Hyper-saline brine discharges into tidal coastal waters

Lead Research Organisation: University of Dundee
Department Name: Civil Engineering

Abstract

The project will investigate the processes affecting the dilution of dense, concentrated brine when it is discharged from an industrial outfall diffuser into coastal waters. Concentrated brine is produced as a waste product from solution mining and desalination plants and it is harmful to marine fauna and flora when it is discharged into coastal waters. This project will model the ways in which the concentration of brine is diluted by mixing with the coastal waters and it will quantify the mixing taking place as the brine spreads away from the outfall diffuser under the action of currents and background turbulence. The problem will be modelled by means of laboratory experiments, mathematical analyses and computer simulations so that the important mixing processes can be understood, parameterised and quantified. Archived field monitoring measurements taken on a regular basis from the waters around an existing brine discharge diffuser will also be analysed and compared with the modelling results and predictions. By combining these modelling and field approaches, the results of the project can be used to provide guidance to outfall designers and environmental monitoring agencies to enable them to predict brine dilution and contamination.

Publications

10 25 50
 
Description The work has led to an increased understanding of the mechanism(s) by which the inclined dense buoyant jets emitted from the diffuser sections of brine wastewater outfalls are diluted. The degree of dilution of the jets is found to depend strongly upon whether jets from adjacent diffuser ports merge before the jets reach the sea floor. The work has delineated conditions under which (i) there is no merging, (ii) merging occurs before the jets reach their maximum height in the water column or (iii) merging occurs after reaching the maximum height. These conditions have bene shown to depend upon the angle of discharge from the diffuser outlets, the separation of the diffuser ports and ratio of the moemntum flux to the buoyancy flux of the discharge. For conditions of merging, the work has demonstrated that the so-called leakage flows from individual jets can merge to form a strong "curtain-like" flow that draws brine directly from the jets
Exploitation Route More anlaysis is required before the findings can be taken forward
Sectors Environment

 
Description External Consultative Group 
Organisation Environment Agency
Country United Kingdom 
Sector Public 
PI Contribution Information on the progress of the project (and the results generated within the project) given to the partner
Collaborator Contribution Membership of the project's External Consulatative Group
Impact Conference papers presented to Solution Mining Institute, Croucher Foundation and 3rd International Symposium on Shallow Flows
Start Year 2008
 
Description External Consultative Group 
Organisation Jacobs Engineering Group
Country United States 
Sector Private 
PI Contribution Provision of details of progress of the grant and the results generated by the grant
Collaborator Contribution Provision of field monitoring data and service on the project's External Consultative Committee
Impact Conference presentations to Solution Mining Institute, Croucher Foundation and 3rd International Symposium on Shallow Flows
Start Year 2008
 
Description Presentation to Solution Mining Research Institute (SMRI) Technical Conference (York, UK) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The Fall Technical Conference of the SMRI was attended almost exclusively by engineers and policy makers in the international solution mining industry. The presentation to this audience achieved the objectives of (i) informing this practitioner audience of research work being undertaken to model the brine dilution phenomena with which the practitioners were concerned as engineers, (ii) generating interest within the practitioner audience for closer collaboration with researchers and (iii) stimulating the flow of information and technical data from practitioners.
Year(s) Of Engagement Activity 2011