Assessment of the Physico-Chemical Quality of Untreated and Treated Water Using Water Quality Index (WQI) in the Ain Zada Dam, East Algeria

Abstract

The Ain Zada dam is experiencing a deficit in recent years due to scanty precipitation and reduced water flow, resulting in the dam’s water reserve dropping to 8.3%. Our study’s primary objective is to assess the quality of both untreated (raw) and treated water from the Ain Zada dam by conducting physico-chemical analyses on both samples. Based on the findings, the physico-chemical quality of the treated water is deemed satisfactory, as all samples adhere to Algerian standards. The treated water exhibits an organic matter concentration of 4.94 mg/l, which is the chief contributor to the unfavourable odour and taste of the dam water. To address this, enhancements will be made to the Ain Zada dam treatment station this year through the adoption of a novel ozone disinfection method (ozonation). The Water Quality Index (WQI) for treated water from the Ain Zada dam indicates a favourable suitability for drinking water production from February to May 2022. Two quality categories are discernible for each scenario based on the obtained WQI values: excellent and good for treated water, and excellent and poor for raw water. Water quality diminishes notably in April, where the treated water quality index rises (25 < WQI ≤ 50), while the raw water’s quality classifies as poor (WQI > 50). The decline in water quality during this month can be attributed to stream variations, agricultural activities, and urban wastewater discharges. Consequently, it is imperative to prioritise the reduction of these pollution sources to safeguard water resources and enhance water quality within the watershed.