THE VENTURI AS A SALINE INTRUSION CONTROL FOR SEA OUTFALLS.

The internal hydraulics of the multiport diffuser section in long sea outfalls has been studied by laboratory experiments and numerical modelling. The study has run for five years as a coordinated effort at both the University of Liverpool and the University of Aalborg. The investigations have covered such phenomena as saline intrusion, wave influence and unsteady flow caused by pump operation. Results show that numerous flow regimes exist depending on the boundary conditions. Numerical models have been developed to simulate the flow field in the diffuser section and some of the most interesting phenomena, in particular the wave induced saline intrusion, can now be modelled satisfactorily. Some aspects of the behaviour relating to very low fresh water discharges, e.g. unsteady flow when saline wedges are present, are still not very well described.

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Sludge Disposal to Sea in South Africa

Water Science & Technology ◽

10.2166/wst.1982.0013 ◽

1982 ◽

Vol 14 (3) ◽

pp. 93-107 ◽

Cited By ~ 2

Author(s):

D C Macleod

Keyword(s):

Public Health ◽

South Africa ◽

Marine Environment ◽

Industrial Waste ◽

Domestic Sewage ◽

Monitoring Programme ◽

Environment And Public Health ◽

Research Project ◽

Sludge Disposal ◽

Sea Outfalls

The performance of two sea outfalls that have been in operation off the coast of Durban for over 10 years has been monitored for effects on the marine environment and public health. The discharge has been a mixture of domestic sewage and industrial waste from which a large proportion of the sludge has been removed but a 2-year research project, in which the balance of the sludge is also being discharged, has commenced. Performance of the outfalls and details of the monitoring programme are reviewed.

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Saline intrusion in deep riser outfall systems

Water Science & Technology ◽

10.2166/wst.1995.0097 ◽

1995 ◽

Vol 32 (2) ◽

pp. 175-182

Author(s):

Roger A. Howard

Keyword(s):

Physical Model ◽

Recent Work ◽

Saline Intrusion ◽

Deep Tunnel ◽

Hydraulic Design ◽

Novel Methods

Saline intrusion can seriously affect the performance of outfall systems and an understanding of the mechanisms causing intrusion is important in the hydraulic design of outfalls, particularly for deep riser tunnelled outfalls. The paper outlines the reasons for the occurrence of saline intrusion, the problems that arise when it is present and the methods available for prevention and purging. The paper draws on recent work undertaken on the design of a major deep tunnel outfall system using a physical model and outlines some novel methods devised for purging of the system.

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