In the heart of northeastern Iran, the Atrak River flows, a vital lifeline for agriculture and communities. Yet, this river faces an unseen threat: heavy metal pollution from urban wastewater. A recent study, led by Marzieh Jahani from the Department of Civil Engineering at the University of Bojnord, sheds light on the extent of this pollution and its implications for water quality and the energy sector.
Jahani and her team investigated how heavy metals from the Bojnord Municipal Wastewater Treatment Plant’s discharge affect the Atrak River. They collected water and sediment samples from five stations along the river during the summer of 2024, using rigorous quality assurance and control measures. The heavy metals were quantified using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), a highly accurate analytical technique.
Their findings, published in the journal ‘آب و توسعه پایدار’ (Water and Sustainable Development), revealed that the river’s capacity to transport wastewater-derived pollutants is limited to a range of 50–100 meters from the discharge point. “Under prevailing hydraulic conditions, the river’s self-purification capacity is not sufficient to mitigate the pollution within this range,” Jahani explained.
The study employed several pollution indices to assess the heavy metal contamination. The Contamination Degree (Cd) index indicated moderate contamination at all stations except S2, which is directly downstream of the wastewater treatment plant discharge. The Heavy Metal Evaluation Index (HEI) and Heavy Metal Pollution Index (HPI) confirmed peak contamination at Station S2.
Spatially, the distribution of heavy metals varied. Arsenic (As) and lead (Pb) showed consistent concentrations along the river, while chromium (Cr) and iron (Fe) exhibited an increasing trend downstream. This trend is attributed to their strong correlation, suggesting a common source or similar behavior in the aquatic environment.
The Geoaccumulation Index (Igeo) revealed no sediment contamination for any of the metals, indicating that the sediments are not acting as a significant sink for these pollutants. However, the Contamination Factor (CF) indicated moderate pollution for cadmium (Cd), highlighting the need for targeted monitoring and management strategies.
The study also assessed the potential health risks associated with the heavy metal pollution. The Hazard Index (HI) for children was approximately 0.5, signifying a non-carcinogenic risk. While this value is below the threshold of concern, it underscores the importance of continuous water quality monitoring and management.
The implications of this research extend beyond environmental concerns. The energy sector, which relies heavily on water for cooling and other processes, could face significant challenges if water quality continues to deteriorate. “Effective wastewater management is not just an environmental imperative but also a commercial necessity,” Jahani emphasized.
This study underscores the critical importance of wastewater management and continuous water quality monitoring in similar watersheds. As Jahani noted, “Our findings highlight the need for integrated approaches to pollution control and water resource management.” By addressing these issues proactively, stakeholders can ensure the sustainable use of water resources, safeguarding both environmental health and economic interests.
In the face of growing water scarcity and pollution challenges, research like Jahani’s provides valuable insights and tools for developing effective mitigation strategies. As the energy sector continues to evolve, the need for clean and reliable water sources will only grow, making studies like this invaluable for shaping future developments in the field.