A study during the COVID-19 pandemic conducted by the Indian Institute of Technology-Kanpur (IIT-K) has revealed that the lockdown mitigated the percentage of chemical concentration in the Ganga river by at least 50%. The research was anchored by
a team of IIT-K's scientists to ascertain the impact of restricted anthropogenic activities on the water chemistry resilience of large rivers. The site selected by the team of researchers was downstream of Ganga river at Prayagraj, where they studied the impact from March 25 till May 13.
Uttar Pradesh alone contributes 54% of the total industrial wastewater generation in the Ganga basin
The team analysed the daily geochemical record of the Ganga river, which divulged that reduced industrial discharge during 51 days of mandated nationwide lockdown, reduced the dissolved heavy metal concentrations by a minimum of 50%. In contrast, inputs from agricultural runoff and domestic sewage like nitrate and phosphate remained almost the same as these sources were not impacted by the nationwide confinement. The study findings indicated that reduction in industrial wastewater can substantially reduce heavy metal pollution in Ganga water, within just a few months.
As per the research's data, "The lockdown resulted in a complete shutdown of industrial operations, and in turn, the effluent discharge from various industries was negligible. This industrial discharge usually ends up in nearby water bodies and groundwater despite India's stringent 'zero liquid discharge' laws preventing discharge of untreated effluent in rivers. It is estimated that industrial wastewater contributes nearly 20% of the total volume of wastewater generated in the Ganga basin,."
The researchers also quantified that Uttar Pradesh alone contributes 54% of the total industrial wastewater generation in the Ganga basin, especially the stretch between Kanpur and Prayagraj, which hosts an enormous variety of industries.
Study recently published on the cover of Environmental Science & Technology Letters' journal
In the study, the scientists mentioned, "We emphasise that of the 764 industries in the entire Indian part of the Ganga basin, 90% of the industries are located in the state of Uttar Pradesh alone, consisting mostly of tanneries (64%) and textiles (9%), sugar (8.2%), paper (4.8%) and industries (32%). Even in terms of industrial wastewater generation, Uttar Pradesh also leads all other states in the Ganga basin, generating 269 million liters per day (MLD), which is 54% of the total wastewater generated in the entire basin," the scientists noted in the study.
The research was backed by the Indo-US Science and Technology Forum (IUSSTF), which is a bilateral establishment under the Department of Science and Technology (DST), Government of India and US Department of State. Further, the study was recently published on the cover of Environmental Science and Technology Letters' journal.