White toxic foam on the Yamuna River in Delhi has been in the news recently. Satellite images from space have also captured it. In the photo, foam can be seen flowing in the Yamuna River near two barrages about 3 kilometers apart in the Okhla area of ​​southeast Delhi.
Every year, with the onset of winter, the festive season of October-November reminds people of how polluted the water and air around Delhi are. Yamuna river is one of the main water sources of Delhi. But the river is so polluted that its water cannot even be used for bathing or irrigating fields.
There are many reasons for foam formation in the Yamuna river near Okhla barrage, including the presence of water hyacinth in the catchment area of ​​the barrage, which releases surfactants. Apart from this, sewage (dirty water and other waste) from 18 drains is discharged into the river without treatment. The problem is further exacerbated when industrial waste from sugar and paper mills in Uttar Pradesh is discharged into the Hindong canal and joins the Yamuna river. These pollutants, along with sewage containing phosphates and detergents, pass through the barrage’s spillways, causing foam to form and a toxic white blanket on the Yamuna.
Experts have declared Delhi’s Yamuna river dead, meaning no aquatic animals can survive in the river’s waters. Phanindra Pati, a physicist at Banaras Hindu University (BHU), said this was due to industrial waste killing microorganisms, causing the water temperature of the Yamuna to rise.
Biochemical oxygen demand (BOD) measures the amount of oxygen required to break down organic matter in water. A higher BOD means more oxygen is needed. This means that the amount of oxygen in the water is not enough to meet the needs of aquatic life, so they cannot survive due to stress and suffocation. Human feces or animal waste increases the amount of organic carbon in the water, which also increases biochemical oxygen demand.
Delhi’s Yamuna river is dead
Delhi Pollution Control Board data as of June this year shows that the BOD standard set in the Yamuna river is 3 mg/l or less. Only the BOD in Palla, Haryana, meets the prescribed standards, which is 2 mg/l. The BOD was 28 times higher than normal at Asgarpur at 85 mg/L, the BOD at Okhla Barrage was 17 times higher than normal (50 mg/L), and the BOD at ITO Bridge was 17 times higher than normal (50 mg/L). Oxygen levels are 16 times higher than normal (47 mg/L).
The acceptable standard for oxygen content (dissolved oxygen) in river water is 5 mg/L or more. Only Pala and Wazirabad’s oxygen levels met the standards, but the ISBT Bridge at Yamuna, Nizamuddin Bridge, Okhla Barrage, Asgarpur’s Okhla Barrage and Agra Canal recorded zero oxygen levels. Low levels of dissolved oxygen affect the survival of aquatic life in rivers.
Yamuna river has a lot of foam harmful
“In a country like India, where rivers are considered mothers and goddesses, seeing toxic foam in the Yamuna makes one cry,” said BHU physicist Phanindra Pati. Environmental activist Vimalendu Jha “After the monsoon, the stable environment and rising temperatures create ideal conditions for the formation of foam in the Yamuna. In October, when the temperature drops, this helps stabilize the foam. This foam contains harmful organic substances , which releases toxic gases and dissolves directly into the atmosphere. In addition, organic particulate matter (carbon particles) are also released from the foam, mixing with the air and making it harmful.
