HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Thiry, Y. Articles by Delvaux, B. Search for Related Content PubMed PubMed Citation Articles by Thiry, Y. Articles by Delvaux, B. Agricola Articles by Thiry, Y. Articles by Delvaux, B. Related Collections Biogeochemical Processes Lysimeter/Rhizosphere Studies Radionuclides Plant and Soil Interactions Soil Pollution

Rhizosphere Conference

Rhizospheric Mobilization and Plant Uptake of Radiocesium from Weathered Micas

II. Influence of Mineral Alterability

^a Radiation Protection Research Unit, Radioecology Section, SCK•CEN, Foundation of Public Utility, Boeretang 200, 2400 Mol, Belgium
^b Unité Sciences du Sol, Université catholique de Louvain, Place Croix du Sud 2/10, 1348 Louvain-la-Neuve, Belgium

^* Corresponding author (ythiry{at}sckcen.be)

Received for publication October 28, 2004. Acute K depletion in the rhizosphere can lead to increased root uptake of radiocesium. Two processes can govern this increase: the very low uptake of potassium and the weathering of Cs-fixing clay minerals. Their respective importance is, however, unknown. We investigated the effects of these processes on radiocesium mobilization by roots of willow (Salix viminalis L.) from three micas: muscovite, biotite, and phlogopite. Willows were grown in a mixed quartz–mica substrate with the three respective ¹³⁴Cs-contaminated micas as sole sources of potassium and radiocesium. After 7 wk of plant growth, the micas were partially weathered. The degree of mica weathering and the prevalent potassium concentration in the solution increased in the order muscovite (5–11 µM K) < biotite (25–32 µM K) < phlogopite (25–35 µM K). The mobilization and root uptake of radiocesium were negligible with muscovite but increased in the same order. These results show that mica weathering directly and chiefly governs the mobility of radiocesium in K-depleted rhizosphere soil. The low mobility of trace Cs in the muscovite rhizosphere is linked with the dioctahedral character of this mica, and hence to its very low alterability.

Abbreviations: FES, frayed edge sites • TF, transfer factor • XRD, X-ray diffraction