Assessment of Water Quality Scenario of Karnaphuli River in Terms of Water Quality Index, South-Eastern Bangladesh

Abstract

River plays an important role to agribusiness, industry, and the necessities of people and natural life. A great many individuals rely upon the river water for irrigation and fish cultivation. Karnaphuli River is the largest and major watercourse of the Chattogram region, Bangladesh. But day by day the river is losing its quality due to several anthropogenic reasons. Several studies have been done considering water quality and sediment quality of Karnaphuli River. But no research conducted specially on the basis of WQI. The main objective of this study is to assess the water quality of Karnaphuli River from Kalurghat to Patenga in terms of water quality index (WQI). For the determination of WQI, the weighted arithmetic method is used in this study. The water quality of River Karnaphuli was monitored for a period of 8 Months (January - August, 2018). After the completion of collection process, the water samples were assessed by analyzing the various physico-chemical parameters, such as pH, EC, total dissolved solids (TDS), total hardness, total alkalinity, dissolved oxygen, biological oxygen demand (BOD), chemical oxygen demand (COD), chloride, nitrate and phosphate. The WQI reveals that the water quality of Karnaphuli river water from Sha- Amanat Bridge to Karnaphuli Halda estuary can be used for irrigation and fish cultivation purpose and from Sandwip channel to Chaktai Khal confluence point proper treatment required before use.