PROJECT DESCRIPTION
BACKGROUND
Air pollution linked to the road transport sector is still one of the main environmental problems in European cities. The negative impact on human health has been widely demonstrated, and the improvement of air quality in highly populated areas is a policy priority. The EU Directive 2008/30/CE defines European air quality standards and seeks to protect public health by establishing limits for certain pollutants.
Road traffic is the main source of nitrogen oxides (NOx) pollutants. In the Madrid urban area and the Henares corridor, NO2 limits are frequently surpassed in the October to February period. In order to reduce this pollution, different strategies have been implemented and tested. One emerging solution is the use of building materials with photocatalytic substances, such as titanium dioxide (TiO2), which, when activated by solar radiation, eliminate these pollutants by means of photocatalytic reactions. This research has led to the commercialisation of several building materials.
OBJECTIVES
The LIFE MINOx-STREET project aimed at evaluating the air pollution abatement strategies for traffic-related nitrogen oxides (NOx ) levels, in particular NO2, in cities. MINOx-STREET was bound to offer local authorities guidelines to apply sustainable, cost effective and integral solutions for air quality management, such as optimise the conditions of use of commercial photocatalytic materials designed to air purification and assess the role that these materials can play in combination with other technologies and strategies (cost/benefit analyses). The following specific objectives were :
- To provide evidences from rigorous essays and tests on the physical-chemical properties and expected efficiency of several commercial photocatalytic materials, both on controlled conditions and real atmosphere.
- To parameterize the sink effect on NOx levels on different photocatalytic surfaces under ambient conditions.
- To provide a real scale demonstration of the depolluting capabilities of these materials implemented on different real urban scenarios.
- To develop and set-up a microscale model to simulate the dispersion of pollutants at urban scale.
- To analyse the individual and combined efficiency of several photocatalytic materials applied to different elements of the urban environment at district scale.
- To determine the photocatalytic deactivation of these materials under real conditions and recommend a regeneration methodology.
- To identify and quantify generated byproducts that could have harmful effects on the public health.
- To achieve a sensible impact on key players: authorities, industry and the media.
- To pave the way for future innovative applications of these materials.
RESULTS
The LIFE MINOx-STREET project team assessed the nitrogen oxide (NOx) removal efficiency of photocatalytic materials, to reduce the levels of these pollutants and greenhouse gases in urban areas.
The project team produced guidelines for air quality managers, and a model to predict the suitability of the use of photocatalytic materials. These and other outputs were satisfactorily developed, but the low capability showed by the photocatalytic materials is unlikely to result in real environmental, economic or social impact.
However, in view of the results obtained, it can be concluded that the main output of the project is the confirmation that photocatalytic materials are not currently an effective tool in the fight against urban atmospheric pollution by NOx.
