Abstr act. This paper presents the monitoring system for the status of soil quality in Romania. This system is organized on three levels. The first level includes a fixed grid of 16x16 km and covers the whole country. In the monitoring system of the status of soil quality is important to determine the soil loading with elements and potentially polluting substances. The content of elements and potentially polluting substances in the soils is determined both by main characteristics of soils and of human actions. Some types of industrial pollution are the most aggressive pollution with heavy metals and oxides of sulphur which is found in (%)#&* +$,-, Zlatna and Baia Mare. Are presented the concentrations of soluble heavy metals and sulphur in the three areas mentioned above and ecological reconstruction measures are proposed. Keywor ds: monitoring, heavy metals, sulphur, soils, pollution.
Copyright ©by the paper’s authors. Copying permitted only for private and academic purposes. a). Level I consist of performing a minimum of investigation in all aspects of fixed networks for the determination of areas with soils in different stages and various processes of degradation. It seeks, regular, evolution of these soils through specific indicators.
b). Level II consists of details of investigations into certain points of the Level I network to identify the causes of soil degradation processes.
c). Level III includes detailed investigations to verify the hypothesis, analysis of soil degradation processes, making forecasts for recommendations to their remediation.
The frequency of measurements is 4 years for grid points without special problems of level I and 1 year for those with special problems.
In Romania, the first level includes a fixed network 16x16 km covering the entire
country. The network has 944 points of which 675 are in areas with agricultural soils
and forest soils 269 territories. Points are located at each network node, the contents
of a square of 400 m (Fig. 1). Soil profile description is based on a medium sample in
modified structure consisting of 20-25 individual samples from the first 10 cm, three
individual samples for each horizon and four samples from each horizon in the
natural structure according to the methodology presented in the "Monitoring the
status of soils quality from Romania". ./-01-*
The paper presents the soil load from monitoring sites of level I with potentially polluting elements and substances.
PPES contents in soils is determined by the main characteristics of soils (texture, pH, organic matter content), and human actions (fertilizer, phytosanitary treatments, pollution, etc.).
An important role in the concentration of pollutants in the soil it is relief, accumulative forms retaining a larger volume of polluting substances. Most sites in Romania are situated on horizontal land - very low pitched (50%) and the remaining land with different inclinations.
Approximately 50% of agricultural sites may suffer pollution by chemicalization works.
In terms of soil classes and soil types
Special issues related to retention and movement of pollutants in the soil raises Luvisol, Spodisols and Cambisols.
Related to soil texture, note the high percentage of Level I monitoring sites, clay soils (41.5%), clay loam (23.1%) and sandy loam (20.5%). Soils with slight texture not hold large PPES content, but favor strong mobilizing them. Fine textured soils retain high PPES content that can reach in the plants.
Soil reaction is of particular importance in terms of mobility PPES. Soils with weak alkaline reaction has very low-average vulnerability and the moderate and strong alkali are not vulnerable.
Vulnerability of soils to pollution with heavy metals is determined by soil characteristics listed above.
The most aggressive industrial pollution is heavy metal and sulfur oxides in Alba, Maramures, Sibiu counties with compounds of fluorine in Prahova Olt, Bacau, Tulcea counties.
Among the types of agricultural pollution, HCH and DDT residues pollution is important, wastewater, sludge livestock pollution.
Soil indicators followed into the monitoring works are: - joint analysis: texture (particle size composition), pH, humus, total nitrogen, mobile phosphorus, mobile potassium, moisture, apparent density, penetration resistance, hydraulic conductivity, total porosity, contraction index;
- specific analysis: the sum of exchangeable bases, hydrolytic acidity, exchangeable aluminum, total cation exchange capacity, base saturation degree, the total content of soluble salts, exchangeable sodium, total carbonates content; - special analysis: heavy metal content, soluble sulphur content, soluble fluorine content, organochlorine pesticide content, the number of bacteria, mushrooms and dehydrogenate activity.
Methodologies used to determine the joint analysis are: - Texture is determined by the sedimentation method and it is extracting a sample of suspension of a certain amount from depth h at time t, using the pipette Kubiena; - Apparent density is determined on soil samples in the structure unchanged, using a metal cylinder from stainless material; - Humidity is determined in the laboratory by oven drying method; - Resistance to penetration was determined in the laboratory on soil samples collected in the cylinder, with humidity of 50% of the capacity of water, using a static penetrometer;
- Hydraulic conductivity in saturated medium is determined "in situ" through the "Auger Hole" method; - Total porosity and the rate of contraction are determined by calculation; - pH is determined potentiometrically in aqueous suspension 1:2.5; - Humus is determined the modified method of Walkley-Black; - Total nitrogen is determined by the method of Kjedhal; - Mobile phosphorus and potassium are determined by extraction solution of ammonium acetate-lactate (by Egner-Riehm-Domingo);
Regarding the specific analysis, the methodology applied is as follows: - Sum of exchangeable bases is determined by the method of Kappen (0.1n HCl); - Hydrolytic acidity is determined by percolation with Na acetate or K 1n; - Exchangeable aluminum is determined by the method of Socolov; - Total capacity of cation exchange is determined by the method of Cernescu; - Degree of base saturation is determined by calculation; - The total content of soluble salts is determined by Conductivity; - The total content of carbonates is determined by gas volumetric method with Scheibler calcimeter; - Exchangeable sodium was determined by the method of Bower; Special analysis refers to: POLLUTANT
CU PB ZN CD CO NI MN
CR
- Heavy metals are determined spectrophotometrically by atomic absorption;
- Soluble sulfur content is determined by gravimetric dosing;
- Soluble fluoride content is determined by extraction in CuCl2, microdiffusion
Brewer;
- Organochlorine pesticide content is determined chromatographic gaseous phase;
Interpretations and size classes for most of the indicators listed above are those of
the Development methodology of soil studies, vol. III
Normal content: heavy metals – Adriano 1986; soluble sulphur – /-01-* and collaborators 1998; soluble fluorine – Larsen and Widdowson 1971, Omuetti and Jones – 1980, total DDT and HCH – /-01-*and collaborators, 1998.
Maximum available limits: heavy metals – Kloke, 1980; soluble sulphur – /-01-* and collaborators, 1998; soluble fluorine – Larsen and Widdowson, 1971; Omuetti and Jones – 1980, total DDT and HCH – /-01-*and collaborators, 1998. 2.2 Results and Discussions
One of the most important types of soil pollution in Copsa Mica, Baia Mare and Zlatna area is pollution with heavy metals and sulphur compounds.
The soil pollution $=*(%)#&*+$,-*&'!&*was determined by non-ferrous metallurgy industry. Pollution is given by heavy metals (Cu, Pb, Zn, Cd) and sulphur compounds. The area is characterized by a great geomorphologic complexity and a wide variety of soils (chernozem, phaeozem, nitisol etc.). In agricultural soils the accumulation of pollutants is achieved in the first cm of the soil, wherefrom through agricultural work the pollutants get into the whole horizon A (Table 2).
From table 2 results that lead exceeds four times the maximum available limits, two times the cadmium and zinc is close to this limit. Copper and sulphur content exceeding 2 times normal.
Soil pollution in Zlatna area was determined by non-ferrous minerals processing companies that eliminate annual significant quantities of SO2, oxides and sulphates of lead, zinc, copper, arsenic, antimony and bismuth in air. These sediment particles were deposited on the ground. .+$?-$@!5,0*A23*($%>&=0*(23*BCCC<2*Pollution is given by heavy metals (Pb, Cu, Zn, Cd) and sulphur compounds (Table 3).
Polluted area is an area of hills and mountains, with varied soils (nitisol, luvisol, eutricambisol etc.) and with periods of calm atmosphere which promotes the stagnation of air masses and deposition of pollutants.
From table 3 results exceeding the maximum available copper limits by 2 times, and the normal lead content of 2.5 times, zinc 4 times and sulphur 6 times. Cadmium content is little high than normal.
In the area Baia Mare, mining companies of non-ferrous ores and their processing have been polluting factor. Soils pollution is given by heavy metals (Pb, Cu, Zn, Cd) and sulphur. The decisive role in the spread of pollutants is the relief. It is mountainous in the north constitute a barrier to pollution and is an alluvial plain in the south-west where the air currents allow the transport of heavy metal particulates. Lower meadows accumulate large quantities of heavy metals than higher landforms. .*D-,-60#0*/2*&=E*,%@@&>%'&6%'53*899F<2
Also, the hydrological regime has an important role in heavy metal pollution. Surface water and groundwater contribute to the spread of pollutants and stagnant waters from micro depressions allow fixing of heavy metals on the surface of clay soils (Table 4).
From table 4 results an excess of 7.5 times of maximum available limits of lead and a small excess of copper. Normal content is exceeded by 5.5 times of zinc and 4.4 times by cadmium. Normal content is exceeded the soluble sulphur by 14.5 times.
Important sources of soils pollution with sulphur compounds are emissions from power plants that do not apply desulphurization processes, from sulphuric acid power plants, from non-ferrous metallurgy, etc.
Oxides of sulphur coming from air pollution generates, after several chemical and biological transformations, SO42- and H+ - ions which contribute to soil acidification. This leads to fewer bacteria and microbiological activity disorder.
The objectives of the national monitoring system of soils quality in Romania are: a). systematic monitoring of quality characteristics of the soil; b). processing the information obtained to assess the quality status; c). elaboration of forecasts on the evolution of soil quality; d). warning agencies and makers on the situations in which appear the dangerous intensification phenomena of pollution, in order to prevent or limit harmful effects on soils;
e). providing data needed to establish the main causes of soil pollution phenomena in order to build and improve prevention and improvement measures, including rehabilitation and / or recycling of waste substances usable and to avoid or mitigate damage to the economy;
f). tracking dynamics of effectiveness of preventive measures against pollution of soils;
g). providing information and data to establish technical and economic measures necessary to ensure the current and future stage, for consistency between the country's socio-economic development, protection of soil and environmental quality; h). providing documentation necessary to support the national program of environmental protection;
i). using data on soils to achieve the national system of integrated environmental monitoring;
j). providing data of soils quality from Romania necessary to participation of the Romanian part to achieve International Reference System or other international programs.
For the reconstruction of agricultural soils contaminated with heavy metals and sulphur dioxide are necessary the works listed below: a). general measures: - reducing the emission of pollutants by upgrading polluting industries; -attachment measures of waste dumps to prevent their scattering (Baia Mare); - setting up perimeters of improvement of affected areas based on their mapping up-to-date; - total or partial restructuring of uses in the areas affected. b). specific measures: - correcting acid reaction soil by applying calcareous amendments to bring the pH from a strong acid domain (pH < 5,8), into a moderately acid or weak acid domain (pH = 5,9-6,8). This reduces soil acidity so mobility of heavy metals and exchangeable aluminum concentrations. Doses of calcareous amendment are calculated using the formula: t/ha (1) DCaCO3 = SBi = [
Vd DK2O =
0,05x8
Pg – P2O5 contribution by organic fertilization;
PFg – P2O5 intake by amendment with phosphogypsum. - potassium fertilization. The dose is calculated with relation: 160 K Al
Kg ! Ccarb kg s.a./ha (4) in which: 160- optimal mobile potassium content ppm;
KAl – initial soil content in potassium mobile; 0,05 – average growth rate of mobile potassium content per kg of K2O applied through fertilization ppm; 8 – number of years that apply ameliorative fertilization with K; Kg – K2O intake of organic fertilization;
Ccarb. – correction for carbonates - afforestation of polluted areas function to intensity of pollution, namely: excessive heavily polluted area (acacia, black pine and bushes), the moderately polluted area (acacia, black pine, bushes, red oak), low polluted area (sessile, beech, hornbeam, mountain and plain maple, linden, cherry and bushes); - establishing waste dumps with fallow furrows and seeding grasses, planting acacia and vine. 2.3
Conclusions
The results of research conducted in (%)#&* +$,-, Zlatna and Baia Mare, lead to the following conclusions:
-soils investigated are vulnerable soils to pollution processes by sulphur compounds and heavy metals;
-the main pollutants that affect agricultural ecosystems are the acidic sulphur compounds, Pb, Cu, Zn and Cd;
-pollution effects on soils were highlighted through acidification and depletion of bases of the adsorption complex;
-due to pollution with heavy metals and sulphur compounds disturbance microbiological activity takes place; -the effect of pollution is destroying the soil structure; - increasing the mobility of aluminum and heavy metals, with toxic effects on vegetation;
- changes of nutritional conditions leading to premature drying of vegetation and loss soil protection functions.