This Action has been developed by the Atmospheric Pollution Characterization Unit and COPs and the Emissions Unit of CIEMAT's Department of the Environment in collaboration with the FOTOAIR group of CIEMAT’s Energy Department, Alcobendas Town Hall and INECO.
In the first phase of Action B4, the NOx sink effect of the chosen material for its real-scale carriageway implementation has been characterized (November 2014 - November 2015). To this end, in a town near Madrid (Alcobendas), Paseo de la Chopera was chosen as the study scenario, a two-way rectilinear street with moderate traffic.
The selected photocatalytic material was implemented in an area of approximately 1000 m2, which occupied 60 linear metres of both lanes per direction of traffic, in addition to the median, so that three consecutive areas were arranged along the chosen street: conventional carriageway-conventional photocatalytic carriageway. The objective of the measurements was to verify if horizontal gradients of NOx are formed by the sink effect induced by the photocatalytic carriageway.
Before applying the photocatalytic material the environmental and atmospheric characteristics were studied on the surface and height of the chosen street and its behaviour as a linear source of atmospheric pollutants. After the application of the photocatalytic material (September 2015) the decontaminating capacity of NOx of the material was evaluated. For this the following activities were carried out:
The results obtained allow us to conclude that:
In the second phase of Action B4 (November 2015 - June 2016), the characterization of the NOx sink effect induced by the material chosen for its implementation on a full-scale pavement was carried out. The chosen scenario was a double "street canyon" built to scale in an urban area of Alcobendas near a public thoroughfare, with moderate levels of pollution but that were not affected by direct traffic.
In collaboration with Alcobendas Town Hall, and to evaluate the NOx decontamination capacity, the following activities were carried out:
The results obtained after the analysis of the measurements have not shown any reduction of the ambient NO concentration attributable to the decontaminating effect of the photocatalytic material implemented.
In the third phase of Action B4 (July - December 2016), the characterization of the NOx sink effect of the chosen material for its real-scale façade implementation was carried out using the exterior wall of the double east-facing “street canyon”. The activities carried out on the façade were as follows:
The results obtained after the analysis of the measurements show that during a short period of time and under specific environmental and meteorological conditions a short episode of significant reduction of the NO concentration unequivocally attributed to the presence of the photocatalytic coating could be seen.
Phase 1 photosField investigation of measurement using a Mobile Air Quality Laboratory Application of the first product of the selected photocatalytic product in an area of 4 m2 on the Paseo de la Chopera carriageway in Alcobendas Implementation of the photocatalytic material over 1000 m2 on the carriageway of the Paseo de la Chopera Intensive field investigations: Particulate material (TiO 2) in ambient and deposited air, VOCs, road traffic, leachate, removal of samples.
Fotos fase 2Area chosen for the implementation of selected photocatalytic material for pavements on a "street canyon" configuration in Alcobendas. Construction of the "street canyon" in Alcobendas. Street canyon pavements with paving slabs treated with photocatalytic material (left) and untreated (right). Mobile unit located outside the "street canyon" for continuous measurement of NO, NO2 , O3 and meteorological parameters. Street Canyon façade with weather sensors. East façade of the Street Canyon with applied photocatalytic material.