Passive Sequestration of Atmospheric CO2 through Coupled Plant-Mineral Reactions in Urban soils David A. C. Manning<http://pubs.acs.org/action/doSearch?action=search&author=Manning%2C+David+A.+C.&qsSearchArea=author> *<http://pubs.acs.org/doi/full/10.1021/es301250j#cor1>† and Phil Renforth<http://pubs.acs.org/action/doSearch?action=search&author=Renforth%2C+Phil&qsSearchArea=author> ‡ † School of Civil Engineering & Geosciences, Newcastle University, Newcastle upon Tyne, U.K., NE1 7RU ‡ Department of Earth Sciences, University of Oxford, Parks Road, Oxford, U.K., OX1 3AN Environ. Sci. Technol., 2013, 47 (1), pp 135–141 DOI: 10.1021/es301250j Publication Date (Web): May 22, 2012 Copyright © 2012 American Chemical Society *Phone: +44 191 222 6610; e-mail: [email protected]<mailto:[email protected]>. This article is part of the Carbon Sequestration<http://pubs.acs.org/toc/esthag/47/1> special issue. [CAS]<http://cas.org/>Section: Air Pollution and Industrial Hygiene<http://pubs.acs.org/topic/industrial_hygiene> Abstract
Photosynthetic removal of CO2 from the atmosphere is an important planetary carbon dioxide removal mechanism. Naturally, an amount equivalent to all atmospheric carbon passes through the coupled plant–soil system within 7 years. Plants cycle up to 40% of photosynthesized carbon through their roots, providing a flux of C at depth into the soil system. Root-exuded carboxylic acids have the potential to supply 4–5 micromoles C hr–1g–1 fresh weight to the soil solution, and enhance silicate mineral weathering. Ultimately, the final product of these root-driven processes is CO2, present in solution as bicarbonate. This combines with Ca liberated by corrosion associated with silicate mineral weathering to enter the soil–water system and to produce pedogenic calcium carbonate precipitates. Combining understanding of photosynthesis and plant root physiology with knowledge of mineral weathering provides an opportunity to design artificial soils or to plan land use in ways that maximize removal and sequestration of atmospheric CO2 through artificially enhanced pedogenic carbonate precipitation. This process requires relatively low energy and infrastructure inputs. It offers a sustainable carbon dioxide removal mechanism analogous to the use of constructed wetlands for the passive remediation of contaminated waters, and is likely to achieve wide public acceptance. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
<<inline: image005.png>>
