10 November 2021.
On November 8, 2021 devotees offered prayers as a part of their four-day Chhath Puja celebrations at the banks of foam-coated Yamuna near Kalindi Kunj. The visuals have worried environmentalists and led political war of words between Aam Aadmi Party (AAP) and other state governments.
- Between Wazirabad and Okhla, Yamuna runs for 22-kilometre.
- It is less than 2 per cent of its length of 1,370 kilometres between Yamunotri and Allahabad.
- But this stretch accounts for 80 per cent of the total pollution load in the river.
What is froth formation?
- Phenomenon of froth formation takes place on several lakes and streams.
- These Foam bubbles are produced on the decomposition of organic matter. The foam-producing molecules comprises of two ends.
- Its one end repels water while another attracts water.
- These molecules work to reduce the surface tension on the surface of water. Foam bubbles are lighter as compared to water.
- Thus, they float on the surface as a thin film and gets accumulated over time.
What are the reasons for froth?
- Major reason behind froth formation is presence of phosphates and surfactants in untreated sewage generating from Delhi, Haryana and Uttar Pradesh.
- Phosphates and Surfactants components comprise of 1 percent of the froth, while 99 per cent is air and water.
Sources of pollution causing foam formation
- Sources of pollution that cause foam formation includes untreated sewage containing soap-detergent particles, organic matter from decomposing vegetation, industrial effluents and presence of filamentous bacteria.
- Pollution from paper and sugar industries in Uttar Pradesh travel through Hindon canal is also a major reason of pollution in the Yamuna.