Issue 3

In this paper, we present the estimate and results of measurement of air pollution in Béjaia
city in Algeria.
We used an enclosure of 0,80 m3 for the collection of gases directly on the outlet side of the
tailpipe of the vehicles. A three-gas detector (MX21 plus), introduced inside the enclosure,
measures the rates of carbon monoxide CO, sulphur dioxide SO2 and nitric monoxide NO. We
studied the exhaust pollutants according to the age of the vehicle (1980 – 2004) and the
acceleration of the engine. Measurements related to a sample of 204 vehicles using gasoline
or diesel oil fuel.
The comparison between the rejections and the standards European, American and
Japanese norms encourages us to challenge the authorities on the urgency of the
introduction of the vehicle inspection and technical control. Except the new vehicles (less than
5 years old), where the results are comparable, the others exceed largely the standards.
We have counted the number of vehicles passing through the Daouadji square during one
month (March 2004) and calculated the total pollution rejected. The comparison with the air
pollution measured in situ confirmed that urban pollution is primarily from automobile sources.
On the curve of the weekly evolution of the air pollution the days and peak hours of the
automobile traffic appear clearly. The correlation with the number of vehicles is very
significant (0,78).
By taking account of the annual rate of increase in the number of vehicles and keeping the
current park without adequate maintenance, a statistical model envisages an unbearable
urban pollution near 2010.

The EU Directives and legislation by worldwide environmental authorities impose constantly
lower levels for the airborne pollutant emissions of internal combustion engines towards the
goal of zero emission vehicles. During the last decade, engine manufacturers, refiners and
fuel companies invest highly in order to comply with the increasingly severe emission
requirements.
The diesel engine is widely used for transportation, manufacture, power generation,
construction and farming operations. There are different kinds of diesel engine depending on
their application: small, high speed, indirect-injection engines or low speed, direct -injection
behemoths with cylinders more than one meter in diameter. Their main advantages are the
efficiency, economy and reliability. The physicochemical properties of the diesel fuels and the
engine design affect the operability, the efficiency and the performance of the diesel engine
and they correlate to the exhaust emissions.
In Greece, the diesel fuel market steadily increases during the last years. The fuels produced
by the refineries usually comply with the existing specifications. However, alterations in the
fuel properties may occur through the supply chain to the service stations due to failures of
the distribution system (i.e. contamination with water, tank sludge and residues) or
adulteration with lower value and taxation fuels (heating oil, marine diesel or industrial
solvents).
The transportation sector is a major source of air pollution. It contributes to harmful exhaust
emissions, such as greenhouse gas emissions, carbon monoxide, sulfur oxides (SOx),
nitrogen oxides (ΝΟx), unburned hydrocarbons (HC) and particulate matter (PM) emissions.
In this paper, PM and exhaust emissions from a stationary single cylinder diesel engine were
examined. For comparison purposes, tests were carried out with a typical automotive diesel
fuel of the Greek market and with adulterated fuels with heating oil or white spirit. The noncomplying
diesel fuels gave increased emissions in all cases with only exception the PM
emissions due to adulteration with white spirit. More specifically, the experimental results for
the adulterated fuels with heating diesel showed an increase of the nitrogen oxide emissions
up to 73.9%, of the unburned hydrocarbons up to 29.6% and of PM up to 121% compared to
the baseline diesel fuel emissions.

The paper describes the development of a fast and easy-to-use qualitative tool for preliminary
assessments of urban air quality related to road traffic. The tool is particularly aimed at the
ability and budget of local government. It uses a novel interaction matrix-type methodology
combined with mapping overlay, performed via a GIS. More specifically, the interaction matrix
provides the weighting factors, which show the impact of each variable involved in a system
on the target variable, air quality, as well as on the system as a whole. These weighting
factors are used in the GIS to produce vulnerability maps. The maps visualise vulnerability to
air pollution due to the combined effect of a number of interacting factors, and thus indicate
areas susceptible to poor air quality. This results in a considerable reduction in computing
time and complexity compared to the use of a sophisticated numerical model, as the user of
the GIS tool only needs to perform mapping overlays in the GIS (using the previously derived
weighting factors).
The particular aim of this study was to compare two different methods for quantifying the
interactions between variables in the matrix. The first method used constant coefficients,
whose values are based on parametric studies performed using an advanced dispersion
model or on good engineering judgement. The second method used a more sophisticated and
versatile quantification of the interactions between variables, via analytical or semi-empirical
relationships. In the latter method, the matrix was formulated computationally, so that the
interaction weightings for different conditions can be obtained automatically.
The technique was applied to the case study of an urban area with a high traffic throughput, in
the UK. Two different interaction matrices were constructed for urban air quality linked to road
traffic, based on the above methods. The GIS results based on both matrix methodologies
were compared to the results of a more intensive dispersion numerical model in terms of
pollutant dispersion patterns and hot spots. Both sets of results were shown to compare
favourably with those of the numerical model. The results based on the more sophisticated
matrix coding were found to be in closer agreement with those of the numerical model.

The capacity of cyclodextrins in trapping VOCs is studied. Cyclodextrins (CDs) are a family of
cyclic oligosaccharides that are composed of α-1,4-linked glucopyranose subunits. The most
notable feature of cyclodextrins is their ability to form inclusion complexes (host–guest
complexes) in solution with a very wide range of solid, liquid and gaseous compounds by a
phenomenon of molecular complexation. Inclusion in cyclodextrins exerts a profound effect on
the physicochemical properties of guest molecules as they are temporarily locked within the
host cavity giving rise to beneficial modifications of guest molecules. Cyclodextrins are non
toxic compounds.
Volatile Organic Compounds (VOCs) are among the most common air pollutants emitted from
chemical, petrochemical, and allied industries. VOCs are one of the main sources of
photochemical reaction in the atmosphere leading to various environmental hazards; on the
other hand, these VOCs have good commercial value. There are many techniques available
to control VOCs emission (destruction based and recovery based) with many advantages and
limitations. Absorption is one of the recovery techniques with a removal efficiency of 95 to
98% but its applications are limited to hydrosoluble VOCs.
The measurements of vapour liquid equilibrium (VLE) data in absence or in the presence of
cyclodextrins were done. These data are needed to perform the design of an absorber for
process application. The determination of Henry’s law constant (Hc) was achieved with a
static headspace coupled with a gas chromatography (HS-GC). Moreover this technique
permits us to calculate the association constant in the aqueous medium between the volatile
solute and different cyclodextrins. The use of cyclodextrins may lead to a reduction of 95% of
the Henry’s law constant for some VOCs.
Dynamical studies were done by using impinger filled with an aqueous solution of
cyclodextrin. By contacting a contaminated air with this solution, we observed the transfer of
the VOCs from the gaseous phase to the liquid phase. These results show that by using
cyclodextrins as liquid solvent, absorption can be used for the removal of a large variety of
VOCs from gaseous effluents. The test in an absorber tower are also performed.