The early research and development which ultimately lead to the Microbial Solutions technology known as Microcycle™ was conducted at NERC’s Centre for Ecology & Hydrology at Oxford and was led by the scientific founders of Microbial Solutions, Prof. Ian Thompson and Dr Chris van der Gast.The high organic content of most metalworking fluids makes them good candidates for the degradation by bacteria for waste treatment. Laboratory research applied novel methods to assemble a patent-protected consortium of five species of aerobic bacteria, all non-pathogenic (formally, ‘Class I’), which were carefully selected following a worldwide search of the hundreds of bacteria that survive naturally in machine sumps, where they eat metal working fluids.
The Microcycle technology is able to treat the COD of whole waste metalworking fluids, without the need for pre-treatment with high efficiency. Essentially, the bacteria eat the nutrients that constitute the COD of the waste fluids (COD is their food) eliminating the risk of downstream problems, and allowing their safe disposal to sewers. The effluent pH, typically strongly alkaline as it comes of the engineering line, is reduced toward neutrality (pH7). The Microbial Solutions bacterial consortium is also able to eliminate (again, essentially ‘eat’) the toxic chemicals present in all metalworking fluids. Measured using industry standard bacterial biosensors, the toxicity of waste fluids were reliably reduced by three orders of magnitude, to be no more toxic than distilled water controls.
The Microcycle™ technology uses a simple bioreactor (a large cylinder) containing a high surface area support matrix upon which the bacterial biofilm establishes itself. An air supply is fed into the reactor through sparging rods to aerate and mix the fluids. An inlet at the top allows the introduction of waste fluids for processing, and an outlet at the bottom allows the venting of treated fluids to sewers. The bacteria thrive in this environment with each bacterial species feeding off different components of the metal working fluids, together ‘eating’ the polluting and toxic elements. The bugs convert the wastes to biomass, and nitrogen and carbon dioxide gas. No hydrogen sulphide, or associated odours are porduced. Note that although some carbon dioxide is produced it is 20 times less harmful than methane (the gas produced from waste sent to landfill) as a greenhouse gas. The resulting grey water is disposed of to sewer, removing the need to transport to landfill, and the next batch of metal working fluid is added to repeat the process.
The technology is a highly efficient and scalable biological treatment process capable of cost effectively reducing waste metalworking fluids to grey water which can be disposed of to sewers within normal water authority discharge consent limits.