Assessment of raw and produced water quality at Al-Doura water treatment plant

Abstract

Abstract The population growth rate has increased rapidly in recent years so there is an obligation to evaluate the productivity of produced water (PW) by investigating the operation of the Water treatment plant (WTP). WTP’s primary goal is to remove and destroy harmful organisms from contaminated water to make it safe for human consumption. The quality of PW depends on the performance of WTP. This study aims to assess the removal efficiency of Al-Doura WTP in Baghdad City/Iraq and ensure that the drinking water quality meets the drinking water standards. Twenty-two water quality parameters are analysed over four years (from January 2020 to December 2023). The samples of raw water are collected from the Tigris River at the intake of the WTP, while the PW samples are collected at the final stage where the water undergoes treatment before being distributed to the consumers through the network. The measured parameters are Temperature, Turbidity, Alkalinity as CaCO3, Total Hardness as CaCO3, Calcium as Ca, Chloride as Cl, Magnesium as Mg, pH, Colour, Electrical Conductivity EC, Free chlorine (Residual chlorine), Sulphate as SO4, Total dissolved solids, Suspended solids, Iron as Fe, Fluoride as F, Aluminium as AL, Nitrite as NO2, Nitrate as NO3, Ammonia as NH3, Silica as Sio2, and Orthophosphate as PO4. In this study, special focus is concerned with some of these water quality parameters, temperature, pH, electrical conductivity EC, and Turbidity. The analysis is sub-categorized into winter and summer seasons. The SPSS software is used to analyse the data. The results indicate that there is no significant difference between the temperature of raw water and that of the produced water, and the pH values indicate slight alkalinity for raw water in both seasons. Electrical conductivity Ec values for both raw and produced water are found always greater in winter than in summer. The turbidity is found to satisfy the permissible limits for both the Iraqi and World Health Organisation standards (Turbidity < 5 NTU). The drinking water produced from the Al-Doura water treatment plant is found to be within Iraqi and WHO standards, The high difference in turbidity concentration before and after treatment and the removal efficiency excellent value of close to 98% indicates that the plant is highly effective and reflects the effective process of Al-Doura WTP in removing particulate matter and improving water clarity. The Pearson, correlation analysis results indicate a strong (positive, and negative) correlation in the relationship among some parameters reported in this article.