Post-treatment of desalinated water and water quality characteristics in Yanbu Industrial City

Abstract

A B S T R A C TYanbu Industrial City (YIC) in Saudi Arabia depends on seawater desalination for its entire fresh water supply. The fresh water is supplied by a desalination plant that consists of nine multi-stage flash (MSF) distillation units and seven reverse osmosis (RO) desalination trains. The product water from the MSF and RO desalination processes requires post-treatment to prepare it for potable use. The distillate from the MSF units is remineralized by adding hydrated lime and carbon dioxide, chlorinated by the injection of chlorine gas, and aerated with compressed air. The remineralization steps result in raising pH, alkalinity, and hardness of the water, thereby stabilizing the water. For the permeate from the RO trains, hydrated lime and sodium hypochlorite are added. This paper presents the potable water quality data for the last 6 years from 2006 to 2011 and the water characteristics in YIC, along with the post-treatment processes of the desalinated water. YIC's potable water produced by seawater desalination is of high quality and prevents bacteriological growth without any microbiological contamination. The water is healthy and suitable for human consumption and use on the basis of the water quality monitoring data with respect to its physical, chemical, and biological characteristics.