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1.
J Environ Manage ; 256: 109953, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31989980

RESUMO

The study evaluated plants with phytoremediation potential that occur spontaneously in an area of copper mining tailings in Southern of Brazil. Eleven plant species were investigated for heavy metal concentrations in its biomass. All species showed copper concentrations greater than 100 mg kg-1, and seven species highlighted for copper concentrations between 321 and 586 mg kg-1 and these species showed Cr concentrations between 25 and 440 mg kg-1. The species S. viarum Dunal and B. trimera Less were highlighted showing the highest concentrations of Cr (586 mg kg-1) and Cu (440 mg kg-1), respectively. Seven species showed Pb phytoextraction potential and four species showed Cu phytostabilization potential. It was concluded that the investigated species are adapted to low nutritional conditions and showed tolerance to heavy metals, mainly Cu, Pb and Cr in its biomass.


Assuntos
Metais Pesados , Poluentes do Solo , Biodegradação Ambiental , Brasil , Cobre , Mineração , Raízes de Plantas
2.
Environ Sci Pollut Res Int ; 26(23): 24132-24142, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31228062

RESUMO

Mining tailing areas may contain metal minerals such as Cu, Pb, Zn, Cr, and Cd at high concentrations and low nutrients for the growth of plants. This kind of conditions of the area, as well as lack of tailing structure, may limit the development of plants on these areas. Thus, the present study determined the metal, macronutrient, and micronutrient concentrations in the tissues of the roots and shoots of the Solanum viarum Dunal species as well as it evaluated the potential use of the plant for phytoremediation of mining tailing areas contaminated with heavy metals. The macronutrients, micronutrients, and heavy metals in the roots and shoots were determined by the digestion method with nitric and perchloric acid (HNO3-HClO4) and quantified by the ICP-OES. In S. viarum, the average concentrations of the metals presented in the dry biomass varied between the shoots and roots, being higher in the roots for metals such as Cu (229 mg kg-1), Zn (232 mg kg-1), Mn (251 mg kg-1), Cr (382 mg kg-1), Ni (178 mg kg-1), Pb (33 mg kg-1), and Ba (1123 mg kg-1). S. viarum indicates the possibility of a potential application in phytoremediation and treatment of areas contaminated with heavy metals.


Assuntos
Recuperação e Remediação Ambiental/métodos , Metais Pesados/análise , Mineração , Poluentes do Solo/análise , Solanum/química , Biodegradação Ambiental , Biomassa , Brasil , Metais Pesados/farmacocinética , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Brotos de Planta/química , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Poluentes do Solo/farmacocinética , Solanum/efeitos dos fármacos , Solanum/metabolismo , Distribuição Tecidual
3.
Int J Phytoremediation ; 21(11): 1145-1152, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31088309

RESUMO

The evaluation of plants occurring naturally at contaminated environments are essential for applying this species in remediation techniques. In this context, the Sagittaria montevidensis with potential for phytoremediation was studied at an anthropogenic polluted stream in southern Brazil. The nutrients and heavy metal content were determined in the phytomass. The phytoremediation indexes were evaluated such as bioconcentration factor (BCF), translocation factor (TF), plant effective number (PEN), and potential phytoremoval (mg m-2). The S. montevidensis was then detected as presenting natural phytoextraction ability for potassium and calcium elements and also demonstrated rhizofiltration potential for phosphorus, manganese, aluminum, vanadium, sulfur, iron, arsenic, copper, magnesium, zinc, sodium, lead, cadmium, nickel, chromium, considering its ability of bioaccumulating these contaminants and retain high levels in the roots. The highest potential for bioremoval (mg m-2) of the S. montevidensis was detected for potassium and calcium (recommending thus the use for phytoextraction) and for aluminum, phosphorus, iron, magnesium, sulfur, and sodium, along with heavy metals (recommended for rhizofiltration). The S. montevidensis decontamination ability, along with its biomass production and its adaptability represents a great advance in order to the recovery of this degraded area and possible application in other contaminated watercourses in Brazil.


Assuntos
Metais Pesados , Sagittaria , Poluentes do Solo , Biodegradação Ambiental , Brasil , Nutrientes
4.
Eng. sanit. ambient ; 24(2): 229-237, mar.-abr. 2019. tab
Artigo em Português | LILACS-Express | ID: biblio-1012043

RESUMO

RESUMO A qualidade de vida é intrinsecamente ligada à disponibilidade de água, e a poluição desse recurso afeta diretamente as populações. O Lago Guaíba possui importância histórica, econômica e cultural para Porto Alegre (RS) e região metropolitana. Este trabalho discute o contexto histórico-cultural da poluição do Lago Guaíba. Com grande região hidrográfica, o lago sofre diversos impactos ambientais e, ao mesmo tempo, possui múltiplos usos para suas águas. Apesar da grande importância do Lago Guaíba para a região metropolitana de Porto Alegre, há um histórico descaso com sua qualidade. O lago apresenta-se poluído, com percepção pública dessa realidade e limitação de usos diretos de suas águas.


ABSTRACT The quality of life is intrinsically linked to water availability; however, pollution on this resource directly affects people. Lake Guaíba has a historical, economic and cultural importance to Porto Alegre (RS, Brazil) and its metropolitan region. This report discusses the historical and cultural context of Lake Guaíba's pollution. With a large watershed, Lake Guaíba suffers many environmental impacts and, at the same time, has multiple uses for its waters. Despite the great importance of Lake Guaíba to Porto Alegre metropolitan region, there is a historical disregard with its quality. The lake is polluted and there is a public perception of this reality with direct limitation of its water's use.

5.
Environ Sci Pollut Res Int ; 25(28): 28312-28321, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30083896

RESUMO

Aquatic environments are widely affected by anthropogenic activities and efficient remediation of these areas requires detailed studies for each natural ecosystem. This research aimed to evaluate the natural phytoremediation potential of Hydrocotyle ranunculoides L., a floating aquatic macrophyte located in a polluted aquatic environment in South of the Rio Grande do Sul, Brazil. Nutrients such as P, K, Ca, Mg, and S and heavy metals such as Cu, Zn, Fe, Mn, Na, Cd, Cr, Ni, Pb, Al, As, Co, and V content in the roots and shoots of the plants were evaluated through nitric perchloric acid digestion (HNO3-HClO4) methods and quantified by ICP-OES. Bioconcentration factor (BCF), translocation factor (TF), plant effective number (PEN), and potential phytoremoval (mg m-2) were carried out. H. ranunculoides showed a substantial ability for phytoextracting P, Na, and As, since showed ability of uptake these elements from the water and translocate them to the shoots of the plants. H. ranunculoides also showed potential for application in rhizofiltration of Mg, S, Cu, Zn, Fe, Mn, Cd, Cr, Ni, Pb, Al, and V, since exhibited high potential to uptake higher levels in the roots. The highest potential for bioremoval (mg m-2) of the H. ranunculoides was detected for K, Ca, P (recommending thus the use for phytoextraction), Fe, and Al (highly recommended for rhizofiltration). Therefore, this species under study showed high potential for in situ phytoremediation at Santa Bárbara stream, and as a widespread species, it might be tested for phytoremediation in other sites.


Assuntos
Centella/crescimento & desenvolvimento , Metais Pesados/análise , Rios/química , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Biodegradação Ambiental , Brasil , Centella/química , Raízes de Plantas/química , Raízes de Plantas/crescimento & desenvolvimento
6.
Eng. sanit. ambient ; 23(2): 275-285, mar.-abr. 2018. tab, graf
Artigo em Português | LILACS-Express | ID: biblio-891642

RESUMO

RESUMO O objetivo deste estudo foi modelar sazonalmente a qualidade da água do Rio dos Sinos, no estado do Rio Grande do Sul, utilizando como suporte o modelo matemático QUAL-UFMG. Foram utilizadas nove seções de monitoramento, compreendidas entre os municípios de Caraá e Canoas, em um trecho de 211 km. As variáveis de qualidade da água foram analisadas entre o período de 2011 e 2012, de forma a abranger as diferentes variações sazonais. O modelo foi calibrado utilizando as seguintes variáveis de qualidade da água: demanda bioquímica de oxigênio (DBO); oxigênio dissolvido (OD); fósforo total (Ptotal); e nitrogênio total (Ntotal). As variações sazonais demonstraram uma influência nas diferentes curvas de calibração simuladas. De forma geral, a utilização do modelo matemático QUAL-UFMG para avaliação da qualidade da água do Rio dos Sinos se mostrou adequado, visto que ocorreu uma similaridade entre os dados observados e a curva simulada no processo de calibração. Para a variável OD, o modelo apresentou uma eficiência boa (Coeficiente de Nash e Sutcliffe - CNS>0,75) e para as variáveis DBO, Ptotal e Ntotal (outono/inverno) o modelo foi considerado aceitável (0,36<CNS<0,75).


ABSTRACT The main goal of this study was to seasonally model the water quality of Sinos River, in Rio Grande do Sul state, Brazil, using as support the QUAL-UFMG mathematical model. Nine monitoring sections were performed, between the counties of Caraá and Canoas, in a 211-km-long stretch. The water quality variables were analyzed between 2011 and 2012, in order to comprehend the different seasonal variations. The model was calibrated using the water quality variables: biochemical oxygen demand (BOD); dissolved oxygen (DO); total phosphorus (Ptotal); and total nitrogen (Ntotal). The seasonal variations demonstrated to influence the different simulated calibration curves. Thus, the utilization of QUAL-UFMG mathematical model in Sinos River water quality evaluation was appropriate, since there was a similarity between the observed data and the simulated curve in the calibration process. For DO, the model presented good efficiency (Nash and Sutcliffe Coefficients - CNS>0.75), and for BOD, Ptotal and Ntotal variables (autumn/winter), the model was considered acceptable (0.36<CNS<0.75).

7.
Eng. sanit. ambient ; 23(1): 63-67, jan.-fev. 2018. tab, graf
Artigo em Português | LILACS-Express | ID: biblio-891627

RESUMO

RESUMO O descarte de resíduos de lodo de curtume no solo tem sido um problema ambiental devido aos altos teores de cromo. O objetivo deste trabalho foi avaliar a dinâmica dos óxidos de ferro e os teores de cromo ligados a esses minerais em áreas de descarte de resíduos de curtume. Para isso, foram determinados os teores de ferro e cromo extraídos por oxalato de amônio dos óxidos de baixa cristalinidade e por ditionito-citrato-bicarbonato (DCB) dos óxidos cristalinos na fração argila do solo. Esses teores variaram entre 3,5 e 4,1 mg kg-1 nos tratamentos sem aplicação de lodo de curtume e entre 19,9 e 56,8 mg kg-1 nos com adição de lodo. Os teores de cromo extraídos dos óxidos cristalinos variaram entre 21,3 e 23,3 mg kg-1 nos tratamentos sem aplicação de lodo e entre 46,4 e 103,0 mg kg-1 nos com uso de lodo de curtume. A aplicação desse material proporcionou um aumento na relação do ferro extraído do óxido de ferro e o ferro extraído com o ditionito (Feo/Fed) dos óxidos da área de descarte, o que evidencia uma diminuição da cristalinidade dos óxidos. Foi encontrada uma redução na relação do ferro extraído com o ditionito e do cromo extraído com o ditionito (Fed/Crd), o que mostra a substituição do ferro pelo cromo nos óxidos, evidenciando uma troca isomórfica. Essa alteração pode ser uma alternativa para a retenção de cromo pelo solo com grande força.


ABSTRACT The tannery sludge disposal in the soil has been a serious environmental problem due to the high chromium concentrations. The aim of this study was to evaluate the iron oxides dynamic and chromium concentrations linked to these minerals in areas of tannery sludge disposal. So, concentration of iron and chromium extracted with ammonium oxalate from oxides with low crystallinity and with dithionite-citrate-bicarbonate from the crystalline oxides in the clay fraction was evaluated. The concentration of chromium extracted from the iron oxides with low crystallinity varied between 3.5 and 4.1 mg kg-1 in the treatments without application of tannery, and between 19.9 and 56.8 mg kg-1 in the treatments with tannery application. The concentration of chromium extracted from the crystalline oxides varied between 21.3 and 23.3 mg kg-1 in the treatments without application of tannery sludge, and between 46.4 and 103.0 mg kg-1 in the treatments with tannery. The application of tannery promoted an increase in the relation between the iron extracted from the iron oxides and the iron extracted with dithionite (Feo/Fed) and the oxides from the disposal area, which is an evidence of the oxide crystallinity decrease. A reduction was found in the relation between the iron extracted with dithionite and the chromium extracted with dithionite (Fed/Crd), what shows the substitution of the iron by chromium in the oxides, emphasizing an isomorphic substitution. This isomorphic substitution can be an alternative to maintain the chromium in the soil with strong retention.

8.
Braz. arch. biol. technol ; 61: e18161189, 2018. tab, graf
Artigo em Inglês | LILACS-Express | ID: biblio-974057

RESUMO

ABSTRACT This study aimed to evaluate the effect of Ilex paraguariensis infusion on redox state of Wistar rats submitted to high-fat and standard diet. Glutathione determination and lipid peroxidation in the hippocampus tissues and liver was performed, as well as the analysis of gene expression of superoxide dismutase, catalase and glutathione peroxidase by real-time polymerase chain reaction. The results from hippocampus showed that the groups fed with standard diet exhibited significant reduction of lipid peroxidation when supplemented with Ilex paraguariensis. The analysis from glutathione determination in the hippocampus showed a significant increase in glutathione activity in the group treated with high-fat diet and Ilex paraguariensis. In the liver, results showed no significant difference in both glutatione and lipid peroxidation analisys. Gene expression of superoxide dismutase, catalase and glutathione peroxidase showed that there was significant difference in the groups treated with high-fat diet and Ilex paraguariensis. In summary, the Ilex paraguariensis showed substantial potential for antioxidant activities.

9.
Environ Monit Assess ; 190(1): 3, 2017 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-29209785

RESUMO

Sediments are formed by deposition of organic and inorganic particles on depth of water bodies, being an important role in aquatic ecosystems, including destination and potential source of essential nutrients and heavy metals, which may be toxic for living organisms. The Lake Guaíba supplies water for approximately two million people and it is located in the metropolitan region of Porto Alegre, Rio Grande do Sul State, Brazil. Thus, the aim of this study was to evaluate the sediment pollution in the margins of Lake Guaíba in the vicinity of Porto Alegre city. Surface sediment was sampled in 12 sites to assess the concentration of several elements (C, N, P, Fe, Al, Ca, Mg, Na, K, Mn, Ba, Zn, V, Pb, Cu, Cr, Ni, Cd, Mo, and Se) and the mineralogical composition. Sediment in margins of Lake Guaíba presented predominantly (> 95%) sandy fraction in all samples, but with significant differences between evaluated sites. Sediments in the margins of Lake Guaíba showed indications of punctual water pollution with Pb, Cu, Cr, Ni, TOC, TKN, and P, mainly derived from urban streams that flow into the lake. In order to solve these environmental liabilities, public actions should not focus only on Guaíba, but also in the streams that flow into the lake.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Brasil , Cidades , Poluição Ambiental , Lagos/química , Metais Pesados/análise , Rios
10.
J Trace Elem Med Biol ; 40: 37-45, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28159220

RESUMO

Selenium is an essential nutrient for all living organisms. Under appropriate conditions lactic acid bacteria (LAB) are capable for accumulating large amounts of trace elements, such as selenium, and incorporating them into organic compounds. In this study, the capacity of selenium bioaccumulation by Enterococcus durans LAB18s was evaluated. The distribution of organic selenium in selenium-enriched E. durans LAB18s biomass was analyzed, and the highest percentage of organic selenium was found in the fraction of total protein, followed by the fractions of polysaccharides and nucleic acids. When the protein fraction was obtained by different extractions (water, NaCl, ethanol and NaOH) it was demonstrated that alkali-soluble protein showed the higher Selenium content. Analysis of protein fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that selenium was present in the proteins ranging from 23 to 100kDa. The cells were analyzed by scanning electron microscopy (SEM); scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) and transmission electron microscopy (TEM). SEM, TEM and SEM/EDS showed the morphology, the selenium particles bioaccumulated into and on the cells and the amounts of selenium present into the cells, respectively. Thus, the isolate E. durans LAB18s can be a promising probiotic to be used as selenium-enriched biomass in feed trials.


Assuntos
Enterococcus/química , Enterococcus/metabolismo , Selênio/análise , Selênio/metabolismo , Biomassa
11.
Environ Sci Pollut Res Int ; 24(6): 5908-5917, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28064395

RESUMO

Adsorption of copper ions onto chitosan films was studied, and the matrix effect was evaluated using a synthetic solution and a real effluent from closed copper mine. Chitosan films were prepared by casting technique and characterized. The adsorption study was carried out by equilibrium isotherms, thermodynamics, and kinetics. The thermodynamic parameters indicated that the copper adsorption onto chitosan film was favorable, spontaneous, and exothermic, suggesting an increased randomness at the solid/solution interface. The matrix effect was evaluated in kinetic assays, where a synthetic solution and a real system were carried out at different stirring rates. The highest values of adsorption capacity reached in all stirring rates were about 20% lower in the real effluent, and this reduction in the competitiveness was due to the presence of other ions in the matrix of the real effluent. The maximum adsorption capacity of copper ions onto chitosan films for the synthetic solution was of 450 mg g-1, and the removal percentage was in the range from 78 to 96%, and these values for the real effluent were of 360 mg g-1 and removal ranging from 62 to 76%. The mapping done of ions present in the water adsorbed of the mine in the films showed that the same was homogeneously distributed in the films' surfaces.


Assuntos
Quitosana/química , Cobre/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Soluções , Termodinâmica , Águas Residuárias/análise , Purificação da Água/métodos
12.
Ciênc. rural ; 46(2): 267-272, fev. 2016. tab, graf
Artigo em Português | LILACS-Express | ID: lil-767646

RESUMO

RESUMO: A destinação final adequada dos resíduos sólidos industriais é um dos principais problemas ambientais. A disposição de resíduos orgânicos em solos pode ser recomendada, dado o potencial corretivo e fertilizante deste. Assim, o objetivo deste estudo foi avaliar o efeito em solos da adição de doses de lodo de estação de tratamento de efluentes (ETE) de um aterro industrial na atividade microbiana, avaliada pela mineralização de carbono. Foi desenvolvido experimento em frascos respirométricos, analisando a mineralização de carbono em três solos, com cinco doses de lodo durante 91 dias de incubação. A aplicação de lodo com 2Mg ha-1 causou menores impactos à microbiota do solo, não apresentando diferenças em relação ao tratamento controle. Os valores de carbono mineralizado aumentaram com o tempo de incubação em função da adição do lodo, proporcionalmente ao aumento das doses de lodo. A atividade microbiana aumentou com a aplicação de doses de lodo de ETE de aterro industrial, sendo a mineralização de carbono proporcional às doses adicionadas.


ABSTRACT: The final disposal of industrial solid waste is a major environmental problem. Disposal of organic wastes in soils can be recommended as corrective and fertilizer. The objective of this study was to evaluate the effect of different doses of wastewater treatment plant sludge (WWTP) from an industrial landfill on soils based in microbial activity measured by carbon mineralization. The experiment was developed in respirometric flasks, analyzing carbon mineralization in three soils with five doses of sludge during 91 days of incubation. Application of sewage sludge with 2 Mg ha-1 caused minor impacts on soil microorganisms, without statistical differences to the control treatment. Amounts of mineralized carbon increased with the time course due to the addition of sludge, proportional to the doses of sludge. Microbial activity increased with the application of WWTP sludge doses of industrial landfill, with mineralization proportional to the increase in carbon added doses.

13.
Eng. sanit. ambient ; 20(4): 699-708, out.-dez. 2015. tab, graf
Artigo em Português | LILACS-Express | ID: lil-769722

RESUMO

RESUMO A produção de resíduos orgânicos durante os processos agroindustriais é um problema tanto ambiental quanto econômico devido às características químicas desses resíduos. Geralmente, resíduos orgânicos estabilizados servem como condicionadores de solos. Esses resíduos podem afetar tanto na composição química quanto nas características das cargas trocáveis dos solos. O objetivo deste trabalho foi avaliar a formação de substâncias húmicas (SH) durante a vermicompostagem em diferentes resíduos agroindustriais, bem como caracterizar a composição química e molecular. Assim, diferentes resíduos - esterco bovino (EB), esterco ovino (EO), restos de alimentos de restaurantes (RA), lodo de arroz parboilizado (LP), restos de frutas e vegetais (RF) - foram submetidos à vermicompostagem. Amostras desses materiais foram secas, trituradas e caracterizadas quimicamente quanto a pH, carbono (C) orgânico, N total, Ca, Mg, K, P, relação C/N, e condutividade elétrica (CE) antes, durante e depois do processo de vermicompostagem. Além disso, foi analisado o fracionamento da matéria orgânica como as SH, análise elementar e espectroscopia de infravermelho. De acordo com o processo de vermicompostagem dos resíduos agroindustriais, o carbono orgânico total (COT) e os ácidos fúlvicos (AF) foram reduzidos; contudo, os ácidos húmicos (AH) aumentaram proporcionalmente. Dentre os vermicompostos estudados diferiram quanto à proporção final de SH formadas decrescendo na sequência: EB>RF>EO>RA>LP. Isso demonstra uma estabilização dos compostos orgânicos por meio da vermicompostagem, podendo, consequentemente, ser utilizados com uma maior segurança na agricultura.


ABSTRACT The production of organic waste during the agro-industrial processes is a problem for both environmental and economical issues due to the chemical characteristics of these wastes. Generally, stabilized organic residues are used as soil conditioners. These residues can affect both the chemical composition and the characteristics of exchangeable charges of the soils. The aim of this study was to evaluate the formation of humic substances during the vermicomposting of different agro-industrial solid residues, as well as characterize the chemical and molecular composition. So, different residues (bovine manure (EB), sheep manure (EO); food waste from restaurants (RA); mud of parboiled rice (LP); waste of fruits and vegetables (RF)) were subjected to vermicomposted. Samples of these materials were dried, smashed and chemically characterized as pH, organic carbon, total nitrogen, Ca, Mg, K, P, C/N ratio, and electrical conductivity (EC) before, during and after the vermicomposting process. In addition, it was analyzed the fractionation of organic matter such as humic substances, elemental analysis and infrared spectroscopy. According to the vermicomposting process of agro-industrial wastes, the total organic carbon and fulvic acids were reduced; however, humic acids increased proportionately. Among the studied vermicomposts, they differ in the final ratio of humic substances formed decreasing following: EB>RF>AND>RA>LP. This demonstrates a stabilization of organic compounds through the vermicompost process, and therefore can be used with greater safety in agriculture.

14.
Biosci. j. (Online) ; 31(1): 135-145, jan./fev. 2015.
Artigo em Português | LILACS | ID: biblio-963700

RESUMO

A fabricação de aço está expandindo sua produção, o que vem aumentando a quantidade de resíduos sólidos gerados. As escórias básicas de aciaria apresentam características de corretivo da acidez do solo e fonte de nutrientes para as plantas, porém apresentam alguns metais pesados em sua constituição. O presente trabalho teve como objetivo avaliar o efeito da aplicação de escória de siderurgia na correção da acidez do solo e no aporte de metais pesados, como manganês (Mn), cobre (Cu), zinzo (Zn), cádmio (Cd), cromo (Cr) e níquel (Ni). O estudo foi conduzido em amostras de um Argissolo Vermelho Distrófico típico, dispostas em colunas e mantidas a céu aberto, em delineamento experimental de blocos casualizados, com quatro repetições. Os tratamentos consistiram em doses diferentes de escória de siderurgia com diferentes granulometrias, incluindo tratamentos com solo sob condição natural (controle) e corrigido (carbonato de cálcio e magnésio e adubação com nitrogênio, fósforo e potássio). Aos 12, 18 e 24 meses após a aplicação dos tratamentos foram coletadas amostras de solo das colunas para avaliação da reatividade da escória. A escória básica de aciaria finamente moída teve efeito similar ao carbonato na correção do pH do solo, no aumento da CTC efetiva e da saturação de bases. Partículas com diâmetro até 15 mm também foram efetivas para aumentar os valores desses atributos. As maiores doses de escória aumentaram os teores de Mn, Cr e Ni no solo em relação ao controle. Os resultados obtidos neste estudo, demonstram que a escória de siderurgia tem potencial para a utilização na correção do pH do solo.


As the majority of industrial processes, siderurgy activities generate large amounts of residues. The siderurgic slags, byproducts of steel production have chemical characteristics that indicate their possible use in agriculture, as liming materials and sources of some plant nutrients. However, they may enclose undesired components, like heavy metals, which may result in situations of environmental hazard. In order to evaluate the effect on soil chemical properties and heavy metals accumulation in the soil by the application of steel basic slag, an experiment was carried out in soil columns (Typic Paleudult; 10 dm3/column soil volume), under natural rainfall conditions, in a completely randomized design with four replications. Soil treatments based on the liming rate do achieve pH 6,5 by the SMP method were: T1) Control; T2) CaCO3+MgCO3 (neutralizing value - PN 100%); T3) Treat. 2 + NPK fertilizers; T4) Slag - 1 x rate (particles < 0,149 mm e PN 60%); T5) Treat. 4 + NPK; T6) Slag - 2 x rate (1/3 particles < 0,149 mm e 2/3 particles 0,149 ­ 0,5 mm) + NPK; T7) Treat. 4 + N fertilizer; T8) Slag - 5 x rate (particles 0,5 ­ 2,0 mm) + Treat. 3; T9) Slag - 10 x rate (particles 2,0 ­ 15,0 mm) + Treat. 3. At equivalent rates both slag and carbonate increased similarly the values of pH, effective CEC and bases saturation in the soil. These attributes were higher for the treatments with slag at higher rates and larger particle size denoting the reactivity of the coarse factions. Among the analyzed metals, only Mn, Cr and Ni at higher slag rates (2, 5 and 10 x) increased in the soil to values significantly higher than the control and carbonate treatments. The results show that the used scoria is efficient as liming material and that it is not expected to provide excessive heavy metals accumulation when applied at rates to rise pH value up to 6,5 in soils with similar characteristics to that of this study. In summary, the slag exhibited a high potential for Ph corrections in soil.


Assuntos
Acidez do Solo , Alimentos , Metais Pesados , Resíduos Industriais
15.
Biosci. j. (Online) ; 31(1): 127-134, jan./fev. 2015.
Artigo em Português | LILACS | ID: biblio-963697

RESUMO

Com a industrialização, a produção de resíduos tem aumentado durante os anos. Além disso, a disposição destes resíduos é uma posição discutida entre os órgãos ambientais. Em virtude disto, o objetivo foi estudar o efeito residual de adições sucessivas de resíduos de curtume e carboníferos sobre as propriedades químicas do solo e o acumulo de metais pesados nas plantas de cenoura. Os tratamentos aplicados a campo foram T1 = Controle, somente solo; T2 = Adubação com NPK + calcário para atingir pH 6,0; T3 = Lodo de curtume em quantidade adequada para atingir pH 6,0 + PK; T4 = Duas vezes a quantidade de lodo de curtume utilizada no tratamento 3 + PK; T5 = Resíduo carbonífero + NPK + calcário em quantidade adequada para atingir pH 6,0; T6 = Resíduo carbonífero + lodo de curtume em quantidade adequada para atingir pH 6,0 + PK; T7 = Serragem cromada + NPK + calcário em quantidade adequada para atingir pH 6,0; T8 = Cr mineral + lodo de curtume em quantidade adequada para atingir pH 6,0 + PK. O experimento foi conduzido em delineamento inteiramente casualizado, com três repetições por tratamento. A adição de cromo, tanto via mineral, quanto via resíduos não afetaram o crescimento da cenoura. Além disso, os teores encontrados na parte aérea, radicular, e córtex da raiz são considerados baixos, demonstrando um baixo potencial de contaminação destes resíduos.


With the industrialization, waste production has been increased over the years. Moreover, the disposition of these wastes is a position discussed among environmental agencies. So, the aim of this study was to evaluate the residual effect of successive additions of tannery waste and coal on the chemical properties of the soil and the accumulation of heavy metals in carrot plants. The treatments were applied to field: T1 = Control, only solo; T2 = fertilization with NPK + lime to reach pH 6.0; T3 = tannery sludge in adequate quantity to achieve pH 6.0 + PK; T4 = Twice the amount tannery sludge used in treatment 3 + PK; T5 = waste coal + NPK + lime in adequate quantity to achieve pH 6.0; T6 = waste coal + tannery sludge in adequate quantity to achieve pH 6.0 + PK; T7 = Sawdust = chrome + NPK + lime in adequate quantity to reach pH 6.0; T8 = Cr + mineral tannery sludge in adequate quantity to achieve pH 6.0 + PK. The experiment was conducted in a completely randomized design, with three replicates per treatment. The results demonstrate that carrot plants grew normally in the treatments with high chromium concentrations, either addition with residues or mineral. Furthermore, the levels found in the shoots, roots and roots cortex were low, indicating a low potential of these waste contamination.


Assuntos
Solo , Curtume , Resíduos , Cromo , Daucus carota , Metais Pesados
16.
Environ Sci Pollut Res Int ; 21(4): 2592-602, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24091525

RESUMO

This study investigated the effectiveness of successive bioaugmentation, conventional bioaugmentation, and biostimulation of biodegradation of B10 in soil. In addition, the structure of the soil microbial community was assessed by polymerase chain reaction-denaturing gradient gel electrophoresis. The consortium was inoculated on the initial and the 11th day of incubation for successive bioaugmentation and only on the initial day for bioaugmentation and conventional bioaugmentation. The experiment was conducted for 32 days. The microbial consortium was identified based on sequencing of 16S rRNA gene and consisted as Pseudomonas aeruginosa, Achromobacter xylosoxidans, and Ochrobactrum intermedium. Nutrient introduction (biostimulation) promoted a positive effect on microbial populations. The results indicate that the edaphic community structure and dynamics were different according to the treatments employed. CO2 evolution demonstrated no significant difference in soil microbial activity between biostimulation and bioaugmentation treatments. The total petroleum hydrocarbon (TPH) analysis indicated a biodegradation level of 35.7 and 32.2 % for the biostimulation and successive bioaugmentation treatments, respectively. Successive bioaugmentation displayed positive effects on biodegradation, with a substantial reduction in TPH levels.


Assuntos
Achromobacter denitrificans/fisiologia , Biocombustíveis , Brucellaceae/fisiologia , Gasolina , Hidrocarbonetos/metabolismo , Pseudomonas aeruginosa/fisiologia , Poluentes do Solo/metabolismo , Achromobacter denitrificans/isolamento & purificação , Biodegradação Ambiental , Brucellaceae/isolamento & purificação , Dióxido de Carbono/metabolismo , DNA Bacteriano/genética , Eletroforese em Gel de Gradiente Desnaturante , Consórcios Microbianos/fisiologia , Reação em Cadeia da Polimerase , Pseudomonas aeruginosa/isolamento & purificação , RNA Ribossômico 16S/genética , Microbiologia do Solo
17.
Biol Trace Elem Res ; 155(3): 447-54, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24037644

RESUMO

Selenium (Se) is an essential micronutrient for several organisms, and there is an increased interest about adequate sources for dietary selenium supplementation. The aim of this study was to evaluate the selenium bioaccumulation capacity of an Enterococcus strain. The isolate LAB18s was identified as Enterococcus durans by the VITEK® 2 system and analysis of both 16S rDNA gene sequence (JX503528) and the 16S-23S rDNA intergenic spacer (ITS). After 24-h incubation, E. durans LAB18s bioaccumulated elevated Se(IV) concentrations, reaching 2.60 and 176.97 mg/g in media containing initial amounts of 15 and 240 mg/l sodium selenite, respectively. The isolate grew optimally and had high selenium bioaccumulation at initial pH of 7.0 and 30 °C. Time course studies showed that E. durans LAB18s displayed the highest bioaccumulation of Se(IV) after 6 h of incubation. Analyses from scanning electron microscopy (SEM) demonstrated the presence of filaments connecting the cells of E. durans LAB18s cultivated in the presence of sodium selenite. It was demonstrated that a considerable amount of Se(IV) was absorbed by E. durans LAB18s. Therefore, this strain may represent an alternative source of organic dietary selenium.


Assuntos
Biomassa , Enterococcus/metabolismo , Selênio/metabolismo , DNA Ribossômico , Suplementos Nutricionais , Enterococcus/classificação , Enterococcus/genética , Probióticos
18.
Biol Trace Elem Res ; 152(3): 411-6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23417495

RESUMO

High copper concentration is toxic for living organisms including humans. Biosorption is a bioremediation technique that can remove copper and other pollutants from aqueous medium and soils, consequently cleaning the environment. The aim of this study was, therefore, to investigate the influence of different copper compounds (Cu(II) as CuCl2; Cu(II) as CuSO4; and Cu(I) as CuCl) on copper bioreduction and biosorption using four copper-resistant bacteria isolated from the rhizosphere of two plants (Avena sativa and Plantago lanceolata) in aqueous matrix. Copper resistance profile, bioreduction, and biosorption after 48 h of incubation were evaluated. The isolates displayed high copper resistance. However, isolate A1 did not grow very well in the CuCl2 and isolate T5 was less resistant to copper in aqueous solutions amended with CuCl (Cu(I)). The best copper source for copper bioreduction and biosorption was CuSO4 and the isolates removed as much as ten times more copper than in aqueous solutions amended with the other copper compounds. Moreover, Cu(I) did not succumb to biosorption, although the microbes were resistant to aqueous solutions of CuCl. In summary, Cu(II) from CuSO4 was furthermost susceptible to bioreduction and biosorption for all isolates. This is an indication that copper contamination of the environment from the use of CuSO4 as an agrochemical is amenable to bioremediation.


Assuntos
Sulfato de Cobre/isolamento & purificação , Cobre/isolamento & purificação , Poluentes Ambientais/isolamento & purificação , Acinetobacter/genética , Acinetobacter/crescimento & desenvolvimento , Acinetobacter/isolamento & purificação , Adsorção , Avena/microbiologia , Biodegradação Ambiental , Biomassa , Farmacorresistência Bacteriana , Oxirredução , Raízes de Plantas/microbiologia , Plantago/microbiologia , Pseudomonas putida/genética , Pseudomonas putida/crescimento & desenvolvimento , Pseudomonas putida/isolamento & purificação , RNA Ribossômico 16S/genética , Rizosfera , Soluções , Stenotrophomonas maltophilia/genética , Stenotrophomonas maltophilia/crescimento & desenvolvimento , Stenotrophomonas maltophilia/isolamento & purificação , Água
19.
Ciênc. rural ; 43(2): 270-276, Feb. 2013. ilus, tab
Artigo em Português | LILACS-Express | ID: lil-665890

RESUMO

O cultivo de olerícolas pode ser produzido no sistema convencional utilizando defensivos agrícolas e fertilizantes sintéticos, ou no sistema orgânico, quando não há a utilização de defensivos sintéticos e tem como principal fonte de adubação, resíduos orgânicos. Este trabalho teve como objetivo avaliar a biomassa e a atividade microbiana do solo em sistemas de cultivo orgânico e convencional com suas respectivas áreas de referência. Para isso, foram coletadas amostras de solo em três propriedades agrícolas com sistema de cultivo convencional e outras três com sistema de cultivo orgânico, além de suas respectivas áreas de referência. Foram determinados o carbono e nitrogênio microbiano e total, e a respiração basal após 57 dias de incubação. A maior variação na taxa de respiração basal entre a área de produção e a área de referência foi observada no sistema orgânico. Os teores de nutrientes no solo, carbono e nitrogênio microbianos foram maiores nas áreas de produção do que os encontrados nas áreas de referência.


The horticultural crops can be produced with the conventional system using pesticides and synthetic fertilizers, or organic system where there is no use of synthetic pesticides and its main source of nutrients are organic wastes. This study aimed to assess the biomass and soil microbial activity in organic production systems and conventional with their respective reference areas. In this study, soil samples were sampled in three farms with conventional tillage and three other with organ system, and their respective reference areas. It was determined total carbon and nitrogen and microbial, and microbial activity after 57 days of incubation. The greatest variation in basal respiration rate between the respective production area and reference area was observed in the organic system. The nutrients in the soil microbial carbon and nitrogen were higher in the production areas than those in the reference areas.

20.
Biodegradation ; 24(3): 319-31, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22983740

RESUMO

Methylmercury (MeHg) is one of the most dangerous heavy metal for living organisms that may be found in environment. Given the crescent industrialization of Brazil and considering that mercury is a residue of several industrial processes, there is an increasing need to encounter and develop remediation approaches of mercury contaminated sites. The aim of this study was to isolate and characterize methylmercury resistant bacteria from soils and sludge sewage from Rio Grande do Sul, Brazil. Sixteen bacteria were isolated from these contaminated sites and some isolates were highly resistant to methylmercury (>8.7 µM). All the isolates were identified by 16S rDNA. Pseudomonas putida V1 was able to volatilize approximately 90 % of methylmercury added to growth media and to resist to copper, lead, nickel, chromate, zinc, cobalt, manganese and barium. In the presence of high concentrations of methylmercury (12 µM), cell growth was limited, but P. putida V1 was still able to remove up to 29 % of this compound from culture medium. This bacterium removed an average of 77 % of methylmercury from culture medium with pH in the range 4.0-6.0. In addition, methylmercury was efficiently removed (>80 %) in temperature of 21-25 °C. Polymerase chain reactions indicated the presence of merA but not merB in P. putida V1. The growth and ability of P. putida V1 to remove methylmercury in a wide range of pH (4.0 and 8.0) and temperature (10-35 °C), its tolerance to other heavy metals and ability to grow in the presence of up to 11.5 µM of methylmercury, suggest this strain as a new potential resource for degrading methylmercury contaminated sites.


Assuntos
Recuperação e Remediação Ambiental/métodos , Compostos de Metilmercúrio/isolamento & purificação , Pseudomonas putida/isolamento & purificação , Microbiologia do Solo , Poluentes do Solo/isolamento & purificação , Brasil , Pseudomonas putida/metabolismo
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