Dufftown: An 800m2 surface flow reed bed, treating 650 m3/d of copper contaminated effluent from three distilleries.
- In operation since: July 2007
- Type of wastewater treated: Industrial: other
- Type of wastewater (other): Distillery effluent
- Hydraulic load: 650 m³/day
- Organic load (PE): N/A
- Organic design load (kg BOD/day): N/A
- Location: Dufftown, Scotland, UK
- Client: Diageo
- Stage 1 type: Free water surface flow
- Stage 1 surface area (m²): 800 m2
- Cost: 167,000.00
Dufftown Distillery, owned by Diageo, produces 4 million litres of whisky per year. The distillery generates an effluent containing a significant amount of copper that is scoured from the stills during the distillation process and cleaning operations. As Dufftown is located in a remote area and lacks access to mains drainage, wastewater from the distillation process is sent to the on-site effluent treatment plant (bioplant) for treatment before being discharged under consent in to the River Dullan. The wastewater treated at the bioplant comes from three distilleries. It is pumped from the Dufftown Distillery and arrives in road tankers from Mortlach and Glendullan distilleries for treatment. The average flow to the bioplant is 650 m3/d with an average soluble copper level of approximately 1.5 mg/l at the discharge point. With increasing restrictions on maximum consent values, Diageo required a final polishing stage to reduce the copper concentration to below 0.5 mg/l prior to discharge to the River Dullan.
ARM designed and constructed an 800m2 horizontal surface flow reed bed treatment system to remove soluble copper from distillery wastewater. The system has a gravel substrate planted with Typha latifolia. Unlike organic pollutants, heavy metals are not degraded in biological processes, but they can be accumulated within the wetland using a variety of removal mechanisms including adsorption, cation exchange and chelation with organic matter and sediments, adsorption to plant surfaces, uptake by plants and precipitation as sulphides and carbonates.
The main benefit of the horizontal flow wetlands, like the majority of reed bed treatment systems, is that it can provide a low-cost and low-maintenance treatment solution without the need for chemical or energy-intensive processes. The reed bed system provides an additional level of treatment securing discharges within consent using a low maintenance treatment solution which has no chemical or power requirements. For Dufftown Distillery the reed bed provides additional security in achieving copper discharge consent levels set by the regulator.