Real-time water quality monitoring along the lower stretch of River Ganges and its connected drains using sensors and Water Quality Index

ABSTRACT In this study, water quality is measured using a Real-Time Water Quality Monitoring System for a total of 84 times at 14 locations, in which four drains discharged sewage directly to river Ganges at Bihar, five locations on river Ganges at West Bengal, two tributaries of river Ganges at West Bengal and three drains discharged wastewater directly to river Ganges at West Bengal. In Bihar, four major drains discharged 377.98 MLD wastewater into the river Ganges which in turn released 8985.17 kg of BOD per day. In West Bengal, three major drains had a total flow of 1630.88 MLD that discharged 11563.77 kg of BOD per day to the River Ganges. The average Water Quality Index of the river Ganges was observed as 64.55 and that of drains of West Bengal and Bihar were recorded as 309.78 and 775.56, respectively. The average BOD to COD ratio of less than 0.6 indicated wastewater from drains of Bihar and West Bengal was nonbiodegradable. DO and pH values were recorded compliant with the bathing water quality standard at all river locations, however, the average BOD value at five monitoring points of the river Ganges and its tributaries was slightly above the bathing water quality standard.