Sürdürülebilir Kalkınma Amaçları

Yazarlar

  • MakaleAçık Erişim2026Scopus SJRQ1
    RGO-CBPAC versus CBPAC for diluted leachate treatment: adsorption isotherms, kinetics and thermodynamics

    Ogedey, A.; Oguz, E.

    This study compares carbon-based activated carbon (CBPAC) and reduced graphene oxide-modified CBPAC (RGO-CBPAC) for removing COD, NH3–N, and turbidity from 1:4 diluted leachate from the Bingöl landfill site. Brunauer Emmett Teller (BET) analysis indicated severe micropore blockage in CBPAC after adsorption (887 → 0.76 m2/g), whereas RGO-CBPAC retained a higher surface area (908 → 23 m2/g) and mesoporous structure, demonstrating enhanced structural stability due to graphene incorporation. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDX) confirmed the presence of surface functional groups and effective pollutant uptake, with RGO-CBPAC showing stronger surface–pollutant interactions. Zeta potential analysis showed pH-dependent surface charge behaviour, with CBPAC exhibiting amphoteric characteristics and RGO-CBPAC maintaining a more negative surface. After adsorption, both became more negatively charged, indicating the accumulation of negatively charged species. Kinetic analysis showed that COD adsorption on CBPAC followed pseudo-first-order and intraparticle diffusion models, whereas NH3–N and turbidity followed pseudo-second-order kinetics. In contrast, RGO-CBPAC exhibited pseudo-second-order and intraparticle diffusion behaviour for all pollutants, suggesting chemisorption with diffusion-controlled contributions. Adsorption equilibrium was best described by the Langmuir isotherm, yielding maximum capacities of 500 and 588 mg O2/g for COD, 17.5 and 36.5 mg/g for NH3–N, and 18.1 and 58.5 mg/g ((NH2)2H2SO4)/g for turbidity on CBPAC and RGO-CBPAC, respectively. Thermodynamic analysis demonstrated that COD and turbidity removal using RGO-CBPAC were spontaneous (∆G° < 0) and endothermic (∆H° > 0), whereas NH3–N removal remained non-spontaneous for both adsorbents. RGO incorporation significantly enhanced adsorption performance.

    • SDG 6 · Temiz Su ve Sanitasyon
    • SDG 12 · Sorumlu Üretim ve Tüketim
    AtıfScopus1WoS1OpenAlex1
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2024Scopus SJRQ2
    Leachate treatment via electrocoagulation–coal-based powdered activated carbon process: Efficiencies, mechanisms, kinetics, and costs

    Ogedey, Aysenur; Oguz, Ensar

    This study aims to improve COD, NH3-N, and turbidity removal from Bingöl's leachate using a single-reactor integrated electrocoagulation (EC)–coal-based powdered activated carbon (CBPAC) process under various experimental conditions. In the EC-CBPAC process, three stainless-steel cathodes and three aluminum electrodes were connected to the negative and positive terminals of the power supply, respectively. The initial concentrations in the leachate were 1044 mg O2/L for COD, 204 mg/L for NH3-N, and 57 NTU (or 71.25-mg (NH2)2H2SO4/L) for turbidity, respectively. After a 40-min EC-CBPAC process, with a CBPAC dosage of 5 g/L and pH of 5 for COD and turbidity, and 9.5 for NH3-N, the optimum removal efficiencies for COD, NH3-N, and turbidity were achieved at 92%, 40%, and 91%, respectively. When the EC process was applied without CBPAC under the same experimental conditions, the removal efficiencies of COD, NH3-N, and turbidity were 87%, 28%, and 54%, respectively. Before and after the EC-CBPAC process, the Brunauer–Emmett–Teller (BET) surface area, pore volume, and mean pore diameter of the CBPAC were found to be (888 m2/g, 0.498 cm3/g, and 22.28 Å) and (173 m2/g, 0.18 cm3/g, and 42.8 Å), respectively. The optimum pseudo-first-order (PFO) rate constants for COD, turbidity, and NH3-N were determined to be 3.15 × 10−2, 4.77 × 10−2, and 8.8 × 10−3 min−1, respectively. With the current density increasing from 15 to 25 mA/cm2, energy consumption, unit energy consumption, and total cost increased from 68.7 to 122.4 kWh/m3, 6.948 to 15.226 kWh/kg COD, and 0.85 to 1.838 $/kg COD, respectively. Practitioner points: EC-CBPAC process has greater COD, NH3-N, and turbidity removal efficiency than EC process. COD and turbidity achieved their optimum disposal efficiencies at 92% and 91%, respectively, at pH 5 The most efficient disposal efficiency for NH3-N was observed to be 40% at pH 9.5. EC-CBPAC process increased removal efficiencies for COD, NH3-N, and turbidity by 20%, 19%, and 38%, respectively, compared with EC alone. The turbidity, NH3-N, and COD disposal fitted PSO model due to high correlation values (R2 0.94–0.99).

    • SDG 6 · Temiz Su ve Sanitasyon
    • SDG 12 · Sorumlu Üretim ve Tüketim
    AtıfScopus3WoS3OpenAlex3
    ScopusWeb of SciencePubMedİncele
  • MakaleAçık Erişim2022Scopus SJRQ3
    The use of Phanerochaete chrysosporium as an alternative bioremedia-tion tool of heavy metal, chemical oxygen demand and phosphate from landfill leachate

    Yildirim, Numan; Kardas, Elif; Ince, Muharrem

    In this study, in order to investigate the bioremediation efficiency of Phanerochaete chrysosporium, chemical oxygen demand (COD) reduction, total phosphate levels and heavy metal (Fe2+, Mn2+, Zn2+ and Cu2+) removal were determined in five different experimental groups (control, X, Y, Z, and T) under static culture conditions containing leachate at different incubation periods (5, 10, and 20 d). At the end of the 20th day of incubation, 84% Mn2+ and Zn2+ removal was achieved in X application group. In the same application group, 90.88% COD reduction was also obtained. The lowest total phosphate value was determined as 2.63 g L–1 in T group compared with control group (5.0 g L–1). Similar improvements have been identified in other application groups in terms of metal removal, total phosphate levels and COD reduction. As a result, the findings obtained from our study show that white rot fungus P. chrysosporium can be used as an alternative biological resource in the studies for improving landfill leachate in terms of metal removal efficacy, COD and total phosphate level reduction capacity.

    • SDG 6 · Temiz Su ve Sanitasyon
    • SDG 12 · Sorumlu Üretim ve Tüketim
    • SDG 15 · Karasal Yaşam
    AtıfScopus3WoS1OpenAlex3
    ScopusWeb of Scienceİncele
  • MakaleYalnız künye2018Scopus SJRQ2
    The determination of present and possible environmental risks in solid waste dumping site, Tunceli, Turkey

    Yildirim, Nuran Cikcikoglu; Demirbilek, Deniz; Erguven, Gokhan Onder; Kayar, Rahime; Basaran, Senay; Tulpar, Dilan

    Leachate was a major cause of high risk classification. This landfill was set as one with highest possible risk classification due to high vulnerability of private water wells to contamination from leachate flows. The aim of this study is to determine the present and possible environmental risks of the leachate spreading from solid waste dumping site in Tunceli and offer solutions for those determined environmental risks. For this purpose, the characteristics of the leachate were monitored at two station points detected in the solid waste dumping site for 7 months. The characteristics of the leachate were found for pH between 7.9 and 8.7. Oxidation reduction potential (ORP) occurred between − 143 and − 48 mV while conductivity was between 2.8 and 2.6 mS. Total solid matter (TSM) and suspended solid matter (SSM) were between 1000 and 7000 mg/l, 0.2–22.5 mg/l, respectively, while total volatile solids (TVS) occurred between 300 and 1800 mg/l for the two stations. Alkalinity was approximately between 290 and 5210 mg/l, while biological oxygen demand (BOD5) and chemical oxygen demand (COD) results were 15–606 mg/l and 60–1160 mg/l, respectively, for two stations in all sampling time. In both stations, orthophosphate, ammonium nitrogen, nitrate, sulfate, and chloride analyses stayed between 3.04 and 921.1 mg/l; 0.29–619.36 mg/l; 8.94–135.04 mg/l; 125.9–1360.9 mg/l and 99.9–1249.9 mg/l, respectively, in 6 months. As a result of the characterization studies obtained from the leachate, it was found that the amounts of water entering into the waste mass and the retention period of the water in the mass were very effective in the temporal character change of the leachate. According to the Discharge Standards for Solid Waste Assessment and Disposal Facilities and Discharge to Waste Water Infrastructure Facilities of waste management regulation, the results were found to be risky. Consequently, the site in question needs to be urgently rehabilitated when considering the environmental risks of the leachate spreading from the site.

    • SDG 6 · Temiz Su ve Sanitasyon
    • SDG 12 · Sorumlu Üretim ve Tüketim
    AtıfScopus1WoS1OpenAlex1
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2013Scopus SJRQ2
    Characterization and pollution potential assessment of Tunceli, Turkey municipal solid waste open dumping site leachates

    Demirbilek, Deniz; Önal, Ayten Oztufekci; Demir, Veysel; Uslu, Gulsad; Arslanoglu-Isik, Hilal

    Environmental monitoring of leachate quality from an open municipal solid waste dumping site in Tunceli, Turkey was studied in this research. The most commonly examined pollution parameters were determined on a seasonal basis. The annual average 5-day biological oxygen demand (BOD5) and chemical oxygen demand (COD) values of station points were measured as 70 and 425 mg/L, respectively, and also the average BOD5/COD ratio (a measure of biodegradability) was calculated as 0.20. The low ratio of biodegradability and slightly alkaline pH values in the leachate samples indicated that the site was characterized by methanogenic conditions. The mean ammonium-nitrogen (NH4 (+)-N) and corresponding phosphate (orthophosphate) values were assayed as 70 and 11 mg/L, respectively. The average solids content in the leachates was measured as 4,681 mg/L (total solids) and 144 mg/L (suspended solids). Very low concentrations of iron, manganese, copper, and zinc in the leachate samples were found and the concentration of cadmium was measured below detection limits. Excessive amount of nutrients and high organic and inorganic pollutant content in the leachates pose serious pollution potential to the environment. Since no drainage system or bio treatment exists in this open dumping site, high permeability of natural soil at the site and in the surrounding area and very fractured and crackled rocks under natural soil are indicators of high groundwater pollution potential in this site.

    • SDG 6 · Temiz Su ve Sanitasyon
    • SDG 12 · Sorumlu Üretim ve Tüketim
    AtıfWoS23OpenAlex21
    Web of SciencePubMedİncele