Seawater desalination by reverse osmosis (RO) is a reliable method for augmenting drinking water supplies. In recent years, the number and size of these water projects have increased dramatically. As freshwater resources become limited due to global climate change, rising demand, and exhausted local water supplies, seawater desalination will play an important role in the world's future water supply, reaching far beyond its deep roots in the Middle East. Emerging contaminants have been widely discussed with respect to wastewater and freshwater sources, but also must be considered for seawater desalination facilities to ensure the long-term safety and suitability of this emerging water supply. Harmful algal blooms, frequently referred to as 'red tides' due to their vibrant colors, are a concern for desalination plants due to the high biomass of microalgae present in ocean waters during these events, and a variety of substances that some of these algae produce. These compounds range from noxious substances to powerful neurotoxins that constitute significant public health risks if they are not effectively and completely removed by the RO membranes. Algal blooms can cause significant operational issues that result in increased chemical consumption, increased membrane fouling rates, and in extreme cases, a plant to be taken off-line. Early algal bloom detection by desalination facilities is essential so that operational adjustments can be made to ensure that production capacity remains unaffected. This review identifies the toxic substances, their known producers, and our present state of knowledge regarding the causes of toxic episodes, with a special focus on the Southern California Bight.
Bibliographical noteFunding Information:
The authors are grateful to Mr. Mark Donovan at Separation Processes, Inc. for providing the data for Fig. 9 . The preparation of this manuscript was supported in part by funding from a contract between the West Basin Municipal Water District, Department of Water Resources and the University of Southern California, National Oceanic and Atmospheric Administration grants NA05NOS4781228 and NA07OAR4170008, Sea Grant NA07OAR4170008, National Science Foundation grants CCR-0120778 (Center for Embedded Networked Sensing; CENS), DDDAS-0540420, MCB-0703159, and a NASA Earth and Space Science Fellowship Grant NNX06AF88H. M.-È. Garneau was supported by a fellowship from the Fonds québécois de recherche sur la nature et les technologies (FQRNT).
- Harmful algal blooms
- Red tides
ASJC Scopus subject areas
- Environmental Engineering
- Civil and Structural Engineering
- Ecological Modeling
- Water Science and Technology
- Waste Management and Disposal