In December 2014, the Edrington Group expanded the production of their world-famous single malt whisky, The Macallan, with a new £100m distillery in Craigellachie, Moray.
The wastewater treatment system of the existing distillery needed to be upgraded to continue to meet the SEPA regulations for discharge into the river Spey.
In 2012, Edrington had commissioned Veolia Water Technologies to carry out a study for the characterisation of the wastewater at the existing site. This set the basis for a feasibility study for the new wastewater treatment plant.
Veolia was awarded a £2.5m contract to build a new treatment plant. The wastewater treatment process is based on two Veolia proprietary technologies: the Idraflot™ dissolved air flotation (DAF) and the Biosep™ membrane bioreactor (MBR) systems.
The wastewater treatment comprises an initial screening stage to remove the coarse solids in the effluent, followed by treatment in the Idraflot™ DAF unit where 80% of the suspended solids and 30% of the copper are removed by coagulation and flocculation.
The clarified wastewater is then passed to the Biosep™ MBR system comprising an 1100m3 conventional activated sludge aeration reactor, where the BOD, COD and ammoniacal nitrogen are biologically degraded, followed by an ultrafiltration (UF) membrane to separate the treated effluent from the sludge.
The final effluent is currently discharged via a monitoring station for flow, pH, temperature, turbidity and total organic carbon, to the River Spey.
The new plant was put into operation in September 2015.
Edrington’s UK Engineering Manager, George McKenzie, is pleased with the result: ‘Based on Veolia’s experience we expected to achieve a good quality discharge – certainly well within the consent limits – and that we have done’, he said.
The new water treatment plant has additional benefits. The modular nature of Idraflot™ DAF system and the UF membranes allows for simple future upgrading.
There is also an option to install a MegaRO™ reverse osmosis plant to generate higher quality effluent which can be reused in many production areas as an alternative to potable water – a step that the distillery hope to take in the future to reduce their water footprint.
Products and technologies used
Biosep™ MBR system