Comparative Analysis of Physicochemical Water Quality of the Phalgu River in Pre-and Post-Monsoon Seasons

The Phalgu River is an important freshwater resource supporting domestic, agricultural, and ecological functions in Gaya and surrounding areas. However, increasing anthropogenic pressures—including agricultural runoff, urban waste disposal, and sand mining—have contributed to growing physicochemical pollution, posing risks to aquatic ecosystems and public health. During the pre-monsoon season, reduced flow conditions tend to concentrate contaminants such as nutrients and heavy metals, potentially lowering water quality and affecting aquatic life.This study examines seasonal variations in water quality during the pre- and post-monsoon periods, with a comprehensive assessment of key physicochemical parameters, including pH, dissolved oxygen, turbidity, nutrients, and selected heavy metals. The river stretch flowing through Gaya district was systematically monitored. Water samples were collected from eight strategically selected sampling stations during both seasons to evaluate spatial and temporal variations.Heavy metal concentrations were analyzed using Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS), ensuring accurate detection and quantification of trace elements. These advanced analytical techniques provided reliable insights into the presence and distribution of potentially toxic contaminants in the river water.The post-monsoon assessment revealed noticeable changes in physicochemical characteristics, primarily influenced by monsoonal runoff and sediment mobilization. Increased suspended matter and altered nutrient dynamics were observed in several locations, reflecting the combined impact of natural hydrological processes and human activities. Data processing and statistical evaluation were conducted using Python-based analytical tools to ensure systematic interpretation of seasonal patterns.Overall, the findings highlight clear seasonal fluctuations in water quality driven by hydrological variability and anthropogenic stressors. Continued long-term monitoring and effective pollution management strategies are essential to protect and sustain the ecological health of the Phalgu River.