201 research outputs found
Influence of the texture on the efficiency of thermal desorption process of soils contaminated with crude oil
No full textThe hereby paper presents the experimental research on the influence of three types of soil texture on the
efficiency of decontamination performed using the technology of thermal desorption. The concentrations of
crude oil of the soil samples, the initial ones as well as those following the depollution process were
determined using the Soxhlet method. The decontamination process with thermal desorption on soil samples
was performed using the electric oven with chamber, and with silicon carbide bars. Experimental researches
were performed on the following types of soils: loamy sand, loam and loamy clay. The main parameters
established for the process of thermal desorption were the temperature 350 °C and the amount of time for
keeping the soil samples in the oven, of 5, 10 and 15 minutes. The results of the experiments indicated that
the type of texture has influenced the efficiency of the thermal desorption, and the highest efficiency was
obtained for the sample of loamy sand, treated for 15 minutes
Influence of the texture on the efficiency of thermal desorption process of soils contaminated with crude oil
No full textThe hereby paper presents the experimental research on the influence of three types of soil texture on the efficiency of decontamination performed using the technology of thermal desorption. The concentrations of crude oil of the soil samples, the initial ones as well as those following the depollution process were determined using the Soxhlet method. The decontamination process with thermal desorption on soil samples was performed using the electric oven with chamber, and with silicon carbide bars. Experimental researches were performed on the following types of soils: loamy sand, loam and loamy clay. The main parameters established for the process of thermal desorption were the temperature 350 °C and the amount of time for keeping the soil samples in the oven, of 5, 10 and 15 minutes. The results of the experiments indicated that the type of texture has influenced the efficiency of the thermal desorption, and the highest efficiency was obtained for the sample of loamy sand, treated for 15 minutes
Experimental Investigation of a Pilot-Scale Concerning Ex-Situ Bioremediation of Petroleum Hydrocarbons Contaminated Soils
No full textThe soil samples were taken from the site of a former oil products depot from an industrial area (Romania). The soil samples taken were analyzed from a physical and chemical point of view: texture, pH, soil micronutrient content, metals concentration and petroleum hydrocarbon concentration (PHCs). The soil contaminated with total petroleum hydrocarbon (TPH (4280 mg kg−1) was disposed in the form of a pile (L × W × H: 3000 × 1400 × 500 mm). Experiments on a pilot-scale were conducted over 12 weeks at constant pH (7.5–8), temperature (22–32 °C), nutrient contents C/N/P ratio 100/10/1, soil aeration time (8 h/day) and moisture (30%). Samples were taken every two weeks for the monitoring of the TPH and the microorganisms content. During the experiment, microorganisms were added (Pseudomonas and Bacillus) every two weeks. Results of the analyses regarding the concentration of PHCs were revealed a linear decrease of the concentration of PHCs after only two weeks of treatment. This decrease in concentration was also achieved in the following weeks. Following the analysis performed on the model at the pilot scale regarding the depollution process, it can be concluded that a soil contaminated with petroleum hydrocarbons can be efficiently depolluted by performing an aeration of 8 h/day, adding microorganisms Pseudomonas and Bacillus to ensure the conditions for increasing in the total number of germs (colony forming units–CFU) from 151 × 105 to 213 × 107 CFU g−1 soil, after 12 weeks of soil treatment—the depollution efficiency achieved is 83%
STUDIES AND RESEARCH ON POLLUTION OF ENVIRONMENTAL FACTORS IN THE AREA SC ROMPLUMB BAIA MARE FROM ANTHROPOGENICAL ACTIVITY
No full textThe main ways of soil pollution are: on path air or atmospheric path and on terrestrial path, pollution path of direct their. Sources of air pollution are two categories: natural sources (volcanic eruptions, decomposition acts, etc.) and artificial, resulting from human activities (mining and metallurgy, energy, etc.). Solid air pollutants are those treated in the paper. They are dispersed in the air from emissions of particles which containing heavy metal ions in the atmosphere having a low sedimentation rate. Finest particles, dispersed in the air gets a considerable stability, for which will persist for a much longer time in air, thereby of increasing pollution. Direct pollution comes from direct deposit of minerals on the soil as raw materials and hazardous waste, particle entrainment by deflation surface dumps, infiltration of sewage from emplacement, accidental discharge of sewage from the emplacement and crack pipes, etc. This paper shows how it is influenced soil pollution and crack pipes, etc. from the perimeter intrauzinal and extrauzinal of SC Romplumb SA by two of the factors leading to pollution, conveying technological waste water and atmospheric emissions, respectivelly
COPPER INFLUENCE ON GERMINATION AND GROWTH OF SUNFLOWER (‟HELIANTHUS ANNUUS”)
No full textHeavy metal pollution is an important issue worldwide and one of the technologies that can be sustainable in treating the contamination is phytoremediation. One of the plants that is known to tolerate heavy metals is Helianthus annuus. It can deal with heavy metals like Zn, Pb, Ni, Cr, Cd, Cu, As, Fe. In this study, our aim was to determine the plant\u27s tolerance to copper and to investigate its influence on the germination of seeds and plant growth. The measurements and collection of data were made one week after establishing the seed germination test. We analysed which was the highest concentration of copper that the seeds of sunflower can tolerate and what is the effect at low and high concentrations. For a low concentration of copper, the germination rate was high, while a high concentration was toxic. We compared the root and shoot lengths and the fresh and dry weight of the plants to determine the effect of copper on the plant\u27s development. Our investigation concluded that the highest seed copper tolerance of 90 % was at 1 ppm concentration and it decreased significantly to 16 % at the concentration of 10 ppm. At the highest concentrations, the tolerance was low and the seeds had an abnormal development
DETERMINATION AND ASSESSMENTS OF PHYSICO-CHEMICAL PARAMETERS OF THE WATER FROM ANTHROPO-SALINE LAKES LOCATED IN THE PROTECTED AREA “SALINA TURDA”, ROMANIA
No full textIt was carried out the monitoring of the qualitative parameters for the Ocnei and Rotund lakes located in the protected area Salina Turda, Romania, and as well it was made a comparative analysis of the results with previous determinations. It was determined the evolution of the physico-chemical parameters on 5 segments of depth. The monitoring was carried out within 2 measurement campaigns. It has been determined that the lakes tend to lose basicity and it was found that the heliotherm phenomenon represents a stable index in comparison with previous determinations
STUDY REGARDING THE PRESENCE OF SOME HEAVY METALS (CHROMIUM, COPPER, MANGANESE AND ZINC) IN THE GREEN WASTE COMPOST
No full textComposting is one of the most effective recycling method of green waste. The presence of some heavy metals, such as chromium, copper, manganese and zinc may influence the compost quality. The bioavailable and unavailable metal forms for plants determined by sequential analysis showed similarities in relation to the percentages of extracted forms. The lowest percentages were recorded for the bioavailable metal forms for plants uptake. Thus, the succession F6>F5>F4>F3>(F1+F2) is characteristic for chromium, the succession F5>F6>F4>F3>(F1+F2) is characteristic for copper and zinc and the succession F5>F4>F6>F3>(F1+F2) is characteristic to zinc and manganese. Thus, by adding some organic additives, like manure, the micronutrients and heavy metals regime is influenced
LEAD AND COPPER REMOVAL FROM MULTI-METAL CONTAMINATED SOILS THROUGH SOIL WASHING TECHNIQUE USING HUMIC SUBSTANCES AS WASHING AGENTS: THE INFLUENCE OF THE WASHING SOLUTION pH
No full textThe effect of three humic washing solution pH values (3.0, 7.0 and 9.6-its natural pH) on the removal efficiency of Pb and Cu from multi-metal contaminated soil collected nearby “Larga de Sus” mine from Zlatna (Alba County, Romania) was investigated, at laboratory scale, by an ex-situ soil washing technique. In this study, a commercial soluble humic sample extracted from German Leonardite was used as washing agent to remove Pb and Cu from polluted soil. Soil washing experiments were conducted in a stirrer with orbital-rotation oscillation at a liquid/solid ratio (L/S ratio; mL:g) of 8:1, concentration of humic washing solution of 2% and various stirring times (4, 6, 12, 24 and 40 hours). The removal efficiency of Cu and Pb increased with increasing pH from 3.0 to 9.6. In investigated experimental conditions, the best removal efficiencies (60.3% in case of Cu and 48.08% in case of Pb) were obtained at alkaline pH values of humic washing solution
STUDY ON TYPES OF SOIL DEGRADATION CAUSED BY FOREST EXPLOITATION
No full textSustainable management and development of forest sector should become an essential element in the strategy of prevention of the degradation of the land of each state. The forests play an important role in debts settlement of water courses, in ensuring the water quality, in maintaining land stability including the erosion control, landslides or avalanches. Forest exploitation represents a main source on degradation on the soil, having a major impact on the environment. Accelerated erosion caused by forest exploitation and soil degradation has become the main factor which limits the sustainable use of the soil. Through irrational forest exploitation, the nature of damage that occurs is ecological, social and economic. Forests are sources of other goods and services for society, such as processed wood and non-wood products, space of recreation, landscaping, etc. The large number of sites affected as a result of the forest exploitation, emphasizes massive environmental risks and their existence without urgent action has a negative impact on human health and the environment
THE INFLUENCE OF POLLUTED SOIL AERATION IN THE PROCESS OF IN SITU BIOLEACHING
No full textThe influence of aeration of soils polluted with heavy metals by using Thiobacillus-type microorganisms was studied using soil samples contaminated with heavy metals (Cu 4074 - 7550 mgkg-1, Zn 5870 - 9310 mgkg-1, Cd 36-50 mgkg-1, Pb 15000 - 42890 mgkg-1), from Romplumb, Baia Mare. The variation of the metal concentration extracted by bioleaching and aerated bioleaching was monitored for 16 weeks. The soil samples treated by bioleaching (Cu: 9 - 53%; Zn: 9 - 62%; Cd: 9 - 24%. Pb: 31 - 71%) have obtained a lower efficiency than the soil samples treated by aerated bioleaching (Cu: 34 - 70%; Zn: 36 - 76%; Cd: 17 - 38%. Pb: 44 - 78%), but there are percentage differences between the two processes (Cu: 17 - 27%; Zn: 14 - 27%; Cd: 8 - 14%, Pb: 7 - 13%)
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