Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026/r/gumushane/13721
  Enhanced cationic dye adsorption using Stenotrophomonas indicatrix -modified MnFe2O4: performance evaluation and adsorption mechanism

  Ozdes, Duygu; Dede, Alper; Turfan, Fatma Asya; Seker, Serdal

  In this study, MnFe2O4 magnetic nanoparticles were modified with the Stenotrophomonas indicatrix bacteria for the first time in the literature to develop an effective and novel bio-adsorbent for the remediation of toxic cationic dyes, specifically Rhodamine 6G (R6G) and Methylene Blue (MB), from contaminated aqueous media. MnFe2O4 and bacteria-loaded MnFe2O4 were thoroughly characterized using FTIR, XRD, and SEM-EDX analyses. XRD results confirmed that the cubic spinel structure of MnFe2O4 was preserved after bacterial modification, while FTIR spectra evidenced the successful incorporation of biological functional groups, including –NH, –OH, amide, and phosphate moieties, onto the nanoparticle surface. Adsorption performance of the dyes was evaluated in terms of parameters including aqueous solution pH, equilibrium time, bacteria-loaded MnFe2O4 dosage, and initial R6G and MB concentration. After investigating the effect of salt on adsorption efficiency, the applicability of the proposed adsorbent was assessed using real water samples. According to the experimental results, the optimum pH and equilibrium period for the uptake of both dyes were determined to be 8.0 and 60 min, respectively. Kinetic analyses showed that the pseudo-second order kinetic model exhibited a superior fit in representing the adsorption rates of both dyes, while isotherm studies indicated that both Langmuir and Freundlich isotherm models fit the experimental data well. While the adsorption capacities of pure MnFe2O4 for MB and R6G were 19.5 mg g− 1 and 15.3 mg g− 1, respectively, these values reached 67.6 mg g− 1 and 59.5 mg g− 1 for the bacteria-loaded MnFe2O4. The obtained data revealed that bacterial modification significantly increased the adsorption capacity of MnFe2O4, suggesting that the developed bio-adsorbent stands out as an effective and promising candidate for the remediation of dye-contaminated effluents.

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• MakaleAçık Erişim2025/r/gumushane/14066
  Green synthesis of iron and silver nanoparticles from aqueous extract of buckwheat husk waste: antibacterial, cytotoxic, and dye decolorization properties

  Karpuz, Ömer; Baltacı, Cemalettin; Gül, Abdulkadir; Gülen, Jale; Bozbeyoğlu, Pınar; Aydoğan, Nebahat

  Iron oxide (BHFeNP) and silver nanoparticles (BHAgNP) were produced using a green synthesis method through the extract of buckwheat husk (BH) waste to remove dye pollutants from water bodies in this study. The BHFeNP and BHAgNP were characterized by TEM, SEM, XRD, EDX, and FTIR techniques. Then, the methylene blue (MB) removal performance of the synthesized nanoparticles (NPs) was investigated. MB adsorption experiments showed that BHFeNPs were more dependent on temperature, adsorbent amount, and pH, while BHAgNPs notably depended on adsorbent amount, initial MB concentration, and pH. BHAgNPs had higher adsorption rates than BHFeNPs, and the Langmuir isotherm was more suitable for the adsorption process. BHAgNP and BHFeNP were shown to have the maximum adsorption capacities of 96.3 and 53.4 mg/g at pH 8 and 25 °C, respectively, in the presence of 0.25 g/L NP. Kinetic and thermodynamic calculations revealed that MB adsorption was spontaneously endothermic and supported the pseudo-second-order kinetic model. The antibacterial potentials of BHFeNPs and BHAgNPs were investigated against two gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two gram-positive (Enterococcus faecalis and Staphylococcus aureus) bacterial strains. BHAgNPs exhibited a higher antibacterial activity against the strains used. In cytotoxicity studies with ARPE-19, A549, HeLa, and DU-145 cell lines, it was observed that BHAgNP had a greater cell growth inhibition effect than BHFeNP and BH extract. Examining the morphological changes in the cells exhibited that BHAgNP significantly inhibited A549 and ARPE-19. Reusability studies of the generated NPs revealed MB removal capabilities of 92.5% and above after the fifth stage. The present study demonstrates that BHAgNP and BHFeNPs are viable nanoadsorbents for the elimination of environmental pollution due to their excellent removal performances and stable adsorbent characteristics.

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• MakaleAçık Erişim2025/r/gumushane/11659
  Valorisation of bread wastes via the bacterial cellulose production

  Güzel, Melih

  The short shelf life of bread can be attributed to changes in its textural and sensory properties, a process termed staling, and large amounts of bread residue and waste are generated daily. Because the main component of bread is starch, the use of bread wastes as a substrate for bacterial cellulose (BC) production can significantly contribute to valorisation and reuse of wastes. This study aimed to investigate the BC production potential of various stale breads, convert these wastes into usable forms for food and other industries, and increase their economic value. Stale breads were hydrolyzed with dilute acid, and BC-producing bacteria from Kombucha tea were isolated and identified as Gluconobacter oxydans MG2021 (GO). BCs were produced from bread hydrolysates with GO and Komagataeibacter hansenii GA2016 (KH), and their properties were examined. The results indicated that stale breads represented a good source for BC production, as high BC yields were obtained using GO (8.81%–25.02%) and all BCs had superior properties such as high crystallinity (75.96%–91.39%), thermal stability, liquid holding capacity, and fine fibers (40.16–85.39 nm). This study demonstrated that bread wastes could be used as a low-cost substrate for large-scale BC production, and the abundance of bread wastes demonstrated their potential as a resource for commercial BC producers.

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