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Waste treatment with polyelectrolytes and other flocculants
Volume8/Number7/July 1977
Clarifyiug Water
Wartime Oil Pollution B. Campbell, E. Kern and D. Horn, 1977. Impact o f 0il
Spillage from World War II Tanker Sinkings. MITSG Report 77-4. Massachusetts Institute of Technology Sea Grant Program. 85 pp. This is a most interesting appraisal of the amount of oil pollution noticed along the east cost of the USA following the havoc created by German submarines among shipping offshore early in 1942 during the first six months after the country entered the last war and before it decided to make use of convoys. It is calculated that nearly half a million tons of petroleum products were released within fifty miles of the coast, a quarter of it around Cape Hatteras, yet remarkably little of it was noticed coming ashore. Examination of the winds and currents suggests that most of it drifted out to sea; thus of the fourteen sinkings off Cape Hatteras only three seem likely to have given rise to slicks which would have come ashore, of which only one was actually noticed, and it caused rather little damage. Examination of another area where there were many incidents, off New Jersey, also revealed only one incident where the oil came ashore and had to be buried to cleanse an amenity beach. It is implied that the risks of oil pollution resulting from current offshore oil developments have been over-rated, It is possible to hold a number of reservations about the conclusions of this study. At that time much of the oil carried by sea was composed of comparatively light refined products unlikely to last long on the water, and much of the oil was burnt when the ships were sunk, so that the total amount loose at sea may not have been as large as is suggested. If we then consider that most obvious victims of oil pollution, birds, while the authors were only able to trace a few reports of limited mortality during the incidents they investigated, they do not appear to have examined even the most obvious ornithological literature. Thus for example two fairly well-known authors, S. Dillon Ripley and then Roger Tory Peterson, report in the nation's most widely-circulated wildlife conservation journal, theAudubon Magazine(44, 86-90; 217-225) that there was massive mortality among seabirds from oil pollution that spring, which wiped out a quarter of the twenty thousand wildfowl wintering off Monomoy, site of the recent Argo Merchant incident, and H. F. Lewis confirms in the Wilson Bulletin (54, 217) that comparable destruction extended north into Canada. It seems likely many more bird bodies drifted out to sea with the oil unnoticed, or only came ashore far to the north of the site of the initial pollution, perhaps after the oiled birds succumbed during their spring migration, If the authors failed to discover what occurred among such obvious animals as birds, it may be wondered what they missed among less conspicuous phenomena,
W. R. P. BOURNE
Sidney Gutcho, 1977. Waste Treatment with Polyelectrolyres and Other Flocculants, Pollution Technology Review No. 31. Noyes Data Corporation, 274 pp. Price $39. The advantage of using polyelectrolytesto clarify water is the low concentration at which they are effective. This up to date review of US patent literature shows that most of the new polymers synthesized for this purpose come within the class of cationic polyelectrolytes, although the subject of anionic, non-ionic and naturally-occurring polyelectrolytes is also covered. Wherever possible the practical application of polyelectrolytes is emphasized and sufficient detail is given to permit assessment of their suitability for particular purposes. For example, one application for saline waters shows how a heavy, colloidal sea bottom sediment is convertible by means of an acrylamide polymer and aluminium sulphate into a flocculant suspension that leaves a clear supernatant liquid on settlement. Sewage treatment is also a promising field for the application of polyelectrolytes, particularly in the flocculation of suspended matter and improvement of the speed with which sludges may be dewatered by mechanical processes. (Another application which does not appear to be described in the book, is the acceleration of dewatering that takes place when polyelectrolyte dosed sewage sludge is applied to land.) With the interest now being shown in the removal from sewage of nutrients likely to cause eutrophication it is not surprising to find polyelectrolytes being recommended as aids to promote the efficient flocculation and settlement of phosphates that have been precipitated with lime. In the treatment of sludges derived from sewage and industrial effluents polyelectrolytes play an important part by helping the sludges to dewater without adding to their bulk. Although naturally occurring polyelectrolytes are included in this section the author may feel that it is outside the scope of the book to mention that biological flocculation is one of the most important functions of purification of sewage by the activated sludge process and that the bacteria active in flocculation are themselves naturally produced polyelectrolytes. In the pulp and paper industry most of the uses or suggested uses for polyelectrolytes are in the treatment of wastewaters and the derived sludges. It is in industries such as sugar refining that ionic impurities in concentrated aqueous solution may be removed by flocculation with ionic polymers of opposite charge. Among the many interesting applications of polyelectrolytes which have been patented is the addition of hydrolysed polyacrylamides to subterranean sandstone formations in order to reduce the quantity of water recovered when hydrocarbons are obtained from such sources; long chain polymers are shown to be effective in flocculating algae grown in nutrient rich wastewater--a process urgently in need of full scale development in order to recover protein from wastes wherever algae can be encouraged to grow; viruses are shown to be adsorbed on polyelectrolytes so that their separation from other material becomes possible; and dredging operations may 167
Marine Pollution Bulletin
be assisted by the addition of a polymer flocculating agent to silt suspensions so as to compact the settled silt. The way in which natural and synthetic polymers may be widely used in many industries and processes will be readily understood because of the concise and exact description of the operation relating to the patent claims, To this statement may be added the fact that this useful book is as up-to-date as it possibly can be, for apart from a few patents of the late 1960s all the patents mentioned are post 1970 and a few even as late as May 1976. The practical value of the book would have been enhanced had the cost of these synthetic flocculating agents been included. The user of conventional flocculants, with knowledge of the cost of equipment for storing chemicals and dewatering with flocculated material, would then have been able to estimate whether savings on equipment would more than offset any possible additional expenditure on synthetic flocculants, It is worth emphasizing that this is an excellent book concerned with the up-to-date US patent literature on the subject, and not with a study of the science or technology offlocculation,
S. H. JENKINS
European Ecological Criteria Principles and Methods f o r Determining Ecological Criteria on Hydrobiocenoses, Editors: R. Amavis and J. Smeets (1976). Proceedings of the European Scientific Colloquium, Luxembourg 1975; 531 pp. Price: £16.00. This book contains the nine papers, a summary of the individual discussions following each paper, concluding comments and two annexes. The annexes report upon studies carried out in relation to the Colloquium. The first summarizes the results of a biological monitoring exercise by representatives from nine member countries of the European community on the water quality of the Rivers Main and Kahl in the Federal Republic of Germany. The second annexe summarizes the approaches available for biological testing in the aquatic environment of the potential effects of polluting chemicals, The papers are given by H. A. Hawkes; L. Tonilli; J. P. Descy; J. Verneaux; H. van Genderen; L. R. Pittwell; H. Knopp; H. J. Hueck; R. Lesel; T. G. Tittizer; and conclusions by G. Tendron and O. Ravera. Each paper is provided in the original language of the presentation as well as a full translation into English. This effectively cuts the pages from 531 to 397 of which 128 are annexes. The presentation papers varies in the style of print and general presentation makes reading rather difficult. There is no general index or alphabetical list of the references which are arranged in chronological order after each paper which results in duplication of references. The papers vary in subject beginning with a general review of the possible effects of biotic and abiotic factors on the macroinvertebrate faunas of rivers by Hawkes. Then follows a series of papers stressing the need to define groupings of such species in relation to environmental
168
factors--Verneaux, Tonolli and their discussion rapporteurs. A paper by Descy suggests methods of data analysis to provide groupings of bryophytes and diatoms by principle components. Van Genderen suggests methods of setting quality objectives using fish and fish eating birds with particular reference to heavy metals. The only marine paper by Hueck then describes the use of mussels for surveys of mercury levels in inshore waters. Pitwell recounts the results of a survey of biological monitoring systems used in various European countries and speculates upon methods of harmonizing these between countries and reinforces the demand made by several authors for species lists from the rivers of each nation. Lesel appeals for field checks on the laboratory methods for identifying acute and chronic toxicity whilst Hueck in Annexe II summarizes in a very useful review the approaches available for biological testing in the environment. The conclusion paper by G.Tendron and O. Ravera provides a good summary of the papers and identifies the main conclusions. With a little expansion, this paper would have provided most of the major points of the conference in a more digestible form than the present publication. Detailed results of the field analysis by the meeting of experts is summarized by Tittizer in the first annexe. The results that are given are difficult to follow but demonstrate the considerable variation in biological evaluation by differing index methods. A suggested realignment of the scales of the indices is proposed to assist in harmonization of sampling results. The reader is unable to judge the value of these results, in spite of the detail that is given, as the original data are missing. Generally, the presentation of the whole proceedings soon after it has taken place is probably preferable to the possible nonappearance of many papers due to the pressure of work on authors who are active in the applied field. In reading the proceedings this has to be continually borne in mind because there is much duplication between papers, which often cover information found in elementary ecology textbooks that describe the aquatic environment. Nevertheless, most of the speakers are of some eminence in this field in their countries and comparison of their approaches to the subject of water quality monitoring are of considerable interest to anyone involved in this subject. The book concentrates upon the objective of monitoring water quality by the presence or absence of various taxa at different organizational and taxonomic levels. It does not cover the subject of criteria and methods for the prediction of biological change in aquatic systems. The title is misleading in its assumption of authority in this field as many questions are posed and left unanswered. Some problems are glossed over such as the difference in tolerance of the closely related but different species that are used in the same role in surveys in different geographical areas. The reader will find this soft covered book of interest but expensive in relation to the information that it contains.
J O H N PETERS
Clarifyiug Water
Wartime Oil Pollution B. Campbell, E. Kern and D. Horn, 1977. Impact o f 0il
Spillage from World War II Tanker Sinkings. MITSG Report 77-4. Massachusetts Institute of Technology Sea Grant Program. 85 pp. This is a most interesting appraisal of the amount of oil pollution noticed along the east cost of the USA following the havoc created by German submarines among shipping offshore early in 1942 during the first six months after the country entered the last war and before it decided to make use of convoys. It is calculated that nearly half a million tons of petroleum products were released within fifty miles of the coast, a quarter of it around Cape Hatteras, yet remarkably little of it was noticed coming ashore. Examination of the winds and currents suggests that most of it drifted out to sea; thus of the fourteen sinkings off Cape Hatteras only three seem likely to have given rise to slicks which would have come ashore, of which only one was actually noticed, and it caused rather little damage. Examination of another area where there were many incidents, off New Jersey, also revealed only one incident where the oil came ashore and had to be buried to cleanse an amenity beach. It is implied that the risks of oil pollution resulting from current offshore oil developments have been over-rated, It is possible to hold a number of reservations about the conclusions of this study. At that time much of the oil carried by sea was composed of comparatively light refined products unlikely to last long on the water, and much of the oil was burnt when the ships were sunk, so that the total amount loose at sea may not have been as large as is suggested. If we then consider that most obvious victims of oil pollution, birds, while the authors were only able to trace a few reports of limited mortality during the incidents they investigated, they do not appear to have examined even the most obvious ornithological literature. Thus for example two fairly well-known authors, S. Dillon Ripley and then Roger Tory Peterson, report in the nation's most widely-circulated wildlife conservation journal, theAudubon Magazine(44, 86-90; 217-225) that there was massive mortality among seabirds from oil pollution that spring, which wiped out a quarter of the twenty thousand wildfowl wintering off Monomoy, site of the recent Argo Merchant incident, and H. F. Lewis confirms in the Wilson Bulletin (54, 217) that comparable destruction extended north into Canada. It seems likely many more bird bodies drifted out to sea with the oil unnoticed, or only came ashore far to the north of the site of the initial pollution, perhaps after the oiled birds succumbed during their spring migration, If the authors failed to discover what occurred among such obvious animals as birds, it may be wondered what they missed among less conspicuous phenomena,
W. R. P. BOURNE
Sidney Gutcho, 1977. Waste Treatment with Polyelectrolyres and Other Flocculants, Pollution Technology Review No. 31. Noyes Data Corporation, 274 pp. Price $39. The advantage of using polyelectrolytesto clarify water is the low concentration at which they are effective. This up to date review of US patent literature shows that most of the new polymers synthesized for this purpose come within the class of cationic polyelectrolytes, although the subject of anionic, non-ionic and naturally-occurring polyelectrolytes is also covered. Wherever possible the practical application of polyelectrolytes is emphasized and sufficient detail is given to permit assessment of their suitability for particular purposes. For example, one application for saline waters shows how a heavy, colloidal sea bottom sediment is convertible by means of an acrylamide polymer and aluminium sulphate into a flocculant suspension that leaves a clear supernatant liquid on settlement. Sewage treatment is also a promising field for the application of polyelectrolytes, particularly in the flocculation of suspended matter and improvement of the speed with which sludges may be dewatered by mechanical processes. (Another application which does not appear to be described in the book, is the acceleration of dewatering that takes place when polyelectrolyte dosed sewage sludge is applied to land.) With the interest now being shown in the removal from sewage of nutrients likely to cause eutrophication it is not surprising to find polyelectrolytes being recommended as aids to promote the efficient flocculation and settlement of phosphates that have been precipitated with lime. In the treatment of sludges derived from sewage and industrial effluents polyelectrolytes play an important part by helping the sludges to dewater without adding to their bulk. Although naturally occurring polyelectrolytes are included in this section the author may feel that it is outside the scope of the book to mention that biological flocculation is one of the most important functions of purification of sewage by the activated sludge process and that the bacteria active in flocculation are themselves naturally produced polyelectrolytes. In the pulp and paper industry most of the uses or suggested uses for polyelectrolytes are in the treatment of wastewaters and the derived sludges. It is in industries such as sugar refining that ionic impurities in concentrated aqueous solution may be removed by flocculation with ionic polymers of opposite charge. Among the many interesting applications of polyelectrolytes which have been patented is the addition of hydrolysed polyacrylamides to subterranean sandstone formations in order to reduce the quantity of water recovered when hydrocarbons are obtained from such sources; long chain polymers are shown to be effective in flocculating algae grown in nutrient rich wastewater--a process urgently in need of full scale development in order to recover protein from wastes wherever algae can be encouraged to grow; viruses are shown to be adsorbed on polyelectrolytes so that their separation from other material becomes possible; and dredging operations may 167
Marine Pollution Bulletin
be assisted by the addition of a polymer flocculating agent to silt suspensions so as to compact the settled silt. The way in which natural and synthetic polymers may be widely used in many industries and processes will be readily understood because of the concise and exact description of the operation relating to the patent claims, To this statement may be added the fact that this useful book is as up-to-date as it possibly can be, for apart from a few patents of the late 1960s all the patents mentioned are post 1970 and a few even as late as May 1976. The practical value of the book would have been enhanced had the cost of these synthetic flocculating agents been included. The user of conventional flocculants, with knowledge of the cost of equipment for storing chemicals and dewatering with flocculated material, would then have been able to estimate whether savings on equipment would more than offset any possible additional expenditure on synthetic flocculants, It is worth emphasizing that this is an excellent book concerned with the up-to-date US patent literature on the subject, and not with a study of the science or technology offlocculation,
S. H. JENKINS
European Ecological Criteria Principles and Methods f o r Determining Ecological Criteria on Hydrobiocenoses, Editors: R. Amavis and J. Smeets (1976). Proceedings of the European Scientific Colloquium, Luxembourg 1975; 531 pp. Price: £16.00. This book contains the nine papers, a summary of the individual discussions following each paper, concluding comments and two annexes. The annexes report upon studies carried out in relation to the Colloquium. The first summarizes the results of a biological monitoring exercise by representatives from nine member countries of the European community on the water quality of the Rivers Main and Kahl in the Federal Republic of Germany. The second annexe summarizes the approaches available for biological testing in the aquatic environment of the potential effects of polluting chemicals, The papers are given by H. A. Hawkes; L. Tonilli; J. P. Descy; J. Verneaux; H. van Genderen; L. R. Pittwell; H. Knopp; H. J. Hueck; R. Lesel; T. G. Tittizer; and conclusions by G. Tendron and O. Ravera. Each paper is provided in the original language of the presentation as well as a full translation into English. This effectively cuts the pages from 531 to 397 of which 128 are annexes. The presentation papers varies in the style of print and general presentation makes reading rather difficult. There is no general index or alphabetical list of the references which are arranged in chronological order after each paper which results in duplication of references. The papers vary in subject beginning with a general review of the possible effects of biotic and abiotic factors on the macroinvertebrate faunas of rivers by Hawkes. Then follows a series of papers stressing the need to define groupings of such species in relation to environmental
168
factors--Verneaux, Tonolli and their discussion rapporteurs. A paper by Descy suggests methods of data analysis to provide groupings of bryophytes and diatoms by principle components. Van Genderen suggests methods of setting quality objectives using fish and fish eating birds with particular reference to heavy metals. The only marine paper by Hueck then describes the use of mussels for surveys of mercury levels in inshore waters. Pitwell recounts the results of a survey of biological monitoring systems used in various European countries and speculates upon methods of harmonizing these between countries and reinforces the demand made by several authors for species lists from the rivers of each nation. Lesel appeals for field checks on the laboratory methods for identifying acute and chronic toxicity whilst Hueck in Annexe II summarizes in a very useful review the approaches available for biological testing in the environment. The conclusion paper by G.Tendron and O. Ravera provides a good summary of the papers and identifies the main conclusions. With a little expansion, this paper would have provided most of the major points of the conference in a more digestible form than the present publication. Detailed results of the field analysis by the meeting of experts is summarized by Tittizer in the first annexe. The results that are given are difficult to follow but demonstrate the considerable variation in biological evaluation by differing index methods. A suggested realignment of the scales of the indices is proposed to assist in harmonization of sampling results. The reader is unable to judge the value of these results, in spite of the detail that is given, as the original data are missing. Generally, the presentation of the whole proceedings soon after it has taken place is probably preferable to the possible nonappearance of many papers due to the pressure of work on authors who are active in the applied field. In reading the proceedings this has to be continually borne in mind because there is much duplication between papers, which often cover information found in elementary ecology textbooks that describe the aquatic environment. Nevertheless, most of the speakers are of some eminence in this field in their countries and comparison of their approaches to the subject of water quality monitoring are of considerable interest to anyone involved in this subject. The book concentrates upon the objective of monitoring water quality by the presence or absence of various taxa at different organizational and taxonomic levels. It does not cover the subject of criteria and methods for the prediction of biological change in aquatic systems. The title is misleading in its assumption of authority in this field as many questions are posed and left unanswered. Some problems are glossed over such as the difference in tolerance of the closely related but different species that are used in the same role in surveys in different geographical areas. The reader will find this soft covered book of interest but expensive in relation to the information that it contains.
J O H N PETERS