Sürdürülebilir Kalkınma Amaçları

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Araştırmacılar(3)

• Ergüven, Gökhan Önder
• Platin, Nida
• Yolcular, Şule Tatar

• MakaleYalnız künye2026Scopus SJRQ3/r/munzur/830
  Optimization and Modeling of Brilliant Yellow Removal Via Neodymium-Infused Polymeric Hydrogel: A Central Composite Design Study

  Pıhtılı Yıldız, Güzin; Tanyol, Mehtap; Demir, Ferhat

  This study investigates the adsorption performance of a neodymium (III)-reinforced Poly(acrylamide-co-N-vinylimidazole) hydrogel composite [P(AAm-co-NVI)/Nd3+] for the removal of brilliant yellow (BY) dye from aqueous media. The hydrogel structure and metal–polymer interactions were characterized using FT-IR, TGA, SEM, and XRD analyses. The adsorption process was systematically optimized using a central composite design (CCD) approach combined with response surface methodology (RSM). The CCD-RSM second-order model exhibited a good fit to the experimental data (R2 = 0.9350), as supported by ANOVA. Numerical optimization revealed a maximum removal efficiency of 99.13% at a hydrogel dosage of 0.08 g/100 mL, an initial BY concentration of 81.68 mg/L, and a contact time of 61.73 min. Langmuir and the Freundlich isotherms were used in modeling the adsorption data. When the correlation coefficients of both models were compared, it was observed that the Langmuir isotherm provided a better fit for adsorption. The enhanced adsorption performance is attributed to the presence of Nd3+ ions, which promote additional electrostatic interactions and coordination sites between the hydrogel matrix and anionic dye molecules. The results demonstrate that Nd3+-reinforced hydrogels can serve as efficient and tunable adsorbent systems, particularly when process parameters are optimized statistically.

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  AtıfScopus1·WoS1·OpenAlex1

  İncele
• MakaleAçık Erişim2024/r/munzur/6304
  Effect of Synthetic Wastewater on Antioxidant Defence System in Dreissena polymorpha

  Serdar, Osman; Erguven, Gokhan Onder; Yildirim, Nuran Cikcikoglu; Korkmaz, Volkan; Erguven, Gozde

  The effects of the synthetic wastewater on antioxidant defence system in Dreissena polymorpha was evaluated. For this purpose, SOD, CAT, GPX activities and TBARS and GSH levels in tissues were determined by using commercial kits. The activities of SOD and CAT were in sythtetic group were determined lower than the control group in D. polymorpha during 24 and 96 h (p<0.05). After exposure of the cells of D. polymorpha samples to synthetic wastewater, depletion in GSH levels and subsequent increase in TBARS levels were observed, reflecting their unstable state. According to the data obtained from the study, It can be inferred that the biomarkers being domestic monitored are beneficial and effective in evaluating the biochemical mechanisms of wastewater as early warning indicators.

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• MakaleAçık Erişim2024/r/munzur/6237
  Evaluating the impact of firm size, firm age, international opportunity recognition, and business network on internationalisation performance

  Ataman, Göksel; Platin, Nida

  This study examines the cumulative impact of firm size, firm age, business network participation, and international opportunity recognition on the internationalisation performance of small and medium- sized enterprises (SMEs). The study population consists of 160 SMEs in the Kayseri, Inegöl, and Istanbul Organized Furniture Industry area, specifically focusing on those involved in business networks. The data was collected through a survey methodology, and the research objective was assessed using a quantitative approach in SPSS 21. The study aims to examine the gradual impact of variables on internationalisation performance. The stepwise regression in the analysis underscores the crucial impact of firm size and various aspects of international opportunity recognition on internationalisation performance. Notably, the business network's structure positively influences performance, providing optimism for firms seeking to enhance their internationalisation efforts. However, the strength of the tie subdimension of the business network does not impact performance significantly. These findings offer valuable insights for firms aiming to improve their internationalisation efforts.

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  AtıfOpenAlex1·TR Dizin1

  İncele
• MakaleYalnız künye2024Scopus SJRQ3/r/munzur/1727
  The RSM-CCD Optimization of Fenton Process for Industrial Wastewater Treatment and Determination of Treatment Efficiency Using Some Biochemical Responses in Dreissena polymorpha

  Tanyol, Mehtap; Serdar, Osman; Ketenalp, Zozan; Yildirim, Nuran Cikcikoglu; Erguven, Gokhan Onder; Yildirim, Numan

  The study investigated antioxidant biomarkers in Dreissena polymorpha to evaluate the efficiency of Fenton process (FP) in Organized Industrial Zone Wastewater (OIZW) treatment. Antioxidant enzymatic activities, including superoxide dismutase (SOD) and catalase (CAT), glutathione peroxidase (GPX), non-enzymatic antioxidants (GSH) and the indicator of lipid peroxidation (TBARS) were measured in D. polymorpha in response to treated OIZW by FP. The performance of the FP has been optimized with response surface methodology (RSM). The optimum conditions (reaction time, and H2O2 and Fe2+ concentration) for OIZW by the FP process were determined. The results showed that the highest COD removal efficiency (83.94 %) was obtained when as Fe2+ concentration=402.35 mg/L, H2O2 concentration=4100.30 mg/L, and reaction time=10.10 min (desirability=1.000). SOD and CAT enzyme was decreased in the 1/25 diluted OIZW group compared to control group. CAT and SOD enzyme activities were increased after treatment compared to control groups. No statistically significant changes were observed in GSH levels and GPx activities. TBARS levels were increased 1/25 diluted OIZW exposure groups compared to the control group. TBARS levels were decreased after treatment. The results revealed that antioxidant parameters are useful biomarkers for determining the treatment efficiency of the FP.

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  AtıfScopus2·WoS1·OpenAlex2

  İncele
• MakaleAçık Erişim2024Scopus SJRQ3/r/munzur/1576
  sThe Bioremediation of Industrial Effluents by Phanerochaete Chrysosporium: The COD, TOC Removal Efficiency and Biochemical Assessment for Dreissena Polymorpha

  Serdar, Osman; Yıldırım, Numan; Onder Erguven, Gokhan; Ketenalp, Zozan; Cikcikoglu Yildirim, Nuran; Durmus, Barbaros

  Bioremediation is one of the cheapest and easy method for biological treatment for most kind of industial wastewater. Bioremediation potential of the Phanerochaete chrysosporium for industrial wastewater from Industrial Zone Wastewater plant in Mardin, Turkey, was evaluated. The chemical oxygen demand (COD) and total organic carbon (TOC) reduction efficiencies of P. chrysoporium of on wastewater studied using biomarkers such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), Thiobarbituric Acid (TBARS) and reduced glutathione (GSH) levels in Dreissena polymorpha. The level of TBARS, a marker of lipid peroxidation was found to be high because of wastewater exposure after treatment. TBARS levels decreased (from 20.2 to 31.6 and from 20.8 to 37.5). GSH levels (from 52.3 to 15.9), CAT levels (from, 119.7 to 15.3 and from 91.1 to 13.4) SOD levels (from 3.8 to 0.9 and from 3.4 to 1.2) and GPX activity (from 177.2 to 104.4 and 174.2 to 100.5) decreased in the wastewater exposure groups during 24 and 96th hour compared to the control groups. GSH levels, CAT, SOD and GPX activity increased after treatment by P. chrysosporium. Results indicate that industrial wastewater caused oxidative stress in Dreissena polymorpha. The findings revealed that the highest removal efficiency for COD and TOC, at 86.3 % and 80.3 % respectively, occurred in the 1/20 diluted medium. P. chrysosporium has proven to be effective in the bioremediation of wastewater from the Industrial Zone Changes in biochemical parameters before and after bioremediation showed that antioxidant parameters such as CAT, SOD, GPx activities and GSH and TBARS levels can be used as biomarker to evaluate bioremediation efficiency.

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  AtıfScopus4·WoS2·OpenAlex4

  İncele
• MakaleAçık Erişim2023/r/munzur/6378
  Bioremediation of Synthetic Prepared Domestic Wastewater with P. chrysosporium

  Erguven, Gokhan Onder; Yildirim, Nuran Cikcikoglu; Aydin, Ekrem; Ergül, Gözde

  In this study, the removal efficiencies were evaluated based on key environmental parameters such as chemical oxygen demand (COD), Total Organic Carbon (TOC), Total Nitrogen (TN), and Total Phosphorus (TP), using P. chrysosporium white rot fungus to treat synthetically prepared domestic wastewater. The research aimed to assess the suitability of bioremediation results with respect to the Urban Wastewater Treatment Regulation. The experiment was carried out over a span of 11th days, employing static 1/1 and 1/5, as well as dynamic 1/1 and 1/5 dilution ratios. The outcomes revealed varying removal efficiencies, with the highest rates observed at dynamic conditions and a 1/5 dilution ratio: 84% for COD, 81% for TOC, 73% for TN, and 56% for TP. Conversely, the lowest removal efficiencies were determined under static 1/1 conditions, reaching 48% for COD, 33% for TOC, 31% for TN, and 45% for TP. Based on the results, it is evident that P. chrysosporium exhibited effective bioremediation capabilities on synthetic domestic wastewater within a reasonable 11th day period. Furthermore, the results aligned with the specified limit values outlined in the Urban Wastewater Treatment Regulation. Consequently, the study highlights the efficacy of P. chrysosporium as a valuable species for biological treatment stages in urban wastewater management

  İncele
• MakaleAçık Erişim2023Scopus SJRQ3/r/munzur/2556
  Bioremediation of herbicide diquat dibromide from aqueous solution with white rot fungus Phanerochaete chrysosporium

  Yildirim, Numan; Ciftci, Emine; Erguven, Gokhan Onder; Durmus, Barbaros

  In this study, the fungal bioremediation of herbicide diquat dibromide (DD) by white rot fungus Phanerochaete chrysosporium was studied. After bioremediation, the reduction in toxicity of the remediated media was evaluated by Daphnia magna as a model organism. For bioremediation studies, flask-level batch experiments were performed at different DD concentrations (10, 20 and 50 ppm) under static and agitated conditions. The highest reduction rates of chemical oxygen demand and total organic carbon were determined as 85.92 (for 20 ppm DD) and 87.46% (for 10 ppm DD), respectively under agitated conditions. After bioremediation, D. magna bioassay was used for toxicity assessment during 24, 48 and 72-h periods. In current study, it was observed that P. chrysosporium has very effective bioremediation capacity for diquat dibromide. The D. magna bioassay revealed that P. chrysosporium provides effective reduction in toxicity of diquat dibromide.

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• MakaleAçık Erişim2023Scopus SJRQ3/r/munzur/1622
  The biosorption of Co(II) by Homalothecium sericeum from aqueous solutions under batch conditions: response surface methodology optimization and Daphnia magna bioassay

  Tanyol, Mehtap; Korkmaz, Volkan; Yildirim, Numan; Erguven, Gokhan Onder; Ayhan, Nagihan Karaaslan; Alatas, Mevlut

  In the present work, Homalothecium sericeum biomass was used for removal of Co(II) from aqueous solution. The effects of process parameters (contact time, biosorbent amount, and initial Co(II) con-centration) on the response (Co(II) % removal) were investigated using a batch adsorption system optimized with response surface methodology/central composite design method. Under optimized conditions the maximum Co(II) removal efficiency achieved is 94.07% at an initial Co(II) concentration of 2.05 mg/L, a H. sericeum amount of 0.34 g/50 mL, and a process time of 36.09 min. In this study, the toxicity of the medium after biosorption carried out under optimized conditions was also tested with Daphnia magna bioassay. When mortality results with D. magna were evaluated, although a removal efficiency of 94.07% was obtained after biosorption, this was not sufficient to reduce mortality of D. magna.

  AtıfScopus1·WoS2

  İncele
• MakaleAçık Erişim2022/r/munzur/5863
  Consumers’ Preferences for Drinking Water in Istanbul City

  Erguven, Gokhan Onder; Kanat, Gurdal; Erguven, Gozde

  Water is an indispensable resource for living things to survive. In addition to its direct consumption, water is also used in the preparation of foods necessary for eating and drinking. Therefore, it is extremely important that the water used is drinkable, healthy and safe. The aim of this study is to determine the place of network water as drinking water in consumer preferences. In accordance this purpose, an online questionnaire was prepared with 274 participants from different age groups, including students from Yıldız Technical University (YTU) Department of Environmental Engineering and their relatives and neighbours, including different ages and occupational groups. With this questionnaire, the factors affecting their water preferences and water usage profiles were determined. As a result of the survey, 54.1% of the participants use carboy water, 33.8% use pet bottle water, 12.1% use network water. The criteria that consumers pay attention to in their water preferences are taste, smell, color, cleanliness and the amount of mineral substances in the water, respectively. The reasons for preferring the carboy water, which is preferred by the majority, are that they find the carboy water cleaner and safer and that it tastes better. On the other hand, participants who preferred tap water stated that 33.3% of them preferred this water because its clean and reliable properties, 33.3% of it was affordable and 22.2% of it was easily accessible. When the degree of trust in the network water was questioned, 12.2% of the participants said that they found the network water safe, 40.5% did not find it safe and 47.3% said they were not sure. In addition, when the participants ranked carboy water, pet bottle water and network water according to the degree of reliability, the network water was found to be reliable with a large rate of 89.2%. 35.1% of the respondents stated that they would prefer to drink tap water if the Water Administration periodically discloses their water quality reports and indicates that the network water is clean enough.

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  AtıfOpenAlex1

  İncele
• MakaleYalnız künye2022/r/munzur/5805
  Bioremediation Performance of Sphingomonas melonis and Bacillus\rmuralis on Herbicide Diquot Dipremide-(ethylene-d4)

  Erguven, Gokhan Onder; Yildirim, Numan; Koçak, Emel; Durmus, Mehmet Harun Bogacbarbaros; Aydin, Ekrem

  Bioremediation is a process that utilizes the degradation potential of microorganism to provide a cost-effective and reliable\rapproach for pesticide biodegradation. For this purpose, chosen bacteria Sphingomonas melonis and Bacillus muralis were isolated\rfrom an agricultural soil sample. The biodegradation performance of these isolated bacteria at different Diquot Dipremide-\r(ethylene-d4) (DDE4) herbicide concentrations (250, 500 and 1000 ppm) was investigated under submerged culture conditions.\rBiodegradation performance of isolated bacteria was monitored with COD, TOC and, BOD5 reduction rates in culture medium at\rdifferent incubation periods. According to the results; S. melonis has the highest bioremediation capacity for COD removal (91%\rat 250 ppm). For TOC, B. muralis has the highest removal rate as 82% at 250 ppm. On the other hand, For BOD5 at 250 ppm 85%\rS. melonis showed the best removal performance. Most effective removal rate at 250 ppm concentrations was obtained as 91%\rand 88 by S. melonis and B. muralis respectively at the end of the 216th hour for COD. Additionally, the increase in turbidity\rrelated with population dynamics at the end of the 216 th hour positively effected the bioremediation parameters included COD,\rTOC and BOD5 reductions. These results showed that it can be used for effective COD, TOC and BOD5 removal in S. melonis and\rB. muralis on DDE4 remediation

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