Percorrer por autor "Weber Macena, Morgana"
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- Competitive Adsorption of Metal Ions by Lignocellulosic Materials: A Review of Applications, Mechanisms and Influencing FactorsPublication . Weber Macena, Morgana; Helena Pereira; Gonçalves Oliveira Valente da Cruz-Lopes, Luísa Paula; Lucas Grosche; Esteves, BrunoThe rapid expansion of industrial and agricultural activities in recent years has significantly contributed to water pollution leading to a decline in water quality and the need for effective treatment and reuse strategies. Metal contamination in water bodies poses severe environmental and health risks, making the development of cost-effective and sustainable remediation methods essential. Among the various treatment approaches, biosorption using biological adsorbents has emerged as a promising alternative due to its low cost and high efficiency. However, while the adsorption mechanisms of single metals are well understood, the competitive interactions between multiple metal ions during the sorption process remain less explored. In this review, we analyze the competitive biosorption of metals in multi-metallic wastewater systems. Key factors influencing metal removal, such as pH, contact time, biosorbent dosage, and initial metal concentration, are discussed, along with the intrinsic properties of biosorbents and metal ions that affect sorption efficiency. Additionally, we highlight recent studies on agroforestry byproducts as effective biosorbents for metal removal, showcasing their potential for sustainable water treatment. Heavy metals pose significant risks even at low concentrations, necessitating robust regulations and advanced treatment technologies; biomass byproducts, as cost-effective biosorbents, can be optimized through pre-treatment, activation, pH and temperature control, and particle size reduction, while effectively manage
- Estudos preliminares de Adsorventes Lenhocelulósicos para a Remoção de CefalosporinasPublication . Gonçalves Oliveira Valente da Cruz-Lopes, Luísa Paula; Araújo, R.; Lopes, Ana Rita Valente da Cruz; Weber Macena, Morgana; Esteves, BrunoIntrodução: A Acacia dealbata foi explorada como biosorvente para remover cefalosporina de soluções aquosas. Este estudo procura demonstrar a viabilidade de utilizar materiais lenhocelulósicos de baixo custona remoção de poluentes, valorizando resíduos de outras indústrias e reduzindo o impacto ambiental associado. Objetivo: O objetivo pretendeu avaliar a capacidade dos resíduos de acácia em adsorver a cefalosporina, analisando o seu potencial de adsorção e os modelos cinéticos envolvidos, de forma a explorar o seu uso no tratamento de águas. Métodos: Esta revisão foi conduzida utilizando uma abordagem sistemática para identificar, analisar e sintetizar a literatura relevante sobre a presença e o impacto dos antibióticos cefalosporínicos em ambientes aquáticos. Paralelamente, foram realizados testes de adsorção utilizando soluções de cefalosporina com concentração de 15 mg L⁻¹, variando o tempo de agitação entre 10 e 120 minutos. A cinética de adsorção foi avaliada com base nos modelos de pseudo-primeira ordem, pseudo-segunda ordem, Elovich e difusão intrapartícula. A adsorção foi analisada através de espectrometria UV-Vis, onde se identificou um pico de absorção característico a 240 nm. Resultados: Os resultados indicaram que o modelo de pseudo-primeira ordem apresentou o coeficiente de determinação mais elevado (R² = 0,991), sugerindo que o mecanismo predominante é a adsorção física. Esta análise confirmou a capacidade da acácia em adsorver cefalosporinas, evidenciando o seu potencial como biosorvente. Conclusão: Este estudo sublinha a relevância dos biosorventes, como a Acacia dealbata, no tratamento de poluentes da indústria farmacêutica. A utilização de materiais sustentáveis oferece uma solução promissora para o tratamento de águas, abrindo caminho para futuras aplicações no campo da biossorção.
- From Invasion to Valorization: Adsorbent Applications of Acacia dealbata Biomass in PortugalPublication . Weber Macena, Morgana; Esteves, Bruno; Jackelline S. Pinto; Rui Novais; Ana P. F. Caetano; Lucas Grosche; Helena Pereira; Gonçalves Oliveira Valente da Cruz-Lopes, Luísa PaulaAcacia dealbata, an invasive species in Portugal, produces large amounts of residual biomass during control operations, thereby presenting challenges and opportunities for sustainable valorization. Heavy metal contamination, including zinc (Zn), remains a critical environmental challenge due to its widespread industrial release and potential ecotoxicological impacts. This study explores the potential use of A. dealbata biomass as a biosorbent for zinc removal from aqueous solutions, comparing the performance of natural biomass and A. dealbata charcoal fines. Adsorption isotherms, kinetics, and surface characterizations were conducted to evaluate their physicochemical properties and sorption efficiency. The A. dealbata charcoal fines exhibited a significantly higher specific surface area (33 m2 g −1 ) and total pore volume (0.030 cm3 g −1 ) compared with the untreated biomass (1.4 m2 g −1 and 0.004 cm3 g −1 , respectively). Despite these structural differences, both materials demonstrated similar maximum adsorption capacities (23.36 and 23.79 mg g−1 for natural and charcoal fines, respectively). These results indicate that untreated A. dealbata biomass can perform as a biosorbent comparably to its carbonized form, representing a simple, low-cost, and sustainable alternative for heavy metal removal, offering a low-energy and sustainable alternative for Zn remediation.
- Plastic Food Packaging: Perceptions and Attitudes of Portuguese Consumers about Environmental Impact and RecyclingPublication . Weber Macena, Morgana; Carvalho, Rita; Cruz-Lopes, Luísa; Guiné, Raquel P. F.The use of plastics for packaging has some advantages, since they are flexible and inexpensive. However, most plastics are of single use, which, combined with low recycling or reuse ratios, contributes substantially to environmental pollution. This work is part of a project studying the habits of Portuguese citizens concerning plastic food packaging and focuses on aspects related to sustainability. The survey was carried out via an online questionnaire about sustainability, recycling, and knowledge of the effects of plastic materials or their residues on the environment. The results were obtained based on a statistical analysis of the data. The participants tend to think about the negative impact of plastic packages on the environment; 39% sometimes do not buy plastic; and 30% try to look for alternatives. A substantial fraction, 81%, support the avoidance of plastic utensils and reduction in the use of plastic bags. Most participants have a good knowledge of recycling and strongly agree with the use of recycled materials, and 87% of respondents practice separation of different types of waste for recycling. Changing plastic consumption habits has not been an easy task. Nevertheless, it is expected that society will increasingly move toward sustainable habits, questioning its actions and considering their impact on the environment.