Development and environmental implication of pedotransfer functions of Cd desorption rate coefficients in historically polluted soils
LIN, Zhongbing
State Key Laboratory of Water Resources and Hydropower Engineering Science
Sun Yat-sen University [Guangzhou] [SYSU]
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State Key Laboratory of Water Resources and Hydropower Engineering Science
Sun Yat-sen University [Guangzhou] [SYSU]
LIN, Zhongbing
State Key Laboratory of Water Resources and Hydropower Engineering Science
Sun Yat-sen University [Guangzhou] [SYSU]
< Reduce
State Key Laboratory of Water Resources and Hydropower Engineering Science
Sun Yat-sen University [Guangzhou] [SYSU]
Language
en
Article de revue
This item was published in
Environmental Pollution. 2020, vol. 257, p. 1-10
Elsevier
English Abstract
The desorption rate is an important factor determining cadmium (Cd) ecotoxicity and pollution remediation in soils. The pedotransfer functions (PTFs) of desorption rate coefficients of fresh Cd in soils have been developed ...Read more >
The desorption rate is an important factor determining cadmium (Cd) ecotoxicity and pollution remediation in soils. The pedotransfer functions (PTFs) of desorption rate coefficients of fresh Cd in soils have been developed in literature. We hypothesized that the aging of Cd pollution would alter Cd desorption process. Taking historically polluted soils as the object, this study aimed at testing the hypothesis and developing new PTFs of desorption rate coefficients for historical Cd. 15 d batch extraction experiments and 13 kinetic models were employed to define Cd desorption rate coefficients in 27 historically polluted soil samples. Compared with fresh Cd, the desorption rate coefficients of historical Cd were lower, and the break time of biphasic desorption processes was retarded to 3 d (4320 min). Different with the usual models for fresh Cd desorption (e.g. parabolic diffusion and two constant rate models), the best models to mimic the historical Cd desorption processes were the pseudo first order, logarithmic, Elovich, and simple Elovich models. The rate-limiting step controlling Cd desorption was changed from the intraparticle diffusion to the interface reaction with aging of pollution. New PTFs of desorption rate coefficients of historical Cd were established (R2 ≥ 0.71). Cd desorption rate coefficients increased with organic matter and clay contents, but decreased with oxalate extractable Fe content, solution pH, cation exchange capacity, and silt content. The key soil properties influencing desorption rate coefficients were not altered by the aging of pollution. The developed PTFs could guide us to adjusting the ecotoxicity and pollution remediation of Cd in historically polluted field soils.Read less <
English Keywords
cadmium
desorption rate coefficient
pedotransfer function
historical pollution
Origin
Hal imported