Biogeodisponibilidade de metais em áreas impactadas por hidrocarbonetos policíclicos aromáticos (HPAs) utilizando a técnica phytoscreening
Carregando...
Data
2021-05-06
Autores
Prieto-Hernández, Ingrid Johanna
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O principal objetivo deste estudo é determinar o teor de metais presentes no solo e no caule das arvores de um local contaminado por Hidrocarbonetos Policíclicos Aromáticos (HPAs), bem como a avaliação de sua transferência na vegetação florestal usando a técnica Phytoscreening (Tree Coring). Phytoscreening é uma ferramenta não invasiva e de baixo custo, bastante utilizada na Europa, que emprega núcleos de árvores como bio-indicador para detectar poluentes nos solos e será aplicada na madeira de Piptadenia gonoacantha, Croton floribundus, Allophylus edulis e Alchornea gladulosa. A escolha das árvores foi feita baseando-se na abundância representativa das espécies no local de estudo para identificar potenciais contaminantes metálicos e delimitação da pluma da contaminação na subsuperfície do local. Os núcleos das árvores foram retirados do tronco, para as análises foi realizada a secagem das amostras até peso constante, depois foram moídas em um moinho criogênico para homogeneização e digeridas em um forno de micro-ondas. Os extratos obtidos na digestão foram analisados pela técnica de espectrometria de massas com plasma indutivamente acoplado (ICP MS). As amostras do solo foram secas em temperatura ambiente, homogeneizadas e peneiradas para ser digeridas em micro-ondas e analisadas por ICP MS para determinar o teor total dos elementos, adicionalmente as mesmas amostras foram tratadas pelo método de Mehlich, segundo o manual da EMBRAPA para a extração dos microelementos por meio de solução mista de ácidos. A determinação dos elementos foi feita espectrômetria de emissão ótica com plasma indutivamente acoplado (ICP-OES). Para avaliar a relação dos resultados de elementos traços nas amostras, foi realizada uma análise estatística dos dados, para detectar diferenças significativas entre resultados das áreas de estudo impactadas e das áreas de referências e se existe correlações entre as concentrações de metais no solo e as concentrações de metais analisadas por phytoscreening. Foram analisados um total de 17 elementos para as amostras dos núcleos das árvores e solos, dos quais foram discutidos os resultados dos elementos com valores superiores que o LD. Para os elementos Cr, Fe, Cu, Mn, Ni a média não é representativa estatisticamente na comparação entre área controle e área impactada, o que sugere que não ouve aparentemente alteração nas concentrações ambientais. Comparando os resultados do Fator de Bioconcentração entre as espécies do local de estudo concluímos que a espécie Croton floribundus é a que mais bioconcentra metais. Os metais Cu, Fe, Mn, Ni, Pb e Zn não tem correlação entre o teor lábil e o teor dos troncos, o que significa que a planta não está absorvendo tudo o que está biodisponível e que não tem diferença entre a área controle e a área impactada. A exceção do Ferro os metais Cromo, Cobre, Manganês, Níquel, Chumbo e Zinco analisados pelo teste de Mann-Whitney de comparação de grupos não têm uma diferencia significava entre área controle e a área impactada. A técnica Tree Coring associada a outras técnicas quantitativas pode ser uma ferramenta útil na avaliação de metais.
The main objective of this study is to determine the content of metals present in the soil and in the stem of trees in a site contaminated by Polycyclic Aromatic Hydrocarbons, as well as the evaluation of their transfer in forest vegetation using the Phytoscreening technique (Tree Coring). Phytoscreening is a non-invasive and low-cost tool, widely used in Europe, which uses tree cores as a bio-indicator to detect pollutants in soils and will be applied to the wood of Piptadenia gonoacantha, Croton floribundus, Allophylus edulis and Alchornea gladulosa. The choice of trees was made based on the representative abundance of species at the study site to identify potential metallic contaminants and delimitation of the contamination plume in the subsurface of the site. The nuclei of the trees were removed from the trunk, for analysis the samples were dried to constant weight, then they were ground in a cryogenic mill for homogenization and digested in a microwave oven. The extracts obtained in the digestion were analyzed by the technique of inductively coupled plasma mass spectrometry (ICP MS). Soil samples were dried at room temperature, homogenized and sieved to be digested in microwaves and analyzed by ICP MS to determine the total content of the elements, additionally the same samples were treated by the Mehlich method, according to the EMBRAPA manual for the extraction of microelements through mixed acid solution. The elements were determined using inductively coupled plasma optical emission spectrometry (ICP-OES). To assess the relationship of trace element results in the samples, a statistical analysis of the data was performed to detect significant differences between results from the impacted study areas and the reference areas and whether there are correlations between metal concentrations in the soil and concentrations of metals analyzed by phytoscreening. A total of 17 elements were analyzed for the samples of tree cores and soils, from which the results of elements with values higher than the LD were discussed. For the elements Cr, Fe, Cu, Mn, Ni the mean is not statistically representative in the comparison between the control area and the impacted area, which suggests that there is apparently no change in environmental concentrations. Comparing the results of the Bioconcentration Factor among the species in the study site, we concluded that the species Croton floribundus is the one that more bioconcentrates metals. The metals Cu, Fe, Mn, Ni, Pb and Zn have no correlation between the labile content and the content of the trunks, which means that the plant is not absorbing everything that is bioavailable and that there is no difference between the control area and the impacted area. With the exception of Iron, the metals Chromium, Copper, Manganese, Nickel, Lead and Zinc analyzed by the Mann-Whitney test of comparison groups do not have a significant difference between the control area and the impacted area. The Tree Coring technique combined with other quantitative techniques can be a useful tool in metals evaluation.
The main objective of this study is to determine the content of metals present in the soil and in the stem of trees in a site contaminated by Polycyclic Aromatic Hydrocarbons, as well as the evaluation of their transfer in forest vegetation using the Phytoscreening technique (Tree Coring). Phytoscreening is a non-invasive and low-cost tool, widely used in Europe, which uses tree cores as a bio-indicator to detect pollutants in soils and will be applied to the wood of Piptadenia gonoacantha, Croton floribundus, Allophylus edulis and Alchornea gladulosa. The choice of trees was made based on the representative abundance of species at the study site to identify potential metallic contaminants and delimitation of the contamination plume in the subsurface of the site. The nuclei of the trees were removed from the trunk, for analysis the samples were dried to constant weight, then they were ground in a cryogenic mill for homogenization and digested in a microwave oven. The extracts obtained in the digestion were analyzed by the technique of inductively coupled plasma mass spectrometry (ICP MS). Soil samples were dried at room temperature, homogenized and sieved to be digested in microwaves and analyzed by ICP MS to determine the total content of the elements, additionally the same samples were treated by the Mehlich method, according to the EMBRAPA manual for the extraction of microelements through mixed acid solution. The elements were determined using inductively coupled plasma optical emission spectrometry (ICP-OES). To assess the relationship of trace element results in the samples, a statistical analysis of the data was performed to detect significant differences between results from the impacted study areas and the reference areas and whether there are correlations between metal concentrations in the soil and concentrations of metals analyzed by phytoscreening. A total of 17 elements were analyzed for the samples of tree cores and soils, from which the results of elements with values higher than the LD were discussed. For the elements Cr, Fe, Cu, Mn, Ni the mean is not statistically representative in the comparison between the control area and the impacted area, which suggests that there is apparently no change in environmental concentrations. Comparing the results of the Bioconcentration Factor among the species in the study site, we concluded that the species Croton floribundus is the one that more bioconcentrates metals. The metals Cu, Fe, Mn, Ni, Pb and Zn have no correlation between the labile content and the content of the trunks, which means that the plant is not absorbing everything that is bioavailable and that there is no difference between the control area and the impacted area. With the exception of Iron, the metals Chromium, Copper, Manganese, Nickel, Lead and Zinc analyzed by the Mann-Whitney test of comparison groups do not have a significant difference between the control area and the impacted area. The Tree Coring technique combined with other quantitative techniques can be a useful tool in metals evaluation.
Descrição
Palavras-chave
Phytoscreening, ICP MS, Labilidade, Biodisponibilidade, Contaminação de solo, Hidrocarbonetos Policíclicos Aromáticos (HPAs), Lability, Bioavailability, Soil contamination, Polycyclic Aromatic Hydrocarbons (HPAs)