JULIANA DE CARVALHO IZIDORO

JULIANA DE CARVALHO IZIDORO

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Avaliação dos níveis de radioatividade natural produzidos na atividade carbonífera e em amostra de clínker
2022 - FUNGARO, DENISE A.; SILVA, PAULO S.C.; IZIDORO, JULIANA C.; GROSCHE, LUCAS C.; BIBIANO, RAMIRO H.N.
Os Produtos de Combustão de Carvão são materiais produzidos em usinas termelétricas que contêm radionuclídeos de ocorrência natural derivados da matriz de carvão, enriquecidos em até uma ordem de magnitude em relação aos níveis originais. A avaliação do impacto radiológico dos ambientes circundantes das usinas termelétricas é de fundamental importância para monitorar os níveis de radiação, a qual as pessoas estão expostas direta ou indiretamente, visto que níveis aceitáveis podem ser ultrapassados com essas atividades. A análise de ativação de nêutrons foi usada para determinar 238U e 232Th e a espectrometria de raios gama para determinar os conteúdos de 226Ra, 228Ra, 210Pb e 40K presentes no carvão, nas cinzas sílico-aluminosas, nos materiais zeolíticos sintetizados a partir de cinzas e em amostras de solo coletadas nas proximidades de Usina termelétrica de Figueira, localizada no Paraná. As concentrações de atividade foram comparadas com a média mundial das diferentes amostras. A análise de ativação de nêutrons também foi utilizada para avaliar os riscos radiológicos decorrentes da presença de cinzas sulfatadas e clínquer em materiais de construção. As cinzas sulfatadas podem substituir o gesso natural em matrizes cimentícias.
Trace elements in coal, coal combustion products and soil from coal-fired power plant area evaluated by neutron activation analysis
2021 - FUNGARO, D.A.; SILVA, P.S.C.; IZIDORO, J.C.; HOWER, J.C.
The concentrations of trace elements were determined in coal, fly ashes from baghouse and cyclone filter, and bottom ash from the Figueira thermal power plant (FPP) by a neutron activation analysis technique. Study of the enrichment factor indicated that coal ashes were moderately enriched for all elements, except for Zn that exhibits significant to very-high enrichment. The mobilization of elements was observed in the zeolite products obtained from the three coal ashes. With regards to the amount present in each type of ash, most of the elements were present at same level in zeolites, with the exception of As which exhibited much lower concentration. The trace element concentrations of two soil samples collected in the vicinity of the FPP was also investigated. The results indicate that the FPP contributes mainly to the Zr and Ba pollution in nearby soils, particularly Zr pollution.
Physical and chemical characteristics of feed coal and its by-products from a Brazilian thermoelectric power plant
2019 - IZIDORO, JULIANA de C.; MIRANDA, CAIO; CASTANHO, DAVI; ROSSATI, CARLOS; CAMPELLO, FELIPE; GUILHEN, SABINE N.; FUNGARO, DENISE A.; WANG, SHAOBIN
In this study, feed coal (FC) from the Figueira Thermoelectric Power Plant (FTPP), located in the state of Paraná (PR), Brazil was characterized by X-ray fluorescence (XRF), X-ray diffractometry (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), particle size distribution analysis by laser diffraction, loss of ignition (LOI), total carbon content (TC), pH and conductivity. FC-derived by-products (CCBs) collected at the FTPP were: bottom ash (BA), fly ash from cyclone filter (CA) and fly ash from bag filter (FA). In addition to the techniques used for feed coal characterization, CCBs were also characterized by total surface area (by using BET method), external surface area (by using laser diffraction), cation exchange capacity (CEC), bulk density, besides leaching and solubilization tests. FC sample contains 72.2% of volatile material, of which 55.3% is total carbon content. LOI, FTIR, TGA and TC analyzes corroborated with these results. The main crystalline phases in the FC sample were found to be quartz, kaolinite and pyrite. The elements As, Cr, Ni and Pb were encountered in the FC sample, indicating that the use of FTPP feed coal should be monitored due to the toxic potential of these elements. The three coal ashes were classified as class F according to ASTM and presented similar chemical composition, with total content of the main oxides (SiO2, Al2O3 and Fe2O3) above 72%. Ashes enrichment factor analysis (EF) showed that As, Zn and Pb concentrate mainly in fly ash from bag filter (FA), whereas the elements K and Mg presented higher enrichment in the bottom ash (BA) . All ashes presented quartz, mullite and magnetite as crystalline phases, as well as the same functional groups, related to the presence of humidity, organic matter and Si and Al compounds. XRD, XRF, TGA, FTIR, LOI and TC techniques were correlated and confirmed the obtained results. Total and external surface area values of CCBs were related to the total carbon content (TC), as well as to the results of particle size distribution and the scanning electron micrographs of the samples. On the other hand the CEC of the ashes showed relation with the particle size distribution and with the external surface area. Leaching and solubilization tests of CCBs showed that FA sample was considered hazardous and classified as class I waste, while CA and BA samples were considered non-hazardous and non-inert wastes and classified as class II-A. FA sample from Figueira power plant must be discarded only after treatment or a stringent disposal criterion must be followed to avoid contamination on site. In this work, feed coal sample was also compared to the CCBs samples generated from it. The results showed the differences between fuel and products through the different characterization techniques. In addition to contributing to the understanding of the relationship between coal and its combustion products, this work can also help to reduce the environmental impacts caused by the CCBs disposal, as well as can also be used to compare the characteristics of CCBs from FTPP with the new wastes that will be generated by the same thermal power plant that will be soon modernized.
Application of high-purity zeolite a synthesized from different coal combustion by-products in carbon dioxide capture
2019 - IZIDORO, JULIANA; CASTANHO, DAVI; ROSSATI, CARLOS; FUNGARO, DENISE; GUILHEN, SABINE; NOGUEIRA, THIAGO; ANDRADE, MARIA de F.
High-purity zeolites A were synthesized from different coal combustion by-products (baghouse filter fly ash, cyclone filter ash, and bottom ash) and characterized in terms of morphology, chemical, and mineralogical composition. The products were tested for carbon dioxide capture by using a continuous CO2 flow system passing through a column packed with the adsorbent material, which was connected to an analyser that directly measures the concentration of CO2. The values of CO2 adsorption capacities calculated for the unmodified Na-A zeolites (ZABF, ZACF, and ZABA) were 556.48, 494.29 and 654.82 mg g–1, respectively. These values were higher than those achieved by the calcium-modified zeolite samples. ZABA adsorbent presented the best performance in CO2 capture when compared to the other adsorbent material and achieved an adsorption capacity 32% higher than a 4A commercial zeolite. In the adsorption cycles study, the percentage of CO2 desorption by ZABA at the second and third cycles reached 93%, showing that zeolite A can be regenerated by heating at 150 ºC. The use of coal ashes to obtain zeolites and the application of these products for the CO2 adsorption can be an important strategy to mitigate both the problem of waste management and the greenhouse gases emission in coal-fired power plants.
Synthesis of nanocrystalline zeolite Na-A from coal fly ash and different aluminum sources
2018 - FUNGARO, DENISE A.; IZIDORO, JULIANA C.; GUILHEN, SABINE N.; SILVA, KATIA C.; WANG, SHAOBIN
This chapter describes the synthesis process to obtain zeolite Na-A from coal fly ash via fusion with NaOH followed by hydrothermal reaction. Coal fly ash is a low cost source of both silica and alumina. The molar ratio of SiO2/Al2O3 for zeolite 4A formation was achieved by the addition of sodium aluminate solution or aluminum waste from tertiary industry as aluminum sources. The effects of temperature and time at the fusion step and the hydrothermal reaction time on crystalline products were investigated. The synthesized products were studied for their purity and yield as well as were characterized by different techniques such as Xray powder diffraction (XRD), scanning electron microscopy (SEM) and cation exchange capacity (CEC), among others. Analysis of the properties of the raw materials and the products demonstrates that the by-products can be used to produce a high purity zeolite A. The optimum conditions related to the synthesis was set and the samples were pure, highly crystalline and white. The synthesized zeolites were used for both the removal of Cd (II) and Zn (II) from aqueous solution. The results showed that coal fly ash and aluminum source can be transformed into zeolite A, which is considered as value-added material with adsorption properties.
Immobilization agents study of toxic elements in coal ash
2018 - IZIDORO, JULIANA; FUNGARO, DENISE; CAMPELLO, FELIPE; GUILHEN, SABINE
Metal leaching from coal fly ashes into the environment is of a much concern. A series of batch tests were performed to investigate the potential leaching of metals from fly ash modified with organosilane (OS) and quaternary ammonium surfactant (SF). The fly ash was collected at the Figueira Thermal Power Plant, located in the city of Figueira, State of Paraná. Firstly, the influence of ash mass/water volume ratio on the concentration of the elements in the leachates from untreated fly ash was evaluated. Subsequently, the capacities of immobilization of toxic elements by the different immobilizing agents were determined by measuring the pH and conductivity of the leachates from the treated fly ash. A significant reduction in the concentration of the elements was observed for all the leachate samples obtained from the ashes treated with OS. The concentrations were reduced by 89%, 77%, 42% and 11% for Cr, Mo, As and Se, respectively. When SF was used for the ash treatment, the concentration reduction in the leachates was found to be above 60% for all elements. These results show that both the OS and SF can be used as immobilizing agents for the retention of toxic elements presented in coal ashes.
Evaluation of radionuclide contamination of soil, coal ash and zeolitic materials from Figueira Thermoelectric Power Plant
2019 - FUNGARO, D.A.; SILVA, P.S.C.; CAMPELLO, F.A.; MIRANDA, C.S.; IZIDORO, J.C.
The feed pulverized coal used at Figueira thermoelectric power plant (FTPP) presents a significant amount of uranium concentration and the potential radiological impact pathways into the surrounding environments should be monitored frequently. Neutron activation analysis was used to determine 238U and 232Th, and gamma-ray spectrometry was used to determine 226Ra, 228Ra, 210Pb and 40K contents present in coal, different types of coal ashes, their synthesized zeolites and two different soil samples collected in the vicinity of FTPP as well as, radiological indices to determine possible health effects due to radiation exposition. The natural radionuclide concentrations in pulverized coal were 216 Bq kg–1 for 238U, 180 Bq kg–1 for 226Ra, 27 Bq kg–1 for 228Ra, 28 Bq kg–1 for 232Th and 192 Bq kg–1 for 40K. The ashes fraction presented concentrations ranging from 683.5 to 1479 Bq kg–1 for 238U, from 484 to 1086 Bq kg–1 for 226Ra, from 291 to 1891 Bq kg–1 for 210Pb, from 67 to 111 Bq kg–1for 228Ra, from 80 to 87 Bq kg–1 for 232Th and from 489 to 718 Bq kg–1 for 40K. Similar ranges were observed for the different zeolitic products. The activity concentration of 238U was higher than worldwide average concentration for all samples. The concentration of the uranium series found in the ashes was lower than the values observed in similar studies carried out 10 years ago and under the limit adopted by the Brazilian guideline (CNEN-NN-4.01). The radiological indices indicated that the environmental disposal of fly ashes may represent a risk for public health, therefore, the resulting data can be used for systematic studies on radiological implication due to the release of TENORM caused by coal-fired power plant.
In vitro and in vivo toxicity of coal fly Ash Lechatee
2018 - DAMASCENO, K.C.; CAVALCANTE, A.K.; MAZIERO, J.S.; MARTINI, G.A.; ORMENIO, M.B.; MAMEDE, F.C.; MIRANDA, C.S.; CAMPELLO, F.A.; IZIDORO, J.C.; ROGERO, S.O.; FUNGARO, D.A.; LOPES-FERREIRA, M.; ROGERO, J.R.
Coal Fly ash is a major solid waste from coal-fired power stations. In Brazil, more than 4 million tons per year of fly ash are generated and only 30% is applied as raw material for cement and concrete production. The remaining is disposed in on-site ponds, nearby abandoned or active mine sites and landfills. The inadequate disposal of fly ash may pose a significant risk to the environment due to the possible leaching of hazardous pollutants into the surrounding soil and groundwater. A combination of leaching tests, cytotoxicity and ecotoxicological assays were used in this studyin order toevaluate the possible adverse effects of coal fl y ash in non-target organisms. The sample was collected from coal-fi red power plant located in Southern Brazil and the coal fly ash was submitted to a leaching procedure using USEPA SW 864 Method 1311. The leachate was prepared in six dilutions: 1.56%, 3.12%, 6.25%, 12.5%, 25% and 50%. Acute toxicity tests were performed on NCTC clone 929 (CCIAL-020) culture cells by neutral red uptake cytotoxicity method; acute ecotoxicity usingDaphnia similisand Danio rerio embryos according to ABNT NBR 12713 and OECD 236, respectively were employed. The cytotoxicity index (CI50) obtained was 33%; the EC50of D. similis after 48 h of exposure to the leachate was 7.25% and the LC50of D. rerio after 96 h of exposure was 4.39%. The results of these bioassays indicated toxicity of the coal fly ash leachate toward exposed organisms.
Treatment of coal ash landfill leachate using zeolitic materials from coal combustion by-products
2018 - IZIDORO, JULIANA de C.; MIRANDA, CAIO da S.; GUILHEN, SABINE N.; FUNGARO, DENISE A.; WANG, SHAOBIN
Three different zeolitic materials derived from coal combustion by-products (CCBs) were used to treat local coal ash landfill leachate at the same power plant. The zeolitic materials properties were characterized in terms of mineralogical composition (XRD), chemical composition (XRF), total carbon content, morphological analysis (SEM), specific surface area (BET method), cation exchange capacity (CEC), loss of ignition, pH, conductivity and bulk density. XRD indicated that sodalite zeolite was formed in all the samples after hydrothermal activation of CCBs. One zeolitic product from baghouse fly ash (ZFB) presented the lowest SiO2/Al2O3 ratio, highest CEC and specific surface area, thus having a high capacity in removal of heavy metal pollutants. The zeolitic products were efficient to reduce arsenic concentration to a value below the legislation. All zeolitic materials also showed a significant removal of Ni, Cd, Zn and Co except of Cr at a dose of 10 g L-1. Thus, this work provides a sustainable strategy to resolution of solid waste from power plants.
Evaluation of radionuclide contamination of soil, coal ash and zeolitic materials from figueira thermoelectric power plant
2017 - FUNGARO, DENISE A.; SILVA, PAULO S.C. da; CAMPELLO, FELIPE A.; MIRANDA, CAIO da S.; IZIDORO, JULIANA de C.
Neutron activation analysis and gamma-ray spectrometry was used to determine 238U, 226Ra, 228Ra, 210Pb, 232Th and 40K contents in feed pulverized coal, bottom ash, fly ash from cyclone and baghouse filters, zeolites synthesized from the ashes and two different soil samples. All the samples used in the study was collected at Figueira thermoelectric power plant, located in the city of Figueira, Paraná State, which coal presents a significant amount of uranium concentration. The natural radionuclide concentrations in pulverized coal were 4216 Bq kg–1 for 238U, 180 Bq kg–1 for 226Ra, 27 Bq kg–1 for 228Ra, 28 Bq kg–1 for 232Th and 192 Bq kg–1 for 40K. The ashes fraction presented concentrations ranging from 683.5 to 1479 Bq kg–1 for 238U, from 484 to 1086 Bq kg–1 for 226Ra, from 291 to 1891 Bq kg–1 for 210Pb, from 67 to 111 Bq kg–1for 228Ra, from 80 to 87 Bq kg–1 for 232Th and from 489 to 718 Bq kg–1 for 40K. Similar ranges were observed for zeolites. The activity concentration of 238U was higher than worldwide average concentration for all samples. The concentration of the uranium series found in the ashes were lower than the values observed in similar studies carried out 10 years ago and under the limit adopted by the Brazilian guideline (CNEN-NN-4.01). Nevertheless, the concentrations of this specific area are higher than others coal mines and thermoelectric power plants in and out of Brazil, so it is advisable to evaluate the environmental impact of the installation.