Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Astrobiology ; 21(3): 323-331, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33370540

RESUMO

The order of magnitude of increased growth, multiplication rate, and decreased sporulation of Bacillus subtilis after exposure to nanotesla magnetic fields (MFs) relative to control samples were observed experimentally. Earth's total magnetic field intensity was reduced from 47.9 ± 0.4 µT to cover the range from 97.5 ± 1.7 nT to 1115 ± 158 nT in eight subsequent experiments by using three pairs of Helmholtz coils combined with Mu-metal shielding. The growth, multiplication rate, sporulation, and potassium content were measured in the probe and control containing B. subtilis cultures after 24 h of exposure to nanotesla and Earth's magnetic fields, respectively. The observed effect is discussed with regard to its possible repercussions on Earth's living species during geomagnetic reversals that occurred when the magnetic field was much weaker than the field that exists today. In addition, effects on future manned voyages into deep space, an environment with reduced magnetic field intensity, are considered.


Assuntos
Bacillus subtilis , Campos Magnéticos
2.
Artigo em Inglês | MEDLINE | ID: mdl-29517406

RESUMO

The purpose of this study was development of the optimal conditions for the inertization of the polluted marine sediments using groundwater treatment sludge highly enriched in iron and aluminum. For that purpose fine-grained sediment (>85% clay and silt fraction) highly enriched in copper and zinc was amended with the waste sludge (from 10% to 50%). The sample with the optimum percentage of the waste sludge was further subjected the thermal treatment at 200-800°C. The efficiency of the treatment was determined by the leaching tests and toxicity testing using Hordeum vulgare L. as biosystem. The percentage of the seed germination, the root elongation, and the germination index before and following the treatment were determined. Untreated sediment leachate caused significant arrest in the percentage of the seed germination (6.7 ± 6.7%), the root elongation (1.9 ± 2.2%), and the germination index (0.2 ± 0.3%) with EC50 of 24.9%, suggesting a significant toxic potential of the sediments. After amendment with 30% of the waste sludge the concentrations of the considered micropollutants decreased below regulated values while all three toxicological parameters showed no significant difference compared to the negative control. The toxicity of the sediment was completely removed following the thermal treatment at 400°C.


Assuntos
Biodegradação Ambiental , Sedimentos Geológicos/química , Esgotos/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Alumínio/isolamento & purificação , Alumínio/toxicidade , Cobre/isolamento & purificação , Cobre/toxicidade , Poluição Ambiental/análise , Germinação/efeitos dos fármacos , Hordeum , Ferro/isolamento & purificação , Ferro/toxicidade , Sementes , Poluentes Químicos da Água/toxicidade , Zinco/isolamento & purificação , Zinco/toxicidade
3.
Chemosphere ; 168: 1075-1081, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27829507

RESUMO

Since the production of printed circuit boards (PCBs) generates wastewater contaminated with heavy metals and organic matter, PCB factories represent potential pollution sites. The wastewater toxicologically tested in this study contained several metals and the most abundant were copper and iron. At two exposure times tested (4 and 24 h) PCB wastewater (PCBW) proved to be cytotoxic (decreased cell viability) and genotoxic (increased comet assay tail intensity and tail moment) to human blood peripheral lymphocytes in vitro, and the oxidative stress parameter (malondialdehyde concentration) was also found to be higher. After application of combined treatment by waste base, ozone and waste sludge methods, concentrations of metals in purified PCBW were below the upper permitted levels and all tested toxicological parameters did not differ compared to the negative control. Taken together, similar methods could be implemented in PCB factories before discharging potentially toxic wastewater into the environment because purified PCBW does not represent a threat from the aspect of cytotoxicity and genotoxicity.


Assuntos
Cobre/toxicidade , Resíduos Industriais/análise , Ferro/toxicidade , Linfócitos/efeitos dos fármacos , Metais Pesados/análise , Esgotos/análise , Poluentes Químicos da Água/análise , Adulto , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ensaio Cometa , Cobre/análise , Equipamentos e Provisões Elétricas , Humanos , Ferro/análise , Masculino , Malondialdeído/sangue , Medição de Risco/métodos , Águas Residuárias/toxicidade
4.
Ecotoxicol Environ Saf ; 114: 164-70, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25638522

RESUMO

Boats are washed periodically for maintenance in order to remove biofoulants from hulls, which results in the generation of wastewater. This study aimed at evaluating the cyto/genotoxic and mutagenic properties of wastewater produced by pressure washing of boats. The chemical characterisation of this wastewater showed that Cu, Zn, V, Cr, Fe, Pb, and select organic contaminants exceeded the maximum allowable values from 1.7 up to 96 times. The wastewater produced negative effects on human lymphocytes resulting in decreased cell viability after 4 and 24h of exposure. Chromosome aberration, micronucleus, and comet assay parameters were significantly higher after 24h of exposure. At the same time, the Salmonella typhimurium test showed negative for both TA98 and TA100 strains at all of the concentrations tested. After the treatment of wastewater using electrochemical methods/ozonation during real scale treatment plant, removal rates of colour, turbidity and heavy metals ranged from 99.4% to 99.9%, while the removal of total organic carbon (TOC) and chemical oxygen demand (COD) was above 85%. This was reflected in the removal of the wastewater's cyto/genotoxicity, which was comparable to negative controls in all of the conducted tests, suggesting that such plants could be implemented in marinas to minimise human impact on marine systems.


Assuntos
Metais Pesados/toxicidade , Mutagênicos/toxicidade , Navios , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ensaio Cometa , Feminino , Humanos , Linfócitos/efeitos dos fármacos , Linfócitos/patologia , Metais Pesados/química , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Testes para Micronúcleos , Mutagênicos/química
5.
Environ Sci Pollut Res Int ; 22(1): 516-26, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25087498

RESUMO

The purpose of this work was detailed physicochemical, radiological, and toxicological characterization of the composite sample of water intended for human consumption in the Cameron/Tuba City abandoned uranium mining area before and after a combined electrochemical/advanced oxidation treatment. Toxicological characterization was conducted on human lymphocytes using a battery of bioassays. On the bases of the tested parameters, it could be concluded that water used for drinking from the tested water sources must be strictly forbidden for human and/or animal consumption since it is extremely cytogenotoxic, with high oxidative stress potential. A combined electrochemical treatment and posttreatment with ozone and UV light decreased the level of all physicochemical and radiological parameters below the regulated values. Consequently, the purified sample was neither cytotoxic nor genotoxic, indicating that the presented method could be used for the improvement of water quality from the sites highly contaminated with the mixture of heavy metals and radionuclides.


Assuntos
Técnicas Eletroquímicas , Urânio/toxicidade , Poluentes Químicos da Água/toxicidade , Poluentes Radioativos da Água/toxicidade , Purificação da Água/métodos , Animais , Ensaio Cometa , Humanos , Peroxidação de Lipídeos , Metais Pesados/análise , Mineração , Ozônio , Radioisótopos/análise , Medição de Risco , Testes de Toxicidade , Raios Ultravioleta , Urânio/análise , Urânio/efeitos da radiação , Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/efeitos da radiação , Poluentes Radioativos da Água/análise , Poluentes Radioativos da Água/efeitos da radiação , Qualidade da Água
6.
Artigo em Inglês | MEDLINE | ID: mdl-24798899

RESUMO

The purpose of this work was to develop a pilot plant purification system and apply it to groundwater used for human consumption, containing high concentrations of arsenic and increased levels of phosphates, ammonia, mercury and color. The groundwater used was obtained from the production well in the Vinkovci County (Eastern Croatia). Due to a complex composition of the treated water, the purification system involved a combined electrochemical treatment, using iron and aluminum electrode plates with simultaneous ozonation, followed by a post-treatment with UV, ozone and hydrogen peroxide. The removal of the contaminant with the waste sludge collected during the electrochemical treatment was also tested. The combined electrochemical and advanced oxidation treatment resulted in the complete removal of arsenic, phosphates, color, turbidity, suspended solids and ammonia, while the removal of other contaminants of interest was up to 96.7%. Comparable removal efficiencies were obtained by using waste sludge as a coagulant.


Assuntos
Amônia/química , Arsênio/química , Fosfatos/química , Poluentes Químicos da Água/química , Alumínio/química , Eletrodos , Água Subterrânea/química , Peróxido de Hidrogênio/química , Ferro/química , Oxirredução , Ozônio/química , Raios Ultravioleta , Purificação da Água/métodos
7.
Artigo em Inglês | MEDLINE | ID: mdl-24410684

RESUMO

The purpose of this work was development of a new method for the neutralization/purification of printed circuit boards wastewater (PCBW) originating from Zagreb, Croatia, using two industrial by-products. PCBW was characterized with low pH value (2.11) and high concentration of TDS (50190 mg L(-1)), copper (4190 mg L(-1)) and iron (2660 mg L(-1)). Waste base (WB), by-product of the alumina production, and waste sludge, by-product of the electrochemical treatment of groundwater, were employed as neutralization/adsorption agents. Due to its high neutralization capacity WB was used for pH adjustment to pH 8 and heavy metals removal from both effluents, yet the final removal of the contaminants down to the regulated values was assessed by adsorption/coagulation with the iron and aluminum rich waste sludge. Following the combined treatment the removal efficiency of iron and copper was higher than 99.99% with their final concentration in the treated water of 0.151 mg L(-1) and 0.129 mg L(-1), respectively. Following the ozone base oxidation the removal efficiency of the organic contaminants was more than 83%. The successful application of the industrial waste by-products for neutralization/purification of the PCBW with the removal efficiencies of the contaminants comparable or better than those obtained with conventional treatment represented the main advantage of our presented method.


Assuntos
Esgotos/química , Resíduos/análise , Águas Residuárias/química , Purificação da Água/métodos , Adsorção , Cobre/química , Croácia , Eletrônica , Resíduos Industriais/análise , Ferro/química , Metais Pesados/química
8.
Biochim Biophys Acta ; 1840(1): 565-76, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24140394

RESUMO

BACKGROUND: The main objective of the present study was to investigate chemical composition and possible cyto/genotoxic potential of several medical implant materials commonly used in total hip joint replacement. METHODS: Medical implant metal alloy (Ti6Al4V and CoCrMo) and high density polyethylene particles were analyzed by energy dispersive X-ray spectrometry while toxicological characterization was done on human lymphocytes using multi-biomarker approach. RESULTS: Energy dispersive X-ray spectrometry showed that none of the elements identified deviate from the chemical composition defined by appropriate ISO standard. Toxicological characterization showed that the tested materials were non-cyto/genotoxic as determined by the comet and cytokinesis-block micronucleus (CBMN) assay. Particle morphology was found (by using scanning electron and optical microscope) as flat, sharp-edged, irregularly shaped fiber-like grains with the mean particle size less than 10µm; this corresponds to the so-called "submicron wear". The very large surface area per wear volume enables high reactivity with surrounding media and cellular elements. CONCLUSIONS: Although orthopedic implants proved to be non-cyto/genotoxic, in tested concentration (10µg/ml) there is a constant need for monitoring of patients that have implanted artificial hips or other joints, to minimize the risks of any unwanted health effects. GENERAL SIGNIFICANCE: The fractal and multifractal analyses, performed in order to evaluate the degree of particle shape effect, showed that the fractal and multifractal terms are related to the "remnant" level of the particles' toxicity especially with the cell viability (trypan blue method) and total number of nucleoplasmic bridges and nuclear buds as CBMN assay parameters.


Assuntos
Ligas/efeitos adversos , Materiais Biocompatíveis/efeitos adversos , Dano ao DNA/efeitos dos fármacos , Linfócitos/patologia , Polietileno/química , Próteses e Implantes/efeitos adversos , Titânio/efeitos adversos , Sobrevivência Celular , Células Cultivadas , Cromo/química , Cobalto/química , Ensaio Cometa , Citocinese , Humanos , Linfócitos/efeitos dos fármacos , Teste de Materiais , Testes para Micronúcleos , Molibdênio/química , Espectrometria por Raios X
9.
Artigo em Inglês | MEDLINE | ID: mdl-23802163

RESUMO

The aim of this research was development of new system for the treatment of highly polluted wastewater (COD = 10240 mg/L; SS = 2860 mg/L) originating from vine-making industry. The system consisted of the main treatment that included electrochemical methods (electro oxidation, electrocoagulation using stainless steel, iron and aluminum electrode sets) with simultaneous sonication and recirculation in strong electromagnetic field. Ozonation combined with UV irradiation in the presence of added hydrogen peroxide was applied for the post-treatment of the effluent. Following the combined treatment, the final removal efficiencies of the parameters color, turbidity, suspended solids and phosphates were over 99%, Fe, Cu and ammonia approximately 98%, while the removal of COD and sulfates was 77% and 62%, respectively. A new approach combining electrochemical methods with ultrasound in the strong electromagnetic field resulted in significantly better removal efficiencies for majority of the measured parameters compared to the biological methods, advanced oxidation processes or electrocoagulation. Reduction of the treatment time represents another advantage of this new approach.


Assuntos
Peróxido de Hidrogênio/química , Ozônio/química , Raios Ultravioleta , Eliminação de Resíduos Líquidos/métodos , Poluentes da Água/química , Poluentes da Água/efeitos da radiação , Amônia/química , Amônia/efeitos da radiação , Análise da Demanda Biológica de Oxigênio , Cobre/química , Cobre/efeitos da radiação , Eletroquímica/métodos , Ferro/química , Ferro/efeitos da radiação , Nefelometria e Turbidimetria , Oxidantes/química , Oxirredução , Fosfatos/química , Fosfatos/efeitos da radiação , Sonicação , Sulfatos/química , Sulfatos/efeitos da radiação , Águas Residuárias , Vinho
10.
Chemosphere ; 93(6): 939-45, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23790829

RESUMO

In this research, toxicological safety of two newly developed methods for the treatment of landfill leachate from the Piskornica (Croatia) sanitary landfill was investigated. Chemical treatment procedure combined chemical precipitation with CaO followed by coagulation with ferric chloride and final adsorption by clinoptilolite. Electrochemical treatment approach included pretreatment with ozone followed by electrooxidation/electrocoagulation and final polishing by microwave irradiation. Cell viability of untreated/treated landfill leachate was examined using fluorescence microscopy. Cytotoxic effect of the original leachate was obtained for both exposure periods (4 and 24 h) while treated samples showed no cytotoxic effect even after prolonged exposure time. The potential DNA damage of the untreated/treated landfill leachate was evaluated by the comet assay and cytokinesis-block micronucleus (CBMN) assay using either human or plant cells. The original leachate exhibited significantly higher comet assay parameters compared to negative control after 24 h exposure. On the contrary, there was no significant difference between negative control and chemically/electrochemically treated leachate for any of the parameters tested. There was also no significant increase in either CBMN assay parameter compared to the negative control following the exposure of the lymphocytes to the chemically or electrochemically treated landfill leachate for both exposure periods while the original sample showed significantly higher number of micronuclei, nucleoplasmic bridges and nuclear buds for both exposure times. Results suggest that both methods are suitable for the treatment of such complex waste effluent due to high removal efficiency of all measured parameters and toxicological safety of the treated effluent.


Assuntos
Plantas/efeitos dos fármacos , Eliminação de Resíduos/métodos , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/toxicidade , Linhagem Celular , Ensaio Cometa , Croácia , Monitoramento Ambiental , Humanos , Testes para Micronúcleos
11.
Artigo em Inglês | MEDLINE | ID: mdl-23705621

RESUMO

This article presents a pilot-plant study of the electroplating wastewater treatment by the processes of electroreduction with iron electrode plates, and electrocoagulation/ozonation with aluminum electrode set, followed by the process of ozonation. The initial effluent was found to be highly enriched in heavy metals and to possess the elevated levels of organic contaminants. The values of Cr(VI), Fe, Ni, Cu, Zn, Pb, TOC, and COD exceeded the upper permissible limits of 63, 220.2, 1.1, 7, 131.3, 1.7, 12.3, and 11.4 times, respectively. The heavy metal removal was forced either by the coagulation/flocculation using Fe(II), Fe(III), and Al(III) ions released into the treated solution by the electrochemical corrosion of the sacrificial iron and aluminum electrodes, or the precipitation of the metal hydroxides as well as co-precipitation with iron and aluminum hydroxides. The principle organic matter destruction mechanisms were ozone oxidation and the indirect oxidation with chlorine/hypochlorite formed by the anodic oxidation of chloride already present in the wastewater. Following the combined treatment, the removal efficiencies of Cr(VI), Fe, Ni, Cu, Zn, Pb, TOC, and COD were 99.94%, 100.00%, 95.86%, 98.66%, 99.97%, 96.81%, 93.24%, and 93.43%, respectively, thus complying with the regulated values.


Assuntos
Eletroquímica/métodos , Galvanoplastia/métodos , Ozônio , Poluentes Químicos da Água/química , Purificação da Água/métodos
12.
Artigo em Inglês | MEDLINE | ID: mdl-23379949

RESUMO

The aim of this work was the development and application of the pilot plant with the capacity of 1000 L/day for the purification of groundwater used for human consumption characterized with high concentration of arsenic and increased values of organic pollutants, ammonia, nitrites, color and turbidity. For that purpose, groundwater from the production wells supplying the towns Zrenjanin and Temerin (Vojvodina, Serbia) was used. Due to its complex composition, the purification system required the combination of the electroreduction/electrocoagulation, using iron and aluminum electrode plates with/without ozonation, followed by the electromagnetic treatment and the finally by the simultaneous ozonation/UV treatment. The electroreduction was used for the removal of nitrates, nitrites, and Cr(VI), while the removal of arsenic, heavy metals, suspended solids, color and turbidity required the application of the electrocoagulation with simultaneous ozonation. Organic contaminants and ammonia were removed completely in the last treatment step by applying the simultaneous ozonation/UV treatment. All measured parameters in the purified water were significantly lower compared to the regulated values. Under the optimum treatment conditions, the removal efficiencies for color, turbidity, suspended solids, total arsenic, total chromium, Ni(II), total copper, sulfates, fluorides, chemical oxygen demand, ammonia, nitrates, and nitrites were 100%. The removal efficiencies of the total manganese and iron were 85.19% and 97.44%, respectively, whilst the final concentrations were 4 and 7 µg/L, respectively.


Assuntos
Água Potável/química , Técnicas Eletroquímicas/métodos , Purificação da Água/métodos , Arsênio/química , Arsênio/isolamento & purificação , Análise da Demanda Biológica de Oxigênio , Cromo/análise , Cromo/isolamento & purificação , Cobre/análise , Cobre/isolamento & purificação , Técnicas Eletroquímicas/instrumentação , Eletrodos , Água Subterrânea/química , Ferro/análise , Ferro/isolamento & purificação , Metais Pesados/análise , Metais Pesados/química , Ozônio , Sérvia , Sulfatos/análise , Poluentes Químicos da Água/química
13.
Arh Hig Rada Toksikol ; 63(3): 337-44, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23152383

RESUMO

In this study we compared three methods for the treatment of electroplating sludge highly loaded with zinc and iron: (1) calcium oxide-based solidification/stabilisation; (2) conversion into inert material by adsorption of organic and inorganic pollutants onto activated carbon; and (3) conversion of mobile waste components into insoluble phosphates. All three methods proved highly efficient in the conversion of hazardous waste into inert material. Under optimum treatment conditions zinc concentration in the leachate of solidified waste was reduced by 99.7 % compared to untreated sludge. Zinc retention efficiency in the waste treated with activated carbon and phosphoric acid was 99.9 % and 98.7 %, respectively. The advantages of electroplating sludge treatment with activated carbon over the other two methods are high sorption capacity, insignificant pH and volume changes of the sludge, and simple use.


Assuntos
Compostos de Cálcio/química , Carbono/química , Galvanoplastia/métodos , Óxidos/química , Ácidos Fosfóricos/química , Esgotos/química , Adsorção , Humanos , Resíduos Industriais/análise
14.
Artigo em Inglês | MEDLINE | ID: mdl-22755521

RESUMO

The aim of this research was development of appropriate procedure for the treatment of landfill leachate taken from the Visevac, Mraclinska Dubrava and Piskornica sanitary landfills. Due to the complex nature of the effluents a combined treatment approach was applied. The pretreatment step included simultaneous treatment with calcium oxide and electrocoagulation/electrooxidation by stainless steel electrode set. The main treatment included electrocoagulation/electrooxidation using the set of stainless steel, iron and aluminum electrodes. The pretreatment allowed the destruction and/or coagulation of the high molecular weight organic substances as well as optimization of pH values for the formation of reactive oxidative species, and the transformation of NH(4)-N into volatile NH(3)-N. In the presence of added calcium oxide and electrochemically generated coagulant the removal of the fluorides, phosphates and heavy metals occur through the formation of poorly soluble fluorapatite, hydroxyl apatite, and various hydroxides. During the main treatment electrochemically generated reactive oxidative species carried out rapid decomposition of the organic matter and ammonia, resulting in the removal of COD from 74.9% to 94.2%, color from 98.8% to 99.7%, turbidity from 98.4% to 99.3%, suspended solids from 97.1% to 99.3%, and ammonia from 99.6% to 99.7%. Slightly better results for the removal efficiency of color, turbidity and suspended solids were obtained in the case of Piskornica landfill compared with the other two landfills, while the COD removal efficiency decreases in the following order: Piskornica >Mraclinska Dubrava >Visevac. This could be related to the age of the landfill, which increases in the same order. Consequently, with the increasing age of the landfill the degree of degradability of the organic matter reduces significantly. Applied treatment approach resulted in clear, colorless and odorless effluent with the values of all measured parameters significantly lower compared to the upper permissible limit for discharge into the environment.


Assuntos
Compostos de Cálcio/química , Eletroquímica/métodos , Óxidos/química , Eliminação de Resíduos/métodos , Croácia , Eletrocoagulação , Ferro/química , Oxirredução
15.
Artigo em Inglês | MEDLINE | ID: mdl-22702811

RESUMO

The present study aimed to characterize chemical properties of clay bricks containing 20 % of sewage sludge. After detection of potentially hazardous metals, we simulated precipitation exposure of such material to determine the amount of heavy metals that could leach out of the bricks. Metals, such as copper, zinc, nickel, cobalt, chromium, etc., were detected in leachate in low concentrations. Moreover, human peripheral blood lymphocytes were exposed to brick leachate for 24 h in order to evaluate its possible negative impact on human cells and genome in vitro. Cytotoxicity tests showed no effect on human peripheral blood lymphocytes viability after exposure to brick's leachate. On the contrary, the alkaline comet assay showed slight but significant increase in DNA damage with all three parameters tested. As we might predict, interactions of several heavy metals in low concentrations could be responsible for DNA damaging effect. In that manner, our findings suggest that leachates from sewage sludge-produced bricks may lead to adverse effects on the exposed human population, and that more stabile bricks should be developed to minimize leaching of heavy metals into the environment. Bricks with lower percentage of the sludge may be one of the solutions to reduce the toxic effect of the final product.


Assuntos
Silicatos de Alumínio/química , Materiais de Construção/toxicidade , Dano ao DNA/efeitos dos fármacos , Metais Pesados/toxicidade , Esgotos/química , Poluentes Químicos da Água/toxicidade , Laranja de Acridina/química , Argila , Ensaio Cometa , Etídio/química , Humanos , Linfócitos/efeitos dos fármacos , Masculino , Metais Pesados/química , Azul Tripano/química , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/química , Adulto Jovem
16.
Artigo em Inglês | MEDLINE | ID: mdl-22702819

RESUMO

The subject of this study was chemical and radiological characterization of the fly and bottom ash, by-product of the combustion of coal used as an energy source in the former sulfate pulp factory in Plaski. The research involves determination of the concentration of macro, micro and trace elements and activities of the radionuclides in: (i) ash from different positions of the landfill; (ii) soil samples in the zone of the influence of the landfill; (iii) control soil samples and (iv) sediment sample from the river Dretulja. Besides, in situ measurement of an effective dose rate above ash/soil was also determined. In relation with the control soil the average increase of the concentrations of the elements Ca, Cd, Hg, Ni, Se, Sr, Th and U in the samples taken from the fly and bottom ash landfill as well as soil samples within the radius of 300 m from the landfill was 38.3, 6.7, 9.9, 8.5, 9.4, 7.2, 3.6 and 5.7 times, respectively. In these samples, the concentrations of the above mentioned elements were in the following ranges: calcium from 7.94 to 19.7 %; cadmium from 0.33 to 1.66 mg/kg; mercury from 0.18 to 0.49 mg/kg; nickel from 260 to 1500 mg/kg; selenium from 2.7 to 21 mg/kg; strontium from 176 to 542 mg/kg; thorium from 8 to 55 mg/kg and uranium from 5.6 to 19.7 mg/kg. Compared to the world's average soil concentration, uranium and thorium values increased 3.7 and 1.7 times, respectively. The mean value of the total effective dose rate measured in the air at the height of 1 m for all samples of ash and soil under the influence of the landfill was 1.60 mSv/yr. Compared to the Croatian average (0.7015 mSv/yr), the determined mean value for the Plaski landfill is two times higher. However, compared to the local background (0.14 mSv/yr), the mean value of the total effective dose rate measured above the Plaski landfill is 11.4 times higher. In the samples of ash and contaminated soil regardless of the sampling location the activity concentrations of the radionuclides in Bq/kg vary in the following ranges: (226)Ra from 82.10 to 314.90 (mean value 145.99), (232)Th from 32.50 to 223.60 (mean value 76.76) and (238)U from 69.10 to 243.20 (mean value 134.38). Compared to the mean values found in the background soil (226)Ra and (238)U mean activity concentrations increased from 1.6 to 6.4 times and (232)Th from 1.4 to 4.3 times. In order to reduce total effective dose rate to the local "background" values and to prevent redistribution of the radionuclides and heavy metals from the deposited material into the environment fly and bottom ash landfill must be sealed with 10 cm thick layer of the material with low permeability.


Assuntos
Cinza de Carvão/análise , Recuperação e Remediação Ambiental , Poluentes Radioativos do Solo/análise , Poluentes do Solo/análise , Carvão Mineral , Cinza de Carvão/química , Cinza de Carvão/toxicidade , Croácia , Monitoramento Ambiental , Centrais Elétricas , Doses de Radiação , Monitoramento de Radiação , Poluentes do Solo/química , Poluentes do Solo/toxicidade , Poluentes Radioativos do Solo/química , Poluentes Radioativos do Solo/toxicidade , Espectrometria gama , Espectrometria por Raios X , Gerenciamento de Resíduos
17.
Artigo em Inglês | MEDLINE | ID: mdl-22506711

RESUMO

The purpose of this work was development and application of the purification system suitable for the treatment of the acid mine drainage (AMD) accumulated in the "Robule" Lake, which represents the part of the Bor copper mining and smelting complex, Serbia. The study was undertaken in order to minimize adverse effect on the environment caused by the discharge of untreated AMD, which was characterized with low pH value (2.63) and high concentration of heavy metals (up to 610 mg/L) and sulfates (up to 12,000 mg/L). The treatment of the effluent included pretreatment/pH adjustment with CaO followed by electrocoagulation using iron and aluminum electrode sets. Following the final treatment, the decrease in the concentration of heavy metals ranged from 40 up to 61000 times depending on the metal and its initial concentration. The parameters, color and turbidity were removed completely in the pretreatment step, while the removal efficiencies for other considered parameters were as follows: EC = 55.48%, SO(4) (2-) = 70.83%, Hg = 98.36%, Pb = 97.50%, V = 98.43%, Cr = 99.86%, Mn = 97.96%, Fe = 100.00%, Co = 99.96%, Ni = 99.78%, Cu = 99.99% and Zn = 99.94%. Because the concentrations of heavy metals in the electrochemically treated AMD (ranging from 0.001 to 0.336 mg/L) are very low, the negative impact of this effluent on the aquatic life and humans is not expected. The sludge generated during the treatment of AMD is suitable for reuse for at least two purposes (pretreatment of AMD and covering of the flotation waste heap). From the presented results, it could be concluded that electrochemical treatment is a suitable approach for the treatment of AMD.


Assuntos
Ácidos , Compostos de Cálcio/química , Técnicas Eletroquímicas , Mineração , Óxidos/química , Poluentes Químicos da Água/isolamento & purificação , Água Doce/química
18.
Arh Hig Rada Toksikol ; 63(1): 21-6, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22450202

RESUMO

The aim of this study was to investigate the efficiency of (1) chemical precipitation by calcium oxide, (2) coagulation/flocculation by ferric chloride (FC), and (3) the combination these two methods in reducing the toxicity of wastewater generated by boat pressure washing. All three methods gave satisfactory results in the removal of colour, turbidity, Cr, Fe, Cu, Zn, and Pb. The concentrations of heavy metals were lowered below national limits with 1 g of CaO, 2.54 mg of Fe3+ in the form of FeCl3x6H2O, and the combination of 0.25 g of CaO and 5.08 mg of Fe3+ per 50 mL of wastewater. Both CaO (1.50 g per 50 mL of wastewater) and FC proved efficient, but their combination yielded a significantly better performance: 99.41 %, 100.00 %, 97.87 %, 99.09 %, 99.90 %, 99.46 % and 98.33 % for colour, turbidity, Cr, Fe, Cu, Zn, and Pb respectively. For colour, Cr, Cu, Zn, and Pb removal efficiencies increased in the following order: FC

Assuntos
Compostos de Cálcio , Cloretos , Compostos Férricos , Metais Pesados/isolamento & purificação , Óxidos , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água , Precipitação Química , Floculação
19.
Artigo em Inglês | MEDLINE | ID: mdl-22320699

RESUMO

A combined treatment approach using advanced oxidation, electrochemical methods and microwaves was developed and applied for the treatment of landfill leachate taken from Piskornica (Koprivnica, Croatia) sanitary landfill. Due to the complex nature of the effluent and extremely low bio-degradability (BOD(5)/COD ratio = 0.01) the purification of the leachate started with pre-treatment with ozone followed by simultaneous ozonation and electrocoagulation/electrooxidation using the set of iron and aluminum electrodes, and finally, the degradation of organic residue and ammonia with microwaves. Applied treatment approach resulted in clear, colorless and odorless effluent with the values of all measured parameters significantly lower compared to the upper permissible limit for discharge into the environment. The removal percentages of the parameters: color, turbidity, suspended solids, ammonia, COD and iron following the combined treatment were 98.43%, 99.48%, 98.96%, 98.80%, 94.17% and 98.56%, respectively.


Assuntos
Amônia/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Purificação da Água/métodos , Amônia/análise , Análise da Demanda Biológica de Oxigênio , Cor , Eletroquímica , Oxirredução , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/efeitos da radiação , Raios X
20.
Artigo em Inglês | MEDLINE | ID: mdl-22092157

RESUMO

The purpose of this work was development and application of the purification system suitable for the treatment of groundwater used for human consumption, satisfying following criteria: (a) no need for external addition of the chemicals; (b) simultaneous removal of wide range of contaminants present in the treated water; (c) low sensitivity to the changes in the composition of the treated water; (d) high quality of treated water with regards to all measured parameters. Therefore the well water from the 60 m deep water layer situated near the city of Osijek (Eastern Croatia) with elevated values of heavy metals, color, turbidity, suspended solids, ammonia and organic contaminants was processed. Due to the complex composition of the treated water, the purification system required the combination of electroreduction/electrocoagulation, using iron and aluminum electrode plates followed by the simultaneous ozonation/UV treatment. The electroreduction/electrocoagulation approach was used for the removal of heavy metals, suspended solids, color and turbidity, while the organic contaminants and ammonia were removed by the ozonation/UV treatment. All measured parameters in the purified water were significantly lower compared to the regulated values. Under the optimum treatment conditions, the removal efficiencies for color, turbidity, nickel and arsenic were 100%. The removal efficiencies of V, Cr, Mn, Fe, Cu, Zn, Pb, ammonia, fluorides, sulfates and COD were 94.5%, 96.0%, 98.3%, 99.6%, 99.7%, 97.8%, 96.7%, 96,7%, 93.4%, 51.4%, 72.2% and 93.8%, respectively, increasing with the increased initial concentrations.


Assuntos
Água Potável/química , Água Subterrânea/química , Poluentes da Água/química , Purificação da Água/métodos , Arsênio/análise , Arsênio/química , Arsênio/normas , Análise da Demanda Biológica de Oxigênio , Cor/normas , Água Potável/análise , Água Potável/normas , Eletroquímica , Fluoretos/análise , Fluoretos/química , Fluoretos/normas , Água Subterrânea/análise , Metais Pesados/análise , Metais Pesados/química , Metais Pesados/normas , Nefelometria e Turbidimetria , Compostos de Nitrogênio/análise , Compostos de Nitrogênio/química , Compostos de Nitrogênio/normas , Oxirredução , Espectrometria por Raios X , Sulfatos/análise , Sulfatos/química , Sulfatos/normas , Poluentes da Água/análise , Poluentes da Água/normas , Organização Mundial da Saúde
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...