Desalination Brine Disposal by Submerged Pipes in the Red Sea

Abstract

Badescu, V.; Ciocanea, A.; Cathcart, R.B., and Finkl, C.W., 2013. Desalination brine disposal by submerged pipes in Red Sea. Journal of Coastal Research, 29(6A), 81–92. Coconut Creek (Florida), ISSN 0749-0208. Seawater desalination plants, especially those in Saudi Arabia, require the disposal of useless posttreatment brine— generally about 50% of the volume of seawater processed by such plants designed to make freshwater. This article focuses on the sustainability of the brine disposal process. A proper decision about the brine disposal method must take into account technical, environmental, and economic constraints. Brine disposal by submerged pipes is considered here; the case of desalination plants in Saudi Arabia on the Red Sea shore is considered as an example. The central concept is the available head at the discharge point. Higher values of the available head ensure larger jet dispersion lengths and better conditions for submarine brine dilution. We assessed the quality of the dilution process by calculating the Froude number of the brine discharge jet, whose optimum values are between 20 to 25. Using the Froude number allows us to find the optimum pipe length and the optimum depth of the discharge point for a sustainable brine disposal. Comments concerning the cost of the submerged pipes are presented.