در هنگام جستجو کلمه در قسمت عنوان میتوانید کلمات مورد جستجو را با کاراکتر (-) جدا کنید.
کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Particle Science & Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Heavy metal ions,Molecular Dynamics Simulation,Ion-exchange,Zeolite particles
- چکیده:
- چکیده انگلیسی: In present study, molecular dynamics simulation of Cadmium (II), Lead (II) and Copper (II) removal from aqueous electrolyte solutions using the ion-exchange process with the zeolite particles was done. The results showed that, most of the particles had the highest affinity of ion exchanging with Lead (II) and the lowest affinity with Copper (II). The calculated mean ion-exchange ratios showed that, except for the zeolites which their pore sizes are in the same range of heavy-metal ions’ size, an inverse relationship exists between this ratios and pore size of the zeolites. Furthermore, the ion-exchanging of zeolites LTJ, ANA, SVR, BEC and MER with aqueous electrolyte mixtures containing equal amounts of Cadmium (II), Lead (II) and Copper (II) were simulated. The results demonstrated that in the competitive exchange of electrolyte mixtures, the maximum mean ion-exchange ratio belongs to the ion which has the highest ratio in the single-ion system. Moreover, ion-exchanging of zeolites LTJ, ANA, SVR, BEC and MER with an aqueous electrolyte solution containing Copper (II), in the temperature range of 300-345 K were simulated. The results showed that, no significant change in the mean ion-exchange ratios were found as a result of temperature variations.
- انتشار مقاله: 07-12-1393
- نویسندگان: Mohsen Mehdipour Ghazi,Milad Mohammadi,Hamid Modarres
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Photocatalytic degradation,Clinoptilolite Zeolite-Silver,Diazinon,Microwave Irradiation,photocatalytic reactor
- چکیده:
- چکیده انگلیسی: photocatalytic reactor was tested in the degradation of diazinon in water using photocatalyst clinoptilolite zeolite-silver. The photocatalyst clinoptilolite zeolite-silver was synthesized using a microwave energy technique. The influence of AgO in the photocatalytic reactor was investigated for diazinon treatment. The prepared photocatalyst was authenticated by X-Ray Diffraction (XRD), for Field Emission Scanning Electron Microscope (FESEM), Brunner-Emmet-Teller (BET), and Diffuse Reflectance Spectroscopy (DRS) analysis methods. Every one of the mixtures was analyzed using XRD, and the three distinctive peaks (2Ɵ = 9.84, 11.17, and 22.35) of clinoptilolite were chosen for which the calculations of the peak intensity summation were done. The experiments appraised the influence of various empirical factors, e.g., pH, photocatalyst dosage, initial diazinon, and irradiation time on the degradation efficiency. The results showed that the optimum conditions for diazinon degradation were a pH of 9, photocatalyst dosage of 1 g/L and irradiation time of 120 min. The point of zero charge (pzc) of the photocatalyst clinoptilolite zeolite-silver, the point when the surface charge density is zero, was identified to be 8. This excellent catalytic ability was mainly attributed to the hybrid effect of the photocatalyst and adsorbent.
- انتشار مقاله: 19-05-1397
- نویسندگان: Milad Hallajiqomi,Mohsen Mehdipour Ghazi,Farshad Varaminian
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Methyl orange,Photodegradation,CuO/α-Fe2O3,Nano composite,Respond surface method
- چکیده:
- چکیده انگلیسی: This study investigated the photo-degradation of methyl orange (MO) as a type of azo dye using a CuO/α-Fe2O3 nanocomposite. A CuO/α-Fe2O3 powder with a crystalline size in the range of 27-49 nm was successfully prepared using simple co-precipitation along with a sonication method. The characterization of the synthesized sample was done via XRD, FE-SEM, EDS, FTIR and DRS analyses. The Tauc equation revealed that the band gap of the nano composite in the direct mood was 2.05 ev, which is in the visible light range. The effect of operating factors containing dye concentration, photocatalyst dosage and pH on dye degradation efficiency was measured. Response Surface Method (RSM) was employed to specify the parameter effects. The photocatalytic activity of the CuO/α-Fe2O3 nanocomposite was evaluated by degradation of MO under visible light irradiation. The results showed that the pH value played a very effective role in the dye degradation process efficiency. Also, the photocatalytic degradation of MO obtained was equal to 88.47% in the optimal values.
- انتشار مقاله: 23-03-1394
- نویسندگان: Mohsen Mehdipour Ghazi,Mohammad Ilbeigi,Mansour Jahangiri
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: photocatalyst,Visible light,Semnan natural zeolite,tetracycline,P25
- چکیده:
- چکیده انگلیسی: This study investigated the photocatalytic behaviors for the nanocomposite of TiO2 P25 and Semnan natural zeolite in the decomposition of tetracycline under visible light in an aqueous solution. The structural features of the composite were investigated by a series of complementary techniques that included X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), surface area (BET) measurement, and ultraviolet-visible diffuse reflectance spectroscopy (DRS). The surface area measurement disclosed an enhancement of surface area by ~2 times for the synthesized TiO2/Semnan natural zeolite than that of commercial TiO2 P25. The as-prepared photocatalyst (TiO2/Semnan natural zeolite) showed pH dependence and more than 87% of the tetracycline could be degraded from the solution under visible irradiation within 90 min at a pH of 6. This excellent catalytic ability was mainly attributed to the hybrid effect of the photocatalyst and adsorbent. The results provided new insight into the performance of active photocatalysts on the treatment of pharmaceutical wastewater. In addition, the immobilization of TiO2 onto Semnan natural zeolite permitted easier separation of the adsorbent from the treated water.
- انتشار مقاله: 24-03-1395
- نویسندگان: Farzaneh Saadati,Narjes Keramati,Mohsen Mehdipour Ghazi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: photocatalyst,Degradation,Magnetic ferrite,CoFe2O4,Ag2O
- چکیده:
- چکیده انگلیسی: The magnetic and recyclable nanoparticles of CoFe2O4 were synthesized by a reverse co-precipitation process. Sonication was used to couple the CoFe2O4 surface with Ag2O. The characteristics and optical properties of the catalyst were studied by powder X-ray diffraction, UV–visible reflectance spectroscopy and scanning electron microscopy analyses. Pure CoFe2O4 and CoFe2O4/Ag2O were utilized to determine the visible light photocatalytic degradation of Direct Orange 26. The effects of pH, the initial concentration of catalyst and initial dye concentration on the photocatalytic process were investigated. It was found that the presence of Ag2O remarkably improved the photocatalytic adsorption capacity and degradation efficiency of CoFe2O4/Ag2O when compared with the pure CoFe2O4. Moreover, due to the magnetic behavior of CoFe2O4, these coupled nanoparticles can be easily separated from the aqueous solution by applying an external magnetic field. The prepared Ag2O-modified CoFe2O4 exhibited much higher (about 40%) photocatalytic activity than the unmodified one. The results showed that the loading of the Ag2O significantly improved the photocatalytic performance of the CoFe2O4 in which the Ag2O acted as a charge carrier to capture the delocalized electrons.
- انتشار مقاله: 15-02-1395
- نویسندگان: Mohsen Mehdipour Ghazi,Fatemeh Azhdari
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: CuO doped ZnO,Photocatalytic degradation,Visible light,4-Chlorophenol
- چکیده:
- چکیده انگلیسی: In the present investigation, a ZnO nanostructure was synthesized by means of precipitation and sonochemical methods. The X-ray diffraction (XRD) pattern indicated that the wurtzite structure of ZnO had a hexagonal symmetry and there was no impurity. The average ZnO particles crystallite size was calculated at about 41 nm. The SEM and TEM images revealed nanostructure ZnO particles with a cauliflower-like and rod morphology with dimensions of 85, 79 and 117 nm. In order to investigate the increment of ZnO photoactivity under visible light, the CuO doped ZnO nanostructures were fabricated by a wet impregnation method using copper oxide as the copper source and ZnO as the precursor. The XRD analysis confirmed that the CuO phase was present in the as-prepared sample and the average size of nano crystalline decreased to about 36 nm. The DRS spectra indicated the extended absorption of CuO-ZnO to the visible range as a result of band gap reduction to 2.9 eV (in comparison of 3.2 eV in ZnO). In order to investigate the photocatalytic activity of the synthesized photocatalyst, the degradation of 4-Chlorophenol under visible light was performed. Sixteen experiments using full factorial were executed by adjusting four parameters (amount of catalyst, initial concentration of 4-Chlorophenol, pH, and time of irradiation). An empirical expression was proposed and successfully used to model the photocatalytic process with a high correlation, and an optimal experimental region was also obtained. According to the developed model for degradation and the subsequent ANOVA test using Design Expert software, the time of irradiation with a 46.57% effect played the most important role in the photocatalytic activity, while the influences of parameters on each other were negligible. Optimal experimental conditions for 4-Chlorophenol concentration (0.01 g/L) were found at an initial pH =8 and a catalyst loading of 0.07 g/L. The results indicated that CuO-ZnO can remove 95% of 4-chlorophenol from water under optimal conditions.
- انتشار مقاله: 26-06-1394
- نویسندگان: Afsaneh Shokri,Mohsen Mehdipour Ghazi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: MEUF,Ultrafiltration,Manganese,SDS
- چکیده:
- چکیده انگلیسی: In the present study, micellar-enhanced ultrafiltration (MEUF) was used to remove manganese (Mn) (II) from synthetic wastewater. The effects of different operational conditions on the filtration performance of MEUF or the membrane were studied. It was found that the transmembrane pressure has a major influence on the permeate flux and an insignificant effect on the rejection coefficient. The permeate flux increased almost linearly with operating pressure, ranging from 0.35 L min-1 m-2 at 1 bar to 1.79 L min-1 m-2 at 4 bar. When the pH of the feed solution was changed from 3 to 13, the permeate manganese concentration decreased considerably while the rejection of manganese increased from 75.37% to 99.78%. The results showed that by adding SDS anionic surfactant, the permeate flux and the removal efficiency of manganese increased. The retention of Mn (II) increases from 47% in the absence of SDS to around 97% with 10mM SDS.
In this state, the MEUF system has a rejection of above 97 percent of manganese. The Mn rejection increased slightly with an increase of operating pressure, ranging from 89.658 at 1 bar to 97.971 at 4 bar. Adding NaCl to the solution provokes the complexation of metal cations with chloride ions and the adsorption competition of sodium cations with the metal ions; therefore, the conductivity increment decreases the metal retention. The presence of 60 mM of NaCl reduced the removal efficiency by 50–60%.- انتشار مقاله: 08-06-1393
- نویسندگان: Mohsen Mehdipour Ghazi,Milad Hallaji Qomi
- مشاهده