Water Desalination: Environmental Impacts and Brine Management

Abstract

This chapter discusses the evolution of water desalination in the United Arab Emirates (UAE), analyzes the environmental challenges associated with the desalination industry and proposes solutions for the alleviation of desalination-related problems.

The MEOW (State of the environment report—United Arab Emirates. Ministry of Environment and Water, p 36, 2015) stated that: “The UAE adopted water desalination since early 1970s to bridge the gap between limited natural water resources and the escalating water demand for all purposes”. ICBA (Developing federal environmental guidelines and standards to monitor and manage the discharges from desalination plants in the United Arab Emirates, UAE Ministry of Environment and Water, p 119, 2012) reported: “The production of desalination plants increased from 7 Mm³ in 1973 to 1,750 Mm³ in 2015, and in the present, the UAE has 266 desalination plants in operation. The majority of the plants constructed in coastal areas desalinate seawater, while a few plants installed in desert regions are desalinating brackish and saline groundwater”.

Alsharhan et al. (Hydrogeology of an Arid Region: The Arabian Gulf and Adjoining Areas. Published by Elsevier B.V, Amsterdam, 2001) mentioned that: “The multi-stage flash (MSF) distillation is the main desalination technology in use in the UAE, representing 99.8% in Dubai, 88% in Abu Dhabi and 52% in Sharjah. The multi-effect distillation (MED) method represents 30% in Sharjah and 10% in Abu Dhabi”. The reverse osmosis (RO) desalination is 18% in Sharjah, 2% in Abu Dhabi and 0.2% in Dubai. The desalination technologies in the Northern Emirates are mostly RO, with a few MED and MSF plants. Solar desalination is only practiced in Abu Dhabi, which has 3 experimental solar desalination plants in Umm El Nar (Abu Dhabi Island) and Umm Az Zamoul, in the southeastern corner of the UAE. The total production capacity of solar desalination plants is 640 m³/d.

Water desalination has negative environmental impacts on the marine and terrestrial environments. In addition, the desalination plants face several problems such as corrosion, scale formation, membrane fouling and sedimentation. Al Asam and Rizk (Desalination and water environment in the United Arab Emirates: impacts and solutions. International Desalination World Congress. Dubai. UAE, p 41, 2009) referred to: “the disposal of reject brine from coastal or inland desalination plants and its adverse effects on the ecosystems of the marine environment and groundwater”.

Alleviating the negative impacts of the desalination industry in the country should focus on achieving zero-brine discharge by extracting salts and valuable chemicals from reject brines for industrial and commercial uses, incorporating solar-pond technology, using renewable energy sources in desalination and funding research and development in water desalination.