Publications

Abstract Micro- and nanoplastics (MNPs) are an important atmospheric aerosol constituent. However, there still needs to be a standard procedure for their sampling and size fractionation, which is an obstacle to the aggregation and critical analysis of results obtained by different research groups. This review focuses on the sampling and fractionation methodologies used for MNPs. Moreover, a streamlined, simplified methodology for sampling and fractionation is proposed.

Abstract Green carbon-based materials (GCM), i.e., carbon materials produced using renewable biomass or recycled waste, ought to be used to make processes sustainable and carbon-neutral. Carbon nanomaterials, like carbon dots and the nanobichar families, and carbon materials, like activated carbon and biochar substances, are sustainable materials with great potential to be used in different technological applications. In this review, the following four applications were selected, and the works published in the last two years (since 2022) were critically reviewed: agriculture, water treatment, energy management, and carbon dioxide reduction and sequestration. GCM improved the performance of the technological applications under revision and played an important role in the sustainability of the processes, contributing to the mitigation of climate change, by reducing emissions and increasing the sequestration of CO<inf>2</inf>eq.

Abstract The Mediterranean basin is highly susceptible to climate change, with soil salinization and the increase in average temperatures being two of the main factors affecting crop productivity in this region. Following our previous studies on describing the detrimental effects of heat and salt stress co-exposure on tomato plants, this study aimed to understand if substrate supplementation with a combination of arbuscular mycorrhizal fungi (AMF) and biochar could mitigate the negative consequences of these stresses. Upon 21 days of exposure, stressed tomato plants grown under supplemented substrates showed increased tolerance to heat (42 degrees C for 4 h/ day), salt (100 mM NaCl), and their combination, presenting increased biomass and flowering rate. The beneficial effects of AMF and biochar were associated with a better ionic balance (i.e. lower sodium accumulation and higher uptake of calcium and magnesium) and increased photosynthetic efficiency. Indeed, these plants presented higher chlorophyll content and improved CO2 assimilation rates. Biochemical data further supported that tomato plants grown with AMF and biochar were capable of efficiently modulating their defence pathways, evidenced by the accumulation of proline, ascorbate, and glutathione, coupled with a lower dependency on energy-costly enzymatic antioxidant players. In summary, the obtained data strongly point towards a beneficial role of combined AMF and biochar as sustainable tools to improve plant growth and development under a climate change scenario, where soil salinization and heat peaks often occur together.

Abstract Green carbon-based materials (GCM), i.e., carbon materials produced using renewable biomass or recycled waste, ought to be used to make processes sustainable and carbon-neutral. Carbon nanomaterials, like carbon dots and the nanobichar families, and carbon materials, like activated carbon and biochar substances, are sustainable materials with great potential to be used in different technological applications. In this review, the following four applications were selected, and the works published in the last two years (since 2022) were critically reviewed: agriculture, water treatment, energy management, and carbon dioxide reduction and sequestration. GCM improved the performance of the technological applications under revision and played an important role in the sustainability of the processes, contributing to the mitigation of climate change, by reducing emissions and increasing the sequestration of CO2eq.

Abstract The rapid evolution of Artificial Intelligence (AI) is profoundly shaping our society. Among various AI tools, ChatGPT stands out for its user-friendly nature and wide accessibility to the public. However, despite their countless potential benefits, these tools also face significant challenges, especially in sensitive areas like Education. In this publication, we conduct a prompt engineering essay with ChatGPT to understand the potential and challenges of this tool in designing new, high-quality chemistry laboratory activities. We aimed to assess its performance in proposing scientifically and pedagogically suitable protocols for chemistry laboratory activities based on the 11th-grade Portuguese curriculum. The initial exploratory essay was conducted to fine-tune the prompt, followed by the analysis of proposals for the five mandatory laboratory activities in this subject. ChatGPT demonstrates the ability to interpret and reproduce the specialized symbolic language of chemistry, effectively conceptualizing problems and laboratory activities in a clear and understandable manner for a broader audience (i.e., chemistry students). However, it is crucial to highlight the scientific-pedagogical limitations concerning the accuracy and appropriateness of the proposed laboratory activities, particularly in terms of safety and sustainability. Therefore, the use of AI in education should be approached critically and reflectively. While AI holds immense potential to transform the dynamics of teaching and learning, the role and expertise of the Chemistry teacher remain of the utmost importance to ensure the scientific and pedagogical quality of Chemistry classes.

Abstract Carbon dots (CDs) are fluorescent carbon-based nanomaterials with remarkable properties, making them more attractive than traditional fluorophores. Consequently, researchers focused on their development and application in fields such as sensing and bioimaging. One potential advantage of employing CDs is using organic waste as carbon precursors in their synthesis, providing a pathway for waste upcycling for a circular economy. However, waste-based CDs often have low fluorescence quantum yields (QY(FL)), limiting their practical applications. So, there is a need for a well-defined strategy to consistently produce waste-based CDs with appreciable QY(FL), irrespective of the starting waste material. Herein, we developed a fabrication strategy based on the hydrothermal treatment of waste materials, using citric acid as a co-carbon precursor and ethylenediamine as N-dopant. This strategy was tested with various materials, including corn stover, spent coffee grounds, cork powder, and sawdust. The results showed consistently appreciable QY(FL), reaching up to similar to 40 %. A Life Cycle Assessment (LCA) study demonstrated that producing these waste-based CDs has lower environmental impacts compared to CDs made solely from commercial reagents. Thus, we have established a framework for the environmentally friendly production of CDs by upcycling different waste materials without significant sacrifices in performance (QY(FL)).

Abstract In Portugal, Decree-Law no 102-D/2020 determines the establishment of networks for the selective collection of biowaste or the separation and recycling of biowaste at the source. The goal of this demanding is to decrease landfill deposition and ensure that, starting from 2030, landfills will not accept waste that can be recycled or recovered, such as biowaste from urban solid waste. This study determines the potential for energy generation through anaerobic digestion of biowaste collected from 14 Portuguese municipalities based on a previously published report on solutions for the separation, collection, and recycling at the source of biowaste. Assuming a population of 181,839 inhabitants and a selective collection of biowaste ranging from 11,659 to 17,808 tons by 2030, it is possible to generate up to 7.6 GWh of electricity. This electricity can meet the energy needs of up to 1650 people for a year and avoid until 1402 tons of CO2.

Abstract Lithium mining driven by the growing demand for lithium-ion batteries, has environmental consequences linked to soil and water pollution. Nevertheless, research on the environmental impacts of lithium extraction still needs to be improved, highlighting the imperative for additional research. The article addresses the potential impact of the C57 lithiniferous feldspar mine on water quality, specifically focusing on surface, groundwater and spring water samples collected at the mining site and surrounding area in Gonçalo (Guarda, Portugal). The objective is to evaluate the environmental consequences of mining activities, with particular emphasis on mineral leaching. This study aims to evaluate the water quality around the C57 mine and the potential environmental impacts of mining operations. Water samples were collected from different sources, such as surface, underground, and spring waters, and chemical analyses were carried out to determine concentrations of different parameters, which were later compared with national and international reference guidelines. In addition to analysing the water samples, weathering tests were carried out using the Soxhlet extractor method to simulate the leaching of minerals over a shorter period (about 125 days). The concentrations of the analysed elements by atomic absorption spectroscopy (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb and Zn) in the weathering solutions were generally low and decreased throughout the testing period, with significant concentrations of aluminium and chromium exceed Canadian environmental quality guidelines for surface waters. The detected lithium concentrations are quite different, ranging from 8.7 to 19.8 μg/L in surface waters, from 6.9 to 74.1 μg/L in groundwater, and from 25.6 to 35.4 μg/L in spring waters, but are all below the US EPA (2021) recommendations threshold of 0.7 mg/L. Based on the findings, the article concludes that there is currently no clear evidence to indicate the environmental impact of mining activities on water quality in the analysed samples. However, weathering tests suggest potential long-term implications regarding the leaching of specific chemical elements, particularly aluminium and chromium. © The Author(s) 2024.

Abstract <jats:p>Esta investigação tem por objetivo identificar as melhores soluções para implementar sistemas de recolha de biorresíduos num conjunto de municípios da Região Centro de Portugal, dos distritos de Castelo Branco e da Guarda, através da reciclagem na origem e/ou da recolha seletiva, no sentido de valorizar e reduzir os impactes ambientais deste tipo de resíduos. A reciclagem na origem e a recolha seletiva diferenciam-se pelo seu método de tratamento: a primeira recorre a compostores domésticos, compostores comunitários e biocompostores, responsabilizando os cidadãos pelo tratamento dos seus biorresíduos; e a segunda consiste no processo de recolha seletiva dos resíduos sólidos, separados por tipo de material (vidro, papel, plástico, biorresíduos, entre outros) para que possam ser reciclados pelas infraestruturas disponibilizadas pelos municípios. Contudo, ambas as modalidades são complementares na resposta às necessidades económicas e ambientais da sociedade. Metodologicamente, desenvolve-se uma dupla abordagem: inicialmente efetua-se a revisão de literatura, com base na legislação que propõe medidas de proteção do ambiente e da saúde humana, por meio da prevenção ou redução de resíduos; e, posteriormente, uma análise estatística descritiva, suportada na informação disponibilizada pelo conjunto de municípios, que evidencia os recursos económico-financeiros necessários para suportar o investimento requerido num período de dez anos.</jats:p>