Role of carbonic anhydrase as an activator in carbonate rock dissolution and its implication for atmospheric Co-2 sink

Authors
Citation
Zh. Liu, Role of carbonic anhydrase as an activator in carbonate rock dissolution and its implication for atmospheric Co-2 sink, ACT GEO S-E, 75(3), 2001, pp. 275-278
Citations number
14
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
ACTA GEOLOGICA SINICA-ENGLISH EDITION
ISSN journal
1000-9515 → ACNP
Volume
75
Issue
3
Year of publication
2001
Pages
275 - 278
Database
ISI
SICI code
1000-9515(200109)75:3<275:ROCAAA>2.0.ZU;2-D
Abstract
The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic a nhydrase (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 a fter the addition of CA at a high CO2 partial pressure (Pco(2)) for limesto ne and about 3 at low Pco(2) for dolomite. This shows that reappraisal is n ecessary for the importance of chemical weathering (including carbonate roc k dissolution and silicate weathering) in the atmospheric CO2 sink and the mysterious missing sink in carbon cycling. It is doubtless that previous st udies of weathering underestimated weathering rates due to the ignorance of CA as an activator in weathering, thus the contribution of weathering to t he atmospheric CO2 sink is also underestimated. This finding also shows the need to examine the situ distribution and activity of CA in different wate rs and to investigate the role of CA in weathering.