Dairy recycles half of its wastewater

A Scottish dairy is now recycling half of its wastewater as part of an environmental drive across the business, it said today (31 August).

The Bridgwater dairy is aiming to reach its water reduction target of 25% across its network of dairies by 2015.

ELGA Process Water, a subsidiary of Veolia, is using a wastewater treating process to help recycle wastewater produced by Robert Wiseman Dairies by processing wastewater using reverse osmosis. The wastewater is then recovered and can be used for use in the dairy.

The dairy, which supplies 30% of the UK’s milk, can process 1.25M litres of milk every day, with its Bridgwater dairy producing about 400m3/day of process wastewater. This water was originally treated and then poured into the local waterways.

However, using the reverse osmosis system 200m3/day of its process wastewater is now recovered and recycled for use in the dairy.

ELGA’s MegaRO reverse osmosis technology uses a membrane to remove 99% of residual COD, dissolve salts and bacteria from the treated wastewater to produce water of quality at least equal to the mains supply.

According to ELGA, the low pressure membranes and high efficiency pumps means the system is energy efficient and low energy, which helps not only reduced carbon emissions but also operating costs.

The plant has been in operation for ten months, and Robert Wiseman Dairies is in discussions with ELGA about a potential second plant to help recover a further 80m3/day of the wastewater.

Robert Wiseman Dairies’ project manager, Eleanor Walton, said: “Because the operating cost of the MegaRO is low, the recovered water actually costs less than mains water even after including capital amortisation. We expect to get a payback on the £130k investment in about two and half years.”

Carys Matthews

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