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pH-Dependent kinetics of tuff dissolution
Year:
1999
Source of publication :
Geoderma
Authors :
Bar-Yosef, Bnayahu
;
.
Silber, Avner
;
.
Volume :
93
Co-Authors:
Silber, A., Institute of Soils, Water Environ. Sci., Agric. Res. O., Bet Dagan, Israel
Bar-Yosef, B., Institute of Soils, Water Environ. Sci., Agric. Res. O., Bet Dagan, Israel
Chen, Y., Seagram Ctr. for Soil and Water Sci., Fac. Agric., Hebrew Univ. J., Rehovot, Israel
Facilitators :
From page:
125
To page:
140
(
Total pages:
16
)
Abstract:
Despite the widespread use of commercial tuffs as growth substrates, their dissolution kinetics and the time variation of their solution compositions have not hitherto been investigated. To fill this gap in our knowledge, rates of ion release by two tuffs were measured as a function of pH in batch and in steady-solution-flow suspensions. Reaction kinetics was characterized by rapid H+/OH- consumption, and Si, Al, Ca, Mg, and P release during the first day. This was followed by a period in which H+ consumption and ion release were linear functions of time for at least 720 h. On the basis of reaction stoichiometry and equilibrium calculations, rapid short-term H+ consumption of the studied tuffs was related to cation exchange and rapid dissolution of fine particles of volcanic glass and hydroxyapatite (HA). The rate laws for long-term acid consumption were fractional-order with respect to H+ concentration in the pH ranges 3.4-6.5 and 3.6-9.6, black and yellow tuffs, respectively. On the basis of proton-consumption rate data and ionic solution composition, long-term acid consumption was attributed to the dissolution of halloysite-like allophane in yellow tuff, volcanic glass in black tuff, and HA in both tuffs. Aluminum dissolution from black tuff under batch conditions at pH below 4 may create a toxic environment for plant roots.
Note:
Related Files :
Aluminum
chemical weathering
Growth substrate
Halloysite-like allophane
Hydroxyapatite
pH
Silicon
Tuff
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Related Content
More details
DOI :
10.1016/S0016-7061(99)00048-8
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
19803
Last updated date:
02/03/2022 17:27
Creation date:
16/04/2018 23:31
Scientific Publication
pH-Dependent kinetics of tuff dissolution
93
Silber, A., Institute of Soils, Water Environ. Sci., Agric. Res. O., Bet Dagan, Israel
Bar-Yosef, B., Institute of Soils, Water Environ. Sci., Agric. Res. O., Bet Dagan, Israel
Chen, Y., Seagram Ctr. for Soil and Water Sci., Fac. Agric., Hebrew Univ. J., Rehovot, Israel
pH-Dependent kinetics of tuff dissolution
Despite the widespread use of commercial tuffs as growth substrates, their dissolution kinetics and the time variation of their solution compositions have not hitherto been investigated. To fill this gap in our knowledge, rates of ion release by two tuffs were measured as a function of pH in batch and in steady-solution-flow suspensions. Reaction kinetics was characterized by rapid H+/OH- consumption, and Si, Al, Ca, Mg, and P release during the first day. This was followed by a period in which H+ consumption and ion release were linear functions of time for at least 720 h. On the basis of reaction stoichiometry and equilibrium calculations, rapid short-term H+ consumption of the studied tuffs was related to cation exchange and rapid dissolution of fine particles of volcanic glass and hydroxyapatite (HA). The rate laws for long-term acid consumption were fractional-order with respect to H+ concentration in the pH ranges 3.4-6.5 and 3.6-9.6, black and yellow tuffs, respectively. On the basis of proton-consumption rate data and ionic solution composition, long-term acid consumption was attributed to the dissolution of halloysite-like allophane in yellow tuff, volcanic glass in black tuff, and HA in both tuffs. Aluminum dissolution from black tuff under batch conditions at pH below 4 may create a toxic environment for plant roots.
Scientific Publication
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