Surface and Colloid Chemistry in Natural Waters and Water Treatment

Surface and Colloid Chemistry in Natural Waters and Water Treatment

Surface and Colloid ChelDistry in Natural Waters and Water TreatlDent Edited by Ronald Beckett Water Studies Centre Monash University Melbourne, Australia Springer Science+Business Media, LLC

Library of Congress Cataloging-ln-Publ1cat1on Data Surface and colloid chemistry in natural waters and water treatment / edited by Ronald Beckett, p. cm. "Proceedings based on a symposium on the role of surface and colloid chemistry in natural waters and water treatment, held June 16-17, 1987, in Melbourne, Australia" Verso ot t.p. Includes bibliographical references and index. TSBN 978-1-4899-2512-1 1. Surface chemistry Congresses. 2. Colloids Congresses. 3. Water chemistry Congresses. I. Beckett, Ronald. QD506.A1S84 1990 546'. 22 dc20 90-21580 CIP Proceedings based on a symposium on The Role of Surface and Colloid Chemistry in Natural Waters and Water Treatment, held June 16-17, 1987, in Melbourne, Australia ISBN 978-1-4899-2512-1 ISBN 978-1-4899-2510-7 (ebook) DOI 10.1007/978-1-4899-2510-7 1990 Springer Science+Business Media New York Originally published by Plenum Press, New York in 1990 Softcover reprint of the hardcover 1st edition 1990 All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher

PREFACE The discipline of surface and colloid chemistiy has experienced a considerable resurgence since the early sixties. This perhaps reflects a growing realisation of the wide applicability of modern colloid and surface theory to many important industrial, medical and environmental problems. This increased activity has resulted in a very complex and at times even confusing area of science being consolidated within a firm theoretical framework. The clearer insights gained into the underlying principles have no doubt acted in an autocatalytic manner to stimulate further interest in an expanding range of applications. A good example in the area of environmental chemistry has been the realization of the important role played by colloidal material and surface interactions in natural biogeochemical processes that has been the subject of increasing attention over the last few decades. This is well illustrated by the numerous studies carried out to elucidate the speciation, toxicity, transport and fate of pollutants in aquatic systems. In the vast majority of cases these have clearly implicated some involvement of an association between the pollutant (e.g. trace metal, toxic organic compound or nutrient) and a colloidal component (e.g. particle, humic substance, foam). In order to understand these interactions fully and their effect on pollutant mobility it is important to develop a full appreciation of the surface chemistry of these complex systems. Australian SCientists have long been prominent in the area of colloid and surface chemistry particularly during the latter half of this century. There now exists a strong network of academic departments and research groups around this country as well as in New zealand and some of these have become involved in various aspects of aquatic colloid and surface chemistry. Although not intended to be a comprehensive treatise, the aim of this book is to review the important role of surface and colloid chemistry in natural aquatic systems and in water treatment processes. The idea for the book developed following a two-day Symposium on the topic sponsored jointly by the Victorian Branch Physical Chemistry Group of the Royal Australian Chemical Institute and the Water Studies Centre, Department of Chemistry and Biology, Chisholm Institute of Technology, which was held in Melbourne on 16-17th June 1987. The volume gathers together chapters dealing with areas in which there have been significant advances in knowledge over the past few years. Each is written by a SCientist from Australia or New zealand who is actively involved in research into that particular field. Some up to date reviews are included on topics of current interest such as humic substances, aquatic photochemistry, properties of natural microbes and water treatment processes. In addition the book contains some more detailed accounts of specific recent advances. Examples include the kinetics and mechanism of estuarine coagulation, transport of ground water radiocolloids, mechanism of water treatment processes involving magnetic particles and coagulation by iron salts, biological removal of phosphorous from wastewater and the effect of dam destratification on manganese speciation and behaviour. The task of editing this book has been greatly facilitated by the quality of the contributions from my coauthors and their cooperation in performing the various editorial tasks so efficiently. v

Finally, I wish to acknowledge Ms Rosa Villani who is largely responsible for the layout of the book and whose assistance In its production has been Invaluable. RONBECKETr MELBOURNE MARCH 1990 vi

CONTENTS SECITON I PROCESSES IN NATURAL WATERS The Surface ChernistIy of Humic Substances in Aquatic Systems.................................... 3 R Beckett Microbial Processes Occurring at Surfaces.......................... 21 KC. Marshall Photochemistry of Colloids and Surfaces in Natural Waters and Water Treatment... 27 T.D. Waite Kinetics and Mechanisms of Iron Colloid Aggregation in Estuaries........................................45 KA. Hunter The Generation of Suspended Sediment in Rivers and Streams... 57 B.L. Finlayson Application of the Uranium Decay Series to a Study of Ground Water Colloids................................ 71 RT. Lawson and S.A. Short SECITON II WATER TREATMENT PROCESSES Water Treabnent Technology in Australia..... 87 B.A. Bolto The Role of Surface and Colloid Chemistry in the SIROFLOC Process....103 D.R Dixon and L.O. Kolarik Coagulation and Flocculation - Destabilizing Practices? (With Particular Reference to Metal Ion Coagulants)... 119 P.R Hutchison and T.W. Healy Enhanced Biological Removal of Phosphorus from Wastewater..............135 A. Duncan, RC. Bayly, J.W. May, G. Vasiliadis and W.G.C. Raper Some Effects of Dam Destratification upon Manganese Speciation... 143 B. Chiswell and M.B. Mokhtar vii

Contrtbutors... 153 Index... 155 viii