Abstract

• Myanmar has a favorable situation of fresh water resources and adverse environmental effects degrade the strength of river water quality when utilizing natural resources. Measurements of aquatic biota in terms of water quality parameters have been essential for the assessment of river health. Some anthropogenic activities have a potentially negative cumulative impact on rivers and wetlands water quantity and quality, hence negatively impacting river-dependent people. This research will be emphasized on the evaluation of quality of Dokhtawaddy (Myitnge) river water near Mandalay Region. For this purpose, Dokhtawaddy river water samples were selected from four different points [the upstream (near Ta-Lin-Gyi village and near Shwesaryan Pagoda) and downstream (near Myitnge Bridge) places of Mandalay Industrial Sewage Ditch] in the middle of Dokhtawaddy (Myitnge) river near Mandalay environs. River water samples were collected seasonally (January, April, July and November during 2019 -2020). To evaluate the river water quality, its physico-chemical characteristics such as pH, color, conductivity, turbidity, total alkalinity, total hardness, calcium hardness, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and traces of minerals like chloride, iron, manganese, sulfate, arsenic, copper, cyanide and lead were determined. In addition, its biological characteristics in terms of probable coliform count and Escherichia coli count (E.coli) were also examined. To reduce the contaminants, conventional water treatment methods such as plain sedimentation, filtration through the medium consisting of sand, gravel, broken bricks, rice straw, cotton fiber, rice husk char and charcoal. It was then again filtered with secondary filtration using sand column and rice husk char column. Effort of these stepwise treatment processes clearly shows that traces of contaminated ions, BOD and COD values were reduced within the desirable values. Benefits of this research would be helpful for the knowledge of simple water treatment technology in rural communities along the river bank of Dokhtawaddy (Myitnge) near Mandalay environs.