Angela Michnea - Academia.edu (original) (raw)
Papers by Angela Michnea
PubMed, 2001
The S.C. Aurul S.A. is a joint venture company owned by the Esmeralda from Australia and the "Rem... more The S.C. Aurul S.A. is a joint venture company owned by the Esmeralda from Australia and the "Remin" National Company of Precious and Non-ferrous Metals in Romania, established in 1992. The design concept was to transport the mining waste away from the city, while the gold and silver in the tailings could be recovered, using efficient and modern technology that was not available at the time the dam was established. On 30 January, 2000, at 22.00, the dam burst and released 100,000 cubic meters of tailing pulp, heavily contaminated with cyanide and cyanide complexes, especially with copper, into the Lapus and Somes tributaries of the river Tisa. The paper deals with the impact of metals on the environment associated with their presence in surface waters, river sediments and soils.
Acta Chemica Iasi, Dec 1, 2014
Creative Mathematics and Informatics, 2014
Eleven samples of honey collected from different locations spread in the Baia Mare area and situa... more Eleven samples of honey collected from different locations spread in the Baia Mare area and situated at various distances from the pollution source, the company Romplumb S.A. (while it has been in operation and after its closure in January 2012) were studied to determine the presence of the Pb and Cd by electrothermal atomic absorption spectrometry. It has been found that the concentration of lead and cadmium is generally correlated with the degree of pollution of the environment with these heavy metals, as well as with the distances from the pollution source and the directions of circulation of the contaminated air. In order to characterize the contamination of honey we introduced the index of contamination (IC) that shows a medium contamination for Pb and weak contamination for Cd in the period the pollution source was active and a weak contamination for Pb and no contamination for Cd after the closure of the metallurgical plant. We obtained a mathematical model representing the concentration of Pb in honey with respect to the geographical position in case the air was also contaminated with Pb, and showing more clearly the influence of air flows on the contamination of honey.
Creative Mathematics and Informatics, 2013
American Journal of Applied Sciences, Aug 1, 2007
Influence of temperature and collector concentration on its adsorption rate on mineral surface wa... more Influence of temperature and collector concentration on its adsorption rate on mineral surface was studied as regarding to the 8-hydroxyquinoline/malachite system. Theoretical equations as well as experimental data may be useful to estimate the adsorption rate and kinetics connected to the conditioning stage in mineral flotation in order to optimise the selectivity and the recovery of the desired mineral.
The paper Wet Deposition Analysis Using UV-VIS Spectrometry in Maramures County presents the expe... more The paper Wet Deposition Analysis Using UV-VIS Spectrometry in Maramures County presents the experimental results obtained for wet deposition using Perkin Elmer Lamba 25 UV-VIS spectrometer. Four parameters were analysed: chloride, sulphate, nitrate anions and ammonium cation. The samples were collected from four location of Maramures County (Baia Mare, Sighet, Viseu and Borsa) during May-September 2014. The analysis of these parameters aims to investigate the air quality in Maramures County and in the Romanian-Ukraine transboundary area. The level of the wet deposition expressed in liter/square meter (L/mp) was different in the studied areas. The highest average level of wet deposition was in Borsa (52.03±23.64) followed by Baia Mare (43.95±23.33). The values of the wet deposition pH, considering all the sampling locations, ranged between 4.813 and 7.45. In the rain samples collected in Baia Mare area were found the highest average values of the concentrations of SO4 2-(1.569±0.693) and NO3-(1.603±0.917) and also of ammonium cation (0.676±0.193) due to industrial influence while in Sighetu Marmatiei was found the highest average value for Cl-(1.187±1.072).
Process Metallurgy, 1999
Biological degradation of cyanide in a complex wastewater has been investigated. The wastewater c... more Biological degradation of cyanide in a complex wastewater has been investigated. The wastewater comes from a tailing dam from the processing of gold bearing ores and contains 10–20 ppm of WAD cyanide. Detailed investigations were performed on the growth of bacteria using several wastes of the local industry (whey from a dairy and malt from a brewery) as a replacement for glucose. The tests showed that an addition of 1–5% of these carbon sources resulted in a satisfactory growth of the bacteria. The paper describes the experiments for the degradation of cyanide in the wastewater, using two bacterial strains. The tests involved the biomass growth “in situ”, direclty in the wastewater, in a laboratory unit running in a discontinous mode for 96 hours. The results revealed that the degradation of the cyanide was in the range of 70–91% for the strain A and 60–78% for the strain B. This study shows that biodegradation can be an economical alternative for the destruction of cyanide in the effluent of the Bozanta dam and outlines some parameters that should be considered in a possible biological approach to wastewater treatment.
Process Metallurgy, 1999
ABSTRACT
American Journal of Environmental Sciences, May 1, 2011
Problem statement: The objective of this research was to assess the degree of soil pollution and ... more Problem statement: The objective of this research was to assess the degree of soil pollution and also of Plant contamination with lead (Pb) and cadmium (Cd) in Baia Mare city (located in NW Romania) area which used to be one of the most important nonferrous metallurgical centers in Romania. Approach: Soil and plant samples were collected from 3 districts of Baia Mare: Ferneziu, located near the metallurgical plant producing lead, Săsar district, along the Săsar River in the preferential direction of the wind blowing from the metallurgical plant and the central area (Center) of the city of Baia Mare. As reference area, Dura area was considered located in a less polluted zone. The Pb and Cd assay was carried out by inductively coupled plasma atomic emission spectrometry. Statistical analysis of the data was performed and correlations and similarities between the variables were highlighted. Principal component analysis was applied in order to improve the significance and to reduce the number of variables. Results: The highest contents of Pb and Cd both in soil and in plants were found in Ferneziu district where Pb average content in soil was 4400 mg kg −1 Dry Weight (DW) at 0-10 cm depth and 3100 mg kg −1 DW at 10-20 cm depth while in plants ranged between 1.04-255 mg kg −1 DW. Cd content in soil was 29 mg kg −1 at 0-10 cm depth and 23 mg kg −1 at 10-20 cm depth. In plants, Cd content ranged between 0.015-4.81 mg kg −1 DW. In Sasar district and in Center area moderate soil pollution with Pb was found. Data analysis indicated significant correlations between Pb and Cd contents in the superficial soil level of 0-10 cm as well as between Pb and Cd contents in soil at the depth of 10-20 cm, showing that the powder coming from the metallurgical plants is the common source of these elements. Conclusion: The study shows a non-uniform spread of Pb and Cd both in soil and plants in Baia Mare city, due to anthropogenic influences. The highest contents of these elements were found in Ferneziu area in soil as well as in plant samples. Remediation measures are required prevalently in Ferneziu district around the lead smelter.
Process Metallurgy, 1999
Biological degradation of cyanide in a complex wastewater has been investigated. The wastewater c... more Biological degradation of cyanide in a complex wastewater has been investigated. The wastewater comes from a tailing dam from the processing of gold bearing ores and contains 10–20 ppm of WAD cyanide. Detailed investigations were performed on the growth of bacteria using several wastes of the local industry (whey from a dairy and malt from a brewery) as a replacement for glucose. The tests showed that an addition of 1–5% of these carbon sources resulted in a satisfactory growth of the bacteria. The paper describes the experiments for the degradation of cyanide in the wastewater, using two bacterial strains. The tests involved the biomass growth “in situ”, direclty in the wastewater, in a laboratory unit running in a discontinous mode for 96 hours. The results revealed that the degradation of the cyanide was in the range of 70–91% for the strain A and 60–78% for the strain B. This study shows that biodegradation can be an economical alternative for the destruction of cyanide in the effluent of the Bozanta dam and outlines some parameters that should be considered in a possible biological approach to wastewater treatment.
International journal of occupational medicine and environmental health, 2001
The S.C. Aurul S.A. is a joint venture company owned by the Esmeralda from Australia and the &quo... more The S.C. Aurul S.A. is a joint venture company owned by the Esmeralda from Australia and the "Remin" National Company of Precious and Non-ferrous Metals in Romania, established in 1992. The design concept was to transport the mining waste away from the city, while the gold and silver in the tailings could be recovered, using efficient and modern technology that was not available at the time the dam was established. On 30 January, 2000, at 22.00, the dam burst and released 100,000 cubic meters of tailing pulp, heavily contaminated with cyanide and cyanide complexes, especially with copper, into the Lapus and Somes tributaries of the river Tisa. The paper deals with the impact of metals on the environment associated with their presence in surface waters, river sediments and soils.
Process Metallurgy, 1999
ABSTRACT
Process Metallurgy, 1999
ABSTRACT
The paper Wet Deposition Analysis Using UV-VIS Spectrometry in Maramures County presents the expe... more The paper Wet Deposition Analysis Using UV-VIS Spectrometry in Maramures County presents the experimental results obtained for wet deposition using Perkin Elmer Lamba 25 UV-VIS spectrometer. Four parameters were analysed: chloride, sulphate, nitrate anions and ammonium cation. The samples were collected from four location of Maramures County (Baia Mare, Sighet, Viseu and Borsa) during May- September 2014. The analysis of these parameters aims to investigate the air quality in Maramures County and in the Romanian-Ukraine transboundary area. The level of the wet deposition expressed in liter/square meter (L/mp) was different in the studied areas. The highest average level of wet deposition was in Borsa (52.03±23.64) followed by Baia Mare (43.95±23.33). The values of the wet deposition pH, considering all the sampling locations, ranged between 4.813 and 7.45. In the rain samples collected in Baia Mare area were found the highest average values of the concentrations of SO4 2- (1.569±0.6...
In this paper, the content of four heavy metals (Cu, Zn, Cd and Pb) in honey was determined by at... more In this paper, the content of four heavy metals (Cu, Zn, Cd and Pb) in honey was determined by atomic absorption spectrometry. The main goal of this study was to relate the heavy metals contents in honey samples to the pollution of the environment as a result of the industrial activities running in this area. The honey samples were harvested between 2005 and 2012 from the neighbour area of Baia Mare city that used to be known as one of the most polluted cities in Romania. The metals concentrations in honey were compared with the metals concentrations in air, in falling dust and soil, during the investigated period of time. Our results reveal a very good correlation between the metals content in honey and air and falling dust and a less relevant correlation with the metal content in soil.
Creative Mathematics and Informatics, 2014
Eleven samples of honey collected from different locations spread in the Baia Mare area and situa... more Eleven samples of honey collected from different locations spread in the Baia Mare area and situated at various distances from the pollution source, the company Romplumb S.A. (while it has been in operation and after its closure in January 2012) were studied to determine the presence of the Pb and Cd by electrothermal atomic absorption spectrometry. It has been found that the concentration of lead and cadmium is generally correlated with the degree of pollution of the environment with these heavy metals, as well as with the distances from the pollution source and the directions of circulation of the contaminated air. In order to characterize the contamination of honey we introduced the index of contamination (IC) that shows a medium contamination for Pb and weak contamination for Cd in the period the pollution source was active and a weak contamination for Pb and no contamination for Cd after the closure of the metallurgical plant. We obtained a mathematical model representing the concentration of Pb in honey with respect to the geographical position in case the air was also contaminated with Pb, and showing more clearly the influence of air flows on the contamination of honey.
Creative Mathematics and Informatics
Statistical methods were applied to the assessment of the multi-elements pollution degree of the ... more Statistical methods were applied to the assessment of the multi-elements pollution degree of the soil with heavy metals and arsenic (microelements) in Baia Mare area, NW Romania. The content of several microelements were analyzed in soil samples from four zones in the studied area. Pollution indices were used to define the pollution degree compared to the Romanian regulation. Cluster analysis was used to classify the analyzed microelements (Cu, Zn, Pb, Cd, As, Co, Ni, Cr, Sn, Sb). Based on iso-contents maps for Pb and As, their contents in soil in whole Baia Mare area are assessed. The sampling point coordinates (latitude and longitude) were registered with a GPS (Global Positioning System) instrument. Considering the coordinates of each sampling point and the corresponding concentration of the considered microelement in the sampling point, a matrix XYZ was obtained where X was the longitude; Y was the latitude and Z the concentration of the microelements. A continuous surface was g...
The publications of the MultiScience - XXIX. MicroCAD International Scientific Conference
PubMed, 2001
The S.C. Aurul S.A. is a joint venture company owned by the Esmeralda from Australia and the "Rem... more The S.C. Aurul S.A. is a joint venture company owned by the Esmeralda from Australia and the "Remin" National Company of Precious and Non-ferrous Metals in Romania, established in 1992. The design concept was to transport the mining waste away from the city, while the gold and silver in the tailings could be recovered, using efficient and modern technology that was not available at the time the dam was established. On 30 January, 2000, at 22.00, the dam burst and released 100,000 cubic meters of tailing pulp, heavily contaminated with cyanide and cyanide complexes, especially with copper, into the Lapus and Somes tributaries of the river Tisa. The paper deals with the impact of metals on the environment associated with their presence in surface waters, river sediments and soils.
Acta Chemica Iasi, Dec 1, 2014
Creative Mathematics and Informatics, 2014
Eleven samples of honey collected from different locations spread in the Baia Mare area and situa... more Eleven samples of honey collected from different locations spread in the Baia Mare area and situated at various distances from the pollution source, the company Romplumb S.A. (while it has been in operation and after its closure in January 2012) were studied to determine the presence of the Pb and Cd by electrothermal atomic absorption spectrometry. It has been found that the concentration of lead and cadmium is generally correlated with the degree of pollution of the environment with these heavy metals, as well as with the distances from the pollution source and the directions of circulation of the contaminated air. In order to characterize the contamination of honey we introduced the index of contamination (IC) that shows a medium contamination for Pb and weak contamination for Cd in the period the pollution source was active and a weak contamination for Pb and no contamination for Cd after the closure of the metallurgical plant. We obtained a mathematical model representing the concentration of Pb in honey with respect to the geographical position in case the air was also contaminated with Pb, and showing more clearly the influence of air flows on the contamination of honey.
Creative Mathematics and Informatics, 2013
American Journal of Applied Sciences, Aug 1, 2007
Influence of temperature and collector concentration on its adsorption rate on mineral surface wa... more Influence of temperature and collector concentration on its adsorption rate on mineral surface was studied as regarding to the 8-hydroxyquinoline/malachite system. Theoretical equations as well as experimental data may be useful to estimate the adsorption rate and kinetics connected to the conditioning stage in mineral flotation in order to optimise the selectivity and the recovery of the desired mineral.
The paper Wet Deposition Analysis Using UV-VIS Spectrometry in Maramures County presents the expe... more The paper Wet Deposition Analysis Using UV-VIS Spectrometry in Maramures County presents the experimental results obtained for wet deposition using Perkin Elmer Lamba 25 UV-VIS spectrometer. Four parameters were analysed: chloride, sulphate, nitrate anions and ammonium cation. The samples were collected from four location of Maramures County (Baia Mare, Sighet, Viseu and Borsa) during May-September 2014. The analysis of these parameters aims to investigate the air quality in Maramures County and in the Romanian-Ukraine transboundary area. The level of the wet deposition expressed in liter/square meter (L/mp) was different in the studied areas. The highest average level of wet deposition was in Borsa (52.03±23.64) followed by Baia Mare (43.95±23.33). The values of the wet deposition pH, considering all the sampling locations, ranged between 4.813 and 7.45. In the rain samples collected in Baia Mare area were found the highest average values of the concentrations of SO4 2-(1.569±0.693) and NO3-(1.603±0.917) and also of ammonium cation (0.676±0.193) due to industrial influence while in Sighetu Marmatiei was found the highest average value for Cl-(1.187±1.072).
Process Metallurgy, 1999
Biological degradation of cyanide in a complex wastewater has been investigated. The wastewater c... more Biological degradation of cyanide in a complex wastewater has been investigated. The wastewater comes from a tailing dam from the processing of gold bearing ores and contains 10–20 ppm of WAD cyanide. Detailed investigations were performed on the growth of bacteria using several wastes of the local industry (whey from a dairy and malt from a brewery) as a replacement for glucose. The tests showed that an addition of 1–5% of these carbon sources resulted in a satisfactory growth of the bacteria. The paper describes the experiments for the degradation of cyanide in the wastewater, using two bacterial strains. The tests involved the biomass growth “in situ”, direclty in the wastewater, in a laboratory unit running in a discontinous mode for 96 hours. The results revealed that the degradation of the cyanide was in the range of 70–91% for the strain A and 60–78% for the strain B. This study shows that biodegradation can be an economical alternative for the destruction of cyanide in the effluent of the Bozanta dam and outlines some parameters that should be considered in a possible biological approach to wastewater treatment.
Process Metallurgy, 1999
ABSTRACT
American Journal of Environmental Sciences, May 1, 2011
Problem statement: The objective of this research was to assess the degree of soil pollution and ... more Problem statement: The objective of this research was to assess the degree of soil pollution and also of Plant contamination with lead (Pb) and cadmium (Cd) in Baia Mare city (located in NW Romania) area which used to be one of the most important nonferrous metallurgical centers in Romania. Approach: Soil and plant samples were collected from 3 districts of Baia Mare: Ferneziu, located near the metallurgical plant producing lead, Săsar district, along the Săsar River in the preferential direction of the wind blowing from the metallurgical plant and the central area (Center) of the city of Baia Mare. As reference area, Dura area was considered located in a less polluted zone. The Pb and Cd assay was carried out by inductively coupled plasma atomic emission spectrometry. Statistical analysis of the data was performed and correlations and similarities between the variables were highlighted. Principal component analysis was applied in order to improve the significance and to reduce the number of variables. Results: The highest contents of Pb and Cd both in soil and in plants were found in Ferneziu district where Pb average content in soil was 4400 mg kg −1 Dry Weight (DW) at 0-10 cm depth and 3100 mg kg −1 DW at 10-20 cm depth while in plants ranged between 1.04-255 mg kg −1 DW. Cd content in soil was 29 mg kg −1 at 0-10 cm depth and 23 mg kg −1 at 10-20 cm depth. In plants, Cd content ranged between 0.015-4.81 mg kg −1 DW. In Sasar district and in Center area moderate soil pollution with Pb was found. Data analysis indicated significant correlations between Pb and Cd contents in the superficial soil level of 0-10 cm as well as between Pb and Cd contents in soil at the depth of 10-20 cm, showing that the powder coming from the metallurgical plants is the common source of these elements. Conclusion: The study shows a non-uniform spread of Pb and Cd both in soil and plants in Baia Mare city, due to anthropogenic influences. The highest contents of these elements were found in Ferneziu area in soil as well as in plant samples. Remediation measures are required prevalently in Ferneziu district around the lead smelter.
Process Metallurgy, 1999
Biological degradation of cyanide in a complex wastewater has been investigated. The wastewater c... more Biological degradation of cyanide in a complex wastewater has been investigated. The wastewater comes from a tailing dam from the processing of gold bearing ores and contains 10–20 ppm of WAD cyanide. Detailed investigations were performed on the growth of bacteria using several wastes of the local industry (whey from a dairy and malt from a brewery) as a replacement for glucose. The tests showed that an addition of 1–5% of these carbon sources resulted in a satisfactory growth of the bacteria. The paper describes the experiments for the degradation of cyanide in the wastewater, using two bacterial strains. The tests involved the biomass growth “in situ”, direclty in the wastewater, in a laboratory unit running in a discontinous mode for 96 hours. The results revealed that the degradation of the cyanide was in the range of 70–91% for the strain A and 60–78% for the strain B. This study shows that biodegradation can be an economical alternative for the destruction of cyanide in the effluent of the Bozanta dam and outlines some parameters that should be considered in a possible biological approach to wastewater treatment.
International journal of occupational medicine and environmental health, 2001
The S.C. Aurul S.A. is a joint venture company owned by the Esmeralda from Australia and the &quo... more The S.C. Aurul S.A. is a joint venture company owned by the Esmeralda from Australia and the "Remin" National Company of Precious and Non-ferrous Metals in Romania, established in 1992. The design concept was to transport the mining waste away from the city, while the gold and silver in the tailings could be recovered, using efficient and modern technology that was not available at the time the dam was established. On 30 January, 2000, at 22.00, the dam burst and released 100,000 cubic meters of tailing pulp, heavily contaminated with cyanide and cyanide complexes, especially with copper, into the Lapus and Somes tributaries of the river Tisa. The paper deals with the impact of metals on the environment associated with their presence in surface waters, river sediments and soils.
Process Metallurgy, 1999
ABSTRACT
Process Metallurgy, 1999
ABSTRACT
The paper Wet Deposition Analysis Using UV-VIS Spectrometry in Maramures County presents the expe... more The paper Wet Deposition Analysis Using UV-VIS Spectrometry in Maramures County presents the experimental results obtained for wet deposition using Perkin Elmer Lamba 25 UV-VIS spectrometer. Four parameters were analysed: chloride, sulphate, nitrate anions and ammonium cation. The samples were collected from four location of Maramures County (Baia Mare, Sighet, Viseu and Borsa) during May- September 2014. The analysis of these parameters aims to investigate the air quality in Maramures County and in the Romanian-Ukraine transboundary area. The level of the wet deposition expressed in liter/square meter (L/mp) was different in the studied areas. The highest average level of wet deposition was in Borsa (52.03±23.64) followed by Baia Mare (43.95±23.33). The values of the wet deposition pH, considering all the sampling locations, ranged between 4.813 and 7.45. In the rain samples collected in Baia Mare area were found the highest average values of the concentrations of SO4 2- (1.569±0.6...
In this paper, the content of four heavy metals (Cu, Zn, Cd and Pb) in honey was determined by at... more In this paper, the content of four heavy metals (Cu, Zn, Cd and Pb) in honey was determined by atomic absorption spectrometry. The main goal of this study was to relate the heavy metals contents in honey samples to the pollution of the environment as a result of the industrial activities running in this area. The honey samples were harvested between 2005 and 2012 from the neighbour area of Baia Mare city that used to be known as one of the most polluted cities in Romania. The metals concentrations in honey were compared with the metals concentrations in air, in falling dust and soil, during the investigated period of time. Our results reveal a very good correlation between the metals content in honey and air and falling dust and a less relevant correlation with the metal content in soil.
Creative Mathematics and Informatics, 2014
Eleven samples of honey collected from different locations spread in the Baia Mare area and situa... more Eleven samples of honey collected from different locations spread in the Baia Mare area and situated at various distances from the pollution source, the company Romplumb S.A. (while it has been in operation and after its closure in January 2012) were studied to determine the presence of the Pb and Cd by electrothermal atomic absorption spectrometry. It has been found that the concentration of lead and cadmium is generally correlated with the degree of pollution of the environment with these heavy metals, as well as with the distances from the pollution source and the directions of circulation of the contaminated air. In order to characterize the contamination of honey we introduced the index of contamination (IC) that shows a medium contamination for Pb and weak contamination for Cd in the period the pollution source was active and a weak contamination for Pb and no contamination for Cd after the closure of the metallurgical plant. We obtained a mathematical model representing the concentration of Pb in honey with respect to the geographical position in case the air was also contaminated with Pb, and showing more clearly the influence of air flows on the contamination of honey.
Creative Mathematics and Informatics
Statistical methods were applied to the assessment of the multi-elements pollution degree of the ... more Statistical methods were applied to the assessment of the multi-elements pollution degree of the soil with heavy metals and arsenic (microelements) in Baia Mare area, NW Romania. The content of several microelements were analyzed in soil samples from four zones in the studied area. Pollution indices were used to define the pollution degree compared to the Romanian regulation. Cluster analysis was used to classify the analyzed microelements (Cu, Zn, Pb, Cd, As, Co, Ni, Cr, Sn, Sb). Based on iso-contents maps for Pb and As, their contents in soil in whole Baia Mare area are assessed. The sampling point coordinates (latitude and longitude) were registered with a GPS (Global Positioning System) instrument. Considering the coordinates of each sampling point and the corresponding concentration of the considered microelement in the sampling point, a matrix XYZ was obtained where X was the longitude; Y was the latitude and Z the concentration of the microelements. A continuous surface was g...
The publications of the MultiScience - XXIX. MicroCAD International Scientific Conference