Assessment of the quality of bottled water marketed in Addis Ababa, Ethiopia

Abstract

The consumption of bottled drinking water has been increasing in the world. But, the quality of bottled water used for human consumption is not subjected to any stringent quality control measure in Ethiopia. The present study was carried out to determine the physicochemical quality parameters of twenty brands of bottled drinking water available in Addis Ababa and to compare with drinking water guidelines set by World Health Organization (WHO) and Compulsory Ethiopia Standards (CES). The samples were collected by random sampling technique. The physicochemical parameters such as pH; TDS and EC; total alkalinity, total hardness, HCO₃^-, Cl^-; SO₄^2-, NO₃^-, NO₂^-, F^-) and common cations (Ca²⁺, Mg²⁺, Na⁺, and K⁺) were determined by pH meter, conductivity meter, titration, UV-Visible spectrometry, fluoride ion selective electrode and microwave plasma-atomic emission spectrometry, respectively. The mean physicochemical concentration of TDS, total alkalinity, total hardness, HCO₃^-, SO₄^2-, NO₃^-, NO₂^-, F^-, Cl^-, Ca²⁺, Mg²⁺, Na⁺, K⁺,  pH and EC in bottled water samples were found in the range (4.67-139), (12-165), (4-97), (16.3-202 ), (0.05-3.84), (0.02-0.84), (0.08-0.28), (0.03-1.26), (4.28-20.8), (0.19‑8.9), (0.02‑2.5), (1.8‑24.5), (0.14‑8.08 mg/L), (6.43-7.69) and (9.8-289 µs/cm), respectively. The drinking water quality index (WQI) was calculated based on 15 important quality parameters and the results were found in the range 3.85-49.2. The mean concentrations of physicochemical parameters in almost all the bottled drinking water were below the permissible limit set by WHO and CES. Hence, all the tested bottled water samples are safe for drinking purpose.

KEY WORDS: Bottled water, Common cations, Common anions, Physicochemical parameters, Water quality index

Bull. Chem. Soc. Ethiop. 2019, 33(1), 21-41

DOI: https://dx.doi.org/10.4314/bcse.v33i1.3