Castrol cleans up cutting fluid waste problem

Castrol Industrial, in partnership with Pall Filters, has installed the latest filtration technology to recycle waste coolant at the South Wales site of customer ArvinMeritor

ArvinMeritor cleans up with benefits from Castrol and Pall Alliance.

Castrol Industrial, in partnership with Pall Filters, has installed the latest filtration technology to recycle waste coolant at the South Wales site of customer ArvinMeritor - an American manufacturer of brake assemblies.

For the past eight years, ArvinMeritor has used Castrol cutting fluids to machine the castings and other brake components that are fitted to tractor units and trailers of heavy goods vehicles.

Recently, Castrol was briefed together with a number of other companies, to help ArvinMeritor reduce the COD (Chemical Oxygen Demand) count in its waste-water from 25,000 parts per million to 4,000 parts per million, as part of a company-wide environmental programme.

Castrol's response, in partnership with Pall Filters, was to install a filtration system using a Pall Clarisep machine.

Taking up the story ArvinMeritor Chief Production Engineer Steve Phillips says the new system is far superior to the previous one - a flocculating process that left the company with a heavy sludge waste.

The oil separated from the sludge was pressed into cakes that were classified as special waste and could only be disposed of at one of three landfill sites.

The separated water was sent to the local area treatment works, which charged a great deal of money to process it.

With both wastes subject to surcharges and transport costs, disposal was an inconvenient and costly business.

Describing the new process, Castrol's Contract Manager Steve Green says dirty coolant is now fed into a tank, where the Clarisep machine processes it through a special filter to separate the oil from the water.

Separated water is then fed through a reverse osmosis (RO) unit to remove borons and chemicals, leaving both clean water that achieves a COD count of 4,000 parts per million, and soapy water.

Continues Steve Phillips: "Having worked with Castrol to achieve the 4000ppm target we then discussed other uses for the clean water and the soapy water.

As we were looking for further environmental benefits we eventually decided to use the soapy water extracted in the RO process for washing down machines and floors.

On floors in particular this has proved to work better than the soap bought specifically for the job, which has the added advantage that we don't have to buy as many cleaning products".

He says the same is happening with the clean water, which is now of such a quality that it can be re-used - for example to dilute the water-soluble products - instead of being discharged to the effluent plant.

This also means that ArvinMeritor has greatly reduced its intake of mains water.

The waste oil, which after processing is a mix of approximately 80% oil and 20% water, is currently removed by a specialist cleaning company that presses it to take the water out and turns into a neat cutting oil.

For the future, Castrol plans to extend the process to allow the oil to be re-used, and is investigating its use as cutting oil or fuel oil for heating, with the option to use it on site or sell it commercially.

Reporting on the cumulative effect of the recycling programme Steve Phillips says the total amount of wastewater has been dramatically reduced and the amount of chargeable wastewater is now about 10% of what it used to be - so ArvinMeritor also saves significantly on its water treatment bills.

As a bonus for Castrol, its costs have also been reduced by not having to purchase floccing agents.

Complimenting Castrol on its contribution Steve Phillips says that, as a full member of the ArvinMeritor environmental committee, Steve Green has made a major contribution to the programme.

"We are very happy with the results of our close working relationship with Castrol, and confident that the new system will provide even more environmental benefits in future", he says, adding: "We are delighted to be re-using something that would normally go to waste".

As a final footnote to the story, during a recent routine visit from the Environmental Agency its inspectors were so pleased with the results that they suggested putting the company forward for an environmental award!.

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