Abstract
In this study, water samples were taken seasonally (two months per season) from eight locations inside Shaqlawa district from July 2024 to May 2025 in the area northeast of Safeen Mountain in Shaqlawa District, Erbil, Iraq. The analysis of physical and chemical properties of water, including heavy metals. Additionally, the identification of algae, as well as their spatial distribution and periodic patterns, has been carried out.
The results of physical and chemical parameters indicated that Air and surface water temperature were changed from 9-43 oC and 8-29 oC respectively; turbidity values of studied sites between 0.46 and 541.0 NTU, Site 6 (Kani Aqubani Khawaru) tended to have higher turbidity value. and the higher level was observed during May. Electrical conductivity, total dissolved solid and pH ranged from 911 µs.cm-1 to 304 µs.cm-1, 154 mg.l-1 to 457 mg.l-1, 6.60 to 8.41, respectively. The minimum and maximum values of total alkalinity varied between 190 and 449 mg CaCO3.l-1 in Sites 6 (Kani Aqubani Khawaru) and 8 (Kani Mewraka) respectively. However total hardness in the current survey ranged from 154 to 566 mg CaCO3.l-1 in Sites 7 (Kani Pungina)and 4 (Kani Zhnan) respectively.
On the other hand, results of major cations and anions revealed the following values records : calcium, magnesium, sodium and potassium were ranged from 20.6 to 177.0 mg. l-1, 2.0 -70.0 mg. l-1, 2.30 to 24.50 mg. l-1 and 0.0- 10.7 mg.l-1 respectively; Sulfate and chloride values varied from 2.04 to 252. 8 mg.l-1 and the values chloride ion ranged from 2.0 mg.l-1 to 50.0 mg.l-1 respectively in studied spring sites, the maximum chloride level was observed at Kani Sard during April,2025 but the minimum chloride level was Kani Pungina during August,2024.
The concentration of nitrate and orthophosphate ranged from 0.37 to 51.70 mg.l-1 and 0.10 to 3.9 μg.P-PO4.l-1 respectively. Concentration of dissolved oxygen in spring sites varied between 1.20 and 14. 40 mg.l-1 in Kani Zhnan, Aqubani Khwaru village during October 2024 and February 2025 respectively. Lower value of BOD5 was 0.2 mg.l-1 measured in January,2025, whilst higher value was 16 mg.l-1 found in May,2025.
The water quality index for potable water uses was determined seasonally in the study sites, with values ranging from 44.0558 (excellent) at Site 3 (Kani Sard) in the summer season to 2404.48 in spring period at Site 6 (Kani Aqubani Khawaru), indicating unsuitable status for drinking purposes. Also, the water quality index for irrigation purposes ranged from a lower value of 28.71 at Site 8 (Kani Mewraka) during the winter season to a higher value of 52.98 at Site 3 (Kani Sard) in the spring season except in the summer period, it valued 58.27.
The concentration of all measured heavy metals showed that the Ag value ranged from (0.62 and 0.88 µg.l-1 ), Al concentration ranged from (5.62 to 10.7 µg.l-1); the values of arsenic(As), barium (Ba), cadmium (Cd), cobalt (Co), chromium(Cr), copper(Cu), iron(Fe), nickel(Ni), lead(Pb), selenium(Se), and zinc(Zn) ranged from (0.31-1.01 µg.l-1), (30.20-49.30 µg.l-1), (0.02-0.28 µg.l-1), (0.13-1.85 µg.l-1), (3.97-8.99 µg.l-1), (0.992-1.35 µg.l-1), (0.43-1.10 µg.l-1), (0.20-1.14 µg.l-1), (1.63-2.69 µg.l-1), (1.26-2.26 µg.l-1) and (53.9-123 µg.l-1) respectively. In this investigation the value of manganese (Mn) in all studied sites was 1 µg.l-1, while lithium concentration ranged from 57.4 to 73.3 µg.l-1. The values of all heavy metals were lower than the permissible level for drinking purposes in both summer and winter seasons, according to WHO guideline except Lithium concentration being higher than allowable level for drinking purposes in all sites. Relying on the heavy metal pollution index (HPI) the results varied between 76.455 to 88.213 in Kani Pungina and Kani Aqubani Khawaru in summer seasons, and 77.045 to 96.585 in Kani Pungina and Kani Zhnan respectively, which is less than 100, which is the standard level for potable water uses, and this indicates that the water is not seriously contaminated with considering the heavy elements studied. Also, single factor index for all heavy metals in this study was less than 1 at many sites, being considered uncontaminated except lithium in all spring sites, which is calculated at more than 3 being considered heavily contaminated.
A total of 70 species included 30 genera, 23 families, 15 orders, 8 classes and 7 divisions in spring sites in Shaqlawa district. Chlorophyta species dominant includes 38 species (54.28%) from all algal taxa recorded, most of them belonging to Zygnematales with 17 species and Chlorococcales with 16 species. Among green algae, the highest number of species recorded return to Microspora spp. and Cosmarium spp. with 6 species (8.57%) for each species after that about 5 species of Spirogyra (7.14%), then Pedistrum 4 (5.71%), Scenedesmus 4 species (5.71 %), Closterium with 3 species (4.28 %), and 2 species belonging to Oedogonium and Zygnema.
According to Shannon Weiner diversity index (H¯), the current study indicates that the diversity of algal species ranges from 2.380 to 2.9093 in Sites 1 (Kani Chneran) and 6 (Kani Aqubani Khawaru) in order and also varied between 2.0431 in February,2025 to 2.9883 in August,2024; As a result, the diversity index showed the water body around moderate pollution in this study.
Jaccard similarity index (JS) revealed the highest similarity was observed between Sites 3 (Kani Sard) and 7 (Kani Pungina) at 46.80%, while the lowest similarity was observed between Sites 1 (Kani Chneran) and 4 (Kani Piawan) at 10.20%.
Phytoplankton productivity ranged from 62683.13 cells.l-1 at Site 7 (Kani Pungina) in November to 1778436 cells.l-1 at Site 3 (Kani Sard) in October during the autumn season, in contrast, during the spring period, it ranged from 123786.09 cells.l-1 at Site 2 (Kani Aqubani Saru) through April,2025 to 1631868.31 cells.l-1 at Site 1 (Kani Chneran) during May,2025.
