Seasonal Variations of Phytoplankton Community and Physico-Chemical Characteristics of Water Desalination Plants at Red Sea Governorate, Egypt

Saber, Hani; Samir, Asmaa; Farghl, Abla A.M.; Galal, Hamdy R.M.

doi:10.21608/ejbo.2025.359632.3189

Seasonal Variations of Phytoplankton Community and Physico-Chemical Characteristics of Water Desalination Plants at Red Sea Governorate, Egypt

Document Type : Regular issue (Original Article)

Authors

¹ Department of Botany and Microbiology, Faculty of Science, South Valley University, 83523 Qena, Egypt

² Department of Botany and Microbiology, Faculty of Science, South Valley University, 83523 Qena, Egypt., Holding Company of Water and Wastewater, Red Sea Water and Wastewater Company.

10.21608/ejbo.2025.359632.3189

Abstract

Desalination of seawater offers a promising solution to local water shortages and provides safe drinking water. Reverse osmosis (RO) is currently the most widely used method for seawater desalination. This study monitored five RO desalination plants: El Yosr, Safaga, and Shalateen (which use open intake for feed water), and Qusser and Marsa Alam (which use shore well feed water). Over the course of a year, seasonal samples were collected to observe the abundance of phytoplankton in relation to the physicochemical quality of Red Sea water. Various physicochemical parameters were analyzed, and phytoplankton communities were identified. The analysis revealed that the type of feed water significantly influenced water quality, with shore well feed water showing better physicochemical characteristics compared to open intake feed water. This difference contributes to longer RO membrane lifespans and improved desalination efficiency. A total of thirty-two algal species from four distinct phytoplankton groups were identified: Bacillariophyceae (23 species), Dinophyceae (4 species), Chlorophyceae (3 species), and Cyanophyceae (2 species). The RO technique demonstrated excellent performance in maintaining water quality within Egyptian standards, effectively reducing or eliminating algae in the permeate water. Throughout all research seasons, bacterial loads remained low due to the high salinity of Red Sea water. All sites were free of fecal coliforms, and the permeate water met the quality standards set by the Egyptian Ministry of Health’s Decision 458/2007 for drinking water and domestic use.

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