Physico-Chemical Characteristics of the River Kulik of the Uttar Dinajpur District of West Bengal, India

The river Kulik is an internationally important river between India and Bangladesh. Till date, no work has been done to understand the physico-chemical characteristics as well as the pollution status of the river Kulik at the Raiganj and Hemtabad blocks in the Uttar Dinajpur district, West Bengal, India. The goal of this investigation was to analyse different physico-chemical parameters to understand the present level of pollution in the river Kulik for two years, from November 2019 until October 2021. The investigation was carried out on a monthly basis at five selected sampling sites along the river Kulik. Different physico-chemical parameters were analysed following the methods of APHA, 2017. The pH varied from 5.90 to 7.86, which indicates the slightly acidic to slightly alkaline nature of the water. The lowest dissolved oxygen (DO) value recorded at site 5 (1.60 mgL-1) during the winter season of the first year may have been caused by excessive fertilizer application in agricultural fields close to the river Kulik. The abrupt rise in DO levels from March 2020 to June 2020 at every site might be due to the lesser anthropogenic activities during the lockdown in India because of the COVID-19 Pandemic situation. The highest BOD was found in April 2020 at Site 5, which crossed the limits of the CPCB standard set for drinking and bathing. Public awareness is crucial for river pollution control and revival; further study is needed to understand water quality and productivity.