The Red Sea-Dead Sea project (RSDSP), agreed upon in principle by the governments of Israel and the Hashemite Kingdom of Jordan, is to desalinate seawater from the Gulf of Eilat and convey the reject brine, with or without additional seawater, to the Dead Sea. One of the environmental concerns with the project is the fate of the gypsum expected to precipitate in the lake. If this gypsum will remain suspended in the water column it could lead to increased turbidity and, under an extreme scenario, also to "whitening" of its surface water. The factors that control whether the gypsum precipitating in the lake would remain suspended or sink to the bottom are the crystal morphology and size distribution. We have studied gypsum precipitation in mixtures of Dead Sea brine with seawater, concentrated seawater, and reject brine. Our results show that brine composition and oversaturation control crystal morphology which in turn determines the turbidity that develops in the brine. In addition, we found that scale inhibitors in the reject brine retain their inhibiting capabilities in Dead Sea-reject brine mixtures, and impact the rate of nucleation and consequently the size and number of the precipitating crystals. Our experiments show that under laboratory conditions, a spontaneous rise in turbidity requires higher oversaturation than that created in any mixture of Dead Sea and seawater or reject brine. However, the natural environment differs from the controlled conditions in the lab. Moreover, fundamental properties, such as the ratio between fluid and the surface of the reaction cell or lake bottom greatly vary and can impact results. Thus, while our experiments cannot unequivocally determine whether the turbidity of the lake would increase or if the surface water will 'whiten', our study details the parameters that should be monitored if the RSDSP is constructed.
|State||Published - 11 May 2021|
|Event|| Israel Geological Society annual meeting - Yeruham, Israel|
Duration: 3 May 2021 → 5 May 2021
|Conference||Israel Geological Society annual meeting|
|Period||3/05/21 → 5/05/21|