Assessment of Surface Water Quality Parameter of Hatirjheel Lake In Dhaka City

Abstract

The study was conducted in the Department of Civil Engineering at Sonargaon University with the objectives to prepare a project and thesis with a view to partial fulfillment of the requirements for the degree of Bachelor of Science (B.Sc.) in Civil Engineering. The specific objective of the study was to study the surrounding environment at a few selected sites around Hatirjheel Lake, to assess the lake's water quality in terms of very important water quality parameters, to investigate the causes leading to it. This serious water pollution and finally to provide some suggestions to improve the existing condition. To determine the suitable locations of water collection, the whole area in and around the lake was preliminarily surveyed and necessary photographs were taken. Then water samples were collected such that the samples represent the characteristics of lake water. With a view to finding out the water quality some parameters water samples were tested at field and several data was tested DPHE central laboratory. We get pH scale varied from 7.5 to 8.0. with a weighted average of 7.75 that’s samples 100% maintain the quality (ECR.97) and World Health Organization guideline. The Dissolve Oxygen of the Lake water has shown a variation from 4.75 to 6.05 mg/l. with a weighted average of 4.06 the study value not exceeded the minimum requirement so the water was not good for drinking. BOD varied from 15mg/l to 32 mg/l with a weighted average of 23.33 mg/l, 100% samples showed deviation from the standard. COD varied from 60 to 120 mg/l with a weighted average of 88.67 mg/l, which is so far from the BECR standard and WHO guideline. Electrical Conductivity of water of the Hatirjeel lake was found to vary from 550 to 740 (micro mhos/cm) and the average value was 616.33 (micro mhos/cm). According to WHO guideline and BECR standard electrical conductivity value should not exceeded 1000 μs/cm so the water 100% maintain the quality. The Total Dissolved Solid of water of the Hatirjheel lake was found in a range of 275 mg/l to 370 mg/l with a weighted average of 308.50 mg/l. Hence, the range was acceptable and concentration of TDS is not harmful. And Hardness varied from 153 to 171 mg/l as CaCO3 and a weighted average 163.00 mg/l. Hence WHO guideline and BECR standards the hardness value was low. This helps to assess the need to prevent water and pollution of Hatirjheel Lake