Annals of West University of Timisoara

Ser ies Chem is t ry 17 (1 ) (2008) 97 -102

97

ASPECTS REGARDING THE POLLUTION OF

AGRICULTURAL LANDS FROM BANAT WITH

PETROLEUM HYDROCARBONS

I . Z isu aaaa , Gh . Ianoş bbbb aWest University of Timişoara, Chemistry-Biology-Geography Faculty, Chemistry Department, 16, Pestalozzi Street , Timişoara, 300115, ROMANIA izisu@cbg.uvt.ro bWest University of Timişoara, Chemistry-Biology-Geography Faculty, Geography Department, 16, Pestalozzi Street , Timişoara, 300115, ROMANIA ianos@cbg.uvt.ro

Received: 17 June 2008 Modified: 19 June 2008 Accepted: 25 June 2008

SUMMARY

The main cause of the pollution with petroleum hydrocarbons of agricultural lands

from Banat is represented by the industrial activity of extraction and processing of

petroleum from this area. The contamination of soils leads to the reduction of their quality

state, manifested through the decrease of bio-productivity. On a national level,

approximately 50000 hectare of land are polluted with petroleum hydrocarbons and in

Banat the surfaces contaminated with this kind of compounds surpass 200 hectare. The

majority of polluted lands are out of the agricultural circuit.

Keywords: petroleum hydrocarbons, pollution, agricultural land, Banat.

INTRODUCTION

The main cause of the soil pollution with hydrocarbons of petroleum origin, at

Banat level as well as at the national one, is represented by the industry of extraction and

processing of petroleum. Cotigaru et al. [1] specify that the man is responsible for the lost of

5x1010

tons of petroleum as a result of oil extractive activity. From this quantity of oil a big

part, meaning 1,7x107 ton, gets into soil.

Hydrocarbons form an impermeable film on the soil surface preventing water

circulation and the exchange of gases, which leads to the plant roots suffocation and favor

the reduction processes. While the anaerobic environment is developing, the number of

bacterium in the sol decreases, and in the same time their metabolic activity reduces too.

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The presence of petroleum hydrocarbons on the cultivated lands affects the seeds

germination, plants development and even the whole crop (tab.I). Hydrocarbons have the

capacity to penetrate in the seeds of the plants and can destroy the embryo or they can

prevent germination through the reduction of seeds hydration and through the reduction of

oxygen need [2].

Table I. The harmful effect of petroleum hydrocarbons on soils and

on soy and cereals crop [3]

Oil in soil (%)

Effects on crops on equal surfaces

<0.5 Improvement of plant development

0.5 Possible reduction of plant development speed

0.5-1.0 Production decrease of until 40%

1.0-2.0 Delicate plants, production decrese with until 100%

4.0 All plants die

The contamination of pedologic cover leads to its quality decrease. According to

White [4], the soil quality depends on the land use and on its propensity for that use or

function.

The most important consequence of soil pollution is the reduction of its bio-

productive capacity from a qualitative as well as from a quantitative point of view. If in the

case of water or air pollution, one can understand the penetration of some outside noxious

elements, in the case of soil, the contamination manifests itself through the disturb of one of

its compound which attracts after it the affection of fertility or of its normal function [5].

MATERIAL AND METHODS

For the diagnose of pollution the start has been given by written, graphic and oral

information sources connected to the history of petroleum hydrocarbons pollution in Banat

area. Lots of the informative materials have been delivered by O.S.P.A. Timişoara. This

stage was followed by studies in the polluted fields.

The data obtained from O.S.P.A. Timişoara was defined through the next methods:

- pH in H2O was defined through the potentiometrical method;

- electroconductivity (E.C.) is calculated for 25º C temperature after the relation:

EC at 25º C = EC at tº C·ft·k (1)

where:

EC at tº C = electrical conductivity measured at the temperature at which the

determination was made;

ft = termical factor;

k = apparatus constant.

POLLUTION OF AGRICULTURAL LANDS FROM BANAT WITH PETROLEUM HYDROCARBONS

99

- adsorbted sodium percent (PSA) = it is expressed in percent from the value of

total cationic exchange capacity and it is calculated after with the formula:

PSA (%) = Na+

ad /TNA·100 (2)

where:

TNA = cationic exchange capacity, expressed in miliequivalent at 100 g dry soil at

105º C, determinated through Bower et al. Method [6].

For the localization, mapping and representation of the polluted area with

petroleum hydrocarbons, as well as for the drillings and extraction installations of oil the

Banat Soils Map has been used on a scale of 1:40000 cm. The map has been processed with

the help of Geographical Informational System ESRI ARCGIS 9.1. For the

characterization and classification of the country south-western soils, polluted with

petroleum products, a lot of criterions have been considered, such as: the type and source of

pollution, the contamination degree of soil, affected surface, as well as the activity which

generated the pollution.

The surfaces affected by pollution have been delimitated and distinguished on the

Pedologic Map of Banat through distinct conventional signs. The legend of the soil map has

been completed with the explanation of utilized signs. To distinguish the pollution of

agricultural surfaces, on the map legend have also been specified the productivity grades of

soils (Figure 1).

RESULTS AND DISCUSSIONS

Pollution of agricultural lands with hydrocarbons can be a result of disorderly

storage around oil wells or around oil tanks, a result of eruptions coming after drilling

activities or after infiltrations in soil due to trickling from fissured buried pipes. On small

surfaces, contamination coming from the utilization of some defective function installations

or agricultural machines can be observed.

In the perimeter where oil is extracted and processed, in Banat all the types of

degradation mentioned on top have been point out. The affected areas varies in time,

according to the intensity of drilling activity or to the functionality of the extraction well

and the pollution degree depends on the quantity of sloop contaminator [7]. In the second

table chemical values of affected soils from a few specific extraction areas are presented.

Table II. Chemical characteristics of oil polluted soils epipedon

from Banat [7]

Localization pH oil (%)

E.C. (mmho/cm)

Mineral residu (mg/1000g sol)

PSA (%)

Sat Chinez 8.5 1.76 0.33 110 7.9

Călacea 6.9 4.49 - - -

Valcani 8.9 0.10 0.48 151 42.5

Beba Veche 8.4 0.3 0.19 63 2.9

Pordeanu 8.1 5.0 - - -

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Analyzing the classification of the soil loading degree with petroleum

hydrocarbons made by Toti et al. [8] and the one of the soil degree of pollution in

accordance with the qualitative and/or quantitative reduction of vegetal production made by

Rauţă and Cârstea [5] we can observe that the bio-accumulative horizon of soils in Banat

presents a strong to very strong petroleum hydrocarbons loading. Because of this fact a

significant reduction of agricultural crop on this fields can be observed (Table III)

Table III. The degree of vegetal production reduction on

agricultural lands in Banat polluted with petroleum hydrocarbons

Localisation Oil (%)

The soil degree of oil hydrocarbons loading

estimation

The reduction of vegetal production*

Sat Chinez 1,76 strong 26-50 % Călacea 4,49 strong 26-50 % Valcani 1,10 strong 26-50 %

Beba Veche 0,3 slight 11-25 % Pordeanu 5,0 very strong 51-75 %

*Theoretical estimation.

In Romania, the agricultural damages due to soil pollution with petroleum

hydrocarbons are estimated to an equivalent of approximately 50000 ton of cereals per year [8].

Table IV. The situation of Banat lands degraded through

petroleum products pollution [7, with modifications]

Locality

Surface (ha)

Pollution source

Estimation of damage brought to agricultural production (% of

production)*

Zădăreni 0.35 petroleum products 85 Diniaş 0.03 Water deposit 80 Variaş 0.88 Water deposit+oil 90

Sat Chinez 1.60 Raw oil 65 Foeni 0.06 Raw oil 75

Valcani 0.25 Raw oil 90 Dudeştii Vechi 0.15 Raw oil 75

Cherestur 0.65 Raw oil 70

Carani 1.30 Petroleum products 60 Cheglevici 0.40 Raw oil 70 Jimbolia 0.13 Petroleum products 90

Biled 0.12 Petroleum products 75 Şandra 1.00 Petroleum products 80 Călacea 0.50 Petroleum products 70

TOTAL 8.92

*Practical estimation.

The reduction of extraction activity in the last years determined a decrease of

polluted areas and also a very slow decontamination of anterior affected areas.

POLLUTION OF AGRICULTURAL LANDS FROM BANAT WITH PETROLEUM HYDROCARBONS

101

According to the information provided by the Research Institute for Soil Science

and Agrochemistry Bucharest (ICPA), in our country there are approximately 50000 hectare

of land affected by the pollution with petroleum hydrocarbons most of them representing

agricultural surfaces. At the end of the 20th century approximately 3380 hectare polluted

with oil have been registered from which 2850 hectare agricultural lands completely out of

production. Most of these affected lands can be found around oil wells and along petroleum

products transport pipes [9].

Figure 1: Main types and subtypes of Banat soils and the sites polluted with petroleum hydrocarbons

The state of quality and the productive potential of agricultural lands (classes of productivity):

I – 100-80; II – 80-60; III – 60-40; IV – 40-20; V – 20-0

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In Banat, the surface affected by pollution with hydrocarbons of petroleum origin

is approximately 203,6 hectare of which 194,7 hectare have been effectively removed out of

agricultural circuit as a result of depot and station of gasoline reduction positioning (80

hectare), of oil wells (83,4 hectare), roads of access (76,3 hectare) [10] (Figure 1). Without

the up mentioned perimeters, small areas have been identified, of 10-50 m2, in the perimeter

of about 15 localities, around wells, around oil parks or on the range of transport pipes

(Table IV) where, the negligence or accidents contributed to total or partial pollution of

about 8,9 hectare of agricultural lands [7]. The largest surfaces with high degree of

pollution, as a result of petroleum hydrocarbons infiltration in soil, can be found in north-

western part of Banat, in the perimeter between the localities Variaş, Sat Chinez, Biled and Gotlob.

In this area are affected soils which register in the highest class of agricultural productivity.

CONCLUSIONS

1. The main cause of Banat agricultural surfaces pollution with petroleum

hydrocarbons is represented by the extractive and processing industry of petroleum.

2. The most serious consequence of soil pollution with hydrocarbons is the qualitative

and quantitative reduction of agricultural production.

3. In Banat, pollution with petroleum hydrocarbons can be register on a surface of

over 200 hectare, affecting mostly soils with the biggest agricultural productivity

from the north-western part of the region.

4. A reduction of polluted surfaces can be seen, in the last years, as a result of the

decrease of extractive activity in the area.

REFERENCES

1. Cotigaru B., Mihăiţă M., Petrescu V., Ţigănescu D., Necesitate şi responsabilitate – modelul dezvoltării economico-sociale durabile între cunoaştere şi realizare, Orizont XXI, ASE, AGIR, Facultatea de Îmbunătăţiri Funciare şi Ingineria Mediului şi Fundaţia Internaţională Sănătate, Mediu, Dezvoltare Durabilă, Bucureşti, 1996, p.87

2. Dumitru M., Toti M., Ceauşu C., Constantin C., Voiculescu A. R., Căpitanu V., Pîrvulescu E., Popa D., „Bioremediation of petroleum contaminated soils”, Ştiinţa solului, XXXII(1-2) (1998), 163-175

3. Cristu A. A., Eficienţa economică şi protecţia mediului pe exemplu industriei petrolului, Editura A.S.E., Bucureşti, 2005, p. 113-114.

4. White R.E., Principles and Practice of Soil Science. The Soil as a Natural Resource, IVth edition, Blackwell Publishing, Padstow, 2006, p. 333-335.

5. Răuţă C., Cîrstea S., Prevenirea şi combaterea poluării solului, Editura Ceres, Bucureşti, 1983, p. 47-51 6. Bower C. A., Reitemeier R. F., Fireman M., “Exchangeable cation analysis of saline and alkali

soils”, Soils Science, 73 (1952) 251-261. 7. Ianoş G., Riscuri naturale şi tehnogene pe terenurile agricole ale Banatului, Editura Universităţii

de Vest, Timişoara, 2006, p.181-182. 8. Toti M., Constantin C., Drăcea M., Căpitanu V., Damian M., „Some aspects concerning the oil

pollution and brine in Romanian soils”, Ştiinţa solului, XXXII(1-2), (1998) 177-187 9. Toti M., Căpitanu V., Constantin C., Drăcea M. (1997), “Poluarea cu petrol şi apă sărată în

România. Repartiţia suprafeţelor poluate pe grade de mişcare, pe schele petroliere, pe judeţe şi pe ţară”, Public. SNRSS, (29B), p. 250-257.

10. Ţimbota I., Ianoş G. (1992), Contribuţii la cunoaşterea poluării solurilor cu reziduuri petroliere, Arhiva OSPA Timişoara, manuscris.