فهرست مطالب هومن پژند

Nowadays, wastewater produced by industries becomes one of the most crucial environmental challenges. Due to significance of water treatment numerous researches have been done to address this issue. In this study, it was tried to present a new method for synthesizing highly photo catalytically active silver nanoparticle decorated zinc oxide nanorods (Ag/ZnO NRs). ZnO nanorods were successfully synthesized on zinc foil through a facile hydrothermal method and then Ag nanoparticles were prepared directly on the surface by photodeposition method. The structural, morphology and optical properties of the as-synthesized materials were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV-visible absorption spectroscopy respectively. The Results showed that the fabricated films have nanorod morphology. UV-visible spectra showed an increase in the visible absorption relative to bare ZnO NRs sample. The photo-catalytic activity of prepared samples was evaluated by analyzing degradation of methylene blue (MB) dye under Xe light illumination and it was observed that Ag nanoparticle decorated ZnO nanorods effectively affected on band gap energy of photo catalysts and showed significantly enhanced photo-catalytic activity for degradation of MB, as compared to bare ZnO NR. According to the obtained results, optimized Ag/ZnO nanoparticles degraded MB to 93% meanwhile amount of degradation by ZnO particles was approximately 23%.

In recent years, concerns about the presence of drug compounds as part of emerging pollutants have been growing. In this study, we tried to make aerogels with a high specific surface area and use them to remove the antibiotic oxytetracycline. Similarly, the resorcinol formaldehyde organic aerogel was synthesized using the sol-gel method and ambient drying. The synthesized RF aerogel was modified by the incorporation of 1 wt.% of amine-functionalized graphene oxide (GOA) and Meta-phenylenediamine during the synthesis process to prepare RF-GOA1 and RF-PmPDA1., and finally the performance of all three samples as adsorbents under different parameters such as pH solution, initial concentation of antiobiotic, adsorbent dose and different contact times adsorbent with antibiotics was investigated. FTIR, RAMAN, XRD, FESEM, BET, CHN, EDS tests were used to characterize the samples and then the performance efficiency of the samples oxytetracycline antibiotic remove was investigated using UV-Vis spectroscopic test. The results of BET test showed that the highest specific surface area is related to RF aerogel containing 1 wt.% amine-functionalized GO (RF-GOA1) with 266 m2/g. Also, according to the results, the adsorption capacity in aerogel samples was RF, RF-GOA and RF-PmPDA1 were 386.6, 257.6 and 277.8 mg / g, and the removal rate of oxytetracycline was 51.5 ,77.3 and 70.1% obtained, respectively.

For decades, aluminum alloys have been known as one the most vital materials utilized in diverse fields of industry. In spite of significance, Al alloys can be easily exposed to corrosion. In this study, it has been tried to investigate anodic oxide coating made by hard anodizing of 5083 aluminum alloy in sulfuric acid at the temperature of 0 ºC and different voltages (20, 27 and 35 V). Subsequently, all samples were characterized using X- Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Field Emission Scanning Electron Microscope (FESEM). Low angle XRD results showed that the amorphous alumina coatings were formed in the surface of the samples. SEM images showed that the coatings are porous which is directly related and affected by anodizing voltage. FESEM images of fracture surfaces were indicant of formation and growth of oxide nano-cells in the cross section of the coatings. In order to investigate the properties of the coatings, micro-hardness, roughness and thickness measurement was carried out. Results showed that micro-hardness, roughness and thickness of the coatings increase by increasing the anodizing voltage. Furthermore, potentio dynamic polarization and electrochemical impedance spectroscopy (EIS) tests were performed. Electrochemical analysis proved that by increasing the anodizing voltage, corrosion resistance of the samples declined due to increasing the porosities on the surface of the coatings.

In recent years, volume of waste water produced by diverse field of industries is one the most vital challenges. To tackle this issue, numerous solutions have been submitted and among them, utilizing Metal- Organic Frameworks (MOFs) has been considerably paid attention as an appropriate option for water treatment due to their unique properties, such as low band gap and high specific surface area. In this study, MIL53 (Fe) was synthesized using nitrite salt source (FeNO3.9H2O) via solvo-thermal method at 120ºC, 150ºC and 180ºC. Subsequently, obtained powders was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and UV-vis DRS. Eventually, photocatalytic efficiency of prepared samples was analyzed via Methylene Blue (MB) degradation under halogen lamp (500 W). Obtained results showed that the synthesized powder at 180ºC (sample C) had the most percentage of crystallinity and light absorption. Likewise sample (C) was the most efficient sample and possessed the highest band gap and the most rate of dye degradation.

Nowadays, the facts such as papulation growth, climate change, development in industries e.g. (textile industry) and so on threaten the water resources. Waste water which produces by industries contains millions of organic compounds which is so dangerous to ecology and human health.  To solve this important issue, researchers carried out a huge number of studies on it and suggest various solutions including water recycling and water treatment. Water treatment is classified in four major aspects such as chemical, physical, biological and advanced oxidation process method ( AOP) . Among them, advanced oxidation process and the use of materials like photo catalysts  have received great attention due to their low cost and high efficiency.  Among photo catalysts, MOFs are assumed as the new generation of porous materials which are utilized due to the degradation and adsorption behavior, the feasibility of synthesis, and high chemical and physical resistance. This paper aims to investigate the water treatment process using MOFs.