Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2026Scopus SJRQ1/r/bayburt/11105
  Upcycling marble waste into construction materials and heavy metal adsorbents via hot-pressed geopolymerization technique

  Öksüzer, Nurullah; Uslu, Emin; Gökçe, H. Süleyman

  This study presents a sustainable approach to utilizing marble dust waste by producing bifunctional metakaolin-based geopolymers via a synchronized hot-pressing technique. In this study, the environmental footprint was minimized by designing mixtures in which marble waste constituted 50% of the total volume. Three stoichiometric series were investigated by varying the activator modulus (SiO2/Na2O = 3 and 4) and the Si/Al ratio (2 and 3) under two curing temperatures (150 and 300 °C) and three compaction stresses (5, 25, and 50 MPa). Thus, a high-volume industrial byproduct was transformed into a functional component. In this context, it investigated the transformation of industrial products into next-generation materials by using them to produce cementless composite geopolymers for civil engineering and to adsorb heavy metal (Cu2+). As a result of the research, an early compressive strength of 58 MPa was obtained through heat treatment and pressing applied at 300 °C and 50 MPa. This optimum strength was achieved in the SiO2/Na2O = 3, Si/Al = 3 series, whereas excess silica (SiO2/Na2O = 4) and excess aluminum (Si/Al = 2) limited the strength to 16.8 and 35.2 MPa, respectively. Microstructural analyses (SEM/EDS and FT-IR) revealed that marble dust was used as a filler material in the microstructure to produce an N-A-S-H-containing matrix. The produced materials were then ground after their service life and used to purify water containing heavy metals. More than 99.75% of Cu2+ was removed through ion exchange between copper ions used as heavy metals. The residual Cu2+ concentration fell below 0.25 mg/L from an initial concentration of 100 mg/L, and the released Na+-to-adsorbed Cu2+ molar ratio of approximately 1.8–2.3 confirmed an ion-exchange-dominated uptake mechanism. This structural and environmental impact demonstrates that marble waste, which is otherwise discarded as waste, is considered inert, offering an alternative model for the circular economy and environmental applications.

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• MakaleAçık Erişim2024Scopus SJRQ1/r/bayburt/12888
  Removal kinetics of vinyl acetate under aerobic and anoxic conditions in a batch bioreactor

  Yalçın Çelik, Beste; Nuhoğlu, Alper; Kul, Sinan; İrdemez, Şahset

  Vinyl acetate is a volatile organic compound widely used in the chemical industry, and there is a need for effective and economic removal of this volatile organic compound from wastewater and waste gases in chemical industries. This study aims to determine the biological treatability of vinyl acetate both under aerobic and anoxic conditions using mixed cultures obtained from a wastewater treatment plant. Considering the previous studies in the literature, testing the biodegradability of vinyl acetate under both aerobic and anoxic conditions, together with evaluating the effect of other mechanisms, such as adsorption and volatilization, on the removal of vinyl acetate, can be regarded as the prominent part of this study. Wastewater containing artificially prepared vinyl acetate was treated in a batch bioreactor, and performance and kinetic constants were investigated. Aerobic treatment under batch conditions conformed to the Haldane biokinetic equation, and the biokinetic constants of μmax, Ks, and Ki were calculated as 0.66 h−1, 19.67 mg L−1 and 50.56 mg L−1, respectively. Anoxic treatment under batch conditions conformed to the Monod biokinetic equation, and the biokinetic constants of μmax and Ks were calculated as 0.31 h−1 and 33.88 mg L−1, respectively. Experiments revealed that vinyl acetate was not volatile, and its adsorption and biological treatment performances were 28% and 72%, respectively. The mixed culture had a very high performance for removing vinyl acetate under batch operating conditions. The primary mechanism of vinyl acetate removal was found to be biological treatment.

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  AtıfOpenAlex1

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• MakaleAçık Erişim2016Scopus SJRQ1/r/bayburt/12369
  Performance investigation of a jet loop membrane bioreactor for the treatment of an actual olive mill wastewater

  Değermenci, Nejdet; Cengiz, İbrahim; Yildiz, Ergun; Nuhoglu, Alper

  In this study, following the pre-treatment of olive mill wastewater (OMW), its treatment in a jet loop membrane bioreactor (JLMBR) was investigated. Among the pre-treatment options, the configuration composed of physical settling, cartridge filter and ceramic membrane showed the best performance in terms of investigated parameters. For the JLMBR that was fed by pretreated OMW, up to 93 and 87% removal efficiencies were achieved for the chemical oxygen demand (COD) and total phenol, respectively, at volumetric organic load (VOL) of 17.8 kg COD/m3 day. The calculated specific oxygen uptake rate (SOUR) values were in the range 7.7–34.7 g O2/kg MLVSS h. When even hydraulic retention times (HRT) values decreased by a factor of 1:24, system performance in terms of COD and total phenol removal remained almost stable. Decreasing the sludge retention time (SRT) to three days made considerable perturbations for the system performance, increasing the effluent COD and total phenol values in 900 and 80 mg/L, respectively. The JLMBR showed a high overall performance for the treatment of an actual OMW under the evaluated operational conditions.

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  AtıfScopus33·WoS28·OpenAlex33

  İncele
• MakaleYalnız künye2008Scopus SJRQ1/r/bayburt/13965
  The removal of lignin and phenol from paper mill effluents by electrocoagulation

  Uǧurlu, M.; Gürses, A.; Doǧar, Ç.; Yalçin, M.

  This study aims to investigate the treatment of paper mill effluents using electrocoagulation. Removal of lignin, phenol, chemical oxygen demand (COD) and biological oxygen demand (BOD) from paper mill effluents was investigated at various current intensities by using different electrodes (Al and Fe) and at various electrolysis times (1.0, 2.5, 5.0 and 7.5 min). It was observed that the experiments carried out at 12 V, an electrolysis time of 2 min and a current intensity of 77.13 mA were sufficient for the removal of these pollutants with each electrode. The removal capacities of the process using an Al electrode were 80% of lignin, 98% of phenol, 70% of BOD, and 75% of COD after 7.5 min. Using an Fe electrode the removal capacities were 92%, 93%, 80% and 55%, respectively. In addition, it was found that removal of lignin, phenol, BOD and COD increased with increasing current intensity. In the experiments carried out at different current intensities, higher removal can be explained through a decrease in intra-resistance of solution and consequently an increase at the transfer speed of organic species to electrodes. It was also found that Al electrode performs higher efficiency than Fe electrode except for COD removal. However, the time required for removal of BOD was more than that of COD. The results suggest that electrocoagulation could be considered as an effective alternative to paper mill effluents treatment.

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  AtıfScopus257·OpenAlex275

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