Publications Scientifiques
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Item Sustainable starch-based bioplastics reinforced with carob filler: characterization and biodegradability assessments(Taylor and Francis Ltd., 2024) Guemmour, Hind; Kheffache, Djaffar; Khier, NawalStarch-based thermoplastic polymer is a biopolymer that is being widely explored as a replacement for conventional polymers. Since thermoplastic starch suffers from mechanical defects, certain mechanical and thermal properties of starch-based polymers can be improved by incorporating fillers or reinforcements derived mainly from natural substances. This article reports the preparation, physicochemical, and mechanical characterization and biodegradation of starch-based bioplastics extracted from potato (Solanum tuberosum) peels using glycerol (G) as plasticizer and reinforced with carob powder, a readily growing plant in Mediterranean climates. The present study investigates the effect of incorporating different proportions (0, 2, 5, 10, and 15 wt.%) of carob powder (Cb) in the films thus prepared. These biopolymer films were fully characterized using analytical techniques including Fourier transform infrared spectroscopy with attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD), optical microscopy (OM), Scanning electron microscopy (SEM), mechanical evaluations, and biodegradability assessments. The biodegradability of the obtained bioplastic samples was evaluated. Scanning electron microscopy (SEM) revealed strong interfacial adhesion between the constituent filler and the polymer matrix.Item Biodegradability assessment of HDPE-based biocomposites: Influence of starch and fiber composition(Elsevier Ltd, 2024) Zighed, Mohammed; Benotmane, Bénamar; Ferkous, Hana; Ramdane, Nora; Boublia, Abir; Ahmed, Mukhtar; Bourbia, Amel; Lemboub, Samia; Yadav, Krishna Kumar; Benguerba, YacineThis research aims to analyze the biodegradation dynamics of a tertiary composite blend, including High-Density Polyethylene (HDPE), starch and linen fiber, and their combined effect on decay processes in authentic environmental settings. It investigates the relationship between fiber content and decomposition rates, details the biodegradation mechanisms, and evaluates the reactive profiles of the involved constituents. Decay kinetics and the biodegradation mechanism of three formulations: HDPE60S40, HDPE60S20F20, and HDPE60S30F10, representing composites with 60 % HDPE, complemented by 40 %, 20 % starch and 20 %, 10 % linen fiber, respectively, are examined. HDPE60S30F10 is noted for its superior biodegradation rates, showing a 1.2 % weight loss in soil and 9.89 % in marine conditions and an increased resistance to shearing forces, whereas HDPE60S40 recorded a weight loss of 0,63 % in soil and 2.59 % in seawater against 1,7 % and 6.64 % in soil and seawtaer, respectively recorded with HDPE60S20F20. Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations complement these findings, presenting HDPE60S40 as the most rigid, HDPE60S20F20 as the most ductile with a bulk modulus of 13.34 GPa, and HDPE60S30F10 exhibiting the best shear resistance with a shear modulus of 12.48 GPa. Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR) analyses confirm microbial involvement and significant surface erosion, particularly indicating particularly starch degradation. The results suggest that integrating linen fiber into the composites enhances biodegradation.Item The degradation of methylene blue by bacterial strains isolated from the peel of Red Beet(Université M'Hamed Bougara Boumerdes, 2018) Abai, N.; Abed, F.; Babakhouya, N.; Benrachdi, K.The textile industry generates half of the industrial pollution flows, these effluents can be very colorful and difficult to treat. The treatment of these effluents has become a priority in the world, the development of methods and the optimization of existing processes, are the subject of a large number of works. In the present work the methylene blue was degraded by two bacterial strains BP1 and BP2 isolated from the peel of red beet, identified as Acinetobacter Johnson II BP1 and BP2 as Bacillus weihenstephanensis. The effect of the initial concentration, pH, temperature, and addition of the carbon source and nitrogen source on the biodegradation of the dye was determined.Item Biodegradation of Petroleum hydrocarbons and Biosurfactant production by an extremely halophilic Archaea Halovivax sp. A21(Aljest, 2017) Khemili-Talbi, S.; Kebbouche-Gana, Salima; Akmoussi-Toumi, S.; Gana, M.L.; Lahiani,S.; Ferrioune ,I.; Angar,Y.Over the recent few years, biosurfactant has played an important role in the industrial application especially in oil recovery; even in high salinity conditions. The potential of biosurfactant production by the extreme halophilic archaeon Halovivax sp. A21 in the presence of petroleum hydrocarbons (2% v/v) as sole carbon source at high salinity (25% NaCl) has been investigated. The results show the ability of Halovivax sp. A21 to grow and reduce surface tension under an optimum range of pH (7-9), salinities (15-35% NaCl) and temperature (40-45°C) for an optimized volume of 100 ml of the medium for 1000 ml capacity Erlenmeyer flasks with an optimum agitation of 120 rpm. The rates of biosurfactant production on petroleum hydrocarbons were enhanced with increasing NaCl concentration in the medium with an optimum of 25%. Biosurfactant production by Halovivax sp. A21 showed high emulsifying activity (more than 80%) and decreased surface tension (24.5 mN/m). The stability of the produced biosurfactant was determined by different physico-chemical conditions like pH, temperature and salinity. Moreover, the partial purification of the derived biosurfactant by silica gel column chromatography and Thin-layer chromatography revealed that it belongs to the lipopeptide group. Although both catechol dioxygenases participated in the degradation of petroleum hydrocarbons, more induction of catechol 1,2 dioxygenase was observed than the catechol 2,3 dioxygenase which indicated the predominance of the ortho cleavage pathways in the petroleum hydrocarbons degradation by the halophilic strain Halovivax sp. A21. The results demonstrated that strain Halovivax sp. A21 was able to increase the bioavailability of insoluble hydrocarbons, thus facilitating their uptake and their biodegradation even at high salt concentration. Likewise, the search of novel biosurfactants in extremophiles, or the use of microorganisms that present excellentItem The degradation of methylene blue by bacterial strains isolated from the peel of Red Beet(Aljest, 2019) Abai, Nadjet; Abed, F.; Babakhouya, N.; Benrachdi, K.The textile industry generates half of the industrial pollution flows, these effluents can be very colorful and difficult to treat. The treatment of these effluents has become a priority in the world, the development of methods and the optimization of existing processes, are the subject of a large number of works. In the present work the methylene blue was degraded by two bacterial strains BP1 and BP2 isolated from the peel of red beet, identified as Acinetobacter Johnson II BP1 and BP2 as Bacillus weihenstephanensis. The effect of the initial concentration, pH, temperature, and addition of the carbon source and nitrogen source on the biodegradation of the dye was determinedItem Biodegradation of diclofenac by activated sludge and membrane bioreactor-a review(Aljest, 2015) Cherik, Dalila; Louhab, KrimDiclofenac (DCF) is a pharmaceutical residue of therapeutic class of non-steroidal anti-inflammatory which is often detected in the wastewater treatment plants (influent and effluent) and surface waters. This review focuses its elimination by biodegradation with activated sludge (CAS) or bioreactor membrane (MBR) in which microorganisms plays a key role in the elimination of diclofenac and in which a lot of factors can affect the efficiency of the removal as physicochemical properties of diclofenac, sludge retention time (SRT), temperature, pH, redox conditions and sludge characteristics.The objective of this study was to describe a review of the literature by recent publications on the biodegradation of diclofenac. We inspect the performance of biodegradation using biological process technology by activated sludge and membrane bioreactor in the elimination of diclofenacItem Biodegradation of aromatic hydrocarbons by an extremely halophilicarchaeNatrialbasp. C21 isolated fromoilcontaminated saline water in Ain Salah, Algeria(2015) Khemili-Talbi, S.; Kebbouche-Gana, Salima; Akmoussi-Toumi, Siham