Influence of the photosynthesis on the pollution with carbon dioxide in Timisoara.

Dobren, Flavius Andrei ; Dumitrescu, Constantin Dan ; Istrat, Nicolae 等

1. INTRODUCTION

The development of industry and discovery of enhanced fossil fuels, allowed that, by the combustion process, numerous air pollutants such as: carbon mono and dioxide, nitrogen oxides, sulfured oxides, powder and carbon dioxide, are released into the atmosphere (Ionel et al., 2004).

Closely correlated with the enhanced emissions of carbon dioxide, a phenomenon indirectly proportional is represented by the plant photosynthesis process, a natural process by which plants use the energy from sun light to produce sugar, which cellular respiration converts into ATP (adenosine triphosphate), the "fuel" used by all living things. During the photosynthetic process, plants absorb carbon dioxide from the atmosphere and release oxygen. Technically speaking, this process is a reverse reaction of cellular respiration taking place only in the presence of the sun's rays (Coste et all., 2001).

2. CASE STUDY--THE CALCULUS OF THE LEAVES SURFACE IN TIMISOARA AND THE ESTIMATION OF THE C[O.sub.2] FROM PHOTOSYNTHESIS IN COMPARISION WITH THE EMISSIONS OF C[O.sub.2]

Regarding the adsorption of C[O.sub.2], according to V.Ciupa and his co-authors in "Timisoara verde (Green Timisoara)", plant leaves assimilate C[O.sub.2] with an average intensity of 10-20mg C[O.sub.2]/[dm.sup.2]/h. According to this paper, a cubic meter of the crown has about 3 square meters of foliar surface (total leaves surface) (Ciupa et al., 2005).

In average, the carbon dioxide adsorption is 30mg/ dm2/ [h.sup.*] 300[dm.sup.2] (foliar surface of a cubic meter of crown), respectively 9g/h. Finally, the photosynthetic carbon dioxide adsorption capacity of a cubic meter of crown is 9g/h (Coste et al., 2001).

The assessment of the crown volume of all the trees in a whole city like Timisoara, inventorying all of the trees, other plants and green spaces, measuring the surface of all the green spaces and much more are described in the book "Timisoara Verde", also quoted in the bibliography. Using the data presented in this book, we can try to assess the quantity of carbon dioxide photosynthetically adsorbed by the town vegetation (Ciupa et al.,2005).

The total area occupied by grassy vegetation and flowers in Timisoara is 826503 [m.sup.2], plus the added 613.2 ha of the green forest. According to some studies (Ciupa et al.,2005), in 1 square meter area, the foliar surface is 4[m.sup.2], where as a result, the whole foliar area of the grassy vegetation is (826503 [m.sup.2] + 6132000 [m.sup.2]) *4 = 27834012 [m.sup.2].

According to the same study, the volume of standard wood crown vegetation is 3548000 [m.sup.3], plus the 10650000 [m.sup.3] corresponding volume of the green forest's trees ((1), pg. 157) in the year 2004, a summing total 14198000 [m.sup.3]. The growth factor is 5%/year, of which, in 2006 a crown volume of 15617800 [m.sup.3] results, which corresponds to a foliar area of 46853400 [m.sup.2]. Summing up this surface with the foliar area of the grassy vegetation, we obtain 74687412 [m.sup.2]. For an adsorption rate of 30mg C[O.sub.2]/ 0.1m 2/h to 74687412 [m.sup.2] leaf surface, we obtain an adsorption capacity of 22406.22 kg C[O.sub.2]/h, of which the adsorption rate in C[O.sub.2]/h of the resinous plants is 2108.403kg/h--it represents 15% of total trees (foliar area of 7028010 [m.sup.2]). Corresponding to the months of January, April, July and October, the periods of daily allowance are 282.72, 398.7, 469.03 and 341.62 hours respectively. As for the months, January photosynthesis is made only by resinous species, proper C[O.sub.2] adsorption of this month through the process of photosynthesis will be 282.72h (light of the month January) * 2108.403 kg/h meaning 596087.7 kg C[O.sub.2] corresponding to the month January. In April, the adsorption of C[O.sub.2] will be 398.7 h * 22406.22 kg C[O.sub.2]/h meaning 8933360 kg; In July, C[O.sub.2] adsorption will be 69.03 h * 22406.22 kg C[O.sub.2]/h, meaning 10509189 kg; In October adsorption of C[O.sub.2] will be 341.62 h * 22406.22 kg C[O.sub.2]/h, meaning 7654413 kg.

The table bellow presents the adsorption rate of C[O.sub.2] through photosynthesis corresponding to the months of January, April, July and October, as well as the C[O.sub.2] emissions from road transport, Coltherm, and other combustion sources.

The next three charts present the status of the carbon dioxide emissions for the data of table1 and the carbon dioxide absorption by plants for the same time range.

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

[FIGURE 3 OMITTED]

The first chart represents, for the studied periods, the evolution of the C[O.sub.2] emissions according to the main sources (road transport, Colterm and other burning and incineration installations).

The second one presents the evolution of the C[O.sub.2] adsorption capacity through the process of photosynthesis:

The last chart presents the C[O.sub.2] adsorption ratio through the process of photosynthesis depending on the total C[O.sub.2].

3. CONCLUSIONS

The global heating potential (GHP) can be evaluated related to the carbon dioxide considered as standard: C[O.sub.2] = 1 (Ertl et all., 1999) and after analyzing the charts, we noticed that the adsorption of carbon dioxide by photosynthesis in comparison with the carbon dioxide emissions is extremely important because although we live in a city polluted with carbon dioxide coming from different sources, the photosynthesis attenuates the local summer temperature increase due to the local greenhouse effect and because from the total amount of emissions, the carbon dioxide adsorption through photosynthesis is 35%. While the number of cars, thermal power demands, housing and population are significantly and constantly increasing in the last 10 years (well above 100%), even the photosynthesis phenomenon will no longer face the increasing pollution if drastic measures will not be taken.

Due to such a high percentage of carbon dioxide adsorption, over 35% in July and quite low in the winter months in the absence of 85% of this phenomenon (vegetation outside the resinous, which represents 15% of all trees, does not have the leaves and does not synthesize substances, thus doesn't photosynthesize), we could draw the conclusion that during summer the greenhouse phenomenon is reduced with 35% which greatly prevents temperature increase and in winter in the absence of 85% of this phenomenon (photosynthesis), the greenhouse effect emphasizes and materializes in Timisoara by temperature increases during winter to little below 0 [C.sup.0] for a short period of time, low temperatures maintaining only when cold air fronts from Northern Europe are present.

At the same time, these issues bring along irreversible negative effects resulting in the disappearance of seasons and their homogenization (winter is heating and summer is cooling). These effects attract remarkable weather and climate phenomena, major climate changes, increasingly frequent occurrence of devastating weather phenomena (storm, hurricane, tornadoes, heavy rain, etc.), (Wehner et al., 2004), even in areas where there were no reported history of such phenomena (i.e. tornados in Dobrogea and along the Romanian coast) and which have an impact and repercussions on the population (floods, landslides, and so on). Although these "alarm signals" appear more and more often, carbon dioxide emissions are increasing more and more over the assimilation limit of plants direct proportionally to the increasingly wider areas of forest cleared due to human expansion.

4. REFERENCES

Ciupa, V. Radoslav, R.; Oarcea, C. & Oarcea, Z. (2005). Timisoara verde. Sistemul de spatii verzial Timisoarei--Green Timisoara. The green spaces of Timisoara, Marineasa Printing House, Timisoara

Coste, I.; Borza, I. & Arsene, G.G.(2001). Ecologie Generala si Agricola--General and Agricultural Ecology, Orizonturi Universitare Printing House, Timisoara

Ertl, G.; Knozinger, H. & Weitkamp, J. (1999). Environmental Catalysis, Weinheim

Ionel, I.; Popescu, Fr.; Oprisa-Stanescu, D.P.; Bisorca, D. & Gruescu, Cl. (2004). Energoecologia combustibililor fosili. Teme experimental--Energoecology of fossil fuels. Experimental subjects, pg. 130, ISBN 973 625 186 1, Politehnica Printing House, Timisoara

Wehner, B.; Philippin, S.; Wiedensohler, A.; Scheer, V. & Vogt, R. (2004). Variability of non-volatile fractions of atmospheric aerosol particles with traffic influence. Atmospheric Environment 38 (36), 6081-6090

Tab. 1: The status of the emissions of C[O.sub.2]

Month C[O.sub.2]- C[O.sub.2]- C[O.sub.2]
 emissions emissions emissions from
 from Colerm[t] road other burning
 transportation[t] instalations
 and incinera

January 82517 23381.17 79397.29
April 35239 23381.17 33906.72
July 3311 23381.17 3185.821
October 30362 23381.17 29214.11
Total 151429 23381.17 79397.29

Month Photosynthetic Unabsorbed
 C[O.sub.2] C[O.sub.2] [t]
 adsorption[t]

January 596.0877 184699.4
April 8933.360 83593.53
July 10509.189 19368.8
October 7654.413 75302.86
Total 27693.05 184699.4