From waste to watts: Kerala's Muttathara plant to turn sewage sludge into power

Thiruvananthapuram, Sep 24 (PTI) Human waste is no longer just garbage.

In a groundbreaking initiative, a plant at the heart of Kerala capital will soon turn sewage sludge into electricity.

On Wednesday, LSGD Minister M B Rajesh inaugurated the construction of the Rs 36-crore Omni Processor at the Muttathara sewage treatment plant.

The entire cost has been funded by the Bill and Melinda Gates Foundation.

Sharing the news on Facebook, Rajesh said the philanthropic organisation set up by Microsoft founder Bill Gates and his wife had funded the project.

Officials said Thiruvananthapuram has the state's only extensive sewer system.

Wastewater from residential and commercial areas is sent to the 107 million litres per day (MLD) sewage treatment plant at Muttathara, where 90–100 trucks deliver faecal sludge daily.

The plant uses the Activated Sludge Process (ASP), which includes screening, aeration tanks, clarifiers, sludge thickeners, drying beds, and chlorination units.

It treats 55-65 MLD of sewage, including faecal sludge, they said.

Officials said for over a decade, sludge management has been a problem, with around 5-8 tons of sludge accumulating daily and often dumped on-site due to a lack of demand.

The Omni Processor was proposed as a solution to this long-standing issue.

It is a decentralised thermal waste treatment system that kills pathogens while recovering valuable resources from faecal sludge, biosolids, and other waste streams.

The plant generates electricity for its operation, treated water, distilled water, and ash as by-products, they said.

The Muttathara plant, the largest liquid sewage treatment facility in Kerala, can process 10.7 million litres of sewage every day.

The water is treated through the ASP system, while the solid sludge left behind will now be channelled into the Omni Processor to generate electricity.

"This means that not only will the plant be able to produce all the electricity it needs to operate, but the remaining sludge will also be completely eliminated," Rajesh said.

The project is being hailed as the latest example of Kerala taking a leap forward in waste management. Construction is expected to be completed by next March, when the plant will begin operations.

Rajesh added that it was the active and effective intervention of the state government and the Swachh Bharat Mission that brought the initiative to Kerala.

Hyderabad had originally been proposed as the location, but with the support of the WASH Institute, which provides technical assistance to the Swachh Bharat Mission, it was possible to bring the project to Thiruvananthapuram.

The next challenge was obtaining clearance from the Airport Authority.

Initially, there were obstacles and concerns about whether the location would have to be changed, but through the continuous intervention of the state government, these issues were resolved, and clearance from the Airport Authority was secured.

"This is how the project has now reached the stage of its construction inauguration," Rajesh said. PTI TGB TGB ROH