Observation of Water Quality of Buriganga River and Different Lakes in Dhaka City

Abstract

The Buriganga River is a vital source of water for the city, supplying water for residential, commercial, and agricultural uses. Even while they might not be direct sources of municipal water supplies, lakes like Uttara, Hatirjheel, and Dhanmondi can however help with local water availability and irrigation for surrounding communities. The river and other lakes in Dhaka city's water quality were evaluated and compared through a thorough investigation that is presented in this paper. The river and other nearby lakes become contaminated for a variety of causes; the primary cause of the pollution is industrial chemical waste. Here, we collected the water from these locations and examined a wide range of parameters, such as pH, BOD, COD, DO, and Turbidity. Seasonal changes are noted once a thorough investigation of these factors is conducted. This study was conducted to differentiate the water quality of three different lakes in Dhaka City and Buriganga River in two different seasons. Additionally, we compared the water quality of the Buriganga River and selected lakes. In this study, we have checked the water quality by the standard of WQI and determined the effect size ofevery parameter by using Cohen's d. According to the study, the summer and winte seasons' pH values are restricted to 7.2 to 7.6. However, BOD, COD, Turbidity, and DO values vary greatly. During the summer, the minimum BOD value in the river is 7.5 mg/l, and during the winter, it is 14.3 mg/l. In rivers, the DO value drops to zero throughout the winter, whereas there are no appreciable variations in lakes. The values of COD, BOD, pH, DO, and turbidity decrease in the winter compared to the summer. When the three lakes are compared, Hatirjheel Lake has the highest pH value (9.94), while Dhanmondi Lake has the lowest pH value (6.8). During the winter, Dhanmondi Lake had 120 NTU the highest value of Turbidity. This study does a thorough evaluation of many water quality indicators, including pH, Turbidity, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), and Chemical Oxygen Demand (COD), in Buriganga River, Dhanmondi Lake, Hatirjheel Lake, and Uttara Lake. The Water Quality Index (WQI) is computed to assess the overall water quality of these areas. Turbidity is identified as a critical element, with the highest Quality Index, indicating a potentially large influence on water quality. The impacts of pH and dissolved oxygen (DO) are relatively minimal, but biochemical oxygen demand (BOD) and chemical oxygen demand (COD) have a moderate influence. The study places these findings within the framework of existing water quality standards, emphasizing the ever-changing nature of water quality and underscoring the importance of specific management measures to protect and improve environmental health in the areas under investigation. Continual surveillance is crucial for monitoring shifts and evaluating the efficacy of applied solutions.