The use of rate equations for a quantitative description of K desorption from soils in an external electric field (electro‐ultrafiltration)
作者:
H. Grimme,
期刊:
Zeitschrift für Pflanzenernährung und Bodenkunde
(WILEY Available online 1979)
卷期:
Volume 142,
issue 1
页码: 57-68
ISSN:0044-3263
年代: 1979
DOI:10.1002/jpln.19791420107
出版商: WILEY‐VCH Verlag
数据来源: WILEY
摘要:
AbstractIons can be extracted from soils by applying an external electric field to a soil suspension. When a constant field strength is employed characteristic desorption parameters can be calculated from the results, such as maximum desorbable quantity, halftime, and rate constant. The method consists of a combination of electrodialysis and ultrafiltration and is called electro‐ultrafiltration (EUF).It was found that the K transfer from the central compartment A to the cathode compartment B follows a first order rate law, if compartment A contains only the solution of a strong electrolyte such as KCl. If a soil suspension is introduced into compartment A the bulk of K that is transferred to compartment B has first to be desorbed from the soil particles hence the designation as desorption for the transfer from a soil suspension. In this case a second order rate law is followed.The rate equations allow the calculation of the quantity of K involved in the desorption process and the rate with which it is released. It was found that invariably only the exchangeable K takes part in the desorption reaction. The desorption rate differs between soils and depends on clay content and the quantity of exchangeable K present in the soil. It is suggested that the desorption data may provide a means of describing the soil K status by kinetic parameter
点击下载:
PDF
(545KB)
返 回