An integrated interdisciplinary approach to evaluate potentially toxic element sources in a mountainous watershed

Potentially toxic elements (PTEs, i.e., Cd, Ni, Cr) and their source apportionment in waters are of major environmental concern. Different approaches can be used to evaluate PTEs sources in environment, but single-way approaches are often limited and can easily fail. PTEs sources apportionment should include the evaluation of geochemical background and spatiotemporal trends analyses. We propose an integrated approach, and we apply it to a mountain catchment in the Italian central Alps, where ultramafic terranes crop out. We collected water and glacial sediment samples during the melting season. Then, we analyzed major ions and PTEs in waters, and we quantified the total PTEs load in sediments through acid digestion. Data were then processed through spatial and temporal trends analysis, clustering of variables and the evaluation of partition between the different compartments. We found a high geochemical background of part of the PTEs, consistently with results from other areas worldwide on mafic and ultramafic terranes (high concentrations of Ni, Cr and Fe), while we identified an additional atmospheric deposition source for Zn, Cd and Ag. Also, redundant observations on Cu, As and Pb indicated a possible mixed source. This study elucidates the need for an integrated approach to avoid unnecessary or misleading assumptions in the PTE\u2019s source appointment. A single-way approach application, in fact, can fail in understanding element source in a complicated and dynamic compartment like surface water

What Are Lake Beaches Made of? An Assessment of Plastic Beach Litter on the Shores of Como Bay (Italy)

Plastic waste dispersion is a well-recognized environmental threat, despite continuous efforts towards improving waste disposal management over the last few decades. Plastic litter is known to strongly impact upon water bodies and shorelines, affecting the health of ecosystems and impacting upon the aesthetic value of sites. Moreover, plastic waste that is abandoned on beaches contributes towards different degradation processes that potentially lead to the formation of secondary microplastics (MPs), with likely cascade effects upon the whole ecosystem. In this view, this study aims to characterize the plastic beach litter found on the shores of the western basin of Como Lake (Italy) to better understand the origin of MPs in littoral sediments, including the recognition of object typologies and the chemical characterization of polymers using Fourier-transformed infrared analysis (FTIR). The results highlighted that the most abundant polymers on beaches are polypropylene (PP) and polyethylene (PE), representing 73% of the collected polymers. This confirms that floating, low-density polymers are more likely to accumulate on beaches. Moreover, almost 66% of litter is represented by commonly used manufactured items (disposable objects, packaging, and everyday items). This evidence, combined with the analysis of the main environmental features of the sampling sites (the main winds, distance to urban areas, and the presence of tributaries) indicate that abundance of beached litter is mainly linked to beach accessibility and the local winds. These results highlight that multiple factors affect the environmental fate of plastic litter and give insights into the assessment of secondary microplastics in beach sediments.publishedVersio

MAPEAMENTO DE CARACTERÍSTICAS FÍSICAS DO RELEVO DA CIDADE DE GUARAPUAVA-PR UTILIZANDO TÉCNICAS DE GEOPROCESSAMENTO

The relief is the main physical agent that interferes with human occupation. Normally, occupation begins in favorable areas and only later, with the urban expansion, it extends to unfavorable ones. In this context, this work aims to elaborate an integrated study of the relief physical features of Guarapuava-PR urban perimeter. Three methodological procedures were used: bibliographic research, field and laboratory/cabinet works. Screening of several variables (hydrography and urban river basin, hipsometry, declivity, source exposition, relief soil and shape) was performed through geoprocessing techniques using SPRING version 4.3.3 software. The knowledge of urban space physical features, limitations and potentialities is important to establish more reasonable actions regarding soil usage and to make urban planning that fits better such specifity.O relevo é o principal agente físico que interfere a ocupação urbana. Normalmente, essa se inicia em áreas mais favoráveis e, somente depois, com a expansão urbana acabam ocupando áreas impróprias. É neste viés que se insere a presente pesquisa, visando elaborar um estudo integrado das características físicas do relevo no perímetro urbano da cidade de Guarapuava-PR. Para isso utilizou-se de três procedimentos metodológicos: pesquisa bibliográfica; trabalhos de campo e de laboratório/gabinete. Com o auxílio de técnicas de geoprocessamento e utilização do software SPRING versão 4.3.3, foram realizados mapeamentos para cada variável (hidrografia e bacias hidrográficas urbanas, hipsometria, declividade, exposição de vertentes, solos e formas de relevo). Conhecer as características físicas do espaço urbano, as limitações e as potencialidades torna-se de grande valia para o estabelecimento de práticas mais racionais de uso do solo e de um planejamento urbano mais condizente com tais especificidades

Comparação entre produtos cartográficos gerados a partir de cartas base de diferentes escalas: o caso da cidade de Guarapuava(PR)Comparison of cartographic products generated from maps with different scales: the case of Guarapuava (PR)

A escala de um documento refere-se à relação entre as medidas realizadas sobre o mapa e as distâncias correspondentes no real. Entretanto, a restituição de mapas em diferentes escalas conduz à generalização. Atualmente, os avanços tecnológicos conduziram à criação de Sistemas de Informação Geográfica (SIGs), o que permitiu uma variada gama de procedimentos para a elaboração de documentos cartográficos. Nesse sentido, o presente trabalho teve como objetivo comparar os resultados de cartas de hipsometria, declividades e exposição de vertentes do perímetro urbano de Guarapuava (PR), elaboradas a partir de cartas base de diferentes escalas (1:100.000, 1:50.000 e 1:2.000). Os resultados indicam que, na falta de documentos cartográficos em escala de detalhe, tal como 1:2.000, as cartas topográficas na escala de 1:50.000 podem fornecer, apesar da limitação de generalização topográfica, resultados importantes quanto à amplitude topográfica, declividades e exposição de vertentes em termos gerais, permitindo a visualização de áreas de maior ou menor declividade e as principais classes de orientação de vertentes. Porém, a escala de 1:100.000 deve ser evitada, pois os resultados são claros da generalização topográfica nessa escala. Antes de tudo, deve ser pensado no objetivo de cada trabalho para se poder escolher a escala adequada. AbstractThe scale of a document refers to the relationship between measurements accomplished on the map and the real corresponding distances. However, the restitution of maps at different scales runs to the generalization. Currently, technological advances lead to the creation of Geographic Information Systems (GIS), allowing a wide range of procedures for the preparation of cartographic documents. Accordingly, the present study aimed to compare the results of hipsometry map, steepness and slope aspect of the urban perimeter in Guarapuava (PR), elaborated from different maps on different scales (1:100,000, 1:50,000 and 1:2,000). The results indicate that in the lack of cartographic in scale of detail, as 1:2,000, the topographic maps at 1:50,000 scale can provide, in despite of the limitation of topographic generalization, important results in the topography amplitude, steepness and exposure of slopes in general terms, allowing the visualization of areas of major or minor steepness and the main classes of slope aspects. However, the scale of 1:100,000 should be avoided, the results are clear of the topographic generalization in this scale. Above all, it must be thought about the aim of each job in order to choose the appropriated scale

Untangling the role of biotic and abiotic ageing of various environmental plastics toward the sorption of metals

Plastic particles can impact the environmental fate and bioavailability of essential inorganic micronutrients and non-essential (toxic) metals. The sorption of metals to environmental plastic has been demonstrated to be facilitated by plastic ageing, a phenomenon encompassing an array of physical, chemical, and biological processes. This study deploys a factorial experiment to untangle the role of different ageing processes in determining the sorption of metals. Plastics made of three different polymer types were aged both through abiotic (ultraviolet irradiation, UV) and biotic (through the incubation with a multispecies algal inoculum forming a biofilm) processes under controlled laboratory conditions. Pristine and aged plastic samples were characterized for their physiochemical properties through Fourier-transformed infrared spectroscopy, scanning electron microscopy and water contact angle measurements. Their sorption affinity toward aluminum (Al) and copper (Cu) in aqueous solutions was then assessed as a response variable. All ageing processes (alone or combined) influenced plastic surface properties resulting in reduced hydrophobicity, changes in surface functional groups (i.e., increase of oxygen containing functional groups after UV ageing and the appearance of marked bands as amides and polysaccharides after biofouling), as well as in nanomorphology. The sorption of Al and Cu was instead statistically dependent (p < 0.01) on the degree of biofouling covering the specimens. Biofouled plastic displayed in fact substantial affinity for metal sorption causing the depletion of up to tenfold Cu and Al compared to pristine polymers, regardless of the polymer type and presence or absence of other ageing treatments. These results confirm the hypothesis that the accumulation of metals on plastic is substantially driven by the biofilm present on environmental plastics. These findings also highlight the importance of investigating the implications of environmental plastic for metal and inorganic nutrients availability in environments impacted by this pollution

Unfolding the interaction between microplastics and (trace) elements in water: A critical review

Plastic and microplastic pollution is an environmental and societal concern. The interaction of plastic with organic chemicals in the environment has attracted scientific interest. New evidences have highlighted an unexpectedly high affinity of environmental plastics also for metal ions. The degree and typology of plastic ageing (including from mechanical, UV and biological degradations) appear as a pivotal factor determining such an interaction. These earlier evidences recently opened a new research avenue in the plastic pollution area. This review is the first to organize and critically discuss knowledge developed so far. Results from field and laboratory studies of metal accumulation on plastic are presented and the environmental factors most likely to control such an interaction are discussed. On the light of this knowledge, a generalist conceptual model useful for building hypotheses on the mechanisms at stake and directing future studies was elaborated and presented here. Furthermore, all available data on the thermodynamics of the plastic-metal interaction obtained from laboratory experiments are inventoried and discussed here, highlighting methodological and technical challenges that can potentially affect cross-comparability of data and their relevance for environmental settings. Finally, insights and recommendations on experimental approaches and analytical techniques that can help overtaking current limitations and knowledge gaps are proposed

Geoprocessing applied to the phytosociological survey in permanent plots

The goal with this work was to create a georeferenced data bank to follow the phytosociological changes of types of trees along the time and its geographic distribution in the field of study. To the phytosociological survey permanent parcels were plotted in the field of study along the floodplain of the rivers Carro Quebrado and Cascavel, both located in the Campus of the Universidade Estadual do Centro Oeste (UNICENTRO – CEDETEG), in Guarapuava city, Parana state. In each part the attributes analyzed were: sociologic position (SP); class of crown (CC); characteristics of trees (CT); quality conditions of the trunk (QCT); conditions (Cs). These parts were put into spaces with use of the Global Positioning System (GPS) and the data were sent to the SPRING software with the intention to build a cadastral data bank to follow and analyze the development of the local vegetation. The creation of this data bank allowed following the development of trees in a time scale, showing the evolution of the part of the forest studied.O objetivo deste trabalho foi a criação de um banco de dados de georreferenciado para acompanhar as mudanças fitossociológicas dos indivíduos arbóreos ao longo do tempo e sua distribuição geográfica na área de estudo. Para o levantamento fitossociológico na área de estudo foram demarcadas parcelas permanentes ao longo das planícies de inundação dos rios Carro Quebrado e Cascavel, localizados no Campus CEDETEG da Universidade Estadual do Centro-Oeste (UNICENTRO), no município de Guarapuava, Estado do Paraná.  Em cada parcela foram avaliados atributos como: PS = posição sociológica; CC = classe de copa; Ca = características das árvores; CQT = condição de qualidade de tronco; Cs = condições.  Essas parcelas foram espacializadas a partir da utilização do Sistema de Posicionamento Global (GPS) e os dados foram exportados para o software SPRING com a finalidade de construir um banco de dados cadastral, visando o acompanhamento e a análise do desenvolvimento da vegetação local. A geração do banco de dados permitiu acompanhar o desenvolvimento das árvores dentro de uma escala temporal, mostrando a evolução do fragmento de floresta estudado.Este trabajo en su objeto pretende crear un banco de informaciones geo-referenciado para acompañar los cambios fitosociológicos de los indivíduos arbóreos a lo largo del tiempo y su distribuccíon geográfica en el área del estudio. Demarcamos parcelas permanentes a lo largo de la planicie de inundación de los rios “Carro  Quebrado” y Cascavel” que están localizados en el campus de la Universidad Estadual Del Centro Oeste del Estado del Paraná, municipalidad de Guarapuava ( UNICENTRO –CEDETEG).En cada parcela de tierra separada evaluamos distintos atributos: PS: localización sociológica; CC: tipo de copa; CA: características de los árboles; CCT: condiciones de calidad del tronco; Cs: otras condiciones.  Estas parcelas fueron especializadas a partir de la utilización del Sistema de  Pocsicionamiento Global (GPS) y todos los datos fuero exportados para el sftware SPRING a fin de construir el banco de informaciones cadastrales que permita acompañar el análisis del desarrollo de la vegetación local, lo que permitió  incluso acompañar el estudio de los árboles dentro de una escala temporal mostrando la evolución del fragmento de la floresta estudiada

Physicochemical and biological ageing processes of (micro)plastics in the environment: a multi-tiered study on polyethylene

Pollution by plastic and microplastic impacts the environment globally. Knowledge on the ageing mechanisms of plastics in natural settings is needed to understand their environmental fate and their reactivity in the ecosystems. Accordingly, the study of ageing processes is gaining focus in the context of the environmental sciences. However, laboratory-based experimental research has typically assessed individual ageing processes, limiting environmental applicability. In this study, we propose a multi-tiered approach to study the environmental ageing of polyethylene plastic fragments focusing on the combined assessment of physical and biological processes in sequence. The ageing protocol included ultraviolet irradiation in air and in a range of water solutions, followed by a biofouling test. Changes in surface characteristics were assessed by Fourier transform infrared spectroscopy, scanning electron microscopy, and water contact angle. UV radiation both in air and water caused a significant increase in the density of oxidized groups (i.e., hydroxyl and carbonyl) on the plastic surface, whereby water solution chemistry influenced the process both by modulating surface oxidation and morphology. Biofouling, too, was a strong determinant of surface alterations, regardless of the prior irradiation treatments. All biofouled samples present (i) specific infrared bands of new surface functional groups (e.g., amides and polysaccharides), (ii) a further increase in hydroxyl and carbonyl groups, (iii) the diffuse presence of algal biofilm on the plastic surface, and (iv) a significant decrease in surface hydrophobicity. This suggests that biological-driven alterations are not affected by the level of physicochemical ageing and may represent, in real settings, the main driver of alteration of both weathered and pristine plastics. This work highlights the potentially pivotal role of biofouling as the main process of plastic ageing, providing useful technical insights for future experimental works. These results also confirm that a multi-tiered laboratory approach permits a realistic simulation of plastic environmental ageing in controlled conditions

Untangling the role of biotic and abiotic ageing of various environmental plastics toward the sorption of metals

Plastic particles can impact the environmental fate and bioavailability of essential inorganic micronutrients and non-essential (toxic) metals. The sorption of metals to environmental plastic has been demonstrated to be facilitated by plastic ageing, a phenomenon encompassing an array of physical, chemical, and biological processes. This study deploys a factorial experiment to untangle the role of different ageing processes in determining the sorption of metals. Plastics made of three different polymer types were aged both through abiotic (ultraviolet irradiation, UV) and biotic (through the incubation with a multispecies algal inoculum forming a biofilm) processes under controlled laboratory conditions. Pristine and aged plastic samples were characterized for their physiochemical properties through Fourier-transformed infrared spectroscopy, scanning electron microscopy and water contact angle measurements. Their sorption affinity toward aluminum (Al) and copper (Cu) in aqueous solutions was then assessed as a response variable. All ageing processes (alone or combined) influenced plastic surface properties resulting in reduced hydrophobicity, changes in surface functional groups (i.e., increase of oxygen containing functional groups after UV ageing and the appearance of marked bands as amides and polysaccharides after biofouling), as well as in nanomorphology. The sorption of Al and Cu was instead statistically dependent (p < 0.01) on the degree of biofouling covering the specimens. Biofouled plastic displayed in fact substantial affinity for metal sorption causing the depletion of up to tenfold Cu and Al compared to pristine polymers, regardless of the polymer type and presence or absence of other ageing treatments. These results confirm the hypothesis that the accumulation of metals on plastic is substantially driven by the biofilm present on environmental plastics. These findings also highlight the importance of investigating the implications of environmental plastic for metal and inorganic nutrients availability in environments impacted by this pollution.publishedVersio

Selection of the optimal extraction protocol to investigate the interaction between trace elements and environmental plastic

The interaction between environmental plastic and trace elements is an issue of concern. Understanding their interaction mechanisms is key to evaluate the potential threats for the environment. To this regard, consolidating confidence in extraction protocols can help in understanding the amount of different species present on plastic surface, as well as the potential mobility of trace elements present inside the plastic matrix (e.g., additives). Here we tested the efficacy of different reagents to mimic the elemental phases bonded to meso- and microplastic in the environment, in relation to the grade of ageing and the polymer composition. Results showed that a relatively high portion of trace elements is bonded in a weak phase and that other phases abundant in other matrices (e.g., oxides and bonded to organic matter) are only present to a limited degree in the plastic samples. The comparison of different sample types highlighted the important role of plastic ageing in governing interactions with trace elements, while the polymer composition has a limited influence on this process. Finally, the future steps toward a tailored extraction scheme for environmental plastic are proposed.publishedVersio