Numerical modelling of brine discharges from a desalination plant

• Main Author: Nguyen, Phuong Hanh.
• Other Authors: Law Wing-Keung, Adrian
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Civil engineering::Water resources
• Online Access: http://hdl.handle.net/10356/16830
• Institution: Nanyang Technological University

Brine from desalination plant is usually discharged into the ocean through a diffuser that efficiently mixes the effluent. The use of the diffuser results in the rapidly increasing dilution and reduction in contaminant concentrations along the discharge trajectory upon its impinging point. Regulatory agencies had recognized this situation and usually issued a mixing zone around the discharge to control the pollutant impacts. The project aims to develop a comprehensive analysis of the steps required to meet the mixing zone regulation. Hydrodynamic mixing processes of brine released into a stationary ambient are thoroughly discussed and enhanced with up-to-date concepts, covering the wide range from discharge nozzle up to the end of near-field spreading. Thus far, the research had suggested that the flat discharge angles range of 30 - 45°, other than the usual assumption of 60°, appeared preferable for the design of dense jet outfall located near off-shore location, with considering of the terminal rise height, the flow behaviours in different inclined bottom and impact dilution. In addition, the research also suggested that impact dilution is not only the crucial elements to assess the mixing process at the impingement but also the ultimate dilution caused by additional turbulence around this region. The research, also, went further to study about the microburst in order to formulate the ultimate mixing profile of the dense jet from the microburst velocity profile.