Assessment of Water Quality using Water Quality Index in Jhapjhapia River, Khulna, Bangladesh

In southwest coastal Bangladesh, surface water is a crucial basis both for domestic and irrigation purposes. This study investigated the water quality of the Jhapjhapia River, Khulna, Bangladesh using the Water Quality Index (WQI). For many purposes like agriculture, fish farming, and household and industrial activities, surrounding people depend on these water sources. Hence, this study examined the physico-chemical attributes and Weighted Arithmetic Water Quality Index (WAWQI) of three (03) different stations, collected during the monsoon and winter seasons. Among the investigated parameters, ten (10) crucial parameters were considered for the evaluation of water quality. Throughout the research period, the pH value ranges from 7.65 to 7.79. From Station-1 to Station-3, the concentration of EC, TDS, and DO was steadily reduced (Station-1>Station-2>Station-3). The analytical results found that the water transparency ranged from 5 to 10 cm while BOD ranged from 1.85 to 2.71 mg/l and 1.79 to 2.75 mg/l in the monsoon and winter seasons respectively. The levels of total hardness varied from 95 mg/l to 160 mg/l and 130 mg/l to 225 mg/l whereas total alkalinity ranged from 108 to 140 mg/l throughout the monsoon and winter season. Similarly, Ca 2+ value ranged from 24.71 to 28.05 mg/l and 34.74 mg/l to 42.01 mg/l and Mg 2+ ranged from 10.93 to 6.07 mg/l and from 5.93 mg/l to 8.56 mg/l correspondingly. The overall WQI value is found between 51 to 75, demonstrating the status of water quality is poor (Grade-C), unhealthy for drinking without proper treatment though can be used for irrigation and industrial purposes till now. Therefore, this study seeks appropriate strategic initiatives and conservation measures with proper monitoring to stop the deterioration of the water quality for sustaining the health and livelihood of many people who depend on it.