conducted a systematic study combining modern hydrochemical monitoring and a sediment trap experiment in Fuxian Lake(Yunnan,SW China),the second-deepest plateau,oligotrophic freshwater lake in ***,pH,EC(electrical conductivity),DO(dissolved O2),[HCO3^-],[Ca^2+],SIc,partial CO2(pCO2)pressure,and carbon isotopic compositions of HCO3^-(δ^13CDIc)in water from Fuxian Lake all displayed distinct seasonal and vertical *** was especially apparent in an inverse correlation between pCO2 and DO,indicating that variations of hydrochemistry in the lake water were mainly controlled by the metabolism of the aquatic ***,the lowest C/N ratios and highestδ^13Corg were recorded in the trap *** of the C/N ratio demonstrated that the proportions of AOC ranged from 30%to 100%of all OC,indicating that AOC was an important contributor to sedimentary organic matter(OC).It was calculated that the AOC flux in Fuxian Lake was 20.43 t C km^-2 in ***,AOC produced by carbonate weathering and aquatic photosynthesis could potentially be a significant carbon sink and may have an important contribution to solving the lack of carbon sinks in the global carbon cycle.

关键词： Carbonate weathering Hydrochemical variation Biological carbon pump effect Sediment trap Autochthonous organic carbon Carbon sink

Alleviating eutrophication by reducing the abundance of Cyanophyta due to dissolved inorganic carbon fertilization:Insights from Erhai Lake,China

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Journal of Environmental Sciences 2023年第9期131卷 68-83页

作者： Chaowei Lai Zhen Ma zaihua liu Hailong Sun Qingchun Yu Fan Xia Xuejun He Qian Bao Yongqiang Han Xing liu Haibo He State Key Laboratory of Environmental Geochemistry Institute of GeochemistryCASGuiyang 550081China School of Water Resources and Environment China University of Geosciences(Beijing)Beijing 100083China University of Chinese Academy of Sciences Beijing 100049China Hefei University Hefei 230601China Sichuan Normal University Key Laboratory of Land Resources Evaluation and Monitoring in Southwest China of Ministry of Education Chengdu 610066China

The eutrophication of lakes is a global environmental *** nitrogen(N)and phosphorus(P)on phytoplankton is considered to be the most important basis of lake eutrophication ***,the effects of dissolved inorganic carbon(DIC)on phytoplankton and its role in mitigating lake eutrophication have often been *** this study,the relationships between phytoplankton and DIC concentrations,carbon isotopic composition,nutrients(N and P),and hydrochemistry in the Erhai Lake(a karst lake)were *** results showed that when the dissolved carbon dioxide(CO_(2)(aq))concentrations in the water were higher than 15μmol/L,the productivity of phytoplankton was controlled by the concentrations of TP and TN,especially by that of *** the N and P were sufficient and the CO_(2)(aq)concentrations were lower than 15μmol/L,the phytoplankton productivity was controlled by the concentrations of TP and DIC,especially by that of ***,DIC significantly affected the composition of the phytoplankton community in the lake(p<0.05).When the CO_(2)(aq)concentrations were higher than 15μmol/L,the relative abundance of Bacillariophyta and Chlorophyta was much higher than those of harmful ***,high concentrations of CO_(2)(aq)can inhibit harmful Cyanophyta blooms.

关键词： Dissolved inorganic carbon Nutrients limitation Phytoplankton species composition Eutrophication management Karst lake

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表生和内生钙华的气候环境指代意义研究进展

科学通报 2014年第23期59卷 2229-2239页

作者：刘再华中国科学院地球化学研究所环境地球化学国家重点实验室贵阳550002

钙华分为表生和内生两大类:表生钙华主要起因于水中土壤成因CO2的脱气作用,而内生钙华起因于水中热成因CO2的脱气作用.作为两大类钙华的表生和内生钙华因CO2来源和分压不同,它们的形成机理及其指代的气候环境意义也可能完全不同.本文综... 详细信息

钙华分为表生和内生两大类:表生钙华主要起因于水中土壤成因CO2的脱气作用,而内生钙华起因于水中热成因CO2的脱气作用.作为两大类钙华的表生和内生钙华因CO2来源和分压不同,它们的形成机理及其指代的气候环境意义也可能完全不同.本文综述了表生和内生钙华的形成机理及对气候环境指代意义的研究现状和存在的问题,进而提出钙华沉积速率和碳氧稳定同位素组成等气候环境代用指标的水动力控制、表面控制和CO2慢速转换控制的深入揭示,并对这些指标变化与气候(温度、降水)、人类活动(如土地利用)和地震的关系进行定性或定量重建是未来研究的重点.这些突破将为利用钙华记录高分辨率辨析我国季风气候对全球变化的响应规律和可能的机制提供新的科学支撑.

关键词：表生钙华内生钙华沉积速率碳氧同位素组成温度降水地震土地利用

喀斯特地表水生生态系统生物碳泵的碳汇和水环境改善效应

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科学通报 2017年第30期62卷 3440-3450页

作者：陈崇瑛刘再华中国科学院地球化学研究所环境地球化学国家重点实验室贵阳550081 中国科学院大学北京100049

碳汇研究是全球碳循环研究的重要内容.近年来,陆地水生生态系统的碳汇日益受到重视,被认为是"遗失碳汇"的重要组成部分.最新研究发现,碳酸盐风化碳汇占岩石风化碳汇的94%,因此,喀斯特地表水生生态系统的碳汇显得尤为重要.生物碳泵效应... 详细信息

碳汇研究是全球碳循环研究的重要内容.近年来,陆地水生生态系统的碳汇日益受到重视,被认为是"遗失碳汇"的重要组成部分.最新研究发现,碳酸盐风化碳汇占岩石风化碳汇的94%,因此,喀斯特地表水生生态系统的碳汇显得尤为重要.生物碳泵效应作为一种稳碳和固碳过程,是形成长期稳定碳酸盐风化碳汇的重要机制,是碳循环的重要环节.生物碳泵效应的核心控制元素是碳元素,该效应在富含溶解无机碳(DIC)的喀斯特地表水生生态系统中发挥着重要作用.目前生物碳泵效应的研究主要集中在两个方面:(1)内外源有机碳的区分是准确评价和计算生物碳泵效应碳汇的关键;(2)发现生物碳泵效应影响水环境指标和水质状况.未来,一方面应精确地对陆地水生生态系统碳汇量进行估算,研究不同气候和土地利用对碳汇量的影响;另一方面,揭示生物碳泵效应与水环境的相互作用机制.重点包括以下4个方面:(1)验证地表水生生态系统"元素比值控制假说";(2)生物碳泵效应对水体元素化学计量比的调控潜力;(3)形成不同碳汇机制(生物碳泵效应和富营养化机制)的根本原因;(4)生物碳泵效应通过物理-化学-生物耦合作用改善水环境的可能机制.最后,探究微生物碳泵效应应用于陆地水生生态系统的可能性.

关键词：碳汇水环境改善生物碳泵效应碳酸盐风化富营养化缓解

我国岩溶碳汇和在非岩溶区播撒碳酸盐粉的碳中和潜力

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科学通报 2022年第34期67卷 4116-4129页

作者：曾思博刘再华西南大学地理科学学院重庆400715 中国科学院地球化学研究所环境地球化学国家重点实验室贵阳550081

碳酸盐风化对大气CO_(2)的捕获是陆地碳汇的重要组成部分.我国岩溶地貌广泛分布,岩溶碳汇对我国实现“双碳”目标有较大意义,因而受到广泛关注.同时,由于碳酸盐的快速溶解动力学特性,在非岩溶区富含碳酸盐的土壤可产生类似于岩溶区的碳... 详细信息

碳酸盐风化对大气CO_(2)的捕获是陆地碳汇的重要组成部分.我国岩溶地貌广泛分布,岩溶碳汇对我国实现“双碳”目标有较大意义,因而受到广泛关注.同时,由于碳酸盐的快速溶解动力学特性,在非岩溶区富含碳酸盐的土壤可产生类似于岩溶区的碳汇通量,因此碳酸盐粉末在非岩溶区的播撒具有巨大的碳中和潜力.本文利用高分辨率遥感和气象数据以及碳酸盐溶蚀平衡模型,对全国碳酸盐岩出露区岩溶碳汇通量进行了定量研究.结果表明,这个碳汇通量约为每年每平方公里6.93吨碳,岩溶区产生的总碳汇为每年1760万吨碳;而在非岩溶区播撒碳酸盐粉末可以增加每年3859万吨的碳汇.基于8个CMIP6模式的未来预测,从2015年到2060碳中和年,我国岩溶碳汇通量受到全球变化的影响将增加约每年每平方公里1吨碳,总碳汇增加约每年254万吨碳(+14.4%),而非岩溶区撒播碳酸盐粉的潜在碳中和潜力增加约每年697万吨碳(+18.1%).本研究表明岩溶碳汇对未来全球气候变化的负反馈以及非岩溶区撒播碳酸盐粉的巨大碳增汇潜力将有助于我国未来碳中和目标的实现.

关键词：岩溶碳汇碳酸盐风化气候变化土地利用撒碳酸盐粉碳中和潜力