Bengaluru: BWSSB turns to latest STP technology to improve water quality

In its effort to upgrade the city's Sewage Treatment Plants (STPs), the BWSSB has opted to implement the Integrated Fixed Film Activated Sludge (IFAS) in one of them.

While traditional STPs use sludge activation systems, the IFAS technology provides a superior solution that encourages the growth of biomass, leading to more efficient treatment of wastewater.

“IFAS is a modern technology to treat wastewater,” a senior official of the Bangalore Water Supply and Sewerage Board (BWSSB) said.

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“While it is common in Western countries, we are yet to adopt it extensively. Since we are in the process of upgrading, we felt that we should go for the latest technology,” the official added.

IFAS includes a reactor that encourages the growth of biomass to efficiently degrade organic and nitrogenous loads, which significantly improves the quality of treated water.

“With more awareness, the standards of wastewater treatment are also going up and many of our STPs do not match the latest standards set by the National Green Tribunal (NGT).

“IFAS comes in handy since it can be used to upgrade the existing STPs with minimal intervention,” yet another official explained.

In 2019, the NGT revised the standard for treated water by enforcing stringent norms. It reduced accepted levels of Biochemical Oxygen Demand (BOD) in treated water from 20 milligrams per litre (mg/l) to 10 mg/l, while fixing the levels of Chemical Oxygen Demand (COD) and total nitrogen in treated water to 20 mg/l and 10 mg/l, respectively.

The BWSSB is now upgrading its STPs to the prescribed levels four years after the order.

The IFAS technology will be used at the Yelahanka STP.