Mehmet Şakir Ece

Uçucu organik bir bileşik (UOB) olan benzen, kimyasal ve petrokimyasal gibi faaliyetlerle sanayiden ve endüstriden atmosfere salınmaktadır. Benzen, canlı sağlığı ve çevre için ağır kirliliklerden biri olup, kanserojen, mutajenik ve oldukça toksik polar olmayan kirleticidir. İnsan sağlığı ve ekolojik çevre için bir potansiyel tehlikedir. Bu sebeple benzenin bir kirletici olarak atmosferden uzaklaştırılması büyük önem taşımaktadır. Bu çevresel iyileştirme çalışmasında, Derik Halhalı zeytininin çekirdeği bir doğal selüloz (DS) kaynağı olarak manyetit (Fe3O4) modifikasyonunda kullanıldı. Başarıyla üretilen Fe3O4/DS nano-adsorbentin benzen giderimine karşı adsorpsiyon özellikleri incelendi. Birlikte çökeltme yöntemiyle elde edilen Fe3O4/DS nano-adsorbenti SEM-EDS, FTIR ve BET analizleri ile karakterize edildi. Benzen giderim prosesinde, benzen başlangıç konsantrasyonu, adsorbent miktarı, adsorpsiyon süresi ve adsorpsiyon sıcaklığı gibi farklı parametrelerin etkileri değerlendirildi. Optimum değerler olarak belirlenen 90 dakika adsorpsiyon süresi, 15 ppm benzen başlangıç konsantrasyonu, 100 mg adsorbent miktarı ve 25°C adsorpsiyon sıcaklığı gibi koşullar altında benzen adsorpsiyon kapasitesi 298,15 mg/g olarak bulundu. Bu sonuç, başarıyla üretilen Fe3O4/DS nano-adsorbentin UOB kirleticilerin giderimindeki uygulama potansiyelini ortaya koymaktadır. Öte yandan, Quasi-birinci-dereceden kinetik modeli takip eden gaz halindeki benzenin Fe3O4/DS nano-adsorbenti üzerine adsorpsiyon prosesi fiziksel adsorpsiyon mekanizmasını işaret etmektedir. Ayrıca, 1.74 kJ mol-1 olarak hesaplanan E değeri (Dubinin-Radushkevich model sabiti) adsorpsiyon prosesinin fiziksel etkileşim mekanizması üzerinden gerçekleştiğini desteklemektedir. Son olarak, beş döngüden sonra Fe3O4/DS nano-adsorbenti %90.61'lik yeniden kullanım verimliliği sürdürdüğü görüldü, bu da nano-adsorbentin pratik uygulamalarda büyük potansiyele sahip olduğu anlamına gelir.

Today, the possibilities offered by nanotechnology are undeniable. Nanotechnology has permeated all aspects of our daily lives. Nanotechnology, as an interdisciplinary field, also provides unique products in a variety of engineering fields. These products are more appealing than macro products due to their unique properties such as surface area, volume, conductivity, optical, and magnetic. Magnetite (Fe₃O₄), the most powerful magnetic mineral on the planet, has many properties such as nano size, surface area, morphology, and ferromagnetism at room temperature, and thus Fe₃O₄-based products are being developed for appropriate studies. There are very few materials created by modifying perlite Fe₃O₄, a mineral abundant in nature. In this study, Fe₃O₄ was modified with the mineral perlite to create magnetic nanomaterials. To that end, Fe₃O₄/Perlite magnetic nanomaterials were created using a co-precipitation method, followed by Fe₃O₄/Perlite@SiO₂ magnetic nanomaterials created using a sol-gel method, and Fe₃O₄/Perlite@SiO₂@Sulfanilamide magnetic nanomaterials created using a sol-gel method. The structures of the synthesized magnetic nano materials were clarified by various characterization devices such as BET, FTIR, SEM, SEM-EDX, TGA-DTA, and XRD. The characterization findings revealed that the syntheses and surface coatings of Fe₃O₄/Perlite, Fe₃O₄/Perlite@SiO₂ and Fe₃O₄/Perlite@SiO₂@Sulfanilamide magnetic nanomaterials were successfully performed. Furthermore, in light of these findings, Fe₃O₄/Perlite, Fe₃O₄/Perlite@SiO₂ and Fe₃O₄/Perlite@SiO₂@Sulfanilamide magnetic nano materials were discovered to be in crystalline cubic spinel form, mechanical and thermal stability, and mesoporic size. Since synthesized perlite-supported magnetic nano materials have potential in many applications, such as sustainable technologies, environmental safety technologies such as water reclamation and pollution removal, adsorption technologies, etc., they are brought to the attention of related fields.

In this study, we present the first application of magnetic Fe3O4 functionalized with activated carbon (Fe3O4/AC) as nano-adsorbent for the removal of gas-phase toluene by adsorption process. Magnetic Fe3O4/AC was synthesized via co-precipitation method within the framework of nanotechnology principles. Then, the effects of process conditions such as contact time, initial toluene concentration, and temperature on the adsorption capacity of toluene by the magnetic Fe3O4/AC were investigated using the response surface methodology (RSM). The obtained magnetic Fe3O4/AC was characterized using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and thermogravimetric (TG) analysis. The maximum adsorption capacity of the magnetic Fe3O4/AC for the adsorption of the toluene was determined as 312.99 mg g-1 under optimal process conditions such as 59.48 min contact time, 17.21 mg l-1 initial toluene concentration, and 26.01°C temperature. The adsorption by the magnetic Fe3O4/AC indicated the best fit with the Langmuir isotherm model, and obeyed the pseudo-second-order (PSO) kinetic model. This study indicated that magnetic Fe3O4/AC could be applied as an adsorbent for the removal of gas-phase toluene.

The present study, for the first time, utilized 3,4-diaminobenzophenone (DABP)-functionalized Fe₃O₄/AC@SiO₂ (Fe₃O₄/AC@SiO₂@DABP) magnetic nanoparticles (MNPs) synthesized as a nanoadsorbent for enhancing adsorption and desorption capacity of gaseous benzene and toluene as volatile organic compounds (VOCs). The Fe₃O₄/AC@SiO₂@DABP MNPs used in adsorption and desorption of benzene and toluene were synthesized by the co-precipitation and sol-gel methods. The synthesized MNPs were characterized by SEM, FTIR, TGA/DTA, and BET surface area analysis. Moreover, the optimization of the process parameters, namely contact time, initial VOC concentration, and temperature, was performed by applying response surface methodology (RSM). Adsorption results demonstrated that the Fe₃O₄/AC@SiO₂@DABP MNPs had excellent adsorption capacity. The maximum adsorption capacities for benzene and toluene were found as 530.99 and 666.00 mg/g, respectively, under optimum process parameters (contact time 55.47 min, initial benzene concentration 17.57 ppm, and temperature 29.09 °C; and contact time 57.54 min, initial toluene concentration 17.83 ppm, and temperature 27.93 °C for benzene and toluene, respectively). In addition to the distinctive adsorptive behavior, the Fe₃O₄/AC@SiO₂@DABP MNPs exhibited a high reproducibility adsorption and desorption capacity. After the fifth adsorption and desorption cycles, the Fe₃O₄/AC@SiO₂@DABP MNPs retained 94.4% and 95.4% of its initial adsorption capacity for benzene and toluene, respectively. Kinetic and isotherm findings suggested that the adsorption mechanisms of benzene and toluene on the Fe₃O₄/AC@SiO₂@DABP MNPs were physical processes. The results indicated that the successfully synthesized Fe₃O₄/AC@SiO₂@DABP MNPs can be applied as an attractive, highly effective, reusable, and cost-effective adsorbent for the adsorption of VOC pollutants. Graphical abstract