Journal of Thermal Analysis and Calorimetry - under review
Manuscript number: JTAC-D-23-01548
On the structural consequences in the thermal degradation of styrene block copolymers. Part I. Pristine polymers
Zaharescu Traian, Nicolescu Cristina Mihaela, Bumbac Marius, Borbath T,. Borbath I.
Abstract. The thermal stability of four similar copolymer structures: styrene-isoprene-styrene (SIS), two styrene-butadiene-styrene (SBS) whose compositions differ by the styrene/butadiene ratios and styrene-ethylene-butadiene-styrene (SEBS) was studied by isothermal and nonisothermal chemiluminescence (CL). The activation energies required for the oxidative degradation were calculated starting from the values of oxidation induction times. The following sequence is obtained that demonstrates the influence of molecular constructions as well as the comparative stabilities under...
Journal of Thermal Analysis and Calorimetry - accepted for publication
Manuscript number: JTAC-D-23-01617
Stability effects of added biomass on microalgae styrene-butadiene-styrene composites
Zaharescu Traian, Bumbac Marius, Nicolescu Cristina Mihaela
Abstract. The stability consequences of added microalgae biomass, Chlorella vulgaris and Arthrospira platensis, to styrene-butadiene-styrene triblock composites (SBS) were evaluated by nonisothermal chemiluminescence. The high extract loadings up to 20% for Chlorella vulgaris and 30% for Arthrospira platensis create appropriate conditions for the propagation of oxidation, which is a convenient manner applicable to the degrading digestion of polymer matrix. The CL spectra on these ecological formulations indicate...
Journal of Applied Phycology, 2024
Semi-continuous cultivation for enhanced protein production using indigenous green microalgae and synthetic municipal wastewater
Ikumi Umetani, Michal Sposob, Olga Tiron
Abstract. Cultivation of microalgae has gained significant interest as an alternative protein source, potentially becoming a target commodity recovered from microalgae-based wastewater treatment. This study examined a semi-continuous cultivation strategy to optimize protein accumulation of the indigenous freshwater chlorophytes, Lobochlamys segnis and Klebsormidium flaccidum, and simultaneously remove nutrients from wastewater efficiently. A strain-specific regime was made based on a fixed biomass concentration at the start of 24-h ...
Polymers, 2023
Preparation and Characterization of Microalgae Styrene‐Butadiene Composites Using Chlorella vulgaris and Arthrospira platensis Biomass
Marius Bumbac, Cristina Mihaela Nicolescu, Radu Lucian Olteanu, Olga Tiron, Elena Elisabeta Manea, Costel Bumbac, Laura Monica Gorghiu, Cristiana Radulescu, Geanina Stanescu, Bogdan Catalin Serban, Octavian Buiu
Abstract. The food industry is a high consumer of polymer packing materials, sealing materials, and engineering components used in production equipment. Biobased polymer composites used in the food industry are obtained by incorporating different biogenic materials into the structure of a base polymer matrix. Renewable resources such as microalgae, bacteria, and plants may be used as bio‐ genic materials for this purpose. Photoautotrophic microalgae are valuable microorganisms that are able to harvest sunlight energy and capture CO2 into biomass. They are characterized by their metabolic...
Journal of Science and Arts, 2021
UV-VIS analysis of granular activated algae chlorophyll content
Marius Bumbac, Cristina Mihaela Nicolescu, Radu Lucian Olteanu, Olga Tiron, Elena Elisabeta Manea, Costel Bumbac, Laura Monica Gorghiu, Cristiana Radulescu, Geanina Stanescu, Bogdan Catalin Serban, Octavian Buiu
Abstract. Chlorophyll-a is the pigment whose concentration is an important indicator for the development of microalgae biomass. This study aims at evaluating the concentration of chlorophylls in the biomass of granular activated algae, using acetone and 90% ethanol for the extraction procedures applied. Concentrations of chlorophyll a, b and c were determined by applying three calculation types: methods proposed by Jeffrey and Humphrey for the extracts in acetone, Ritchie method for ethanolic extracts, and monochromatic method with acidification for ethanolic extracts...
Polymers, 2024
Influence of biogenic material content on the biodegradability of styrene-butadiene composites with incorporated Chlorella vulgaris biomass
Bumbac Marius, Nicolescu Cristina Mihaela, Zaharescu Traian, Bumbac Costel, Manea Elena Elisabeta, Ionescu Ioana Alexandra, Gurgu Ion Valentin, Serban Bogdan-Catalin, Buiu Octavian, Dumitrescu Crinela
Abstract. Bio-fillers are intensively studied for advanced polymer composite circular design and production. In this context, the algal biomass may be considered an important and relatively low-cost resource, when harvested as a by-product from wastewater treatment plants. The biomass of the algal species Chlorella vulgaris is frequently used in this type of environmental process, and its macro constituents’ composition ranges from around 15–25% carbohydrates, 10–20% lipids, and 50–60% proteins. Poly (styrene-butadiene-styrene) (SBS)...
BioEnergy Research, 2023
Indigenous green microalgae for wastewater treatment: nutrient removal and resource recovery for Biofuels and Bioproducts
Ikumi Umetani, Michal Sposob, Olga Tiron
Abstract. Microalgae biotechnology can strengthen circular economy concepts in the wastewater treatment sector. This study investigated the Norwegian microalgae strains of Tetradesmus wisconsinensis, Lobochlamys segnis, and Klebsormidium flaccidum for their efficiency in nutrient removal. Their biomass productivity and compositions were evaluated for bioenergy and bi-products development. In the laboratory batch experiment with synthetic municipal wastewater, all strains accomplished total removal of nitrogen and phosphorus. L. segnis removed all NH4+ and PO43−...
Polymers, 2024
Biodegradation study of styrene-butadiene composites with incorporated Arthrospira platensis biomass
Bumbac Marius, Nicolescu Cristina Mihaela, Zaharescu Traian, Gurgu Ion Valentin, Bumbac Costel, Manea Elena Elisabeta, Ionescu Ioana Alexandra, Serban Bogdan-Catalin, Buiu Octavian, Dumitrescu Crinela
Abstract. The preparation of polymer composites that incorporate material of a biogenic nature in the polymer matrices may lead to a reduction in fossil polymer consumption and a potentially higher biodegradability. Furthermore, microalgae biomass as biogenic filler has the advantage of fast growth and high tolerance to different types of culture media with higher production yields than those provided by the biomass of terrestrial crops. On the other hand, algal biomass can be a secondary product in wastewater treatment processes. For the present study, an SBS polymer composite (SBSC) containing 25% (w/w)...
Tehnologie de epurare a apelor uzate și recuperare a resurselor bazată pe nămol granular cu microalge
Cod: RO-NO-2019-0691
Acronim: GRAALrecovery
Working together for a green, competitive and inclusive Europe
Copyright 2024. Toate drepturile rezervate.
Proiect finanțat prin Mecanismul Financiar Norvegian 2014-2021, conform Contractului nr. 27/2020
Program: Cercetare RO-02 operat de UEFISCDI
Finanțare: 1.160.543,00 euro
Perioadă: 2020-2024