Smart Energy and Sustainable Environment , ISSN 2668-957X
2020, Volume 23, Issue 2
Pages 92-106

CWQI index as quality indicator of surface water - An approach on the Olt River, Romania

Claudia Sandru * , Mihaela Iordache , Andreea Maria Iordache , Roxana Elena Ionete , Ramona Ionela Zgavarogea

National Research and Development Institute for Cryogenics and Isotopic Technologies - ICSI Rm. Valcea, Uzinei Street no. 4, PO Box Râureni 7, 240050, Râmnicu Vâlcea, Romania

*Corresponding author: Claudia Sandru, E-mail:

Received 22 October 202; Received in revised form 02 November 2020; Accepted 02 November 202; Available online 03 November 2020


This work aims at assessing the pollution degree of the Olt River (Romania), based on the Canadian Water Quality (CWQI) index, by monitoring twenty twos locations along the middle and south part of the river basin for a period of four months, from March to October, during 2018. A comprehensive physico-chemical analysis involving major cations (Ca2+, Mg2+, Na+), anions (Cl-, SO42-, N-NO3--) and general parameters (pH, electrical conductivity, total dissolve solids) was performed for this purpose. Results demonstrated that CWQI values classified the water in the investigated sectors of the river as fair (values ​​between 66.08 to 79.05), marginal (56.22 to 64.63) and good (value of 85.60). This method appears to be more systematic and provide comparative evaluation of the water quality in different seasons of the year. The results showed that there is a large variations in the parameters in different sections of the river due to different anthropogenic factors. Therefore, this index may be helpful as marker for the public to better understand the quality of water, but also as tool for water quality management.


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  • Keywords

    Canadian water quality index, Pollution, Surface water.

    Tag search Canadian water quality index Pollution Surface water