Kinetics Of Soil Chemical Processes

Kinetics of Soil Chemical Processes Kinetics of Soil Chemical Processes DONALD L. SPARKS College of Agricultural Sciences Department of Plant Science University of Delaware Newark, Delaware ACADEMIC PRESS, INC. Harcourt Brace Jovanovich, Publishers San Diego London New York Sydney Berkeley Tokyo Toronto Boston COPYRIGHT © 1989 BY ACADEMIC PRESS, INC. ALL RIGHTS RESERVED. NO PART OF THIS PUBLICATION MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM OR BY ANY MEANS, ELECTRONIC OR MECHANICAL, INCLUDING PHOTOCOPY, RECORDING, OR ANY INFORMATION STORAGE AND RETRIEVAL SYSTEM, WITHOUT PERMISSION IN WRITING FROM THE PUBLISHER. ACADEMIC PRESS, INC. San Diego, California 9210 1 United Kingdom Edition published by ACADEMIC PRESS, INC. (LONDON) LTD. 24-28 Oval Road, London NWI 7DX Library of Congress Cataloging-in-Publication Data Sparks, Donald L., Ph. D. Kinetics of soil chemical processes I Donald L. Sparks. p, cm, Bibliography: p. Includes index. ISBN O-12-656440-X (alk. paper) 1. Soil physical chemistry. 2. Chemical reaction, Rate of. I. Title. S592.53.S67 1988 88-14656 631.4'I-dcI9 CIP PRINTED IN THE UNITED STATES OF AMERICA 89 90 91 92 987654321 To my wife, Joy, and my late mother, Christine McKenzie Sparks, with love and respect Contents Preface Index of Principal Symbols 1 Introduction 2 Application of Chemical Kinetics to Soil Systems Introduction Rate Laws Equations to Describe Kinetics of Reactions on Soil Constituents Temperature Effects on Rates of Reaction Transition-State Theory Supplementary Reading 3 Xl Xlll 4 5 12 31 33 38 Kinetic Methodologies and Data Interpretation for Diffusion-Controlled Reactions Introduction Historical Perspective Batch Techniques Flow and Stirred-Flow Methods Comparison of Kinetic Methods Conclusions Supplementary Reading 39 40 41 46 57 59 60 vii Contents Vlll 4 Kinetics and Mechanisms of Rapid Reactions on Soil Constituents Using Relaxation Methods Introduction Theory of Chemical Relaxation Pressure-Jump (p-jump) Relaxation Stopped-Flow Techniques Electric Field Methods Supplementary Reading 5 91 95 97 99 101 103 113 117 122 123 127 Kinetics of Pesticide and Organic Pollutant Reactions Introduction Pesticide Sorption and Desorption Kinetics Degradation Rates of Pesticides Reaction Rates and Mechanisms of Organic Pollutant Reactions Supplementary Reading 7 71 Ion Exchange Kinetics on Soils and Soil Constituents Introduction Fickian and Nernst-Planck Diffusion Equations Rate-Limiting Steps Rates of Ion Exchange on Soils and Soil Constituents Binary Cation and Anion Exchange Kinetics Ternary Ion Exchange Kinetics Determination of Thermodynamic Parameters from Ion Exchange Kinetics Supplementary Reading 6