Concern mounts over sludge accumulating at Muttathara STP

Thiruvananthapuram: Concern is mounting over accumulating sludge at the sewage treatment plant (STP) in Muttathara as the monsoon has hit the state.
Ever since the plant began operations six years ago, the STP is generating around 30 cubic metres of sludge on a daily basis.
In the absence of a viable option to scientifically dispose it, the STP officials are laying the dried sludge in open spaces on the plant premises. However, now it seems that even the sprawling 36-acre campus is inadequate for the mounting sludge.
Since the Muttathara STP began treating around 42 million litres of sewage per day, it has been producing sludge, a residue after treatment of effluent.
While the treated effluent can be diverted to Parvathy Puthanar, there is no option for Kerala water authority and city corporation, which run the plant, to dispose the sludge.
Sources close to the project said that a proposal was formulated under AMRUT to construct an in-vessel composting unit to turn sludge into manure. It is still at a preliminary stage. Now the monsoon has become a cause of concern for the authorities.
“Most of the sludge is being kept in open spaces, mostly after drying. As monsoon has arrived, it will be difficult to keep the sludge like this. A solution has to be arrived at the earliest to dispose it,” sources said.
While landfill is the most common practice to dispose sludge, it is also being used for production of biogas, manure etc. Recently, Australia-based RMIT University has found a technology to bake sludge to turn into bricks.
The technology, not only reduces the trouble of using sludge as landfill, it reduces use of clay for making bricks and carbon dioxide emissions during brick-making.
Also a treatment plant at Beckton in London has been making bricks from dried sewage, carbon dioxide, water, sand and cement.
Sources in KWA said that there is urgent need to find a better solution before it turns into a menace.
Water resources minister K Krishnankutty said that he would urgently look into the issue.
Meanwhile, the STP authorities have found use for the treated effluent, all of which is usually diverted into the Parvathy Puthanar.
There were no takers for the treated effluent despite STP offering it free of cost for construction purposes during the past summers. However, this time it was utilized for construction of a mall at Akkulam.