Otilia A. Culicov

Atmospheric deposition of metals in romania studied by biomonitoring using the epiphytic moss hypnum cupressiforme

The results obtained from a study using the epiphytic moss species Hypnum cupressiforme to estimate heavy-metal atmospheric deposition in the province of Moldavia (Romania) are presented. The present study is a part of a biomonitoring programme in Moldavia and could serve as a starting point for further planning of biomonitoring using new moss species in regions where the commonly used Hylocomium splendens and Pleurozium schreberi are not present. Moss samples were collected within the catchment of Prut, a border river between Romania, Republic of Moldova and Ukraine, at a total of 25 sampling points and analysed for a wide range of elements, most of them heavy metals. The samples were analysed by instrumental neutron activation analysis using epithermal neutrons (ENAA) for 40 elements. Using inductively coupled plasma-mass spectrometry (ICP-MS), the elements Cd, Tl, Pb, V, Cr, Ni, Zn, As, Mo, Ag, In, and Bi were determined. Atomic absorption spectrometry (AAS) was used for the determination of Cd, Cu, Pb and Zn. Distribution maps were drawn for nine elements (As, Cd, Cr, Cu, Fe, Pb, Se, V, and Zn). By means of moss monitoring, it was possible to characterize most of the industrial and local sources of pollution within the studied area. The values are lower than those found in the western part of Romania, and the distribution of certain elements (As, Cu, Zn) reflects the predominant agricultural activities in eastern Romania. The highest levels of elements were found in the most industrialised and populated areas of Moldavia. Significant correlations were observed for the results obtained by different analytical techniques.

Assessment of the impact of a phosphatic fertilizer plant on the adjacent environment using fuzzy logic

The impact of a phosphatic fertilizer plant on the adjacent environment was examined. Selected rare earth elements, heavy metals and metalloids were determined in substrates and products, waste by-product, and grass and soil samples. Concentration gradients of elements in grass and soil samples along the southerly and easterly directions were examined and compared with the content of interior soil and grass samples, substrates, and products. Results were compared with available data on soil permissible element concentration levels. Two fuzzy principal component analysis (FPCA) methods for robust estimation of principal components were applied and compared with classical PCA. The efficiency of the new algorithms is illustrated. The investigation explored the impact of the plant on the adjacent environment. The most reliable results, in good agreement with types of samples, were produced using the FPCA-O algorithm

Assessment of Phosphatic Fertilizer Production Impact on Occupational Staff Based on NAA of Hair, Nails, and Inhald Particles

Neutron Activation Analysis (NAA) was performed for the determination of 25 elements in hair, toenails, and PM2.5 (particles smaller than 2.5 μ m in aerodynamic diameter) to assess how human tissues of occupational staff and inhaled particles follow the industrial exposure of Gdansk Phosphatic fertilizer plant in Poland. Statistical analysis was used to elucidate this exposure. The results obtained were compared using box and whiskers plot and the parametric t-test and nonparametric Mann–Whitney U- test. The comparison showed a statistically significant difference between workers and control group concerning for example Br, Ca, Cl, La, Mn, Sm, U and V in hair, Cu, Dy, La, Sm, Ti and U in toenails and Al, As, Cl, I, K, La, Mg, Mn, Na, Sm and Zn in PM2.5 samples.

ENAA Studies of pollution in anoxic Black Sea sediments

The vertical distributions of five potential pollutants - Zn, As, Br, Sn, and Sb - were determined via epithermal neutron activation in the upper 50cm of unconsolidated sediments from the Black Sea, which were collected 600m below sea surface. This analysis demonstrated increasing concentrations towards the upper limits of sediments, which were greater than alert concentrations in the case of As and Br, and in accordance with Romanian Environment Regulations. The utilization of Chernobyl (137)Cs as a time marker allowed for dating of this region to the last 100 years.

Intercomparison Between Neutron Activation Analysis Laboratories for Trace Elements Determination in Lacustrine Sediments

Abstract An intercomparison concerning the concentrations of 23 major and trace elements in recent lacustrine sediments, as determined by Instrumental Neutron Activation Analysis, has been performed by using epithermal neutrons at the Joint institute of Nuclear Research, Dubna, (Russia) and thermal neutrons at the National Institute for Physics and Nuclear Engineering, Bucharest, (Romania). Sc, La, Tb, Yb, Th, Na, Rb, Cs, Ba, As, Sb, Hf, Cr, Fe, Co, and Zn concentrations agreed within one standard deviation, Ce, Sm, Lu, Ca, Br, and Ta concentrations agreed within two standard deviation. The results were interpreted in the framework of the Upper Continental Crust model. The Factor Analysis has shown that all elements form a single cluster, irrespective of the laboratory where the analysis was performed.

Application of Arthrospira (Spirulina) platensis biomass for silver removal from aqueous solutions

ABSTRACT The cyanobacterium Arthrospira (Spirulina) platensis was used to study the process of silver biosorption. Effects of various parameters such as contact time, dosage of biosorbent, initial pH, temperature, and initial concentration of Ag(I) were investigated for a batch adsorption system. The optimal biosorption conditions were determined as pH 5.0, biosorbent dosage of 0.4 g, and initial silver concentration of 30 mg/L. Equilibrium adsorption data were analyzed by the Langmuir and Freundlich models – however, the Freundlich model provided a better fit to the experimental data. The kinetic data fit the pseudo-second-order model well, with a correlation coefficient of 0.99. The analysis of thermodynamic parameters (ΔG°, ΔH° and ΔS°) revealed that the adsorption process of silver ion by spirulina biomass was exothermic and spontaneous (ΔG° < 0), and exothermic (ΔH° < 0) process. The biosorption capacity of biomass A. platensis serves as a basis for the development of green technology for environmental remediation.

Characterization of Heavy Metal Air Pollution in Romania Using Moss Biomonitoring, Neutron Activation Analysis, and Atomic Absorption Spectrometry

ABSTRACT Heavy metal air pollution in Romania was investigated by using passive moss biomonitoring. This study is a component of an international UNECE ICP Vegetation Program – moss survey. A total of 330 samples of Hypnum cupressiforme, Hylocomium splendens, Pleurozium schreberi, and other mosses were collected in Romania in the summer and autumn of 2010. The concentrations of aluminum, cadmium, chromium, copper, iron, lead, nickel, vanadium, and zinc were determined by graphite furnace/flame atomic absorption spectrometry and instrumental neutron activation analysis. The results were statistically processed to obtain spatial distribution maps of factor scores based on elemental concentrations in the moss, together with the spatial distribution maps of heavy metals in moss. The median concentrations of cadmium, 1.20 mg/kg dry weight, and lead, 30.8 mg/kg dry weight, were high compared with other European countries. The results revealed that the atmospheric deposition of these metals is a problem in north and northwest Romania.

Elemental content of mosses and lichens from Livingston Island (Antarctica) as determined by instrumental neutron activation analysis (INAA).

The total content of 8 major and 32 trace elements in four species of mosses and two of lichens as well as neighboring soil and rocks collected from different places of the Livingston Island Antarctica was determined by instrumental neutron activation analysis. The main goals of the project consisted of evidencing the possible trace of anthropogenic contamination as well as the influence of altitude on the distribution of considered elements. In the absence of a unanimously accepted descriptor, enrichment factor, geo-accumulation, and pollution load indices with respect to soil and rocks were used. The data, interpreted within the model of a reference plant, were compared with previous studies regarding the same organisms in similar geographic and climatological areas. The experimental results evidenced different capacity of mosses and lichens to retain the considered elements, but within experimental uncertainties, no traces of anthropogenic pollution were found. At the same time, it was found that the content of most of the elements decreased with the altitude.

Selenium uptake and assessment of the biochemical changes in Arthrospira (Spirulina) platensis biomass during the synthesis of selenium nanoparticles

The process of selenium uptake by biomass of the cyanobacterium Arthrospira (Spirulina) platensis was investigated by neutron activation analysis at different selenium concentrations in solution and at different contact times. Experimental data showed good fit with the Freundlich adsorption isotherm model, with a regression coefficient value of 0.99. In terms of absorption dependence on time, the maximal selenium content was adsorbed in the first 5 min of interaction without significant further changes. It was also found that A. platensis biomass forms spherical selenium nanoparticles. Biochemical analysis was used to assess the changes in the main components of spirulina biomass (proteins, lipids, carbohydrates, and phycobilin) during nanoparticle formation.

Air Pollution Study in the Republic of Moldova Using Moss Biomonitoring Technique

Moss biomonitoring using the species Hypnum cupressiforme (Hedw.) and Pleurocarpous sp was applied to study air pollution in the Republic of Moldova. A total of 41 elements (Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Zr, Cd, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Tm, Yb, Hf, Ta, W, Pb, Th, and U) were determined by instrumental epithermal neutron activation analysis and atomic absorption spectrometry. Principal component analysis was used to identify and characterize different pollution sources. Geographical distribution maps were prepared to point out the regions most affected by air pollution and relate this to potential sources of contamination. Median values of the elements studied were compared with data from the European moss biomonitoring program. The cities of Chisinau and Balti were determined to experience particular environmental stress.