21 research outputs found
Boosting bacterial nanocellulose production from chemically recycled post-consumer polyethylene terephthalate
Funding Information:
This research was funded by the Technological University of The Shannon through the President Seed Fund , the Government of Ireland International Education Scholarship 2020/2021; European Union's Horizon Europe EIC Pathfinder program [grant number: 101046758 (EcoPlastiC)].
Publisher Copyright:
© 2023 The AuthorsThe circular economy is emerging with new sustainable solutions to the ever-growing plastic waste challenge, garnering increasing attention. In this study, the possibility to modify expensive Hestrin–Schramm medium (HS) for bacterial nanocellulose (BNC) production and replace significant amounts of glucose with terephthalic acid (TPA) derived after reactive extrusion processing of mixed plastic waste yielding post consumer TPA (pcTPA), was evaluated from laboratory scale to fermentation at pilot scale. Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Thermogravimetric Analysis (TGA) were used to assess the structural, thermal, and morphological properties of BNC and its generated derivatives. The study's findings highlight the positive impact of pcTPA on BNC yield, surpassing the performance of conventional TPA. The presence of pcTPA in the medium resulted in a BNC yield of 4.01 g/L in a scale-up step of 100 mL cultivation, while the positive control using glucose resulted in a yield of 3.57 g/L. The efficiency of glucose substitution with pcTPA increased with each scale-up step, ultimately reaching a 320% yield increase in comparison to the positive control. Additionaly, the procedure that enhanced the materials' thermoplasticity in the form of derivatives has been established resulting in the production of BNC laurate and BNC octanoate derivatives with melting temperatures of 270 °C and 280 °C, respectively. Overall, this study investigates the potential of this approach as an important circular economic solution, enabling an increased sustainable perspective for polyethylene terephthalate (PET) circularity and significantly a much needed cost reduction for BNC production with enhanced thermoplasticity.publishersversionpublishe
Boosting bacterial nanocellullose production from chemically recycled post-consumer polyethylene terephthalate
The circular economy is emerging with new sustainable solutions to the ever-growing plastic waste challenge,
garnering increasing attention. In this study, the possibility to modify expensive Hestrin–Schramm medium (HS)
for bacterial nanocellulose (BNC) production and replace significant amounts of glucose with terephthalic acid
(TPA) derived after reactive extrusion processing of mixed plastic waste yielding post consumer TPA (pcTPA),
was evaluated from laboratory scale to fermentation at pilot scale. Fourier-transform infrared spectroscopy
(FTIR), Scanning electron microscopy (SEM), Thermogravimetric Analysis (TGA) were used to assess the
structural, thermal, and morphological properties of BNC and its generated derivatives. The study’s findings
highlight the positive impact of pcTPA on BNC yield, surpassing the performance of conventional TPA. The
presence of pcTPA in the medium resulted in a BNC yield of 4.01 g/L in a scale-up step of 100 mL cultivation,
while the positive control using glucose resulted in a yield of 3.57 g/L. The efficiency of glucose substitution with
pcTPA increased with each scale-up step, ultimately reaching a 320% yield increase in comparison to the positive
control. Additionaly, the procedure that enhanced the materials’ thermoplasticity in the form of derivatives has
been established resulting in the production of BNC laurate and BNC octanoate derivatives with melting temperatures
of 270 ◦C and 280 ◦C, respectively. Overall, this study investigates the potential of this approach as an
important circular economic solution, enabling an increased sustainable perspective for polyethylene terephthalate
(PET) circularity and significantly a much needed cost reduction for BNC production with enhanced
thermoplasticity.ye
Silicato de Alumínio em Substrato para Produção de Mudas de Corymbia citriodora
RESUMO Objetivou-se verificar a eficiência de silicato de alumínio na composição do substrato para produção de mudas de Corymbia citriodora. O delineamento adotado foi o inteiramente casualizado com cinco tratamentos e oito repetições. A composição do substrato consistiu de moinha de carvão, esterco bovino, casca de eucalipto e substrato comercial. Foram acrescidos nos tratamentos 0 (testemunha), 5, 10, 15 e 20% de silicato de alumínio. O índice de qualidade de mudas, altura, diâmetro do coleto, massa seca e fresca da raiz, área foliar média e total e relação entre massa seca da raiz e massa seca da parte aérea não foram influenciados. Para massa seca e fresca da parte aérea as testemunhas foram superiores 2,5953 e 4,9323 g, respectivamente. Porém a adição de 12,2% apresentou ganhos crescentes no número de folhas. O silicato de alumínio para produção de mudas de C. citriodora surge como potencial alternativa de destino deste resíduo
Bromine soil/sediment enrichment in tidal salt marshes as a potential indicator of climate changes driven by solar activity: New insights from W coast Portuguese estuaries
This paper aims at providing insight about bromine (Br) cycle in four Portuguese estuaries: Minho, Lima (in the NW coast) and Sado, Mira (in the SW coast). The focus is on their tidal marsh environments, quite distinct with regard to key biophysicochemical attributes. Regardless of the primary bromide (Br-) common natural source, i.e., seawater, the NW marshes present relatively higher surface soil/sediment Br concentrations than the ones from SW coast. This happens in close connection with organic matter (OM) content, and is controlled by their main climatic contexts. Yet, the anthropogenic impact on Br concentrations cannot be discarded. Regarding [Br] spatial patterns across the marshes, the results show a general increase from tidal flat toward high marsh. Maxima [Br] occur in the upper driftline zone, at transition from highest low marsh to high marsh, recognized as a privileged setting for OM accumulation. Based on the discovery of OM ubiquitous bromination in marine and transitional environments, it is assumed that this Br occurs mainly as organobromine. Analysis of two dated sediment cores indicates that, despite having the same age (AD ~1300), the Caminha salt marsh (Minho estuary) evidences higher Br enrichment than the Casa Branca salt marsh (Mira estuary). This is related to a greater Br storage ability, which is linked to OM build-up and rate dynamics under different climate scenarios. Both cores evidence a fairly similar temporal Br enrichment pattern, and may be interpreted in light of the sun-climate coupling. Thereby, most of the well-known Grand Solar Minima during the Little Ice Age appear to have left an imprint on these marshes, supported by higher [Br] in soils/sediments. Besides climate changes driven by solar activity and impacting marsh Br biogeodynamics, those Br enrichment peaks might also reflect inputs of enhanced volcanic activity covarying with Grand Solar Minima.This work was partly supported by IDL through the UID/GEO/50019/2013 program, by C2
TN through the UID/Multi/04349/2013 program, and is a contribution of the project WestLog (PTDC/CTE/105370/2008), funded by the Fundação para a Ciência e a Tecnologia (FCT). João
Moreno benefits from a FCT PhD grant (SFRH/BD/87995/2012). J.J. Gómez-Navarro acknowledges the funding provided through the contract for the return of experienced researches, resolution R-735/2015 of the University of Murcia.info:eu-repo/semantics/publishedVersio
Prevalência de anticorpos IgG antiparvovírus B19 em gestantes durante o atendimento pré-natal e casos de hidropisia fetal não imune atribuídos ao parvovírus B19, na Cidade do Rio de Janeiro Anti-parvovirus B19 IgG antibody prevalence in pregnant women during antenatal follow-up and cases of non-immune hydropsis fetalis due to parvovirus B19, in the City of Rio de Janeiro
Com o objetivo de medir a prevalência de anticorpos IgG contra o parvovírus B19 em gestantes com até 24 semanas de idade gestacional e detectar a ocorrência de casos de hidropisia fetal não-imune atribuídos a esse vírus, coletamos 249 amostras de soro em uma maternidade de referência na cidade do Rio de Janeiro, entre junho de 2003 e março de 2005. As gestantes foram acompanhadas até o termo da gestação, sendo detectados 17 casos de hidropisia fetal. Quatro casos foram atribuídos ao parvovírus B19 e dois destes ocorreram em gestantes residentes na zona oeste da cidade, em fevereiro de 2005. Resultados positivos para anticorpos IgG antiparvovírus B19 foram encontrados em 172 (71,6%) gestantes (IC 95% 65,5-77,7%), sendo esta prevalência de anticorpos comparável à encontrada em outras cidades brasileiras. A única variável associada com aquisição prévia de anticorpos IgG foi número de gestações anteriores maior que um(p= 0,02, IC 95% 0,36-0,94).<br>With the aim of measuring the prevalence of anti-parvovirus B19 IgG antibodies during pregnancy up to 24 weeks of gestation and detecting cases of nonimmune hydrops fetalis, 249 sera from pregnant women attending a reference hospital in Rio de Janeiro city, from June 2003 to November 2004 were collected. They were followed-up until the end of pregnancy, with 17 cases of fetal hydrops detected. Four cases were caused by parvovirus B19 and two of them occurred in pregnant women living in the western zone of the city, during February 2005. Anti-parvovirus B19 IgG antibodies were found in 172 (71.6%) pregnant women (CI 95% 65.5%-77.7%); this antibody prevalence is similar to results found for others Brazilian cities. The only variable associated with previous acquisition of IgG antibodies to parvovirus B19 was number of pregnancies greater than one (p= 0.02, CI 95% 0.36-0.94)
