Short communicationCoastal spreading of olivine to control atmospheric CO2 concentrations: A critical analysis of viability. Comment: Nature and laboratory models are different
Short communicationCoastal spreading of olivine to control atmospheric CO2 concentrations: A critical analysis of viability. Comment: Nature and laboratory models are different
复制标题
简短的通讯橄榄石沿海传播控制大气二氧化碳浓度：可行性的关键分析。
DOI：
10.1016/j.ijggc.2010.04.012
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发表时间：
2010
影响因子：
3.9
通讯作者：
P. D. Boer
中科院分区：
文献类型：
--
作者：
R. Schuiling;P. D. Boer
Hangx和Spiers（2009）对Schuiling和Krijgsman（2006）的结论进行了评论，认为在吸收二氧化碳的情况下，沿海地区300个橄榄砂可能需要长达2100年的化学风化时间，这严重低估了自然环境下的吸收速度，在自然环境下，植物、动物和物理过程加速了橄榄石的风化。大约30亿年以来，地球表面一直被生物群占据，这些生物群刺激了化学风化作用。泥盆纪（416-359 Ma BP）期间大气CO2的急剧下降归因于深根树木对大陆的殖民化（Berner, 1992）。菌根真菌与植物根系共生，通过酸化和释放低分子量有机螯合剂改变矿物质，积极地延伸到土壤中寻找营养物质（landweert等人，2001；Taylor等人，2009），在某种程度上，橄榄石颗粒（来自附近来源）在土壤中不常见（Wilson, 2004）。在海岸带，由于波浪和水流的影响，颗粒与颗粒之间的碰撞会抛光抑制反应的富硅橄榄石表面层，在静态实验室条件下，这些层限制了反应速率。在一个简单的实验室实验中，将封闭体积的橄榄石颗粒连续摇动，结果显示橄榄石重量在1周内下降了4-8%，而pH值在几天内上升到9.6（作者未发表的结果）。因此，溶解橄榄石颗粒的碰撞和刮擦增强了反应，使其比根据橄榄石在（海）水中的溶解动力学理论预测的要快。这就解释了为什么容易耐候性好
The conclusion of Hangx and Spiers (2009), commenting on Schuiling and Krijgsman (2006), that in the coastal zone up to 2100 years may be needed for 300 olivine sand to be chemically weathered under the uptake of CO2 grossly understates the uptake rate in natural settings, where flora, fauna and physical processes accelerate the weathering of olivine.Since some 3 billion years the surface of the Earth has been colonised by biota which stimulate chemical weathering. The sharp decline in atmospheric CO2 during the Devonian (416–359 Ma BP) is ascribed to the colonisation of the continents by deep-rooted trees (Berner, 1992). Mycorrhizal fungi living in symbiosis with plant roots actively extend into the soil and forage for nutrients by altering minerals through acidification and by the release of lowmolecular weight organic chelators (Landeweert et al., 2001; Taylor et al., 2009), to the extent that, eg olivine grains (from nearby sources) are not commonly found in soils (Wilson, 2004). In the coastal zone, grain-to-grain collisions, due to waves and currents, polish reaction-inhibiting Si-rich olivine-surface layers which–under static laboratory conditions–limit the reaction rate. A simple laboratory experiment, in which olivine grains in a closed volume of water are shaken continuously, shows a 4–8% decrease in olivine weight within 1 week, while the pH rises to 9.6 within a few days (authors’ unpublished results). Collisions and scraping of the dissolving olivine grains thus enhance the reaction so that it is faster than theoretically predicted on basis of the dissolution kinetics of olivine in (sea) water. This explains why easily weatherable min-