Synthesis of biomass-based BiOI@Hydrochar heterogeneous catalyst and investigation of its activity in sonocatalytic process
Gözmen, Belgin | Çomak, Gürbüz | Görmez, Özkan
Innovative studies in recent years to remove pollutants discharged into water resources through various means are critically important for protecting existing water resources. An important part of these studies is heterogeneous catalysis-based AOPs, where new generation composite materials are used and high organic pollutant degradation has been achieved. This study used the solvothermal approach to produce a BiOI@BH sonocatalyst doped with hydrochar (BH). A variety of analysis techniques, including XRD, FESEM, EDS, FTIR, DRS, and BET surface analysis, were used to assess changes in the physico-chemical properties of the BiOI@BH structure in comparison to BiOI. Both the adsorption and sonocatalytic degradation processes for the methylene blue aqueous solution were found to be more successf...
Adsorption of Malachite Green on Fe-modified biochar: influencing factors and process optimization
Gözmen, Belgin
Paper sludge and wheat husk biochar was converted to a Fe-composite through a simple coprecipitation process and its adsorption behavior was tested against an emerging pollutant, Malachite Green (MG). Response surface methodology was employed to determine the optimum experimental conditions and the interactions between pH, initial MG concentration, temperature and treatment time. The maximum adsorption percentage obtained experimentally was 97.1%, whereas the Box– Behnken design predicted a maximum adsorption of 98%, at pH 6.16, initial MG concentration of 6.56 ppm, temperature of 34.75°C and treatment time of 22 min. Compared with the original biochar, the Fe-modified sample improved the adsorption of MG by ~34%. The adsorption mechanism followed the Langmuir model (qmax = 172.3 mg/...
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...
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 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...