Multivariate analysis of water quality in the Dhaleshwari River, Bangladesh: identifying pollution sources and environmental implications

ABSTRACT This study aims to evaluate the current water quality status of the Dhaleshwari River, considering seasonal variations, and identify potential pollution sources using physicochemical parameters, multivariate statistical analysis, and the water quality index (WQI) method. Sampling was conducted at six locations along the Dhaleshwari River from January 2021 to April 2022, encompassing both dry and wet seasons. Eleven physicochemical parameters were tested following standard procedures. The calculated WQI values demonstrated that the overall water quality of the Dhaleshwari River is very poor (264.7 ± 64.5). Seasonal variation in water quality was significant, with the worst quality (305.7 ± 54.3) observed during the dry season; however, water quality during the wet season was also unsatisfactory (223.6 ± 46.3). Geospatial analysis shows the distribution of water quality in the study locations. Principal components analysis was performed for source appointment, which indicated that direct wastewater discharge from surrounding industries, particularly tanneries, as well as municipal wastewater, were the major pollution sources. In conclusion, this study sheds light on the deteriorating water quality of the Dhaleshwari River due to industrialization and human activities. The findings underscore the urgent need for interventions to mitigate pollution sources and improve the overall health of the river ecosystem.