Assessment of technologies for water quality control of the Bagmati River in Kathmandu valley, Nepal

The Bagmati River, running through Kathmandu valley, is heavily polluted because of increasing and unmanaged urbanization, solid waste disposal, and uncontrolled domestic and industrial sewage discharge. Centralized wastewater management has achieved little change and further deterioration is anticipated. This paper identifies the principal causes and proposes key measures for improvement using strategies such as artificial aeration, artificial floating islands, improved waste-water treatment, and drainage nets. A Descriptive Solution Model to further enhance the water quality in Bagmati River is described that aims to restore the declining aquatic ecosystem and river environment. The proposed Descriptive Solution Model can be made applicable to any kind of river and/or river corridor. Furthermore, this study also suggests considering export coefficient as a dynamic variable while assessing non-point pollution sources in the future.