Assessment of Desalinated Water from Selected Stations in Janzour, Libya, Compared to Some Bottled Water Plants

Abstract

Desalinated and bottled water are generally considered safe and potable, as they meet strict quality standards. Bottled water is often superior in quality due to its naturally occurring minerals, while desalinated water provides ultra-pure water but may lack some essential minerals. This study evaluates and compares the quality of drinking water produced by selected desalination stations in Janzour, Libya, with several locally bottled water brands based on key physicochemical parameters, including pH, electrical conductivity (EC), total dissolved solids (TDS), oxidation-reduction potential (ORP), and nitrate concentration (NO₃⁻). A total of 27 water samples (coded R1–R27) were analyzed, comprising three bottled water brands (Al-Safiya, Dijlah, Sultan) and one spring water source (Ain Bannon), using a HACH brand MP Series multiparameter meter for pH, EC, TDS, and ORP measurements, while nitrate concentration was determined by UV-Vis spectrophotometry. The results showed that with the exception of one sample (R8) which exhibited relatively higher TDS (669.5 ppm), all analyzed samples complied with the permissible limits set by WHO guidelines and Libyan drinking water standards, with pH values ranging from 6.26 to 8.06, TDS values below 200 ppm for most samples (Dijlah recorded the lowest at 85.8 ppm), EC values ranging from 31.42 to 1098 μS/cm, ORP values between 198 and 258 mV indicating adequate oxidative potential, and nitrate concentrations between 0 and 1.8 mg/L which are far below the WHO maximum of 50 mg/L. The study concludes that most desalinated water from the selected stations and the bottled water brands available in Janzour are safe for human consumption regarding the tested parameters, with Dijlah water exhibiting the lowest TDS and lightest taste, Al-Safiya showing the highest ORP for better preservation, and Ain Bannon Spring water demonstrating excellent quality comparable to commercial bottled water. Regular quality monitoring and proper maintenance of desalination equipment are recommended to sustain this performance, with special attention needed for the source of sample R8.