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RISS 인기검색어
- 검색키워드
- 저자 : Mohsen Vafaie Sefti (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
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Removal of oil from biodiesel wastewater by electrocoagulation method
Mohsen Vafaie Sefti,Saeb Ahmadi,Ebrahim Sardari,Hamed Reza Javadian,Reza Katal 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.3
An attempt has been made to remove oil and grease (O&G) from biodiesel wastewater as well as O&G and turbidity in the presence of H2O2 and polyaluminum chloride (PAC), as a coagulant-aid by an electrochemical method using iron as sacrificial electrodes. The effects of current density, amount of hydrogen peroxide using as an oxidizing agent and addition of coagulant-aid, on percent removal and energy consumption have been investigated. The removal efficiency of O&G was in the range of 62-86%, whereas O&G removal was 100% in the current density range of 10-12.5 mAcm−2 depending on the concentrations of H2O2 and coagulant aid. It is obtained that electrocoagulation in the absence of coagulant aid and oxidant is not too efficient for the treatment of this type of wastewater.
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Farhad Salimi,Mohsen Vafaie Sefti,Khosrow Jarrahian,Majid Rafipoor,Seyyed Saeed Ghorashi 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.6
The effects of clay (montmorillonite and kaolinite) in the hydrogels were investigated on various propertiessuch as syneresis and strength of thermal and salinity situations in one of the southern Iranian oil reservoirs. The X-raydiffraction (XRD) patterns exhibited a significant increase in interplanar spacing between the montmorillonite claylayers, varying from the initial value of 12.43 oA to 19.45 oA, which evidences the intercalation formation. It was revealedthat even increasing of the interlayer spacing due to kaolinite modification had no effect on the clay compositions. Formationwater was used to study the strength of the hydrogel in the presence of ions. The results indicated that 15 wt%increase of kaolinite clay (modified and non-modified) leads to 20% decrease of the hydrogels’ syneresis. The diffusionof polymer chains between the clay layers increased the elastic modulus (G') of the prepared hydrogels with modifiedkaolinite and montmorillonite, where the maximum value of G' was observed in 3 wt% of montmorillonite. Finally,the thermogravimetric analysis (TGA) indicated an increase in the thermal stability of the mentioned hydrogels.
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Amir Farasat,Mohsen Vafaie Sefti,Saeid Sadeghnejad,Hamid Reza Saghafi 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.5
Preformed particle gel (PPG) treatment is now one of the most effective remediation techniques for conformance controlling and selective plugging of high-water flow conduits in mature water-flooded oil reservoirs. Recognizing the intrinsic properties of PPGs, e.g., the swelling ratio, in reservoir condition is of prime importance to the optimization of their performance as plugging agents. In this study, the classical and three-level full factorial experimental design methods are joined with laboratory measurements to investigate the swelling ratio dependency of a new class of enhanced PPGs at different brine salinities and reservoir temperatures. To cover severe reservoir conditions, the reservoir temperature from 298 to 418 K and brine salinity from 0 to 225,000 ppm were considered during the laboratory measurements. The results show that the swelling ratio decreases by rising water salinity. Moreover, the swelling ratio rises by increasing reservoir temperature up to 380K and then starts to decrease. The factor screening illustrates that the swelling ratio is more dependent on salinity than the reservoir temperature in low salinity solutions, while is less dependent on salinity in high salinity solutions. In addition, a precise mathematical model was developed to predict the swelling ratio of PPGs in a wide range of salinities and temperatures. The results of this study present a practical insight into the swelling-related behavior of the PPGs at reservoir conditions.
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Bulk and rheological properties of polyacrylamide hydrogels for water shutoff treatment
Asefe Mousavi Moghadam,Mohsen Vafaie Sefti,Mahsa Baghban Salehi,Hasan Naderi 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.3
Presenting an optimal hydrogel for water shutoff, based on the bulk and rheological properties, was themain purpose of this research. To determine gelation time, a bottle test was conducted using central composite designmethod with two factors, AN125VLM and Cr(OAc)3, as copolymer and crosslinker, respectively. To select hydrogelwith high strength network, crosslinking density and consistency modulus were also measured. Hence, a hydrogel with26,340 ppm concentration of copolymer, 0.12 ratio of crosslinker/copolymer, maximum value of crosslinking density(1,950) and consistency modulus (31,900 Pa) was selected as the optimal one. To study the gelation time among differentfactors in porous media, rheological experiments were carried out by Plackett-Burman design to screen the eightfactors (NaCl, CaCl2, KCl and MgCl2 concentrations, temperature, pH, sodium lactate and nanoclay). Accordingly,temperature was the most effective factor controlling the gelation time, while pH and other factors had negligible effecton the gelation time of the optimal hydrogel.
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Study effect of different parameters on the sulphate sorption onto nano alumina
Reza Katal,Mehdi Jafari,Amir Hossein Saeedi Dehaghani,Seyedmehdi Sharifian,Mohammed Ali Ghayyem,Mohsen Vafaie Sefti 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.1
The aim of this research work is to investigate sorption characteristic of modified nano alumina (n-Al) for the removal of SO42 from aqueous solutions and wastewater. The sorption of SO42 by batch method is carried out. The optimum conditions of sorption were found to be: a sorbent dose of 0.3 g in 100 ml of SO42, contact time of 35 min, pH = 5. In optimum condition, removal efficiency was 85.6% for the SO42. Three equations, i.e. Morris–Weber, Lagergren and pseudo second order have been tested to track the kinetics of removal process. The Langmuir, Freundlich and D–R are subjected to sorption data to estimate sorption capacity. It can be concluded that n-Al has potential to remove SO42 ions from aqueous solutions at different concentrations. It was found that the temperature has positive effect on the process and negative DG values indicated thermodynamically feasible and spontaneous nature of the sorption. Positive value of DS reveals the increased randomness at the solid–solution interface during the fixation of the ion on the active sites of the sorbent. The effect of other anions was studied and it was found the existence of them in the solution has considerable effect on the sulphate removal.
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