Search

Concentrations of seven heavy metals (Cd, Cr, Cu, Fe, Ni, Pb and Zn) in the discharged effluents of four wastewater treatment plants located on the Romanian Black Seacoast, evaluated as average values for four seasons, during 2010-2011 are presented. Total and dissolved metals occurrence was investigated from seasonal samples, to assess the bioavailability of the heavy metals in the discharged effluents. The analytical measurements were performed by flame atomic absorption spectrometry (FAAS) for Fe and Zn, and by graphite furnace atomic absorption spectrometry (GFAAS) for Cd, Cr, Cu, Ni and Pb, after appropriate sample preparation. The obtained results show that the sum of total metals concentration in discharged effluents in the Black Sea was below 2000 µg/L, for all investigated samples. Differences in metal concentrations in the effluent were site-specific and varied with seasons, the maximum total metal concentrations being registered in autumn (900 - 1200 µg/L). Some of the metals were occurring mostly in the dissolved forms, like Cd, Ni, and sometimes Cu or Fe. Due to the living organisms' capacity to absorb or assimilate dissolved heavy metals, they became more toxic to the flora and fauna present in the emissary. Even if the concentrations of the individual or total heavy metals determined in the effluents from the studied wastewater treatment plants were not exceeding the accepted values, they are exhibiting toxicity to the marine environment that underlines the need of responsible decisions regarding pollution prevention and new technologies use, to ensure heavy metals removal from municipal wastewater. [ABSTRACT FROM AUTHOR]

A method based on headspace and capillary gas chromatography with flame ionization detector technique was validated for the simultaneous determination of five individual aromatic volatile pollutants: benzene, toluene, ethylbenzene, m/p-xylene and oxylene. The validation took in consideration liniarity, accuracy, precision, limit of detection, limit of quantification and uncertainty estimation criteria and concluded that the proposed method is suitable to determine the pollutants of interest. The samples were taken from the effluent of petrochemical wastewater treatment plant before, during and after the tertiary biological treatment. The concentrations of the volatile aromatic pollutants in all analysed samples have been found below the internal quality procedure requirements (1 µg/L for benzene and 10 µg/L for its derivatives). It was noticed that the concentration decreases during the tertiary treatment. In the samples of the discharged effluent in the Black Sea the concentrations of all determined compounds were under the limit of detection. [ABSTRACT FROM AUTHOR]

Spent hydroprocessing catalysts from petroleum refining industries have been classified as hazardous wastes due to their content in heavy metal and persistent organic pollutants (POPs). The aim of our paper determine the polycyclic aromatic hydrocarbons (PAHs) residues contents in spent catalysts samples from four different units of the Romanian refinery Rompetrol Rafinare, Constanta: Hydrogen (H), Gas Desulfurization Sulfur Recovery (GDSR), Hydrofining Turbojet Kerosene (HTK) and Petroleum and Diesel Oil Hydrotreating (PDOH).Residual catalysts have been determined using high performance liquid chromatography (HPLC) technique with fluorescence detection (FLD), after the appropriate pretreatment consisting in extraction in acetone and petroleum ether, clean-up and reconcentration.The following polycyclic aromatic hydrocarbons have been found in concentrations range of 0.22-326.2 µg/kg: Naphthalene, Acenaphthene, Fluorene, Phenanthrene, Anthracene, Fluoranthene, Pyrene, Benzo(α)anthracene, Crysene, Benzo(b)fluoranthene, Benzo(k)fluoranthene, Benzo(α)pyrene, Dibenzo(α,h)anthracene, Benzo(ghi)perylene and Indeno(1,2,3,-cd)pyrene. The total PAHs concentrations ranged in the spent catalysts refinery units as follows: 0.1264 mg/kg (in H unit), 0.1623 mg/kg (in GDSR unit), 0.461 mg/kg (in HTK unit) and 0.840 mg/kg (in PDOH unit). The PAHs quantification can further contribute to the assessment of the impact on human health of the spent catalysts products disposal. [ABSTRACT FROM AUTHOR]

It's well known the degradation of many Romanian (including Dobrogea) soils, both in hill and in plain environments, due to the increasing anthropic pressure on natural resources. Soil erosion and organic matter loss are recognized as the main processes responsible of such degradation and of the rising risk of desertification, to which land use changes and politics for agriculture not suitable for land specificities often contribute. The knowledge of land use impact on soil quality is, thus, essential to preserve environmental integrity and to obtain sustainable agricultural productions. The paper aims to present original studies regarding soil characterization from northern, southern and central area, located in Dobrogea in 2008. The most representative soils in Dobrogea are kastanozems, chernozems and regosols. In order to evaluate the desertification degree, investigations about humus (organic carbon) contents, physical (pH) and chemical parameters have been performed. Total carbonates, phosphates and humus have been analyzed in soil samples by titrimetric and spectrometric methods. The obtained results are presented comparatively with the previous reported studies in 1957. The determinations results carried out on the samples places in 2008 showed a notable diminishing of humus content and the other nutritive elements due to the degradation process which took place during time. [ABSTRACT FROM AUTHOR]

The paper presents new studies about the removal efficiency of the biochemical treatment process of the Municipal Wastewater Treatment Plant from Constanta city, during 2008. Influent and effluent samples of biochemical treatment stage were collected and ammonium concentration, chemical oxygen demand (CODCr) and biochemical oxygen demand in five days (BOD5) were measured, aiming to study the evolution of the removal efficiency, during 2008. Additional analyses have been performed in order to explain the achieved performances for nitrates, nitrates and dissolved oxygen. The following monthly mean removal efficiencies have been performed in the biochemical treatment stage: 56-96% for ammonium, 62-70% for CODCr and 68-74% for BOD5. During the studied period, ammonium, nitrites and nitrates mean concentrations in the effluent did not exceed the imposed limits, but sometimes daily higher values have been noticed, due to the higher variation of the influent content of the wastewater treatment plant, from one day to another. In conclusion, in order to increase the plant performances concerning the biochemical treatment stage, the improvement of the analytical control, as well as a better harmonization of the operating parameters is required. [ABSTRACT FROM AUTHOR]

The paper presents new results concerning Cd, Cu, Fe, Mn, Pb and Zn determination in marine biotope (sediment and water) and biocenosis (algae, crustaceans and fish) collected in 2005 and 2006 from the Romanian Black seacoast southern part, between Mangalia and Vama Veche. The solid samples have been subjected to dissolution mineralized with nitric acid and hydrogen peroxide in a Digesdahl device after a careful preparation (washing, drying). Metal concentration has been determined by atomic emission spectrometry with an Agilent 7500a ICP-MS apparatus. In solid samples the levels of Cd varied from 0.03 to 0.26 µg/g, Cu from 1.51 to 9.59 µg/g, Fe from 0.085 to 0.825 mg/g, Mn from 2.70 to 41.25 µg/g, Pb from 1.32 to 5.07µg/g and Zn from 2.08 to 34.31µg/g. In water, mean metal concentrations were of µg/L levels, except Fe. [ABSTRACT FROM AUTHOR]

The paper presents new studies on the removal efficiencies related to the quality specific indicators of municipal wastewater treatment plant. Studies were performed on a modern wastewater treatment plant in Romania, located on the Black Sea coast, which processes about 3200 L·s-1 of effluent from Constanta city, including sewage (60%) and industrial wastewater (food industry and processing, constructions, petroleum products distribution etc.).The dynamics of average removal efficiencies for total suspended solids (TSS), total extractable in ether petroleum (EP), CODCr and BOD5 in 2003 and 2005 are shown. Overall determined efficiencies were: TSS 50 - 86%, EP 37 - 79%, CODCr 53 - 87% and BOD5 53 - 89%. Improved performances in 2005 comparing with 2003 can be noticed. [ABSTRACT FROM AUTHOR]

The paper presents the graduate and post-graduate courses organized in Italian Universities in the field of the Environment protection. The education has a deep interdisciplinary character, the study curricula trying to achieve the equilibrium between theoretical and practical aspects. All the programs are adjusted according to the Education Ministry Decree, No. 509, 3 November 1999. Three years (laurea degree) followed by two-study year's degree (specialized degree) and master I and II level courses have been developed into all Italian Universities. The Environmental Sciences studies in the University of Bologna are presented in details. [ABSTRACT FROM AUTHOR]

Water quality monitoring is a very important task in environmental studies worldwide. The aim of this paper is to present original results concerning Tabacarie Lake water quality parameters monitoring in the last nine years. Tabacarie Lake is located in Constantza district on the Black seaside coast, having a surface of about 9.5x105 m2 and an average water volume of about 1.7x106 m3. Eight sampling sites were established around the lake and analyses were carried out weekly, six months per year. Alkalinity, Chemical Oxygen Demand by potassium permanganate method (CODMn), Dissolved Oxygen (DO), Total and Calcium Hardness, Salinity and Sulfides were the monitored quality parameters, using standard titrimetric analytical methods according to Romanian regulations. The obtained data were processed using chemometric procedures and shown interesting patterns. The yearly averages of the quality parameters for all sampling sites ranged as follows: "p" alkalinity 0-1.03 meq/L, "m" alkalinity 4.39-7.23 meq/L, CODMn 2.17-18.02 mgO2/L, DO 2.21-12.36 mg/L, total hardness 4.32-9.67 meq/L, calcium hardness 1.55-4.73 meq/L, salinity 0.23-0.51g/L and sulfides 0.85-0.99mg/L. The values of quality-monitored parameters are variable in quasi-large ranges, depending on the position of the sampling sites and the seasonal characteristics, but excepting sulfides all of them are in the limits imposed by the last regulations. [ABSTRACT FROM AUTHOR]

The paper presents some new researches concerning pollutants monitoring using two kinds of bioindicators: bioluminescent bacteria for the detection of heavy metals and organic pollutants in soil and water and the honeybees for phytopathogenic microorganisms. [ABSTRACT FROM AUTHOR]

Original investigations about concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in five types of sewage sludge from Constanta Sud wastewater treatment plant are reported. Total metal analyses were carried out by flame atomic absorption spectrometry (FAAS) after the appropriate solubilization of the sludge with nitric acid and hydrogen peroxide. In general, heavy metal levels in all investigated types of sludge are not higher than the "attention limit" for soil pollution and they can be used for soil improvement. [ABSTRACT FROM AUTHOR]

The paper presents new studies on the removal efficiencies related to the quality specific indicators for biochemical stage of petrochemical wastewater treatment plant. Studies were performed on a modern wastewater treatment plant in Romania, located on the Black Sea coast, which processes about 500 L⋅s-1 of effluent from an important petrochemical complex. The dynamics of average removal efficiencies for oil products, total suspended solids, sulfides, phenols, CODCr and BOD5 between September 2002 and April 2003 are shown. The obtained reported performances demonstrate that it is necessary to improve the aeration system in the biochemical treatment stage. [ABSTRACT FROM AUTHOR]

The August 11, 1999 sun eclipse was a very interesting phenomenon, from scientific point of view for researchers from all over the world. The microelements, acting as ions in biological fluids, have a vital role in metabolic activities of live organisms, like to maintain its morphofunctional integrity. This paper tries to demonstrate for the first time the behavior of the plants related to astronomic events. Studies have been performed in Constantza, Romania, in the summer of '99, before, during and after the total sun eclipse, on Zea Mays sp. leaves. The concentration of some heavy metals: cadmium (Cd), chromium (Cr), lead (Pb) and nickel (Ni) have been determined in corn leaves before, during and after the sun eclipse using the ICP AES technique. The obtained values of concentrations vary between 0.05 - 0.75 mg/kg dry weight for cadmium, 1.8 - 6.31 mg/kg dry weight for chromium, 1.45 - 3.58 mg/kg dry weight for lead and 1.28 - 4.49 mg/kg dry weight for nickel. Deviating patterns in trace element concentrations can be discerned: one day before the sun eclipse day all studied concentrations record high values, on August 11 all decrease cadmium and chromium having minimum values, and the day-after cadmium, chromium and lead record maximum values and nickel a minimum. The evolution of metal concentration during the sun eclipse can be considered like a plant "premonition" and response to a stress factor, but the occurring mechanism is difficult to explain. [ABSTRACT FROM AUTHOR]