This study aimed to evaluate the physicochemical characteristics and heavy metal concentrations of surface. Four locations (S1-S4) were selected from the southern part of the Tigris River within the city of Baghdad, where several vital facilities are located, such as the Al-Dora power station and the Al-Dora refinery. Water samples were collected over a period of nine months, at a rate of one sample per month, from October 2024 to June 2025. Water samples were analyzed for temperature, pH, total alkalinity, electrical conductivity, turbidity, total dissolved solids, total suspended solids, dissolved oxygen, biological oxygen demand, major ions, nutrients, and selected heavy metals (Pb, Cd, Cu, and Zn). The results show water temperature varied from 12 to 21.6 °C, exceeding the critical level (15 °C) throughout summer and autumn in all sites but remaining within acceptable limits (7.03–8.10). Total alkalinity was as high as 728 mg CaCO₃ L⁻¹ at S1 during winter, and its value exceeded the guideline limit (200 mg CaCO₃ L⁻¹). EC ranged 678-1180 µS cm⁻¹ with maximum value during summer exceeding (1000 µS cm⁻¹) guideline. Turbidity (5.9–12.8 NTU), TDS (720 mg L⁻¹), and TSS (53.5 mg L⁻¹) surpassed acceptable levels during most seasons as was observed for high suspended/dissolved loads. Dissolved oxygen varied between 3.85–7.4 mg L⁻¹, with minimum values noted during warm seasons while BOD was higher than the permissible limit of (5 mg L⁻¹), at all locations (6.12–11.7 mg L⁻¹). Nitrate levels were kept within acceptable concentrations of 0.41–4.25 mg L⁻¹
Mawla et al. (Sun,) studied this question.