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- MakaleYalnız künye2026Scopus SJRQ2Comparative Analysis of Sequential Electrooxidation and Electrocoagulation Processes for Leachate Treatment
Ogedey, Aysenur; Oguz, Ensar
This study aims to improve the removal efficiency of chemical oxygen demand (COD), NH₃-N, and turbidity from Bingöl leachate through a sequential electrochemical process. This process includes electrooxidation (EO) with Ti/PdO-CoO anodes and stainless-steel cathodes, followed by electrocoagulation (EC) with aluminum anodes and stainless-steel cathodes. The sequential electrochemical process lasted 400 min, consisting of 360 min of EO followed by 40 min of EC process. At pH 5, COD and turbidity reached optimal removal efficiencies of 89% and 99.9%, respectively, while NH₃-N achieved 88.5% at pH 9.5. These results indicate that the sequential electrochemical process was most effective under these pH values for removing organic matter, nitrogen, and suspended solids. The sequential electrochemical process led to significant improvements in the removal efficiencies of COD, NH₃-N, and turbidity, with increases of 32.5%, 44%, and 6.9%, respectively, compared to the EO process. The sequential electrochemical process showed improvements of 9.5% in COD and NH₃-N removal, and 1.2% in turbidity removal, compared to the results of the EC process. The pseudo-first-order (PFO) reaction rates for the EO and EC processes were determined, resulting in high R2 values (0.98–0.99). Additionally, the total consumption cost of the EO process was higher than that of the EC process. After the sequential electrochemical process, the consumption cost increased from $13.586/kg COD to $24.332/kg COD as the current density increased from 15 mA/cm2 to 25 mA/cm2.
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İncele - MakaleAçık Erişim2026Scopus SJRQ1RGO-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.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2024Scopus SJRQ2Leachate 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).
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İncele - MakaleAçık Erişim2024Scopus SJRQ1Application of electrocoagulation process for the disposal of COD, NH3-N and turbidity from the intermediate sanitary landfill leachate
Ogedey, Aysenur; Oguz, Ensar
This study aims to determine the COD, NH3-N and turbidity disposal efficiencies from leachate in the Bingöl landfill and highlight the electrocoagulation (EC) process’s performance in removing these pollutants. After establishing that landfill leachate was intermediate aged, its characteristics were identified using physical, chemical and elemental analyses. Six parallel-connected electrode plates with stainless steel as the cathode and aluminium as the anode were used to construct an electrocoagulation cell. After a 40-min treatment interval, the optimal disposal efficiencies for COD and turbidity from the leachate were determined to be 87% and 62%, respectively, at pH 5. Following a 40-min reaction, BOD5 concentration and BOD5/COD ratio were determined to be 85.75 mg O2/L and 0.64, respectively, at pH 5. At a NaCl concentration of 10 mM, the optimum disposal efficiency for NH3-N was determined to be 33%. The reaction kinetics matched pseudo-first-order (PFO) kinetics due to high correlation coefficients (R2 = 0.93–0.99) in removing COD, NH3-N and turbidity under different experimental conditions. The optimal reaction rate constants were determined as 2.93 × 10−2 min−1, 1.92 × 10−2 min−1 and 7.3 × 10−3 min−1 for the disposal of COD, NH3-N and turbidity, respectively. Energy consumption, unit energy consumption and total consumption cost rose in the EC process when the current density was augmented from 15 to 25 mA/cm2.
AtıfScopus14WoS11OpenAlex12İncele - Yüksek Lisans TeziAçık Erişim2022Beyaz çürükçül mantar Phanerochaete chrysosporium ile sulu çözeltiden Herbisit Dikuat Dibromür'ün biyoıslahı
Emine Çiftçi
Pestisitler toksik ve biyosidal maddeler olup çevre açısından önemli bir kirleticidir. Pestisitlerin kontrolsüz ve aşırı bir şekilde kullanımı ile depolanmaları, bertaraf edilmeleri esnasında yapılan yanlışlıklar çevre kirliliğine yol açmaktadır. Düşük konsantrasyonlarda bile uygulama alanlarından taşınabilir ve toprak hava, su ortamlarına geçerek ciddi çevre sorunlarına neden olabilmektedirler. Çalışmada sulu çözeltiden yabancı ve istenmeyen otlarla mücadelede kullanılan bir pestisit türü olan dikuat dibromür (DD) herbisitinin biyoıslahı (biyoiyileştirme) ve iyileştirme sonrası ortamın toksisitesi araştırılmıştır. Dikuat dibromürün biyoıslahı için bir beyaz çürükçül mantar türü olan Phanerochaete chrysosporium fungusu kullanılmıştır. 10, 20 ve 50 ppm konsantrasyonlarda hazırlanan ortamlardan 1, 3, 5 ve 7 günlük sürelerde örnekler alınmış, bu ortamlarda kimyasal oksijen ihtiyacı, toplam organik karbon ve mortalite değerleri incelenmiştir. Mortalite deneyinde su ortamında her türlü kimyasal değişime duyarlı olan Daphnia magna indikatör canlısı kullanılmıştır. Mortalite deneyinde 24, 48 ve 72 saatlik sürelerde D. magna bireylerinin hazırlanan deney ortamlarındaki ölüm oranları incelenmiştir. Yapılan çalışma sonucunda P. chrysosporium fungusunun sulu çözeltilerden dikuat dibromürün biyoiyileştirmesinde etkili olduğu ve giderim sonrası uygulanan toksisite deneyinde P. chrysosporium'un herbisit dikuat dibromürü daha toksik ürünlere çevirmeden verimli bir şekilde iyileştirilebildiği ortaya konmuştur.
- Yüksek Lisans TeziAçık Erişim2022Pyroxasulfone herbisitinin bazı toprak bakterileriyle biyoremediasyonunun karşılaştırılması ve Daphnia magna üzerindeki mortalite etkisi
Duygu Tekin
Bu çalışma ile tarım toprağından izole edilen M. arthrosphorea, M. radiotolerans ve bunların karışımlarıyla elde edilen zenginleştirilmiş mikrobiyal kültürlerle Pyroxasulfone etken maddeli herbisitin kimyasal oksijen ihtiyacı (KOİ) ve toplam organik karbon (TOK) gibi önemli bazı çevresel parametreler bazında elde edilen giderim verimleri araştırılmıştır. Çalışmada bunlara ek olarak giderim öncesi ve sonrası Daphnia magna (su piresi) üzerindeki mortalite (ölüm oranı) etkisi de belirlenmiştir. Kullanılan bakteriler zenginleştirilmiş ve gerekli hacimlerde alınarak Pyroxasulfone etken maddeli herbisitin tarım alanlarında kullanımı tavsiye edilen konsantrasyonları (375, 500, 750 ve 1000 ppm) esas alınarak hazırlanan çözeltilere ilave edilmiştir. Elde edilen en yüksek giderim oranlarındaki numuneler ve tarım arazilerinde kullanımı tavsiye edilen konsantrasyonlarda hazırlanan numuneler ile Daphnia magna üzerindeki ölüm oranları belirlenmiştir. Elde edilen verilere göre KOİ ve TOK giderim yüzdeleri her iki bakteri türü ve bunların karışımlarında çeşitli zaman dilimlerinde %37 - 90 aralığında belirlenmiştir. Arıtılmamış ortamlarda 96 saat sonunda Daphnia Magna üzerinde %40 - 80 civarında, arıtılmış ortamlarda ise %75 – 100 aralığında değişen bir mortalite etkisi tespit edilmiştir. Çalışma sonuçlarına göre M. arthrosphorea, M. radiotolerans ve bunların konsorsiyumlarının pyroxasulfone etken maddeli herbisitler üzerinde tarlaya atılması tavsiye edilen konsantrasyonlarda etkili bir biyoremediasyon gerçekleştirdiği, ancak elde edilen en yüksek giderime sahip nihai KOİ ve TOK konsantrasyonlarndaki ortamların da Daphnia magna üzerinde toksik etki yarattığı gözlemlenmiştir. Bu durum da pyroxasulfone herbisitinin parçalanma ürünlerinin gösterdiği toksik etki ile açıklanmaktadır. Anahtar kelimeler: Pyroxasulfone, Biyoremediasyon, Daphnia magna, Biyokimyasal oksijen ihtiyacı, Kimyasal Oksijen İhtiyacı, Toplam organik karbon
- MakaleAçık Erişim2021Scopus SJRQ1The bioremediation of glyphosate in soil media by some newly isolated bacteria: The COD, TOC removal efficiency and mortality assessment for Daphnia magna
Korkmaz, Volkan; Yildirim, Numan; Erguven, Gokhan Onder; Durmus, Barbaros; Nuhoglu, Yasar
In this study, the bioremediation capacity of three isolates of Bacillus aryabhattai, Pseudomonas azotoformans and Sphingomonas pseudosanguinis and their consortia at glyphosate added soil medium investigated via the reduction of chemical oxygen demand (COD) and total organic carbon (TOC) parameters in filtrate waters obtained from a designed bioremediation setup. Additionally, mortality assays were performed on the filtrate waters with model organism Daphnia magna. According to the results of the experiments, at the end of the 11 days, the highest COD reduction rate seen in media with S. pseudosanguinis as 92.1% while TOC rate was 69.13% in consortia media. While the mortality rate was 10, 10 and 5% on B, P and S application groups at the end of the 72th respectively, these rates were 100% in control group at the end of the 48th. According to the results obtained from bioremediation and mortality assessment, these bacteria can reach the high bioremediation rate one by one and in consortia media.
AtıfScopus14OpenAlex16İncele - Kitap BölümüYalnız künye2020Microbial release of exopolymeric substances and their role in removal of pollutants from wastewater
Işıl Arslan Topal, E.; Topal, Murat
Activated sludge samples were seasonally collected from the aeration tanks of the Municipal Wastewater Treatment Plant located in Elazığ city (Turkey). Mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), total solids (TS), suspended solids (SS), volatile solids (VS), chemical oxygen demand (COD), and sludge volume index (SVI) of the activated sludge were seasonally monitored in the treatment plant. Exopolymeric substances (EPS) were extracted in the samples collected. The EPS decreased in summer, while the EPS content was the highest in winter. The TB-EPS part of EPS was higher than the LB-EPS part of the EPS in all seasons. The lowest TB-EPS and LB-EPS were determined in summer, while the highest TB-EPS and LB-EPS were determined in winter. The carbohydrate, protein, and humic substance fractions of TB-EPS and LB-EPS followed the order of protein > carbohydrate > humic substance in all seasons. There was a negative correlation between the EPS content and SVI. The relationships between EPS and the removal efficiencies of TS, SS, and VS were quite low, while the relationship between COD removal and EPS was quite high.
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