Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026/r/gumushane/16396
  Mercury Removal from Glycine Leach Solutions Using Sodium Sulfide (Na2S) Precipitation

  Kantarci, Sadiye; Alp, Ibrahim; Youpoungam, Abdou Azizi; Sivircik, Salih

  Amino acid leaching has been considered an environmentally friendly alternative for gold recovery; however, the dissolution of mercury (Hg) during the leaching of amalgamation tailings remains a major challenge. This study is a novelty study that focuses on Hg removal by passing the Hg-containing tailings, previously processed by amalgamation, into solution via glycine (NH(2)CH2COOH) leaching. In this regard, a precipitation method using sodium sulfide (Na2S) was developed to remove Hg from solutions obtained after glycine leaching. The effects of precipitation time, pH, Na2S dosage, and temperature were investigated. The effects of pH, precipitation time, and temperature were found to be limited within the investigated ranges. The results showed that Na2S dosage was the most effective parameter in mercury removal. The initial Hg concentration of 12,160 ppb was reduced to 223 ppb at a Na2S:Hg molar ratio of 60, corresponding to approximately 98% removal efficiency under the selected operating conditions. Increasing the Na2S:Hg ratio to 80 resulted in a slightly higher removal efficiency (similar to 99%) with a final Hg concentration of 144 ppb; however, a ratio of 60 was considered optimal in terms of reagent consumption and process efficiency. The outcomes indicate that Hg removal with Na2S is a rapid and effective process under alkaline conditions, while Au remains in solution and Cu and Ag are partially removed, indicating limited selectivity and the need for further optimization. Therefore, this study provides a basis for developing more environmentally friendly processes for amalgamation tailings.

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• MakaleAçık Erişim2023/r/gumushane/20379
  Physicochemical Analysis of Pomegranate Sours Produced by Traditional Method in Türkiye and The Investigation of Antioxidant Properties

  Baltaci, Cemalettin; Akar, Bülent; Oğuz, Miraç

  In this study, the physicochemical properties and antioxidant activities of the commercially produced 15 pomegranate sour samples and one control sample were determined and their compliance with the TS 12720 (traditional sour pomegranate concentrate standard) was evaluated. Antioxidant activity values of pomegranate sours extracts were determined using 6 different methods. The samples had strong antioxidant capacity, except for N10 and N15. In addition, glucose, fructose, sucrose, HMF and acidity measurements of the same samples did not show compatibility with TS 12720. The pH values of the samples of N7, N8, N10, N11, N14 and N15 were not in accordance with the standard values (2.4-4.0) The titratable acidity values measured in samples of N1, N3, N4, N6, N10, N13, N15 were below the value (>6.0% (m/m)) in the standard. While the brix values of the samples were measured between 59.20-75.70, the brix values of the N12, N13 and N14 samples were determined below the standard brix value (>68%). The highest HMF value of the samples were determined as 8117.66. According to TSE 12720, the HMF content should be not exceed 50 mg/kg. However, the HMF values of the samples were detected above the maximum limit value except for N8 and N16.

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• MakaleAçık Erişim2020/r/gumushane/17678
  Adsorption Of Methylene Blue from Aqueous Solution with Sulfuric Acid Activated Corn Cobs: Equilibrium, Kinetics, and Thermodynamics Assessment

  Baltaci, Cemalettin; Gundogdu, Ali; Duran, Celal; Bozbeyoglu, Pinar

  Three adsorbents with different characteristics were produced in this study by activation of sulfuric acid with different concentrations, from corn (Zea mays L.) cobs, which is an agricultural waste by-product resulting from harvesting. After characterization by the parameters such as Boehm titration, determination of pH-pHpzc, and methylene blue – iodine number, and IR analysis, their methylene blue adsorption potentials from aqueous medium were investigated based on equilibrium, kinetics, and thermodynamics evaluations. This study aims to examine the effects of relatively dilute and concentrated acids on the activation process and to gain an economic value to waste materials through the production of a new adsorbent. It was observed that the initial solution pH did not have a significant effect on the adsorption efficiency. The adsorption process reached the equilibrium at the end of the first 120 minutes, and the kinetic data fit the pseudo-second-order kinetic model. Langmuir adsorption capacity (295.5 mg/g) of the adsorbent produced by activating with 50% sulfuric acid was found higher than those produced with 75% and 98% acids. An increase in ambient temperature effected the adsorption positively. As a result, in this study, very low-cost adsorbents were produced from the waste by-product corn cobs, and a new approach was proposed for cleaning wastewater containing dyestuffs.

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• MakaleAçık Erişim2019/r/gumushane/18155
  Identification of Antioxidant Activity by Different Methods of a Freshwater Alga (Microspora sp.) Collected From a High Mountain Lake

  Akar, Zeynep; Akar, Bülent; Şahin, Bülent

  Algae contain a large amount of biological active compounds functioning as antioxidant,antimicrobial and anti-tumour. In the present research, antioxidant activity of freshwateralga Microspora sp. (Chlorophyta) extract prepared in different solvents (methanol,acetonitrile, ethanol, acetone and ethyl acetate) was determined with three differentmethods; 2,2-diphenyl-1-picrylhydrazyl (DPPH•), Iron (III) Reduction / AntioxidantPower (FRAP) Assay and Copper (II) Reductive Antioxidant Activity (CUPRAC). Thealga samples collected from the high mountain lake (2733 m above sea level) localized inGümüşhane province of Turkey. The algal extracts prepared in different solvents showedantioxidant activity. The values of DPPH• varied from 8.97% (in acetonitrile extract) to31.15% (in methanol extract). As in the DPPH• method, the lowest and highest values inthe FRAP method were measured based on μM TEAC (Trolox Equivalent AntioxidantCapacity) in methanol and acetonitrile extracts as 60.303 μM and 359.394 μM respectively.While the lowest value of CUPRAC test was determined in acetonitrile extract (0.041 μMTEAC ) as in the other tests, highest value was measured in ethanol extract (0.101 μMTEAC ). The values of highest antioxidant activity in both DPPH• and FRAP methodswas measured in the methanol solvent whilst was determined in the ethanol solvent forCUPRAC.

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• MakaleYalnız künye2016/r/gumushane/18809
  Validation of HPLC Method for the Determination of 5-hydroxymethylfurfural in Pestil, Köme, Jam, Marmalade And Pekmez

  Akşit, Zeynep; Baltaci, Cemalettin

  T his study represents a high performance liquid chromatography (HPLC) method for the detection of 5-hydroxymethylfurfural in pestil, köme, jam and pekmez samples. The linearity, selectivity, decision limit, detection capability, detection limit, quantification limit, precision, recovery, ruggedness and measurement uncertainty of the method were determined. The developed method, simple and accurate, showed good recovery values (97-108%). The accuracy of the method expressed with the relative standard deviation was below 6%. The detection limit and quantification limit were 0.03 mg/kg and 0.10 mg/kg, respectively. HMF levels in pestil, köme, jam, marmalade and pekmez samples were determined using the validated method

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• MakaleYalnız künye2016/r/gumushane/18808
  Chemical Composition, Antimicrobial and Antioxidant Activities of Essential Oil from Pedicularis condensata BIEB

  İlter, Şeyda Merve; Baltaci, Cemalettin; Üçüncü, Osman

  T he chemical composition of the essential oil obtained from the dried aerial parts of Pedicularis condensata was analyzed by GC-FID and GC-MS. Thirty-eight components have been identified in the essential oil of P. condensata. The major compounds of the essential oil were pentacosane (21.28%), hexadecanoic acid (18.48%) and tricosane (13.70%). The antimicrobial activity of the essential oil was also investigated and it showed moderate antimicrobial and antifungal activites aganist twelve gram negative bacteria and five fungi. The amount of total phenolic and DPPH reducing activity quantified essential oil in P. condensata were found as 198.28 GGA/L and 10.90 % respectively

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