Tiberg, Charlotta and Sjöstedt, Carin and Gustafsson, Jon Petter
(2018).
Metal sorption to Spodosol Bs horizons: Organic matter complexes predominate.
Chemosphere. 196
, 556-565
[Journal article]
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Official URL: https://doi.org/10.1016/j.chemosphere.2018.01.004
Abstract
While metal sorption mechanisms have been studied extensively for soil surface horizons, little information exists for subsoils, for example Spodosol Bs horizons. Here the sorption of cadmium(10, copper(II) and lead(II) to seven Bs horizons from five sites was studied. Extended X-ray absorption fine structure (EXAFS) spectroscopy showed that cadmium(II) and lead(II) were bound as inner-sphere complexes to organic matter. Addition of o-phosphate (to 1 mu mol l(-1)) did not result in any significant enhancement of metal sorption, nor did it influence EXAFS speciation. An assemblage model using the SHM and CD-MUSIC models overestimated metal sorption for six out of seven soil samples. To agree with experimental results, substantial decreases (up to 8-fold) had to be made for the fraction 'active organic matter', f(Hs), while the point-of-zero charge (PZC) of ferrihydrite had to be increased. The largest decreases of f(HS) were found for the soils with the lowest ratio of pyrophosphate-to oxalate-extractable Al (Al-pyp/Al-ox), suggesting that in these soils, humic and fulvic acids were to a large extent inaccessible for metal sorption. The low reactivity of ferrihydrite towards lead(II) can be explained by potential spillover effects from co-existing allophane, but other factors such as ferrihydrite crystallisation could not be ruled out. In conclusion, organic matter was the predominant sorbent for cadmium(II), copper(II) and lead(II). However, for lead(II) the optimised model suggests additional, but minor, contributions from Fe (hydr) oxide surface complexes. These results will be important to correctly model metal sorption in spodic materials.
Authors/Creators: | Tiberg, Charlotta and Sjöstedt, Carin and Gustafsson, Jon Petter | ||||||
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Title: | Metal sorption to Spodosol Bs horizons: Organic matter complexes predominate | ||||||
Series Name/Journal: | Chemosphere | ||||||
Year of publishing : | 2018 | ||||||
Volume: | 196 | ||||||
Page range: | 556-565 | ||||||
Number of Pages: | 10 | ||||||
Publisher: | Elsevier | ||||||
ISSN: | 0045-6535 | ||||||
Language: | English | ||||||
Publication Type: | Journal article | ||||||
Refereed: | Yes | ||||||
Article category: | Scientific peer reviewed | ||||||
Version: | Published version | ||||||
Copyright: | Creative Commons: Attribution-Noncommercial-No Derivative Works 4.0 | ||||||
Full Text Status: | Public | ||||||
Agris subject categories.: | P Natural resources > P30 Soil science and management X Agricola extesions > X50 Chemistry | ||||||
Subjects: | (A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Soil Science | ||||||
Keywords: | Cadmium, Copper, Lead, Soil, EXAFS, Assemblage model | ||||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-4800 | ||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-4800 | ||||||
Additional ID: |
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ID Code: | 15351 | ||||||
Faculty: | NJ - Fakulteten för naturresurser och jordbruksvetenskap | ||||||
Department: | (NL, NJ) > Dept. of Soil and Environment (S) > Dept. of Soil and Environment | ||||||
Deposited By: | SLUpub Connector | ||||||
Deposited On: | 12 Mar 2018 07:21 | ||||||
Metadata Last Modified: | 09 Sep 2020 14:17 |
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