Browsing by Author "Ozguven, Ayse"

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Determination of Optimum Treatment Conditions for Paint Industry Wastewater With the Coagulation/Flocculation Method
(desalination Publ, 2021) Aldemir, Adnan; Hakkitanir, Esmanur; Ozguven, Ayse
In this study, optimum treatment conditions for paint industry wastewater were determined by response surface methodology (RSM). Wastewater treatment experiments were performed in jar test using the coagulation/flocculation method. FeCl3 center dot 6H(2)O,Al-2(SO4)(3)center dot 18H(2)O, and FeSO4 center dot 7H(2)O coagulants were used in the treatment experiments. pH, coagulant dose, and mixing speed were selected as the most important parameters for wastewater treatment and chemical oxygen demand (COD), total suspended solids (TSS), turbidity, and color analyses were examined for each coagulant. After determining the coagulant (FeCl3 center dot 6H(2)O) which provided the best treatment efficiency, a central composite design (CCD) was applied for optimization of treatment conditions by using RSM. Design Expert 7.0.0. the program was used for the design of treatment experiments and analysis of results. COD, TSS, color, and turbidity values were processed by the program after experiments. 3D graphs and statistical results created by the program were interpreted. The equations obtained using the coefficients in the model created by the program were solved and the optimum values of the independent variables were calculated. Using these values, the lowest pollution values were determined as (mg/L) COD 68.636, color 2.42, turbidity 1.79 NTU, and TSS 10.135. Optimization results from the program were examined and the optimum values of treatment parameters were suggested as pH 7.54, coagulant amount 1,080.49 mg/L, and mixing speed 146.16 rpm. The lowest pollution values under optimum conditions were (mg/L) COD 71.07, color 1.00, turbidity 2.74 NTU, and TSS 7.50. Under optimized conditions COD, TSS, color, and turbidity removal were 94.1%, 95.3%, 97.1%, and 99.5%, respectively.
Green Synthesis, Characterization and Antimicrobial Activity of Silver Nanoparticles Using Ornithogalum Narbonense L
(Taylor & Francis inc, 2022) Ozturk, Dilara; Ozguven, Ayse; Yonten, Vahap; Ertas, Metin
Green synthesis of silver nanoparticles (AgNPs) was performed using extracts from Ornithogalum narbonense L. (ONL) as a cost-effective and eco-friendly approach. A surface plasmon resonance peak was observed at 440 nm after 12 h. The intense reddish-brown coloration was observed higher than 1.5 mM AgNO3 concentrations. Bioactive compounds were found responsible for the reduction, stabilization, and capping of Ag+ to AgNPs. X-ray powder diffraction analysis confirmed the face-centered cubic silver crystalline structure. The average spherical-shaped individual particle size was around 8.46 nm, while hydrodynamic size ranged between 7-13 nm and 36-131 nm. The AgNPs have good stability (zeta = -31.15 mV). Energy-dispersive X-ray spectroscopy analysis proved the presence of elemental Ag (6.76%). The antibacterial activity with the zone of inhibition is as follows: P. aeruginosa > E. coli > S.aureus > B. cereus (10.35 +/- 0.12 mm > 9.40 +/- 0.14 mm > 8.20 +/- 0.10 mm > 7.0 +/- 0.24 mm). The AgNPs did not show antifungal properties against C. albicans.
Investigation of Different Treatment Strategies Such as Membrane Filtration and Fenton Processes in the Treatment of Dairy Industry Wastewater
(desalination Publ, 2021) Ozguven, Ayse; Bayram, Tuba
This study investigated the treatability of dairy industry wastewaters by using the Fenton process and membrane bioreactors. Firstly, the effects of the Fenton process on the reaction time, pH, Fe2+ and H2O2 concentrations on chemical oxygen demand (COD) and total organic carbon (TOC) removal were determined to evaluate the treatment of dairy industry wastewater. According to the results obtained, the optimum reaction time, pH, Fe2+ and H2O2 concentrations were found to be 60 min, pH 3, 1 g/L, 1.5 g/L, respectively, while the COD and TOC removal efficiencies were 87% and 75%. Secondly, biological treatability of wastewater in membrane bioreactors was investigated. The input water COD concentrations of 0.6-2 g/L, sludge age values of 3 h to 10 d and different hydraulic waiting processes were studied. Loading was made to the system at 5 kg COD/m(3)d, and later, loading was increased up to 17 kg COD/m(3)d based on the input water COD values. After treatment with membrane bioreactors, the COD removal efficiency varied between 95%-98%. As the output water concentrations obtained as a result of the study satisfied the discharge limits, the applied biological treatment and advanced oxidation methods were completed successfully.
Multi-response/Multi-step Optimization of Heterogeneous Fenton Process With Fe3o4 Catalyst for the Treatment of Landfill Leachate
(Springer int Publ Ag, 2021) Tasci, Salih; Ozguven, Ayse; Yildiz, Burcin
Since conventional biological treatment methods are not sufficient alone to treat landfill leachate, this study investigated the efficacy of the heterogeneous Fenton process as a preliminary treatment technique. With this aim, a two-level factorial design combined with the response surface methodology (RSM) was used to optimize the operating parameters for the heterogeneous Fenton process used for treatment of leachate. The surface morphology and elemental analysis of Fe3O4 nanoparticles used in the heterogeneous Fenton process were completed with scanning electron microscope (SEM), energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FT-IR). In order to obtain maximum 75% chemical oxygen demand (COD) removal for treatment of leachate with the heterogeneous Fenton process, the optimum conditions for H2O2 and Fe3O4 dosages, stirring rate and initial pH parameters were 800 mg/L, 334.54 mg/L, 255 rpm and 3.34, respectively. The results obtained show the heterogeneous Fenton process abides by the second-order model (R-2 = 0.9896), and the variables mentioned above were confirmed to significantly affect the COD removal efficiency. Response surface graphs show the use of higher pH and chemical agents do not increase the COD removal efficiency. This study proves the applicability of the multi-response optimization program for treatment of leachate from a landfill site representing a serious problem in environmental terms.
A Numerical Optimization Approach for Removal of Astrazon Pink Fg From Aqueous Media by Fenton Oxidation
(Springer Heidelberg, 2023) Ozguven, Ayse; Ozturk, Dilara
In this study, the treatment of aqueous media containing Astrazon Pink FG (AFG) dye, widely used in the textile industry but with limited studies, was investigated using the Fenton process. The system was numerically optimized as Fe2+: 50 mg/L, H2O2: 50 mg/L, pH 3.75, reaction time: 42.54 min, and initial dye concentration: 100 mg/L based on the principle of low-cost high removal efficiency. The quadratic model with central composite design was reliable, valid, and significant (p < 0.0001) for both system responses Theoretical removal efficiencies under these conditions were determined as 80.5% and 94.11% for chemical oxygen demand (COD) and AFG removal, respectively, and were confirmed experimentally as 81.01% and 94.33% under the same conditions. The performance of the Fenton process under optimized conditions was calculated as 51%, 65%, and 73% for COD, AFG and Methyl Orange removal. Reactive Yellow 86, Acid Orange 7, and Reactive Green 19 were removed as 62.72%, 51.73%, and 39.39%, respectively, from real textile wastewater. The generated sludges (v/v) under optimized conditions for AFG dye solution, binary dye solution and real textile wastewater were 6%, 5% and 7%, respectively. AFG removal best fitted the BMG model (R-2 > 0.998). According to the experimental cost estimation based on chemical consumption under optimized conditions, 1 m(3) of AFG solution can be treated at $0.26. It was concluded that the Fenton process could be used as a pretreatment for industrial wastewater containing dye.
A Study About the Performance Evaluation of Medical Waste Sterilization Plant in Van, Turkey
(Taylor & Francis Ltd, 2022) Ozguven, Ayse; Okur, Dilek
In this study, the performance of a medical waste sterilization plant was evaluated. Accordingly, the results were pH 7.26-8.07; temperature 22-25 degrees C; conductivity (EC) 109-182 mu S/cm; chemical oxygen demand (COD) 200-900 mg/L; suspended solids (SS) 12-86 mg/L; NO2- 0.4-1.0 mg/L; NO3- 1.5-8.3 mg/L; NH4-N+ 11-25 mg/L; and PO4-P 4.5-7.3 mg/L. All the heavy metals (Pb, Cd, Cr, Cu, Ni, Zn and Hg) had weak correlations with each other. Cr and Hg were observed to have a negative correlation (-0.5733;p=0.05). In addition, the leaching characteristics of the solid waste from the sterilization plant were investigated in terms of heavy metals. Both the Pb and Cd (1.09-0.19 mg/L) values in the leaching analysis of medical waste were slightly above the Turkish Hazardous Waste Control Regulation (THWCR) limit value. This study shows that it is necessary to use some strategies in order to achieve and implement an effective medical waste management system in the city of Van. For this reason, the operation of the medical waste disposal system established in Van is important in terms of creating a preliminary source for more comprehensive studies to be carried out in our country in the future.
Synthesis and Adsorption Potential of Bc/Feooh Nanoparticles Using Oil-Squeezed Black Cumin (Bc) Seeds as a Waste Material
(Mehmet Sinan Bilgili, 2022) Ozguven, Ayse; Sirp, Zilan; Ozturk, Dilara
In this study, oil-squeezed black cumin seeds (BC), a waste material, were treated with NaOH to enhance the surface area and were evaluated to synthesize a BC/FeOOH/MnO2 hybrid adsorbent for crystal violet (CV) dye removal from aqueous media by adsorption process in a batch system. The effects of initial pH (3-11), adsorbent dose (0.25-1.5 g/L), reaction time (5-60 min), and initial dye concentration (50-200 mg/L) were investigated. Fourier transform infrared spectroscopy ( FTIR) and scanning electron microscopy (SEM)/ energy-dispersive x-ray spectroscopy (EDX) analyses were made before and after the adsorption process. The synthesized adsorbent has a weight ratio for Mn, Fe, Na, and Ca of % 37.29, 26.18 %, 4.38 %, and 0.84 %. The characteristic peaks of FeOOH and MnO2 were observed in the FTIR spectrum. SEM/EDX analysis confirmed the spherical flower-like architecture of MnO2 and rod-like structure of FeOOH nanoparticles. Doping FeOOH and MnO2 gave an advantage to the adsorption of cationic CV to the OH groups. In the FTIR analysis of adsorbent after adsorption, vibration bands of C-N and stretching of CH3 groups with C-H bands were observed, which may verified the CV adsorption. Optimum adsorption conditions were determined for pH of 7.2(natural), adsorbent dose of 1.5 g/L, and initial dye concentration of 50 mg/L. The dye removal efficiency and adsorbed amount of dye were calculated as 94.29% and 31.42 mg/g. The adsorbent showed a good adsorption capacity for CV.
Treatment of Petroleum Refinery Wastewater by Chemical Coagulation Method: Determination of Optimum Removal Conditions Using Experimental Design
(Springer Heidelberg, 2024) Ayhan, Neslihan Nubar; Aldemir, Adnan; Ozguven, Ayse
Wastewater minimization is very important in the production process of petroleum industries due to they have large water demands in their operations. In this study, optimum treatment conditions of petroleum industry wastewater were obtained with the chemical coagulation method. Analyses of the obtained wastewater was carried out and pollution values were determined before the treatment process. The best coagulant is selected for optimization experiments between the Al-2(SO4)(3).18H(2)O, FeCl3.6H(2)O and FeSO4.7H(2)O coagulants. The best removal efficiency was obtained with Al-2(SO4) coagulant and Central Composite Design (CCD) was performed for optimization procedure. pH, coagulant dosage and mixing speed were choosen as the independent parameters and the results of COD, TSS, turbidity and color analyses were used as responses. The three dimensional plots and ANOVA tables, which are the outputs of CCD, were mainly evaluated for their removal efficiency of wastewater treatment. The obtained model equations using the coefficients were solved and the optimum values of the variables were determined. The optimum values of treatment parameters were obtained as pH 9.43, coagulant dosage 36.14 mg/L, mixing speed 145.93 rpm. The highest removal efficiency values at the optimum treatment conditions were obtained as (%) 78.75, 91.21, 72.89 and 98.10 for COD, TSS, color and turbidity, respectively.