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

E Yilkal,B S Chandravanshi,F Zewge

doi:10.4314/bcse.v33i1.3

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, HCO 3 - , Cl - ; SO 4 2- , NO 3 - , NO 2 - , F - ) and common cations (Ca 2+ , Mg 2+ , 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, HCO 3 - , SO 4 2- , NO 3 - , NO 2 - , F - , Cl - , Ca 2+ , Mg 2+ , 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

Highlights

Water is one of the most important of all natural resources known on the earth
The main objective of this study was to determine water quality parameters and calculate the water quality index of bottled water marketed in Addis Ababa, Ethiopia and to compare with the values set by World Health Organization (WHO)
The specific objectives of the study were: (1) to determine (i) common cations (Na+, K+, Ca2+, Mg2+) and anions (F, Cl, SO42, NO3, NO2, HCO3) of bottled water and (ii) Total dissolved solids (TDS), electrical conductivity (EC), hardness, pH, and alkalinity of bottled water; (2) to compare (i) the levels of common ions in bottled water marketed in Addis Ababa with WHO and CES guidelines for drinking water, (ii) the measured values of physiochemical parameters with the labeled values and (iii) the physicochemical parameters of different brands of bottled water and (3) to calculate the water quality index of bottled drinking water in Addis Ababa to assess the quality of water as excellent, good, poor, very poor or unsuitable for drinking

Summary

Introduction

Water is one of the most important of all natural resources known on the earth. It is mainly used for drinking purposes which come from the surface and underground water sources [1]. 97% water exists in the oceans which are not suitable for drinking purpose and 3% is fresh water. Of the 3% fresh water 2.97% is comprised of glaciers and ice caps and remaining little portion of 0.3% are available as a surface and groundwater for human use [2]. A high quality water is required for drinking purposes for better health [3]. The pattern of human settlement throughout the history has often been determined by its availability [5]

Objectives

Methods

Results

Conclusion