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Mixing dispersants
MT 220 gas chromatograph equipped with a NP 3 electron capture detector. The column used was of glass, 'U' shaped, 6' long x ¼" outer diameter. It was packed with a 1 : 1 mixture consisting of 10% I3(2200 silicone oil and 157/o QF1 fluorosilicone coated on a support of chromsorb W AW/DMCS, 80-100 mesh. A small glass precolumn filled with quartz wool was used and was discarded after each set of analyses. The cohnm temperature was maintained at 215°C and the detector at 250°C. The carrier gas was htgh purity nitrogen; it was passed through a filter of Molecular Sieve 5A, 60-80 mesh at a flowrate of 100 ml/min.
Results A total of sixteen samples was analysed and the results obtained were as shown m Table 1. Although the results encompass only four species of marine animals, certain remarkable trends are evident. In both the snoek and rock lobster the DDT concentration m the ¢hgestive tract is several orders of magnitude higher than in the flesh. The same trend apphes to a lesser extent for dieldrin. High concentrations of pesticide residues were also found m the liver of the snook as opposed to the flesh. It is interesting to note that Shannon (1970) found the gross alpha-act~wty in the digestave gland of the rock lobster to be 14800 ± 2000 pc/kg (wet weight) in comparison with 150 ± 30 pc/kg m the tad meat. In the case of Risso's dolphin the concentrations of pesticide residues in the blubber and liver were at comparable levels. Not unexpectedly the level of total DDT is considerably higher than that of dieldrin m all samples analysed. Comparison of our results with figures obtained for slmdar species in other parts of the world is not always feasible. Values obtained by Jonson et al. (1969) for herring, a clupeold fish, could probably be used as
Mixing Dispersants Sir--The mixing energy to produce fine droplets of od m water has been g~ven as 1 W K
-----
A
7
where W K
--
nuxmg energy
A o/w
=
mterfaclal area
70/w
=
lnterfacial tension
o/w o/w
The effect of the addition of a surface active agent (dispersant) is to reduce the mterfacial tension by as much as a whole number of times. Nevertheless, to produce a reasonably stable mixture the dispersant must be applied so that it is available at all of the interface, and the mixing energy must be adequate and properly applied. This fact has been known for a long time and is frequently cited in the literature? When spills occur, dispersants are applied m the hope that wave action and/or the screws of the application vessels, will provide sufficient mixing energy,
a basis for comparison voth anchovy. Total DDT levels m herring ussues range from 0.093 to 2.3 ppm whde in anchovy the values for total DDT are 0 196 to 0 228 ppm for the whole fish. In samples collected from the north east coast of England, Robinson et al. (1967) found 0.64 ppm dieldrin m the blubber of common dolphin (Delphmus delphinus) and 0 04 ppm in the liver. Our values for Rasso's dolphin are 0.068 ppm and 0.048 ppm, respectively. The same authors reported 0.024 ppm dieldrin in the flesh of lobster (Homarus vulgarls) whle our values for the flesh of rock lobster are 0 004 to 0.012 ppm. The results of the analyses reported in this paper are few in number and relate to only four species. Worm is at present m progress which wall increase the number of analyses and extend the sampling to include a greater selection of South African manne species P J. AUCAMP* J L. HENRY G H. STANDER
D~vision of Sea F~sheries, Department of Industries, Beach Road, Sea Point, Cape Town, S. Africa. *Formerly of Department of Agricultural Techmcal Services, South Africa.
de Faubert Maunder, M J, Egan, H, Godley, E W, Hammond, E. W, Roburn, J. and Thomson, J (1964) Analyst, 89, 168 Jenzen, S, Johnels, A. G, Olsson, M. and Otterhnd, G (1969),
Nature, 224, 247.
Peterle, Tony J. (1969) Nature, 224, 620 Robinson, J, Rtehaxdson, A., Grabtree, A. N, Coulson, J. C and Ports, G. R (1967) Nature, 214, 1307 Shannon, L V. (1970) PhD. Thesis, Umvemty of Cape Town
and only too frequently the ¢hspersant is reported as valueless without due consideration being given to the possibtlxty that the nuxing energy was inadequate. Mtxing energy produced by the wind has been calculated ~ to give 6.82 kg m of energy per hour for every square metre vertically through the sea surface with a wind speed of 5 kts. A reahstic spray system has been calculated to give 1.696 kg m per nun for each square metre of sea surface when spraying at 5 kts. The same text gives the mixing energy of a 25 ft (8 2 m) launch as 62.5 kg m per m 2 of area swept, at the same speed; tins assumes that the energy of the propeller is uniformly distributed across the whole width covered by the launch, 10 ft (3 m), voth a 20 ft (6 1 m) spray boom each side, i.e 50 ft (15 3 m) at each pass, which is a dubious assumption. The nuxing energy given by the Warren Spring Laboratory system has been measured under working conchtions 3 The tests show that the 4 fl 6 m (1.57 m) board assembly, when towed at 4 kts, exercised a pull of 30 lb (13 6 kg). If it is assumed that the depth to which the board sinks at the rear is 9 in (0.228 m), then per m ~ of vertical 191
Who Does What
The Marine Pollution Bulletin is pubhahed monthly and sets out to cover all aspects of the fight for the hfe of lakes, estuaries, seas and oceans It includes news, comment, rewews end research reports not only on the threats of noxmus substances to marine hfe but also on the management and product~wty of the manna environment m general It pubhshes accounts of new end proposed research programmes as well as the results of those in progress
Contributions may be in the form of short notes not exceeding 650 words or artlclea of | 500-2000 words and should be submitted to the editor in double-spaced typescript They should be given a short one-line title and the text should be broken by short sub-headings All measurements must be gwen in metric (S I ) units Reprints of artmles can be supphed after pubhcation and an order form for them ts sent to contributors. Bulk orders of copras of the entire issue in which an article appears can be supphed at a reduced rate to the author, provided they are ordered m advance of pubhcation
D S Moulder of the Marine PoUut]on Documentation and Information Centre at the Marine Bmlog~cal Association Lxbrary, Plymouth, has compiled a hst of current research on marine pollution Programmes are broken down according to their general subject (industrial and chemical polluhon, oll and detergent pollution, and so on) and then programmes are listed by country The name of the laboratory, or name and address of the principal lnveshgator are given, together with a brief title of the programme The list is available on request at a charge ot £I 00
The Estuarine Environment
Estuaries, wath their salt marshes and brackish lagoons, are of great interest to bmlog]sts, chemists, Edited by Professor R. B Clark, Department of Zoology, hydrologlsts and geologists. They provide a umque The Unwermty, Newcastle upon Tyne, NE1 7RU, England. environment which is rapidly oscillating with respect Publlshedby. Mscmdlan Journals Ltd, Little Essex to water movement and salm]ty The practical Street, London, WC2 importance in relation to navlgataon and fisheries has Subscriptions: Macmillan Journals Ltd, Subscript,ons Department, Brunel Road, Baslngstoke, Hants, England always been great but, m recent years, w~th the rapat development of industries and urban expansion they Advertisement enquiries from pubhshers should be sent to Jdl Turner, Macmillan Journals Ltd, Little Ease, have become a major focus for problems of water poiluStreet, London, WC2R 3LF (01-836-6633 or 242 tmn and their recreational value has rapidly increased. 3419). Other advertmlng enqu,nes should be made to Alan Kay, as above A number of sclenUsts interested m both the academic Annualsubscrlptlon: £3 50; USA & CANADA and the practical problems of estuaries have decided (Aw Freight) $1 1 1 7 that there is a need for an association which will provide a meeting ground for the many disciplines now being applied in this field With this m view, a one day wave surface at 5 kts, the energy of mixing is 6 7 × 10~ Symposium on 'The Estuarme Environment' was held kg m per mm on October 13th, m the Meeting Room of the ZooloThis is some 10~ to 10' times greater than obtained gical Society of London It was attended by more than with other methods suggested, and shows clearly the two hundred people, amongst whom were blologasts, reason for the vastly improved results which have been chemists, hydrologlsts, geologists and engineers Papers obtained with the Warren Spnng Laboratory equipment were read and &scussed on. Physmtogdcal Problems m practice (L C Beadle), Chemistry (A J Phdlips), Commercial Yours faithfully, Fisheries (P R Wame), Faunal ProducUwty (H Mdne) F SHUTTLEWORTH and Pollution m the Thames Estuary (M J Barrett) Warren Sprmg Laboratory, The proceedings included the inauguration of what Stevenage, Herts, was provisionally entitled 'The Estuarme and BrackishUK water Bmlogtcal Association' Several aspects of the proposed asset]arson were discussed In vmw of the J WARDLEY SMITH wide range of scientific interests mvolved, several lnternattonal Tanker Owners speakers suggested that 'Biological' should be onutted Pollution Federation Ltd., from the title and perhaps be replaced by some more 41 Mincing Lane, London, EC3, appropriate word. UK The first Annual General Meeting at which the 1 Canevan, G P, General daspersaat theory, Proceedings AssociaUon will be formally launched with an agreed Joint Committee on Prevention and Control of Oil Spills, tide, constltutaon and officers, will be held on April A.PI Dee 1969, 171. 2 Off Spdl Treating Agents Te6t Proeedurm Status and Re- 14th, 1972 m York. The provisional Secretary is Dr R S K. Barnes, oommendataons, May 1970, Battelle N W, 16 3 WSL Report LR 151 (ES), D~olO_lam4mt of the WSL Dls- CERL, Marine Blologtcal Laboratory, Fawley, persant spraining equip_merit, May 197I, Warren Spnng Southampton, SO4 1TW Laboratory, Stevenage, Hertfordshire, England. 1971 Macmillan Journals Ltd Printed in Great Britain by S R Verstage & Sonq I td
Rankme Road, Bastngstoke, H,~mpshire Tel Basmgstoke 3326
Results A total of sixteen samples was analysed and the results obtained were as shown m Table 1. Although the results encompass only four species of marine animals, certain remarkable trends are evident. In both the snoek and rock lobster the DDT concentration m the ¢hgestive tract is several orders of magnitude higher than in the flesh. The same trend apphes to a lesser extent for dieldrin. High concentrations of pesticide residues were also found m the liver of the snook as opposed to the flesh. It is interesting to note that Shannon (1970) found the gross alpha-act~wty in the digestave gland of the rock lobster to be 14800 ± 2000 pc/kg (wet weight) in comparison with 150 ± 30 pc/kg m the tad meat. In the case of Risso's dolphin the concentrations of pesticide residues in the blubber and liver were at comparable levels. Not unexpectedly the level of total DDT is considerably higher than that of dieldrin m all samples analysed. Comparison of our results with figures obtained for slmdar species in other parts of the world is not always feasible. Values obtained by Jonson et al. (1969) for herring, a clupeold fish, could probably be used as
Mixing Dispersants Sir--The mixing energy to produce fine droplets of od m water has been g~ven as 1 W K
-----
A
7
where W K
--
nuxmg energy
A o/w
=
mterfaclal area
70/w
=
lnterfacial tension
o/w o/w
The effect of the addition of a surface active agent (dispersant) is to reduce the mterfacial tension by as much as a whole number of times. Nevertheless, to produce a reasonably stable mixture the dispersant must be applied so that it is available at all of the interface, and the mixing energy must be adequate and properly applied. This fact has been known for a long time and is frequently cited in the literature? When spills occur, dispersants are applied m the hope that wave action and/or the screws of the application vessels, will provide sufficient mixing energy,
a basis for comparison voth anchovy. Total DDT levels m herring ussues range from 0.093 to 2.3 ppm whde in anchovy the values for total DDT are 0 196 to 0 228 ppm for the whole fish. In samples collected from the north east coast of England, Robinson et al. (1967) found 0.64 ppm dieldrin m the blubber of common dolphin (Delphmus delphinus) and 0 04 ppm in the liver. Our values for Rasso's dolphin are 0.068 ppm and 0.048 ppm, respectively. The same authors reported 0.024 ppm dieldrin in the flesh of lobster (Homarus vulgarls) whle our values for the flesh of rock lobster are 0 004 to 0.012 ppm. The results of the analyses reported in this paper are few in number and relate to only four species. Worm is at present m progress which wall increase the number of analyses and extend the sampling to include a greater selection of South African manne species P J. AUCAMP* J L. HENRY G H. STANDER
D~vision of Sea F~sheries, Department of Industries, Beach Road, Sea Point, Cape Town, S. Africa. *Formerly of Department of Agricultural Techmcal Services, South Africa.
de Faubert Maunder, M J, Egan, H, Godley, E W, Hammond, E. W, Roburn, J. and Thomson, J (1964) Analyst, 89, 168 Jenzen, S, Johnels, A. G, Olsson, M. and Otterhnd, G (1969),
Nature, 224, 247.
Peterle, Tony J. (1969) Nature, 224, 620 Robinson, J, Rtehaxdson, A., Grabtree, A. N, Coulson, J. C and Ports, G. R (1967) Nature, 214, 1307 Shannon, L V. (1970) PhD. Thesis, Umvemty of Cape Town
and only too frequently the ¢hspersant is reported as valueless without due consideration being given to the possibtlxty that the nuxing energy was inadequate. Mtxing energy produced by the wind has been calculated ~ to give 6.82 kg m of energy per hour for every square metre vertically through the sea surface with a wind speed of 5 kts. A reahstic spray system has been calculated to give 1.696 kg m per nun for each square metre of sea surface when spraying at 5 kts. The same text gives the mixing energy of a 25 ft (8 2 m) launch as 62.5 kg m per m 2 of area swept, at the same speed; tins assumes that the energy of the propeller is uniformly distributed across the whole width covered by the launch, 10 ft (3 m), voth a 20 ft (6 1 m) spray boom each side, i.e 50 ft (15 3 m) at each pass, which is a dubious assumption. The nuxing energy given by the Warren Spring Laboratory system has been measured under working conchtions 3 The tests show that the 4 fl 6 m (1.57 m) board assembly, when towed at 4 kts, exercised a pull of 30 lb (13 6 kg). If it is assumed that the depth to which the board sinks at the rear is 9 in (0.228 m), then per m ~ of vertical 191
Who Does What
The Marine Pollution Bulletin is pubhahed monthly and sets out to cover all aspects of the fight for the hfe of lakes, estuaries, seas and oceans It includes news, comment, rewews end research reports not only on the threats of noxmus substances to marine hfe but also on the management and product~wty of the manna environment m general It pubhshes accounts of new end proposed research programmes as well as the results of those in progress
Contributions may be in the form of short notes not exceeding 650 words or artlclea of | 500-2000 words and should be submitted to the editor in double-spaced typescript They should be given a short one-line title and the text should be broken by short sub-headings All measurements must be gwen in metric (S I ) units Reprints of artmles can be supphed after pubhcation and an order form for them ts sent to contributors. Bulk orders of copras of the entire issue in which an article appears can be supphed at a reduced rate to the author, provided they are ordered m advance of pubhcation
D S Moulder of the Marine PoUut]on Documentation and Information Centre at the Marine Bmlog~cal Association Lxbrary, Plymouth, has compiled a hst of current research on marine pollution Programmes are broken down according to their general subject (industrial and chemical polluhon, oll and detergent pollution, and so on) and then programmes are listed by country The name of the laboratory, or name and address of the principal lnveshgator are given, together with a brief title of the programme The list is available on request at a charge ot £I 00
The Estuarine Environment
Estuaries, wath their salt marshes and brackish lagoons, are of great interest to bmlog]sts, chemists, Edited by Professor R. B Clark, Department of Zoology, hydrologlsts and geologists. They provide a umque The Unwermty, Newcastle upon Tyne, NE1 7RU, England. environment which is rapidly oscillating with respect Publlshedby. Mscmdlan Journals Ltd, Little Essex to water movement and salm]ty The practical Street, London, WC2 importance in relation to navlgataon and fisheries has Subscriptions: Macmillan Journals Ltd, Subscript,ons Department, Brunel Road, Baslngstoke, Hants, England always been great but, m recent years, w~th the rapat development of industries and urban expansion they Advertisement enquiries from pubhshers should be sent to Jdl Turner, Macmillan Journals Ltd, Little Ease, have become a major focus for problems of water poiluStreet, London, WC2R 3LF (01-836-6633 or 242 tmn and their recreational value has rapidly increased. 3419). Other advertmlng enqu,nes should be made to Alan Kay, as above A number of sclenUsts interested m both the academic Annualsubscrlptlon: £3 50; USA & CANADA and the practical problems of estuaries have decided (Aw Freight) $1 1 1 7 that there is a need for an association which will provide a meeting ground for the many disciplines now being applied in this field With this m view, a one day wave surface at 5 kts, the energy of mixing is 6 7 × 10~ Symposium on 'The Estuarme Environment' was held kg m per mm on October 13th, m the Meeting Room of the ZooloThis is some 10~ to 10' times greater than obtained gical Society of London It was attended by more than with other methods suggested, and shows clearly the two hundred people, amongst whom were blologasts, reason for the vastly improved results which have been chemists, hydrologlsts, geologists and engineers Papers obtained with the Warren Spnng Laboratory equipment were read and &scussed on. Physmtogdcal Problems m practice (L C Beadle), Chemistry (A J Phdlips), Commercial Yours faithfully, Fisheries (P R Wame), Faunal ProducUwty (H Mdne) F SHUTTLEWORTH and Pollution m the Thames Estuary (M J Barrett) Warren Sprmg Laboratory, The proceedings included the inauguration of what Stevenage, Herts, was provisionally entitled 'The Estuarme and BrackishUK water Bmlogtcal Association' Several aspects of the proposed asset]arson were discussed In vmw of the J WARDLEY SMITH wide range of scientific interests mvolved, several lnternattonal Tanker Owners speakers suggested that 'Biological' should be onutted Pollution Federation Ltd., from the title and perhaps be replaced by some more 41 Mincing Lane, London, EC3, appropriate word. UK The first Annual General Meeting at which the 1 Canevan, G P, General daspersaat theory, Proceedings AssociaUon will be formally launched with an agreed Joint Committee on Prevention and Control of Oil Spills, tide, constltutaon and officers, will be held on April A.PI Dee 1969, 171. 2 Off Spdl Treating Agents Te6t Proeedurm Status and Re- 14th, 1972 m York. The provisional Secretary is Dr R S K. Barnes, oommendataons, May 1970, Battelle N W, 16 3 WSL Report LR 151 (ES), D~olO_lam4mt of the WSL Dls- CERL, Marine Blologtcal Laboratory, Fawley, persant spraining equip_merit, May 197I, Warren Spnng Southampton, SO4 1TW Laboratory, Stevenage, Hertfordshire, England. 1971 Macmillan Journals Ltd Printed in Great Britain by S R Verstage & Sonq I td
Rankme Road, Bastngstoke, H,~mpshire Tel Basmgstoke 3326