UK dairy food company Dairy Crest made an extensive investment to allow the company to further recover significant volumes of treated process water for reuse within its creamery operations. Nutrient rich process water is first treated to remove the phosphate, which is present in the incoming raw milk. Process water is mixed with solubilised hydrated lime to chemically combine the phosphate to produce a so-called ‘cake’. The resulting cake is rich in both phosphate and calcium and is therefore well suited for reuse in agriculture as fertiliser.
The downstream water treatment and recovery plant then produces high quality water suitable for reuse and a final effluent stream suitable for discharge to the river.
Around 1.7 million litres per day of high quality water will be produced by the recovery plant for reuse within the company’s operations. This is equivalent to the daily fresh water needs of around 11,000 people. The investment also enables the production of recovered water at less than 50% of the purchase price of municipal potable water.