POONAM VERMA, DHIRENDRA YADAV AND VINOD KUMAR
Abstract
Water pollution is defined as any significant alteration in the physical, chemical, or biological quality of water caused directly or indirectly by waste discharge and various anthropogenic activities. Such alterations may deteriorate water quality, making it unsuitable for potable water, domestic use, irrigation, and the sustenance of aquatic life. Water is not pure in a chemical term. In a relatively pristine region, rainwater primarily contains dissolved CO2, O2 and N2. It may also carry suspended dust or other particles acquired during its passage through the atmosphere. The study aims to assess seasonal changes in the physico-chemical characteristics of the Yamuna River at Firozabad and Etawah, Uttar Pradesh, India, during the before and after monsoon periods of 2024. Water samples were analyzed for pH, EC (Electrical Conductivity), Turbidity, TH (Total Hardness), TDS (Total Dissolved Solids), TDS (Total Suspended Solids), DO (Dissolved Oxygen), BOD (Biological Oxygen Demand), COD (Chemical Oxygen Demand), Alkalinity and Nitrate using standard analytical methods. The results revealed marked seasonal variations in most the physico-chemical parameters. pH remained within the permissible limits, indicating slightly alkaline conditions. Turbidity, TDS, TH, and TSS showed elevated values, particularly during the post-rainy season, reflecting the influence of surface runoff and sediment transport. DO increased during post rainy period, whereas BOD and COD, indicating dilution and partial reduction of organic pollution. Alkalinity values were higher than the desirable limit but remained within the permissible range. Nitrate concentration at both locations surpassed the Bis permissible limit in the both seasons, suggesting on going nitrate contamination. Overall, the finding demonstrate that the Yamuna River is under considerable environmental stress due to domestic sewage, agricultural runoff, and industrial discharge. Continuous monitoring and effective pollution to strategies are essential for improving river water quality and protecting aquatic ecosystem health.