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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Progress in Chemical and Biochemical Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Adsorption,Nanofiltration,Membrane,Haloacetonitrile
- چکیده:
- چکیده انگلیسی: In this study removal of haloacetonitriles from aqueous solution by employing a novel hybrid filtration process is investigated. The application potential of the oxidized multi-walled carbon nanotubes (O-MWCNTs) as adsorbent was investigated by evaluating the effect of different process parameters. Solution pH significantly affected the removal of DCAN (as a model of HANs) due to its strong effect on the charges of the adsorbent and the adsorbate. A maximum DOC removal of 98.7% for was achieved with 150 mg/L oxidized MWCNTs dosage and at a solution pH of 8. Finally, the nanofiltration technique using a PBS membrane was effectively employed to reject the wastewater pollutants (HANs) proprly.
- انتشار مقاله: 08-05-1399
- نویسندگان: Mohsen Vaziri,Seyed Mostafa Tabatabaee Ghomsheh,Alireza Azimi,Masoomeh Mirzaei Ghaleh Ghobadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Progress in Chemical and Biochemical Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Carbon Dioxide,Titanium dioxide nanoparticle,Solubility,Diethyl Ethanolamine
- چکیده:
- چکیده انگلیسی: Fossil fuels are the main source of CO2 emissions into the atmosphere, which are sources of air pollutants. Environmental research has confirmed that atmospheric CO2 concentration has risen from 280 ppm in 1800 to 358 ppm in 1994 (an increase of 27.86%). Russia, the United States, China, the rest of the Asian countries, Latin American countries, and African countries accounted for 27, 22, 11, 13, 4, and 3% of the total global CO2 production, respectively. Various processes based on hydrogen sulfide and other acidic gases such as carbon dioxide, carbon disulfide, mercaptans, and carbonyl sulfide have been introduced for natural gas sweetening. One of these processes involves the use of solvents. In the present research, a device that measures solubility of gases in liquids was employed to measure solubility of CO2 in solvent DEEA in the presence of TiO2 at different solvent concentrations (10, 15, 20% w/w), various pressures (5, 10, and 15bar) and different TiO2 concentrations (0.05 and 0.1% w/w) at ambient temperature. Results showed that solubility increased from 25.8 to 42.4% v/v at constant pressure and without the presence of a nanoparticle in the absence of TiO2 at solvent concentrations ranging from 10 to 15% w/w. At a constant concentration of the solvent (15% w/w), solubility increased from 31.8 to 36.7% when the pressure was raised from 10 to 15 bar. Moreover, solubility increased from 32.7 to 36.7% v/v at constant solvent concentration (15% w/w) and pressure (15bar) when TiO2 concentration was raised.
- انتشار مقاله: 30-10-1398
- نویسندگان: Haniyeh Shamsin Beyranvand,Masoomeh Mirzaei Ghaleh Ghobadi,Hamid Sarlak
- مشاهده
- جایگاه : پژوهشی
- مجله: Chemical Methodologies
- نوع مقاله: Journal Article
- کلمات کلیدی: Adsorption,Haloacetonitrile,Nano-filtration,Hybrid adsorption
- چکیده:
- چکیده انگلیسی: The haloacetonitriles (HANs) exist in drinking water exclusively as byproducts of disinfection. HANs are found in drinking water more often with higher concentrations. Human exposure occurs through consumption of finished drinking water, oral and dermal contact as well as when showering, swimming and other activities. The purpose of this study was to investigate the novel hybrid adsorption/ PBS membrane filtration process used to remove haloacetonitriles from aqueous solution. The efficiency of the PAC adsorbent was also evaluated at different pH, which confirmed efficacy of PAC at pH of 8.A maximum removal of DOC (98.7%) was obtained with 150 mg/L PAC dosage at a solution pH of 8. HANs sorption process followed the pseudo second order kinetic model and the Langmuir isotherm gave the best correlation of adsorption.
- انتشار مقاله: 18-03-1399
- نویسندگان: Mohsen Vaziri,Seyed Mostafa Tabatabaee Ghomsheh,Alireza Azimi,Masoomeh Mirzaei
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Carbon Dioxide,absorption kinetics,nanoparticle,anionic surfactant,amine solvent
- چکیده:
- چکیده انگلیسی: Amine solvents are extensively used on an industrial scale for removing carbon dioxide (CO2). The presence of some additives in amine solvents has a desirable effect on CO2 absorption kinetics and also improves the absorption process. In this study, graphene oxide (GO) nanoparticles and the anionic surfactant sodium dodecyl sulphate (SDS) were used as additives to the amine solvent. The number of CO2 moles that were used (ng), the values of the diffusion coefficient (DAB), and the mass transfer coefficients of CO2 gas absorption in the amine solvent (Kc) were determined. Furthermore, the effect of the additives on the kinetics of CO2 gas absorption in the amine solvent was investigated. The results showed that mass transfer coefficients increased with a decrease in pressure and an increase in temperature as well as in the SDS and GO concentrations. The values of the mass transfer coefficient under different conditions varied between 0.0311 and 0.0587 cm/s. The molecular diffusion coefficient of CO2 in the amine solvent increased from 0.000025 to 0.000287 cm2/s with decreases in the pressure and with increases in the temperature and increases in concentrations of additives. The laboratory data were statistically analyzed via Design-Expert software using response surface experiment design and a historical method. A mathematical relation was proposed to estimate the mass transfer coefficients. Moreover, a mathematical relation was introduced to predict the molecular diffusion coefficient of CO2 in the amine solvent.
- انتشار مقاله: 25-07-1397
- نویسندگان: Abdollah Mohammadpoor,Masoomeh Mirzaei,Alireza Azimi,Mostafa Tabatabaee Ghomshe
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Zeolite,Adsorption,Copper,Hydrogel,Sodium alginate
- چکیده:
- چکیده انگلیسی: The study presented in this article investigated the removal of copper ions from aqueous solutions by a synthetic hydrogel-forming adsorbent polymer based on sodium alginate (SA) and hydroxy apatite (HA) nanoparticles. The effect of adding Zeolite on the adsorption performance of this hydrogel was also investigated, and the optimum amount of Zeolite was determined by changing its quantity. The FTIR spectrum determined the structure of the synthesized adsorbent; non-continuous adsorption tests were performed to study the kinetics and thermodynamics of adsorption and also the recovery of the adsorbent. The degree of adsorption of the synthesized nanocomposite was compared with that of Zeolite, and the results showed that the maximum adsorption capacities of Zeolite and the nanocomposite for Cu ions were 29.7 and 75.8 mg/g, respectively. The kinetic studies indicated that the process of adsorption of Cu ions on both absorbents followed a pseudo second order kinetic equation. It took the Zeolite and the hydrogel 90 and 120 minutes, respectively, to reach equilibrium. The thermodynamic studies showed that Cu absorption by both adsorbents matched the Langmuir isotherm very well (R2=0.99). Since adsorbent recovery and its lifespan are of significant importance in absorption processes, recovery was carried out by hydrochloric acid (2% by weight). The repulsion coefficient of the recovered adsorbent and its efficiency in five recovery cycles were measured. The results of the tests indicated that the repulsion coefficient of Cu was 70-82.75 percent and the adsorption efficiency of Cu after 5 recovery cycles was 75 percent of the initial adsorbent.
- انتشار مقاله: 14-05-1396
- نویسندگان: Afsaneh Barekat,Masoomeh Mirzaei
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Adsorption,activated carbon,Competitor ion,Copper
- چکیده:
- چکیده انگلیسی: In this work, the removal of copper from an aqueous solution by granular activated carbon (GAC) in the presence of competitor ions was studied. A batch adsorption was carried out and different parameters such as pH, contact time, initial copper concentration and competitor ions concentration were changed to determine the optimum conditions for adsorption. The optimum pH required for maximum adsorption was found to be 4.5 for copper. Equilibrium was evaluated at 144 h at room temperature. The removal efficiency of Cu(II) was 71.12% at this time. The kinetics of copper adsorption on activated carbon followed the pseudo second-order model. The experimental equilibrium sorption data were tested using the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D-R) equations and the Langmuir model was found to be well fitted for copper adsorption onto GAC. The maximum adsorption capacity of the adsorbent for Cu(II) was calculated from the Langmuir isotherm and found to be 7.03 mg/g. Subsequently, the removal of copper by granular activated carbon in the presence of Ag1+ and Mn2+ as competitor ions was investigated. The removal efficiency of Cu(II) ions without the presence of the competitor ions was 46% at 6 h, while the removal efficiency of Cu(II) ions in the presence of competitor ions, Ag1+ and Mn2+ , was 34.76% and 31.73%, respectively.
- انتشار مقاله: 11-04-1395
- نویسندگان: Saeed Almohammadi,Masoomeh Mirzaei
- مشاهده