Physicochemical and Microbiological Characteristics of Rainwater in Different Land-Use Areas of Mosul City, Iraq: Influence of Meteorological Conditions

Abstract

The quality of rainwater is hardly affected by pollution of atmospheric originating from natural processes and other anthropogenic activities, which making it significant indicator of all environmental conditions. Our study aimed to estimate the physical, chemical and microbiological characteristics of rainwater that collected from three areas in Mosul City, Iraq, including: residential (Hai Al-Sadeeq), agricultural (Al-Rasheedia), and commercial (Al-Nabi Younis) areas, during wet seasons extending from 20 December 2023 to 5 May 2024.

The samples of rainwater collected during six rainfall times were analyzed for many features e.g. temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), turbidity, total hardness, essential ions e.g.: (Ca⁺², Mg⁺², NO₃⁻¹, SO₄^-2), some heavy metals, and the microbiological features that including total plate count bacteria, fecal coliforms bacteria, spore-forming bacteria, and fungi by using analytical standard methods.

The results explained important spatial and provisional variations in the quality of rainwater among our studied areas. The highest turbidity, dissolved and suspended solids, hardness, ionic concentrations, heavy metals, and microbial loads were appeared at the commercial area, especially during the event of the first rainfall and following by the dust storms. In contrast, the agricultural area was mostly showed the lower in acidity and hardness, whereas the residential area offered the lowest scales of all chemical and microbial contamination. Zinc metal was detected as the predominant heavy metals, the total plate count of bacteria and fungi were decidedly higher through the event of the initial rainfall, these were reflecting the accumulated airborne in the atmospheric washout of microorganisms and pollutants.

These results indicate that the rainwater quality is primarily affected by atmospheric precipitation associated with waste burning, emissions of vehicular, storms dusting, and other land-use characteristics. The findings provide the valuable main line information for estimating atmospheric pollution and highlight the significant quality of continuous rainwater that monitoring in urbanizing rapidly environments.