Monitoring of water quality generated by MSF and reverse osmosis at the Kahrama and Mactâa plants in West Algeria

Abstract

Algeria has chosen and has been using seawater desalination substituting natural resources in the majority of its northern cities for nearly 20 years due to several pressing issues, including water stress relief and a lack of rain induced by global warming's adverse impacts. Indeed, Algeria currently possesses 21 desalination plants, six more under development, and 81 dams. All of these desalination plants employ reverse osmosis membrane technology, except the Kahrama plant in Arzew, Oran, which utilizes a Multi-Flash (MSF) distillation process or staged expansion. The current study assessed the quality control of desalinated water at the Kahrama and Mactâa plants. This was accomplished by comparing the physico-chemical and bacteriological characteristics of distilled water, osmosis water, and drinking water. The T-test was applied when comparing seawater, distilled water, and reverse osmosis water, as well as drinking water, with international norms. Except for iron and copper, most of the physical parameters have a p-value < 0.001. The average temperature of distilled water is 32 degrees Celsius, whereas reverse osmosis water is 20 degrees Celsius. However, reverse osmosis produces greater amounts of alkalinity, total hardness, chlorides, calcium, and magnesium than MSF does. When drinking water is compared to international standards, both findings show nearly identical pH levels but at different temperatures. Bacterial analysis indicates that drinking water is free of total coliforms, E. coli, Enterococci, and sulfite-reducing Clostridia. However, because of the brines generated during desalination, this seemingly infinite water resource harms the ecosystem.