Assessing the scope for on-site wetland technology to treat de-icer contaminated runoff at airports

For safety reasons, airports in many parts of the world use large volumes of chemical de-icers during winter months. De-icers are applied directly to runways and taxiways and are spayed onto aircraft to remove ice, snow and frost and to prevent these substances from reoccurring on aircraft prior to take-off. However, de-icing chemicals accumulate on airport surfaces, either following direct application to runways or taxiways or following shearing of the chemicals from aircraft during take-off. Rainfall that subsequently falls on airport surfaces can mobilise de-icing chemicals, generating large volumes of contaminated surface water within airport storm water systems. This contaminated surface water must be treated before being released into the environment. If released into the environment without treatment, negative effects can occur, primarily because de-icing chemicals remove substantial quantities of oxygen from water.

The traditional approach to treating de-icer contaminated runoff from airports involves discharging the runoff to water company sewers for off-site treatment at a waste water treatment works. This involves a substantial financial cost to the airport operator and is also associated with negative environmental effects, including greenhouse gas emissions during off-site waste water treatment. As airports grow in the future to accommodate increased demand for air travel, the volume of de-icer application and the volume of contaminated surface runoff at airports are likely to increase significantly. Under these conditions, it is highly likely that the traditional approach to treatment of de-icer contaminated runoff, through discharge to water company sewer, will become both economically and environmentally unsustainable.

Therefore, alternative treatment options are required to address de-icer contaminated runoff from airports. This internship will draw on NERC-funded science and on-going PhD research at Lancaster University to assess the potential for on-site wetland technologies to treat contaminated runoff. These alternative technologies are based on pollutant removal processes that operate within natural wetland ecosystems. The intern will build on an existing collaboration between Manchester Airport, Lancaster University and Peak Associates to develop and assess on-site wetland treatment options for application at Manchester Airport, but with broader applicability to airports in the UK and worldwide. The intern will evaluate the specific design requirements of a treatment system, examine how on-site treatment systems can be incorporated within airport infrastructure, and undertake an economic feasibility study comparing these alternative treatment systems to traditional approaches for dealing with contaminated surface runoff.

This is a particularly timely opportunity for the internship given the recently announced £1bn, 10-year expansion project at Manchester Airport. Working with our partners, the internship has the potential to directly influence the early stages of the planning for surface water management as part of this expansion. We will also work with the broader UK airport industry to maximize the impact of the NERC-remit science that will form the basis for the intern's work.