Radiological and Chemical Safety Assessment of Drinking Water from Treatment Plants and Rivers in Kut City, Iraq

Abstract

Climate change and increasing anthropogenic activities, particularly wastewater discharge into rivers, have raised pollution levels in the water sources of Kut City, necessitating an assessment of the radiological and chemical safety of drinking water at the city's treatment plants. Thirteen water samples were collected, comprising ten treated and three raw water samples from the source rivers. An HPGe detector was used to measure the radionuclides 214Bi, 214Pb, 212Bi, 212Pb, 40K, and 137Cs. All measured radionuclides were below the minimum detectable activity (MDA). ICP-OES analysis supported these findings, as U concentrations in most samples were below the limit of quantification (LOQ), whereas Th ranged from 0.01 to 0.05 mg/L. In general, these values were below the WHO guideline limits, indicating that the water from the studied plants was radiologically safe at the time of sample collection. Chemically, a significant increase in the concentrations of several toxic heavy metals in the treated water was recorded, including Cd (0.01–0.17 mg/L), Pb (0.01–0.03 mg/L), Ni (0.01–0.29 mg/L), Cr (0.03–0.14 mg/L), and Mn (0.01–0.24 mg/L). The treatment plants showed high removal efficiencies for Mn and Zn and moderate removal efficiencies for K and Pb, while some plants contributed to increased pollution due to inadequate maintenance and insufficient cleaning. Statistical analyses revealed varying correlations among K, Th, Mn, and Zn, and among Cr, Ni, Co, and Cu, suggesting common sources for each group of correlated elements. These results indicate inefficiency in the studied treatment plants and underscore the need for advanced technologies to remove heavy metals.