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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Applied Research in Water and Wastewater
- نوع مقاله: Journal Article
- کلمات کلیدی: Nanofiltration,Nitrate,Diazinon,environment,Contaminated Water,Agricultural wastewater
- چکیده:
- چکیده انگلیسی: The efficiency of diazinon (as insecticides) and nitrate (related to nitrogen fertilizer) removal from contaminated water is investigated through NF membrane technique. The effects of nitrate concentration (40-160 mg/l), diazinon concentration (10-1000 µg/l) and pH (5-9) on the efficiency of a commercial polyamide nanofilter membrane at a constant pressure of (800 KPa) are investigated. The response surface method (Box-Behenken design) is applied in design of experiment. As the diazinon concentration and pH are enhanced, the contaminant removal efficiency increases from 85% to 90%; while nitrate concentration has an opposite effect (removal efficiency reduces about 10%). The regression models obtained for nitrate and diazinon rejection show good fitting to the experimental results (r-squared equal to 94% and 98%, respectively). The models are able to predict the evolution of diazinon and nitrate as a function of concentration and pH at a constant pressure.
- انتشار مقاله: 15-07-1392
- نویسندگان: Peyman Mahmoodi,Mehrdad Farhadian,Ali Reza Solaimany Nazar,Amin Noroozi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: CFD,Photocatalytic degradation,Microcapillary,Microchannel,Langmuir–Hinshelwood
- چکیده:
- چکیده انگلیسی: A three-dimensional (3D) simulation of four photocatalytic microreactors is performed using mass and momentum balance equations. The simulated results are validated with the available experimental data for the photocatalytic removal of methylene blue (MB) in two microcapillaries as well as dimethylformamide (DMF) and salicylic acid (SA) in two microchannels. In the surface layers of the microreactor, a photo removal reaction takes place, and the kinetic rates are described by the Langmuir-Hinshelwood (L-H) model. The Damköhler number for these microreactors is less than one, which indicates that the mass transfer rate is limited by the reaction rate. The numerical study and kinetic constants determination are carried out by using computational fluid dynamic techniques. The 3D modelpredictionsare ingood agreementwith the availableexperimental data sets. The results of the parametric study show that by increasing the microreactor length from 50 to 90mm, the removal efficiency improves from 76% to 93%. Moreover, the removal rate is increased by about 40% by reducing the microchannel depth from 500 to 100 .
- انتشار مقاله: 11-12-1398
- نویسندگان: Elham Sadat Behineh,Ali Reza Solaimany Nazar,Mehrdad Farhadian,Fayazeh Rabanimehr
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Titanium dioxide,Graphene Oxide,Mineral salts,Reaction rate constant,Iron oxide (III)
- چکیده:
- چکیده انگلیسی: A TiO2/Fe2O3/GO photocatalyst is synthesized via the sol-gel method and characterized by X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), FT-IR, Brunauer-Emmett-Teller (BET), and Ultraviolet-Visible Diffuse Reflection Spectroscopy (UV-Vis DRS) analyses. Metronidazole (MET) concentration (10-20 mg/L), photocatalyst concentration (0.5-1.5 g/L), irradiation time (60-120 min), and initial pH (4-6) are investigated through response surface methodology (RSM), and the optimal process conditions are determined. The removal efficiency of MET with the TiO2/Fe2O3/GO photocatalyst is 97% under optimal conditions: a pollutant concentration of 10 mg/L, the irradiation time of 120 min, photocatalyst concentration of 1 g/L, and pH of 5. The influence of mineral salts concentrations (50-800 mg/L), including NaCl, Na2SO4, NaHCO3, KCl, MgSO4, and CaCl2, are examined at the initial pH of 5, photocatalyst concentration of 1 g/L, and pollutant concentration of 20 mg/L. According to the results, the reaction rate constant decreases with an increase in mineral salts concentrations up to 800 mg/L, especially with Na2SO4 (42.43% deactivation) and also with MgSO4 (38.08%) and NaHCO3 (37.73%), under the same operational conditions. The effects of mineral salts such as NaCl and KCl on the reaction rate constant for the contaminant removal efficiency have a downward trend until these salts reach a 200 mg/L concentration, and then they experience an upward trend.
- انتشار مقاله: 16-09-1398
- نویسندگان: Mehrdad Farhadian,Negin Entezami,Nila Davari
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Response surface methodology,photocatalyst,Methylene blue,TiO2/Fe2O3,Natural Zeolite
- چکیده:
- چکیده انگلیسی: The photocatalytic degradation of methylene blue was investigated with TiO2 and Fe2O3 nanoparticles supported on natural zeolite. The synthesized photocatalyst was characterized by XRD, XRF, FT-IR, EDX, FE-SEM, and BET analyses. The results of XRD, FT-IR, and EDX confirmed the successful loading of Fe3+ doped TiO2 nanoparticles on natural zeolite. Further, the FE-SEM results confirmed the deposition of TiO2/Fe2O3 on the zeolite, with the approximate particle size being 52.3 nm. According to the XRF results, the synthesized nanoparticles had Fe3+/TiO2 molar ratios of 0.06 in the synthesized photocatalyst. Based on BET analysis, the surface area of TiO2/Fe3+/natural zeolite was about 112.69 m2/g. The effects of operational factors such as pH (6-10), dye concentration (25-75 mg/L) and H2O2 concentration (10-40 mg/L) were considered and optimized via response surface methodology utilizing Box-Behnken design. The optimization results indicated that the maximum percentage of degradation was achieved at a dye concentration of 25 mg/L, initial pH of 10, and H2O2 concentration of 40 mg/L with a 90 min irradiation time and a 1 g/l photocatalyst concentration. The dye degradation efficiency reached 92% under this optimum condition.
- انتشار مقاله: 20-06-1396
- نویسندگان: Hadieh Taghvaei,Mehrdad Farhadian,Nila Davari,Samira Maazi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Nanofiltration,Box–Behnken design,Hexavalent chromium,Ion interaction,Nitrate,Potable water treatment
- چکیده:
- چکیده انگلیسی: The interaction between the ions and the charge of membranes can affect the efficiency of pollutant removal. The present study investigated the removal efficiency of hexavalent chromium and nitrate ions from both actual and synthetic contaminated water via two different commercial spiral wound polyamide nanofilters. In addition, the interaction of ions under different experimental conditions was investigated by using a Box-Behnken design (BBD). The Box–Behnken design optimized the contributing factors which included pH (5-9), the initial concentration of Cr (VI) (0.05-5 mg/L) and the initial concentration of nitrate (40-160 mg/L). The maximum removal efficiency of both Cr (VI) and nitrate was achieved at a pH of 9.0, as 99 % and 90 % for the Iranian nanofilter (NF-I) and 98 % and 82 % for the Korean nanofilter (NF-K), respectively. The results also indicated that as the initial concentration of Cr (VI) increased, the removal efficiency was enhanced while the removal efficiency of nitrate decreased according to the pH. However, by increasing the initial concentration of nitrate, the removal efficiency of both the Cr (VI) and nitrate increased. For actual water samples at an optimum pressure of 0.6 Mpa (NF-K) and 0.8 Mpa (NF-I), the removal efficiency of Cr(VI) and nitrate obtained was 95% and 76 % for the NF-K and 97 % and 86 % for the NF-I, respectively.
- انتشار مقاله: 12-08-1395
- نویسندگان: Peyman Mahmoodi,Mehrdad Farhadian,Ali Reza Solaimany Nazar,Reihaneh Bashiri
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Nanofiltration,Florfenicol,Total ammonia nitrogen,Trout fish farm,Wastewater
- چکیده:
- چکیده انگلیسی: An aquaculture system can be a potentially significant source of antibacterial compounds and ammonia in an aquatic environment. In this study, the removal of total ammonia nitrogen and florfenicol antibiotic from synthetic aqueous wastewater was assessed by applying a commercial TFC (thin film composite) polyamide nanofilter. The effects of pH (6.5-8.5), pressure (4-10 bar), concentration of total ammonia nitrogen (1-9 mg/L), and florfenicol (0.2-5 mg/L) on the removal efficiency of the nanofilter were studied at a constant 70% recovery rate. It was found that by increasing the pH within the range of 6.5 to 8.5, it enhanced the removal efficiency by up to 98% and 100% for total ammonia nitrogen and florfenicol, respectively. With an increase in pressure from 4 to 7 bar, the removal percentage increased and then, it decreased from 7 to 10 bar. The interactions factors did not have significant effects on the both pollutants removal efficiencies. To obtain optimal removal efficiencies, an experimental design and statistical analysis via the response surface method were adopted.
- انتشار مقاله: 16-04-1395
- نویسندگان: Ali Reza Solaimany Nazar,Fatemeh Cheshmberah,Mehrdad Farhadian
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Wastewater treatment,Water Reuse,Nanofiltration,Ionic dye,Textile Wastewater
- چکیده:
- چکیده انگلیسی: Decolorization of aqueous solutions containing ionic dyes (Reactive Blue 19 and Acid Black 172) by a TFC commercial polyamide nanofilter (NF) in a spiral wound configuration was studied. The effect of operating parameters including feed concentration (60-180 mg/l), pressure (0.5-1.1 MPa) and pH (6-10) on dye removal efficiency was evaluated. The response surface method (RSM) was utilized for the experimental design and statistical analysis to identify the impact of each factor. The results showed that an increase in the dye concentration and pH can significantly enhance the removal efficiency from 88% and 87% up to 95% and 93% for Reactive and Acid dye, respectively. The effect of pressure on the removal efficiency showed different behavior such that by the raise of pressure from 0.5 to 0.8 MPa, the removal efficiency increased to its maximum, then reduction in removal efficiency was observed by further increases in pressure above the optimum range. The maximum dye removal efficiencies which were predicted at the optimum conditions by Design Expert software were 97 % and 94 % for Reactive Blue 19 and Acid Black 172, respectively. According to the results of this study, NF processes can be used at a significantly lower pressure and fouling issue for reuse applications as an alternative to the widely used RO process.
- انتشار مقاله: 30-01-1394
- نویسندگان: Mehrdad Farhadian,Najmeh Askari,Amir Razmjou
- مشاهده