Every day, more than 1.3 million cubic metres of waste water – enough to fill 700 Olympic-sized swimming pools – are treated by Singapore’s six water reclamation plants.
The smell of the waster water, however, permeates the air in the plants’ treatment tanks. The air must be cleaned by costly and hazardous chemicals before it can be released safely into the atmosphere.
But a new method that uses bacteria to gobble up the stink has shown promising results and will be tested on a large scale at Kranji Water Reclamation Plant, starting next month.
The naturally occurring bugs, which eat up the hydrogen sulphide gases that make the air smells like rotten eggs, belong to the thiobacillus family of organisms. They are grown in tanks where the foul air is pumped through for treatment
The operations manager of the water reclamation plant, Ms Noraini Zainal Abidin, said eliminating the current use of sulphuric acid, caustic soda and sodium hypochlorite – which makes up close to 10 per cent of the plant’s operating costs – can significantly reduce costs.
Ms Noraini, 39, said: “Dealing with chemicals not only can be very costly but also is potentially very dangerous and hazardous for staff.
“By totally removing the use id these chemicals, we are also becoming more environmentally friendly.”
The project is a collaboration between national water agency PUB and home-grown biotech company Aromatrix Technologies that first started with a laboratory study more than two years ago.
It is part of PUB’s research and development drive to work with the private sector to spearhead new water technologies, in part by providing the testing facilities necessary.
Director of PUB’s water reclamation (plants) department Wah Yuen Long said: “The method was developed by Aromatrix; we’re giving them the opportunity to test it on a large scale.”
Founder and chairman of Aromatrix Lawrence Koe, who came up with the idea for the method more than five years ago, said the test plant at Kranji is an improved version of what the company has developed over the years.
Aromatrix has since clinched at least five projects overseas that employ the system, in countries like China, the United States and Australia. The projects are worth more than $1.5 million, including a recent contract amounting to nearly $400,000 to treat odours from a tannery plant in Australia.
Associate Professor Koe, 54, who is also a lecturer at Nanyang Technological University’s school of civil and environmental engineering, said: “This pilot plant at Kranji gives us the opportunity to develop better versions of the technology and stay a global player.”