GS-Lyso at Song Do IFEZ II, Korea

What is it?

A designer bacterium which dissolves insoluble organic matter in sewage sludge by digesting the cell walls. GS is applying it in the 68,000m³/d Song Do International Free Economic Zone II wastewater treatment plant in Korea.

Who is responsible?

GS Engineering & Construction of Korea discovered the GS-Lyso enzyme and registered it with the National Institute of Health’s GenBank. GS E&C is supplying the Song Do IFEZ II WWTP, with Siemens supplying the membrane bio-reactor.

What makes it special?

• The greatest challenge for sludge reduction is breaking down the cell walls of the organic matter. There are various energy-intensive physical processes for doing this, but it can also be done biologically using the lysozyme enzyme. GS-Lyso is a remarkable patented bacterium that secretes lysozymes, but because it has a "gram-negative" double thick cell wall, GS-Lyso is itself unaffected by the enzymes. It can reduce sludge volumes by 30%.

• Combining a membrane bio-reactor with biological sludge reduction gives a wastewater treatment plant with a very small footprint which, like the Song Do IFEZ plant, can be hidden beneath a public park.

• Sludge reduction is one of the biggest environmental problems involved in wastewater treatment. Low-energy solutions such as this are an important way forward.