Impacts of brine disposal from water desalination plants on the physical environment in the Persian/Arabian Gulf

Edmo J D Campos,Mohamed Abouleish,Sakib Shahriar,Georgenes Cavalcante,Björn Kjerfve,Reem Mohamed,Arnold L Gordon,Filipe Vieira

doi:10.1088/2515-7620/abd0ed

Abstract

Around the Persian (Arabian) Gulf, a considerable volume of freshwater is obtained by desalination of seawater with the residual brine dumped back into the Gulf. This discharge of saltier waters impacts the marine ecosystem and may also affect dynamic and thermodynamic processes. Here, a fully non-linear, high-resolution numerical model is used to investigate the physical impacts of brine discharge into the Gulf. Twin runs were executed. One with and another without brine discharge at specific points. The results show that, when brine is injected, surface gravity waves irradiate from the locations and induce perturbations in other thermodynamic variables in the far field. Instead of attenuating, the anomalies have long term impact. The differences between the two experiments show marked seasonal and spatial variability. The largest differences occur during the summer and are located mainly along the axis of the Gulf’s deeper channel. After 5 years of run, a budget calculation shows basin wide saline increase of about 0.2 g/kg, in agreement with previous studies. This might appear small when compared with the present Gulf mean salinity. However, the small change seems to be associated with significant variability in the spatial distribution and in the seasonal variability at different locations. It is found that there are regions in the Gulf where the standard deviation may represent serious consequences for living organisms in the marine environment.

Highlights

The discovery of large oil fields in the Arabian Peninsula and other countries in the Middle East has resulted in the fast growth of the human population in the area
The time-history of each realization is represented by the time series of the basin-averaged sea surface height (SSH) and kinetic energy (KE), plotted in figure 2
Since the model is forced with climatological products, with no year-to-year changes, the interannual variability displayed in the KE and SSH curves are certainly associated only with the model’s internal variability

Summary

Introduction

The discovery of large oil fields in the Arabian Peninsula and other countries in the Middle East has resulted in the fast growth of the human population in the area. This has severely augmented the effects of the already existing and chronic shortage of potable water in the region, in the arid Arabian Peninsula, where annual average rainfall lies in between 50 and 100 mm and the average evaporation rate can be higher than 3000 mm per year [e.g.:] (Al-Mutaz 2000, Paleologos et al 2018, Ibrahim and Eltahir 2019). Recent discovery of ‘mega aquifers’ [e.g.:] (Morton 2019), show the existence of some renewable underground water deposits in the Arabian Peninsula. With the ongoing increased demand, the available water supply is expected to be halved by 2050

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Conclusion