Bacteria turns poisons into greywater

A wastewater idea that employs 'designer' bacteria to 'digest' poisons in industrial fluids has been developed by the Microbial Solutions company.

The method uses patented, non-pathogenic bacteria to cleanse toxic metal-cutting lubricants used by engineering industries.

Normally, these waste liquids create a large environmental headache but, after the bacteria have digested the waste, the cleaned-up fluids can be sent down domestic drains as safely as washing-up water.

The UK technology has been trialled with a car manufacturer, and now the company is about to conduct a commercial pilot of its treatment — called Microcycle Technology — at the site of an aerospace manufacturer.

The on-site bacterial process can treat industrial fluids within 7–10 days in an environmentally friendly manner, producing greywater. This is safe enough to be disposed of in the normal sewerage system and has no methane production in the process — thus lowering transport and greenhouse gas impact. Water re-use is also possible.

The process uses a large cylinder as a simple bioreactor containing a mesh grid on which a variety of non-pathogenic bacteria are cultivated.

Each bacterial species feeds off different components of the metal-working fluids, together converting the polluting and toxic elements. Then the next batch of waste fluid is added to repeat the process.

The bacterial clean-up team has been carefully selected following a worldwide search of the hundreds of bacteria that survive naturally in machine sumps, where they consume these oily waste liquids.

But these bacteria can only survive in very low concentrations in machine sumps, because of the conditions, that include the prevalence of other bacteria, such as sulphate reducers that produce hydrogen sulphide.

After isolating complementary bacteria that coexist without destroying each other and that consume the different components of the waste fluids, Microbial Solutions ensures that they can thrive in its bioreactors by providing the correct environment for them to grow and increase in biomass.

For more information, visit Oxford Innovation.