Electrocoagulation and nanofiltration integrated process application in purification of bilge water using response surface methodology
Gözmen, Belgin | Dizge, Nadir | Turabik, Meral | Gülsen, H. Elif
Marine pollution has been considered an increasing problem because of the increase in sea transportation day by day. Therefore, a large volume of bilge water which contains petroleum, oil and hydrocarbons in high concentrations is generated from all types of ships. In this study, treatment of bilge water by electrocoagulation/electroflotation and nanofiltration integrated process is investigated as a function of voltage, time, and initial pH with aluminum electrode as both anode and cathode. Moreover, a commercial NF270 flat-sheet membrane was also used for further purification. Box–Behnken design combined with response surface methodology was used to study the response pattern and determine the optimum conditions for maximum chemical oxygen demand (COD) removal and minimum metal ion conte...
Fe-modified sporopollenin as a composite biosorbent for the removal of Pb2+ from aqueous solutions
Gözmen, Belgin
The role of Fe-modified sporopollenin (Fe-Sp) biomass in Pb2+ removal from aqueous solutions was investigated by batch biosorption technique. The prepared biosorbent was characterized by scanning electron microscopy, energy-dispersive X-ray spectrometry, and Fourier transform infrared spectroscopy. The influence of pH, contact time, biosorbent dose, and initial concentration on biosorption process were optimized by using a four factor Box–Behnken design combined with response surface methodology. The results indicated a positive adsorption behavior of Fe-Sp and a strong pH dependency of the process. The optimum predicted parameters were determined as follows: biosorbent dosage 0.5 g, pH of 6.75, contact time 104 min, and initial Pb2+ concentration of 25.42 ppm. The Freundlich isotherm mode...
Removal of Basic Textile Dyes in Single and Multi-Dye Solutions by Adsorption: Statistical Optimization and Equilibrium Isotherm Studies
Gözmen, Belgin | Turabik, Meral
The removal of three basic dyes by adsorption onto bentonite was investigated forsingle, binary, and ternary solutions in a batch system. Before and after dye adsorption,bentonite samples were analyzed by using X-ray fluorescence spectrometer, SEM,and Fourier transform IR spectrometry. The D-optimal design and response surfacemethodology were applied in designing the experiments for evaluating the interactiveeffects of each initial concentrations variable of the dyes in binary systems. Predictedvalues were found to be in good agreement with experimental values, which definedpropriety of the model and the achievement of D-optimal in optimization of adsorptionof binary dye systems. The competitive adsorption results showed that the adsorptionamount of a dye was suppressed in the presence and i...
Microwave-assisted d-pinitol extraction from carob: application of Box–Behnken design
Gözmen, Belgin | Sönmez, Özgür
This study investigates the effects of temperature (50–80 °C), time (10–60 min), carob-to-solvent ratio (2–8 g/40 mL), and solvent concentration (0–50 ethanol/water%, v/v) on microwave-assisted extraction of d-pinitol compound from carob fruit with optimization using Box–Behnken design. The optimal conditions for maximum d-pinitol yield (64.16 g/kg dry sample) include 50 °C temperature, 5.6 g carob/40 mL solvent, water used as a solvent, and an extraction time of 10 min. The fitness of the model was determined by ANOVA analysis with a high coefficient (R2 = 0.9057). Extraction was performed under optimum conditions for model validation, and 63.89 g/kg dry sample of d-pinitol extraction was achieved. In addition, the effects of the same variables on the total phenolic (TP) content of MEA ex...
Acid Red 1 and Acid Red 114 decolorization in H2O2-modified subcritical water: process optimization and application on a textile wastewater
Gözmen, Belgin
Solutions of Acid Red 1 and Acid Red 114 were treated in H2 O2 -modified subcritical water in the temperature range of 100°C–200°C for up to 60 min. Response surface methodology based on the Box-Behnken design was used to optimize the process. For Acid Red 1, optimum decolorization of 97% can be achieved at 192°C, 181 mM H2 O2 , 51.3 min treatment time, and 121 mg/L dye concentration. For Acid Red 114, the optimum conditions were 195°C, 157 mM H2 O2 , 38 min treatment time and 110 mg/L dye concentration, where 91% decolorization could be obtained from the proposed model. It was determined that temperature is the most important factor, followed by the oxidant concentration. Degradation was less efficient for AR114 due to the double azo bonds, compared to the single azo bond of A...
Degradation of Acid Red 274 using H2O2 in subcritical water: Application of response surface methodology
Gözmen Belgin
In this research, the degradation of Acid Red 274 (AR 274) was investigated under subcritical water conditions using H2O2, which led to the oxidative degradation of Acid Red 274 up to its 80% of mineralization. The Box–Behnken design matrix and response surface methodology (RSM) were applied in designing the experiments for evaluating the interactive effects of the three most important operating variables. Thus, the interactive effects of temperature (100–250 °C), oxidant (H2O2) concentration (50–250 mM), and time (30–60 min.) on the degradation of AR 274 were investigated. A total of 17 experiments were conducted in this research, and the analysis of variance (ANOVA) indicated that the proposed quadratic model could be used for navigating the design space. The proposed model was essential...
Microwave-assisted biodiesel production from waste cooking oil using pyrrolidonium ionic liquid catalyst: optimization, kinetic and thermodynamic studies
Gözmen, Belgin | Sönmez, Özgür
Biodiesel production from waste cooking oil (WCO) has been gaining popularity due to its economical and eco-friendly nature. This study aimed to produce an environmentally friendly fuel by recycling WCO. Using pyrrolidonium-based Brønsted acidic ionic liquid (IL) as a catalyst, microwave-assisted transesterification of WCO was used to produce biodiesel. Reaction conditions, including temperature, catalyst amount, methanol/oil molar ratio, and reaction time, were optimized using response surface methodology (RSM) based on Box-Behnken design (BBD). A biodiesel conversion of 97.3 % was achieved at 115 °C, for 120 min, with 10 % catalyst loading, and a 24:1 methanol/oil molar ratio. The kinetics of the transesterification reaction was investigated, with the activation energy determined to be 1...
The solubility of sebacic acid in subcritical water using the response surface methodology
Gözmen, Belgin | Görmez, Özkan | Yabalak, Erdal | Gizir, Ahmet Murat
The solubility of sebacic acid in subcritical water was investigated. Response surface methodology was used to study the combined effects of the different parameters such as temperature, static and dynamic time to optimize the process conditions for the maximum solubility of sebacic acid. Solubility results of sebacic acid were observed to be highly correlated with quadratic model according to analysis of variance. The solubility of sebacic acid was found as 500 g L-1 in the optimum conditions at 400 K temperature, 4 min dynamic time and 28 min static time. Approximation models were employed for determining solubility of sebacic acid at elevated temperatures.
Degradation of nitroaromatic compounds in subcritical water: application of response surface methodology
Gözmen, Belgin | Gizir, Ahmet Murat
In this study, subcritical water has been used as a medium for degradation of 2,4-dinitrotoluene (2,4-DNT), 4-nitrotoluene (4-NT) and 2-amino-4-nitrotoluene (2-A-4-NT). The effect of temperature, oxidant concentration and time were studied and the optimal combination of reaction parameters was established using response surface methodology in a Box-Behnken design. Of all the parameters examined, temperature showed the most positive effect on the degradation of the nitroaromatic compounds. Optimal reaction conditions were found to be a temperature of 240°C, 210°C and 236°C, time of 180, 178 and 172 min, oxidant concentration of 100, 99.64 and 99.61 mM for 2,4-DNT, 4-NT and 2-A-4-NT, respectively. Since high-temperature was applied, the possibility of formation of subcritical degradat...
Verbascum thapsus L. bitkisi kullanılarak sulu çözeltiden Malachite green adsorpsiyonunun araştırılması
Sime, Ferhat
Boyalı atıksular, özellikle sucul ekosistemler için önemli bir kirletici kaynaktır. Tekstil endüstrisi atıksuları boyalı atıksuların başlıca kaynağını oluşturmaktadır. Adsorpsiyon işlemi atıksulardan boyanın giderilmesinde kullanılan en etkili yöntemlerden biridir. Malachite Green (MG) tekstil endüstrisinde yaygın olarak kullanılan sentetik katyonik bir boyadır. Bu boyanın canlı organizmalarda potansiyel kanserojen ve mutajenik etkisi olduğu bilinmektedir. Boya adsorpsiyonunda kullanılan en etkili adsorban aktif karbon olmakla birlikte pahalı bir üründür. Bu nedenle ucuz ve yaygın bulunan doğal adsorban maddeler üzerine araştırmalar son yıllarda artmıştır. Sığırkuyruğu otu veya çoban çırası olarak da bilinen Verbascum thapsus L. (VTL) bitkisi yol kenarlarında, çayırlarda ve tarımsal alanla...