RESUMO
Given the significant industrial applications of rare earth elements (REEs), supply chain constraints, and negative environmental impacts associated with their extraction, finding alternative sources has become a critical challenge. Previously, we highlighted the potential of living Ulva sp. in the removal and pre-concentration of Y from a solution obtained by sequential acid leaching of spent fluorescent lamps (SFLs). Here, we extended that study to other REEs extracted from SFLs and evaluated the effect of pH (4.5-9.0), light exposure (absence, natural and supplemented with artificial light), and Hg (presence and absence). The results showed small differences in the removal of Y (23-30%) and other REEs at the different pH values, opening the scope of the methodology. However, Ulva sp. relative growth rate (RGR) was negatively affected in the higher acidity condition, without any visible signs of decay. In the absence of light, the RGR also decreased, which was accompanied by a halving of the removal efficiency compared to that with artificial light supplementation (40% for Y). Although Hg had minimal influence on the removal and concentration of REEs by Ulva sp., its presence in the enriched biomass is undesirable. Therefore, this contaminant was selectively removed from the solution using Fe3O4@SiO2/SiDTC nanoparticles before contact with the macroalgae (70% removal in 30 min; 99% in 72 h). In addition to easy solubilization, macroalgae enriched with REEs have a simpler composition compared to SFLs. Calcination of the biomass allowed the REEs to be further concentrated, with concentrations (130 mg/g for Y) up to 240 times higher than in typical apatite ore. This highlights enriched biomass as a sustainable alternative to traditional mining for obtaining these critical raw materials.
RESUMO
Mercury (Hg) is a global and top priority contaminant, toxic at low concentrations. Although it has been progressively eliminated from processes, this metal continues to circulate in the atmosphere, soil, and water. In this work, the Response Surface Methodology (RSM) combined with a Box-Behnken Design (3 factors - 3 levels) was used to optimize key operational conditions that influence the removal and uptake of Hg by living macroalga Ulva sp. in a complex mixture containing several elements used in industry (potentially toxic elements, rare earth elements, and platinum-group elements) (initial concentration 10, 100 and 190 µg/L, salinity 15, 25 and 35, seaweed stock density 1.0, 3.0 and 5.0 g/L). Results evidenced the great capability of Ulva sp. to remove Hg, with removal efficiencies between 69 % and 97 %. 3-D surfaces showed that the most impactful variable was seaweed stock density, with higher densities leading to higher removal. Regarding the uptake, a positive correlation between initial concentration and qt values was observed. The appliance of RSM made possible to obtain optimal operating conditions for removing virtually 100 % of Hg from waters with high ionic strength, which is a pivotal step in the direction of the application of this remediation biotechnology at large scale.
Assuntos
Mercúrio , Metais Terras Raras , Alga Marinha , Ulva , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , SalinidadeRESUMO
To routinely assess whether consumed food meets international guidelines, a single analytical method able to quantify minerals and potentially toxic elements (PTEs) in real food matrices is required. This work validated a simple and efficient method to quantify nine elements in different food matrices by ICP-MS. Samples from local markets (chicken, mussels, fish, rice, and seaweed) and certified reference materials were digested with HNO3 68 % and H2O2 30 %. All performance criteria (working range, linearity, LOD, LOQ, selectivity, repeatability, and trueness) met the requirements of the Portuguese Association of Accredited Laboratories. Comparison between raw and cooked food showed significant changes in most element levels, and PTEs contents complied with the maximum permissible values (EC N° 1881/2006). The minimum and maximum amounts of the foods studied, alone or in combination, raw or cooked, that can be daily consumed to meet EFSA and WHO nutritional and safety requirements were analysed.
Assuntos
Oryza , Oligoelementos , Animais , Peróxido de Hidrogênio , Alimentos , Minerais , Análise Espectral , Oligoelementos/análiseRESUMO
Cellulose biomembranes may be used for difficult-to-treat ulcers. To assess the efficacy and safety of cellulose biomembranes compared to a collagenase dressing for the treatment of chronic venous ulcers. A randomized, controlled clinical trial was performed using two groups: one treated with collagenase dressing and the other with cellulose biomembrane over a 90-day (T90) period. Both groups received compression therapy. The primary outcome was reduction in ulcer area at T90. Secondary outcomes were healing status, decrease in devitalized tissue and exudate, vascular fraction, change in quality of life, and safety. We randomized 46 participants with 73 venous ulcers (21 with 36 ulcers in the collagenase group and 25 with 37 ulcers in the biomembrane group). A decrease in ulcer area occurred at T90 in both groups, but the difference was not significant. Complete healing before T90 occurred for seven ulcers in the collagenase group and 12 ulcers in the biomembrane group, without significant difference. However, the biomembrane promoted increased precocious healing (p = 0.02). Improved bed vitality and quality of life was observed as a function of time (p < 0.01), but this was not significant between the groups. Immunohistochemical analysis of CD34 showed an increase in vascular fraction in both groups (p < 0.01), with a higher level in the biomembrane group (p < 0.05). No adverse events were considered related to the products. Cellulose biomembranes, in combination with compressive therapy, are effective and safe for the treatment of venous ulcers and provide results similar to those with collagenase treatment.
Assuntos
Curativos Biológicos , Celulose/farmacologia , Colagenases/farmacologia , Úlcera do Pé/terapia , Úlcera Varicosa/terapia , Cicatrização/fisiologia , Idoso , Doença Crônica , Bandagens Compressivas , Feminino , Seguimentos , Úlcera do Pé/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Úlcera Varicosa/diagnósticoRESUMO
The experiments performed in this work proved the ability of Gracilaria gracilis to concentrate and recover Critical Rare Elements (CRE) from contaminated waters. The importance of recycling these elements is related to their very limited sources in Nature and progressive use in technologies. Moreover, their mining exploitation has negative environmental impact, and recent studies point them as new emerging pollutants. To the best of our knowledge, this is the first report on the application of living macroalgae for the removal and recovery of CRE. G. gracilis (2.5gL-1, fresh weight) was exposed to mono- and multi-element saline solutions of 500µgL-1 of Y, Ce, Nd, Eu and La. Removal was up to 70% in 48h, with bioaccumulation following Elovich kinetic model. In multi-element solutions, selectivity was not observed although removal of lanthanides improved comparatively to single-element solutions. No mortality or adverse effect on growth was registered. The subsequent macroalgae digestion allowed collecting virtually 100% of all elements in a 300-fold more concentrated solution. The overall results suggest the application of living macroalgae as a simple and effective alternative technology for removing and recovering CRE from wastewaters, contributing to an improvement of water quality and CRE recycling.
Assuntos
Gracilaria/metabolismo , Metais Terras Raras/metabolismo , Reciclagem/métodos , Alga Marinha/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , SalinidadeRESUMO
Objetivo: identificar o perfil epidemiológico e clínico dos casos regulados como acidente vascular cerebral hiperagudo em um hospital referenciado. Método: trata-se de um estudo quantitativo, retrospectivo, que analisou 131 fichas de casos regulados com hipótese diagnóstica de acidente vascular cerebral hiperagudo, em um hospital referenciado. Submeteram-se os dados coletados à análise estatística descritiva com o programa SAS 9.4, considerando-se p<0,05 como o nível de significância. Resultados: detectou-se que a idade média dos pacientes foi de 67,44 anos, do sexo masculino, com sintoma mais frequente a fraqueza de membros, em 119 casos e 107 na referência. Verificou-se a ocorrência do acidente vascular isquêmico em 79 casos e a etiologia de síndrome lacunar em 33. Registra-se que 100 pacientes obtiveram alta hospitalar e 20 faleceram. Percebeuse a significância estatística (p≤0,05) entre os resultados clínicos com o valor do teste de glicemia capilar e a presença do desvio de rima labial no serviço de origem. Conclusão: observa-se que os achados estatisticamente significativos revelam a necessidade da criação de protocolos específicos e a educação permanente das equipes.(AU)
Objective: to identify the epidemiological and clinical profile of cases coordinated as hyperacute stroke in a reference hospital. Method: this is a quantitative retrospective study in which we analyzed 131 medical records of hyperacute stroke cases coordinated in a reference hospital. The data collected were submitted to descriptive statistical analysis with the SAS 9.4 program, considering a p <0.05 statistically significant. Results: the mean age of patients was 67.44 years, most were male, and limb weakness was the most frequent symptom, in 119 cases and 107 referral cases. The occurrence of ischemic stroke was found in 79 cases, and the etiology of lacunar syndrome in 33. One hundred patients were discharged from the hospital and 20 died. A statistically significant (p≤0.05) relation was found between clinical results concerning the capillary glycemia values and the presence of lip rhyme deviation in the service of origin. Conclusion: the statistically significant findings reveal the need to create specific protocols and to implement permanent education of the teams.(AU)
Objetivo: identificar el perfil epidemiológico y clínico de los casos coordinados como ictus hiperagudo en un hospital de referencia. Método: se trata de un estudio cuantitativo retrospectivo en el que analizamos 131 historias clínicas de casos de ictus hiperagudo regulados en un hospital de referencia. Los datos recolectados fueron sometidos a análisis estadístico descriptivo con el programa SAS 9.4, considerando p <0.05 estadísticamente significativa. Resultados: la edad media de los pacientes fue de 67,44 años, la mayoría eran varones y la debilidad de las extremidades fue el síntoma más frecuente, en 119 casos y 107 casos referenciados. La ocurrencia de ictus isquémico se encontró en 79 casos originales y la etiología del síndrome lacunar en 33. Cien pacientes fueron dados de alta del hospital y 20 fallecieron. Se encontró relación estadísticamente significativa (p≤0.05) entre los resultados clínicos de los valores de glucemia capilar y la presencia de desviación de la rima labial en el servicio de origen. Conclusión: los hallazgos estadísticamente significativos revelan la necesidad de crear protocolos específicos e implementar la educación permanente de los equipos.(AU)