1. CASE STUDY in Tirana City CONCLUSIONS AND DISCUSSIONS
The impact of Taxi cars (1 + 4) to the PM air pollution in Tirana, ALBANIA
Edlira F. MULLA
Department of Chemistry
Faculty of Mathematical Engineering & Physical Engineering
Polytechnic University of Tirana – ALBANIA
Keywords: taxi cars; particulate matter; diesel combustion; air pollution.
INTRODUCTION
In the conditions of very limited parking areas, Taxi cars (1 + 4) are a convenient form of transportation in Tirana. At present the taxies’ average age is considerable, with most of them being over 15 years old. Taxi (1+4) cars’ fleet in Tirana is relatively old and almost 100 % of them operate on Diesel [1]. Recently there has been pressure by the Ministry of Transport [2] and the Municipality of Tirana [3] for favoring the licensing of cars produced after the year 2000, which use gasoline instead of Diesel.
The aim of this research was to analyze the target group of Taxies in Tirana regarding the contribution of this type of public transport in the Particulate Matter (PM) air pollution in Tirana City. The database of registration of taxies at the General Directorate of Services to the Road Transport [4] was examined and a questionnaire was filled by drivers. To evaluate the contribution of Taxi cars to the PM air pollution in Tirana, the opacity of exhaust gases released after the Diesel combustion in Taxies’ engines was measured. This was done through the use of opacimeter that measures the absorption coefficient K (in unit m-1) for all vehicle categories, based on their year of production [5].
RESULTS
The description of the Target group of taxies studied, research findings and testing results are summarized in Table 2 below:
CASE STUDY in Tirana City
Population of Tirana City up to December 2009 is registered inhabitants [8].
In the end of 2009, in Tirana District there are registered vehicles, out of which there are private cars [4].
Up to the year 2010, there are about:
650 Taxi cars registered in Tirana City Municipality
200 Taxi cars registered in the Communes of Tirana District,
respecting the norm: 1 Taxi car for 1000 inhabitants [1].
Unlicensed taxies make an unfair competition on this business.
METHODOLOGY
The PM concentration in the exhaust gases was measured from the light weakening after it passes through the mixture of exhaust gases in the tailpipe, by using the Lambert – Beer equation [6, 7]. Coefficient of opacity K (m-1) summons the concentration of PM inside the exhaust gases from the diesel combustion in the engine as well as the dimensions and the nature of these particulates.
I / Io = e – K L = e – a · c · L , where K = a·c
a is the concentration of the particulate matter,
c indicates the dimensions and the nature of particulates,
Io is the light intensity when there is no smoke [PM] at all in the exhaust gases,
I is the light intensity when there is smoke [PM] in the exhaust gases,
L is the length of the tube where the measurement of the light intensity is taking place (in meters).
The absorption Coefficient, K (m-1), and not the real PM concentration in the exhaust gases was measured with this equipment. The higher the K values, the higher the PM concentration in the exhaust gases of cars. The allowed norms of opacity are given in Table 1 below:
CONCLUSIONS AND DISCUSSIONS
It can be clearly seen from the Table 2 and the Figures 1 and 2 above that the taxies in Tirana City have an average age at the moment of purchase younger than the taxies in the Communes. The same trend is for the average value of the K (m-1) indicating that the Taxies in Tirana Communes in average pollute more than the ones in Tirana City, although the taxies in Tirana travel more and consume more diesel daily than the taxies in Communes.
The target group of taxies studied is more than 50 % of all taxies that are licensed in Tirana District, therefore the results can be easily extrapolated for the whole taxi fleet of Tirana District. If the year 2000 would be respected as the minimal production year regarding the taxies licensing, the majority of these Taxies would not qualify for the license. Although understanding the need of taxi drivers to work, the present high PM levels in Tirana require a renewal of the whole vehicle fleet in general and the taxi fleet in particular.
32 % of Taxies studied resulted with a K>2.5 m-1, the minimal norm at present. Although comprising less than 0.8 % of all cars registered in Tirana till December 2009, due to the longer distances traveled and over 10 hours of driving on daily basis , the contribution of these old Diesel taxies in the PM air pollution in Tirana is considerable.
Table 1: The allowed norms for the pollutants (opacity) that are released with the exhaust gases from the Diesel vehicles No
Year of Production
Type of Fuel
Diesel Engine
Absorption Coefficient
K (m-1) 1.
Before 1988
Diesel
Natural induction
With turbocompression
4.0
4.5 2.
3.5 3.
After 1998
2.5
RECOMMENDATIONS
In order to improve the PM levels in Tirana’s air, it is recommended that:
there must be only one standard regarding the inspection of cars for PM emissions, based on g/km driven and not only on their production year;
unlicensed taxies must be severely fined;
the necessary economic mechanisms are found to lower the age of the registered taxies’ and to allow their access in the fast lanes, which at present are used only by buses,
in order to offer an evermore attractive service to the citizens and at the same time to pollute the air of Albania’s capital less than they do at present.
REFERENCES
1. Source: Association of Tirana Taxies (1 + 4). Tirana, Albania. February 2010.
2. Guideline No. 12, dt by the Minister of Public Works, Transport and Communication on “Number of taxies and licensing the taxi service”. Tirana, Albania
3. Decision No. 2, dt by the Municipality Council of Tirana, on “Organizing and Functioning of Taxi service in Tirana”. Tirana, Albania
4. General Directory of Services to the Road Transport. Tirana, Albania. March 2010.
5. Fletore Zyrtare e Republikës së Shqipërisë. Nr Pg
6. Fifield F. W. And Kealey D (1983) – Principles and practice of Analytical Chemistry. 2nd edition. International Textbook Company Limited. London Pgs. 278, 310.
7. Kihara Nobutaka (2001) - PM measurement. Opacimeter MEXA-130S. Readout. (2001) Vol. No 23; Pgs
8. Source: Municipality of Tirana. Civil Status Office. Tirana, Albania. February 2010.