Commercial reverse osmosis point-of-use systems in Egypt failed to purify tap water

• Published in: Journal of water and health 2024-05, Vol.22 (5), p.905-922
• Main Authors: Gad, Mahmoud, Marouf, Mohamed A, Abogabal, Amr, Hu, Anyi, Nabet, Noura
• Format: Article
• Language: English
• Subjects: Acanthamoeba; Activated carbon; Ammonia; bacteria; Chlorine; Coliforms; Contamination; Dissolved solids; Drinking water; Drinking Water - microbiology; Drinking Water - parasitology; Egypt; Filtration - instrumentation; Filtration - methods; Fluorides; Genotypes; Health risk assessment; Health risks; Heavy metals; Indicators; Inlets; Inlets (waterways); Osmosis; Outlets; Physical properties; physicochemical parameters; protozoa; Public health; Quality standards; Reverse osmosis; reverse osmosis point-of-use systems; Sewer systems; Total dissolved solids; Urbanization; Wastewater; Water Microbiology; Water purification; Water Purification - methods; Water Quality; Water quality standards; Water Supply; Water treatment
• ISSN: 1477-8920; 1996-7829
• DOI: 10.2166/wh.2024.036

This study addresses the heightened global reliance on point-of-use (PoU) systems driven by water quality concerns, ageing infrastructure, and urbanization. While widely used in Egypt, there is a lack of comprehensive evaluation of these systems. We assessed 10 reverse osmosis point-of-use systems, examining physicochemical, bacteriological, and protozoological aspects of tap water (inlets) and filtered water (outlets), adhering to standard methods for the examination of water and wastewater. Results showed significant reductions in total dissolved solids across most systems, with a decrease from 210 ± 23.6 mg/L in tap water to 21 ± 2.8 mg/L in filtered water for PoU-10. Ammonia nitrogen levels in tap water decreased from 0.05 ± 0.04 to 2.28 ± 1.47 mg/L to 0.02 ± 0.04 to 0.69 ± 0.64 mg/L in filtered water. Despite this, bacterial indicators showed no significant changes, with some systems even increasing coliform levels. Protozoological analysis identified prevalent (42.5%), less frequent (2.5%), (5%), and potentially pathogenic genotypes. Elevated bacterial indicators in filtered water of point-of-use systems, combined with essential mineral removal, indicate non-compliance with water quality standards, posing a public health concern. Further research on the long-term health implications of these filtration systems is essential.