Combustion reactions produce nitrogen compounds such as nitrogen monoxide (NO) and nitrogen dioxide (NO2), commonly known as NOx. They are a factor in the formation of acid rain and summer smog. A substantial proportion of the NOx generated comes from automobile exhaust. In its ongoing endeavour to develop roads that are increasingly safe, aesthetic and environmentally friendly, Eurovia has embarked on a pro-active environmental policy. The company has developed the innovative NOxer process to efficiently and effectively combat pollution and provide optimum comfort for road users and local residents.

1. COMBATING POLLUTION
NOxer
Improving
air quality

2. NOxer
THE PROCESS THAT
COMBATS POLLUTION
Combustion reactions produce nitrogen compounds such as nitrogen monoxide (NO) and nitrogen
dioxide (NO2), commonly known as NOx. They are a factor in the formation of acid rain and summer
smog. A substantial proportion of the NOx generated comes from automobile exhaust. In its
ongoing endeavour to develop roads that are increasingly safe, aesthetic and environmentally
friendly, Eurovia has embarked on a pro-active environmental policy. The company has developed
the innovative NOxer process to efficiently and effectively combat pollution and provide optimum
comfort for road users and local residents.
KEY BENEFITS
A
daptable to many types of
road infrastructure (pavements,
cobblestones, noise barriers, tunnel
entrances, paint, etc.)
KEY figures
Pollution reduction
exceeding 4mg/m2/hr
echanical and safety performance
M
remains unchanged
ollution reduction at source over
P
broad surfaces
ighly effective in combating
H
atmospheric pollution
ptimum comfort for residents and
O
users
nvironmental enhancement of
E
roads
Overall pollution reduction
of 15
to 25%

3. HIGHLY INNOVATIVE
POLLUTION REDUCTION
A MULTI-PURPOSE
PROCESS
Research carried out by Eurovia resulted in the
development of an effective and reliable process that can
be used in a wide variety of applications. NOxer is used
as a coating on vertical structures (noise barriers) and
horizontal substrates (roads and cobblestones).
By adapting the various materials (slurries, paints, etc.),
NOxer can also be applied in confined spaces (tunnels, car
parks), where the use of appropriate lighting and specific
catalysers is sufficient to initiate the chemical reaction.
NOxer SERVES
THE ENVIRONMENT
The reaction does not displace pollution. The concentrations
of nitrogen compounds removed by rainwater runoff are
very small. Pollution reduction is therefore limited, over time,
only by the service life of the substrate to which the NOxer
coating has been applied.
The additional cost of the technology is small, yet it
significantly reduces the concentration of airborne
pollutants that can cause discomfort and respiratory
complications.
SUSTAINABLE
INNOVATION
The reaction requires no energy input
other than light. Its remains effective
over time since the active ingredient
acts as a catalyst: it is neither
consumed nor altered during the
reaction. Titanium dioxide is a stable,
chemically and biologically inert
compound. It can be recycled and the
substrate to which it is applied can be
recycled at the end of its service life.

4. PROVEN
EFFECTIVENESS
To optimise the process, Eurovia’s research centre
has developed a number of analytical systems to
measure the performance of the NOxer process in the
laboratory.
The test consists in measuring pollution levels in air
flowing through a reactor containing a specimen of the
NOxer coating. In light equivalent to that of a sunny
day, 75% of the NOx entering into contact with the
coating are eliminated; in light equivalent to that of a
cloudy day, the process remains highly active.
Nitrogen oxide (NOx) concentration (ppb)
1,000
900
IN SITU TESTS
SUBSTANTIATING
PERFORMANCE
A large number of measurement campaigns using highperformance analytical resources are being carried out
to estimate the gain in air quality achieved by NOxer.
Monitoring protocols have been developed for the entire
NOxer range, using a specially adapted autonomous
vehicle and other resources. The measurements are
carried out either in line by standardised NOx analysers
or by passive sampling devices.
Effectiveness has been demonstrated for each of the
NOxer applications (noise barriers, pavements, etc.).
The photocatalytic reaction produces stable nitrogen
compounds that are washed off the coating in water either naturally by rain or mechanically by spraying.
Process activation
800
700
600
500
400
300
Light:
cloudy day
Light:
sunny day
200
100
0
Time
TECHNICAL DEPARTMENT
18, place de l’Europe - 92565 Rueil-Malmaison cedex
Tel.: +33 1 47 16 38 00 - Fax: +33 1 47 16 38 01
www.eurovia.com
technique@eurovia.com
- December 2013 – 500 copies – Photos: Eurovia photo library
CONCLUSIVE LABORATORY
TEST RESULTS