The Effect of Tributaries on Water Quality Parameters of Bagmati River
Date
2021
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Chemestry
Abstract
Unplanned urbanization of Kathmandu city is creating many environmental issues,
where worsening of Bagmati river water is one of the serious problems. The water
quality of Bagmati river was characterized by collecting the real-time fine-scale data
along the Bagmati river in the Kathmandu valley, using multi parameter sensor in
winter season. The different physiochemical parameters viz., temperature, pH,
conductivity, ORP, DO, salinity, TDS, and turbidity were monitored at 14 different
locations from Gokarna to Balkhu. The spatial variation of water quality parameters
revealed that the Bagmati river was comparatively less polluted between Gokarna to
Tilganga and molecular oxygen present in the water was enough to decompose the
organic pollutant. However, the water quality at downstream from Tinkune to Balkhu
was degraded drastically making unfit for living organism. Temporal variation of water
quality attributed that human activity significantly enhanced pollutants which severely
degraded the water quality in the day time. The comparative study of water quality of
Bagmati river and its tributaries showed that the chemical composition of the rivers
were different from each other. Most of the parameters of all river water exceeded the
WHO limit, ORP was positive for Bagmati river water but that was negative for other
tributaries, which attributed that the tributaries of Bagmati river was highly polluted.
The physiochemical parameters measured at upstream, downstream and at tributaries
before mixing into the Bagmati river showed that tributaries and local pollutants from
the human activities excessively loaded contaminants into the Bagmati river. The Water
Quality Index (WQI) was varied between 25 to 50 for Bagmati river and its tributaries,
which suggested that water quality of all rivers in the Kathmandu was bad.
Keywords: Dissolved oxygen, oxidation reduction potential, pH, spatial variation,
water pollution.
Description
Keywords
Dissolved oxygen, Oxidation reduction potential, Spatial variation, Water pollution