فهرست مطالب mohammadebrahim olya

Due to the large volume of water consumed in textile industry and producing the colored wastewater containing non-biodegradable organic dyes, in the present study the interaction of hydrogen peroxide and nanophotocatalyst in the advanced oxidation process was investigated.

In this research, after synthesizing of nanophotocatalyst (ZnO:Ag:Nd) the effect of hydrogen peroxide on dye removal process, and its interaction with the catalyst was investigated. photocatalyst was characterize by  (FESEM) Field-emission Scanning Electron (EDS) Energy-dispersive X-ray spectroscopy (XRD) X-ray diffraction methods. Then, the effect of important operating parameters such as dye concentration (10-30 ppm), pH (3-9), The amount of photocatalyst (0.02-0.1g.L-1) temperature (30-50°C), hydrogen peroxide concentration (F=2-11) was evaluated in AOPs process. Process modeling was done by using the response surface methodology.

The results showed that by adding hydrogen peroxide to photocatalyst particles, the efficiency of decolorization was increased, but the addition of catalyst to the optimum amount of hydrogen peroxide reduced the efficiency of decolorization. Also, the optimum conditions for the removal of dye matter (pH=6.21) and the amount of photocatalyst 0.08g.L-1, F=9was achieved. The results of the thermodynamic studies showed the endothermic reaction of the process, and process modeling indicated that the theoretical result were in accord with the experimental results.

Based on the results, combination of using catalysts and hydrogen peroxide is an effective technique for dye removal of aqueous solution.

In the present study, the performance of a batch suspension photoreactor has been investigated and compared with a catalytic-membrane photoreactor (PMR) for removal of Basic Violet 16 (BV16) from synthetic effluent. Initially, influence of the effective parameters on the photocatalytic process in the presence of Zinc oxide doped with calcium (ZnO: Ca) such as photocatalyst dosage, pH, temperature, initial dye concentration and aeration was studied. Based on the results, the optimal condition of the process was: Catalyst dosage (0.06 g.L-1), normal pH (5.5), ambient temperature, Dye concentration: 10 mg.L-1 and Aeration: 5.5 L.min-1, respectively. The results showed that the removal efficiency at the high concentrations decreases in the photocatalytic process. This will reveal the need to integrate a system as pre-treatment of input feed prior to the preparation. In this study, a polyvinylidene fluoride-based membrane (PVDF) was used as a pre-purification agent before the batch rector system. The results of the research and the calculation of process efficiency show that PMR has been successful in removal of BV16 dye in the same concentrations and also more than the optimal dye concentration of suspension system. Comparing the kinetc of the reactions, the constant reaction rate in PMR increased by about 14% in comparison of the batch system at the optimal concentration (60%) and above the optimal concentration (30 mg.L-1).

In this research, ZnO nanoparticles (NPs) were synthesized using a binary Zn(II) Schiff-base complex. The complex heat-treated to prepare ZnO nanoparticles via thermal decomposition route at a temperature of 500 °C. The formation of single-phase ZnO nanoparticles and their microstructures were studied by XRD pattern, SEM and TEM observation. The photo-degradation characteristic of the as-prepared ZnO NPs was evaluated and acid blue 193 was investigated as the organic colorant in a photocatalytic reactor by advanced oxidation process (AOP). The effects of operating parameters such as initial concentration of the dye, amount of catalyst and the pH value of the solutions were studied to determine the optimum condition of the process to improve the photo-degradation performance. According to the results, impressive photo-degradation of acid blue is conceivable by the as-synthesized ZnO NPs. The optimum operating conditions to achieve photo-degradation were found to be a solution with pH value of 6, the catalyst concentration of 0.04 g/L, and the dye concentration of 10 g/L. The highest efficiency would be achieved at natural pH of the solution (pH=~6). The optimum concentration of ZnO NPs is about 0.04 g/L. More or less amount of the photocatalyst could not enhance the photodegradation efficiency. At the constant photocatalyst concentration, any increase in dye amounts leads to decrease in degradation efficiency.

In this study, the TiO2-ZnO-CuO nanoparticles were primed by sol-gel method characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM), for degradation of MTBE solution in water. The effectiveness of the treatment method applied for the degradation of MTBE based on an advanced photocatalytic oxidation process was investigated. The three various key parameters were optimized using response surface modeling namely: pH, TiO2-ZnO-CuO concentration and the initial MTBE concentrations. The optimized values were obtained at the PH (7), TiO2-ZnO-CuO concentration (1.49 g/L), and the initial MTBE concentration (31.46 mg/L). Finally, kinetics reaction of degradtion MTBE was carried in the optimum conditions.

Since groundwaters are a major source of drinking water, their pollution with organic contaminants such as methyl tertiary-butyl ether (MTBE) is a very significant issue. Hence, this research investigated the photocatalytic degradation of MTBE in an aqueous solution of TiO2-ZnO-CoO nanoparticle under UV irradiation. In order to optimize photocatalytic degradation, response surface methodology was applied to assess the effects of experimental variables such as catalyst loading, initial concentration of MTBE and pH on the dye removal efficiency. The optimal condition to achieve the best degradation for the initial concentration of 30.58 mg/L of MTBE was found at a pH of 7.68 and a catalyst concentration of 1.68 g/L after 60 min.

In this paper, CuO - ZnO nanocomposite was synthesized and its photocatalytic dye degradation ability from colored wastewater was studied. Basic Red 18 (BR18) and Basic Violet 16 (BV16) were used as model dyes. The characteristics of CuO - ZnO of were inves tigated using Fourier transfo rm infrared (FT - IR) spectroscopy , scanning electron microscope (SEM) and X - ray diffraction (XRD). Photocatalytic dye degradation by CuO - ZnO was studied by UV - Vis spectrophotometer. The effects of CuO - ZnO dosage, initial dye con centration and salt on dye degradation were evaluated. The results indicated that CuO - ZnO as a photocatalyst could be used to degrade dyes from wastewa ter. Prog. Color Colorants Coat.

Dye removal of colored wastewaters using nanophotocatalytic process was developed in recent years as an effective system. In the present research the nanophotocatalysts were characterized by XRD, SEM and FTIR analysis then compression of TiO2-Ag and ZnO-Ag on the decolorization efficiency was evaluated. Finally, influence of the key operator parameters was studied to optimize the treatment process.

Advanced Oxidation Processes (AOPs) and chemical oxidation process (KMnO4) have been used in de-coloration of dyes in spent dyeing wastewater. In the present study, de-coloration of Indigo Carmine Dye (ICD) was carried out in a batch reactor using combination of these processes as a hybrid advanced oxidation process. The reactor used for UV/H2O2 process was equipped with a low-pressure mercury lamp. Temperature and pH values were studied as the key operating variables. The stoichiometric amount of permanganate required for 1 mol of ICD to complete colour removal was determined (1.08 mol). Also, ICD de-coloration was studied by monitoring the absorbance of dye solutions using UV/H2O2 process. The results demonstrated high rate of dye treatment using hybrid process (KMnO4/UV/H2O2) in comparison with potassium permanganate and UV/H2O2 process. The results show that dye treatment efficiency increased with increase in the amount of potassium permanganate and temperature.