TY - JOUR
T1 - Oil sorption by exfoliated graphite from dilute oil-water emulsion for practical applications in produced water treatments
AU - Takeuchi, Kenji
AU - Fujishige, Masatsugu
AU - Kitazawa, Hidenori
AU - Akuzawa, Noboru
AU - Medina, Josue Ortiz
AU - Morelos-Gomez, Aaron
AU - Cruz-Silva, Rodolfo
AU - Araki, Takumi
AU - Hayashi, Takuya
AU - Terrones, Mauricio
AU - Endo, Morinobu
N1 - Funding Information:
This research was supported by the Center of Innovation Program, “Global Aqua Innovation Center for Improving Living Standards and Water-sustainability” from Japan Science and Technology Agency, JST . The authors wish to thank Prof. Xiaoxi Liu of Shinshu Univ. and Dr. M. Onishi of Hitachi Ltd. for their fruitful discussions.
Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - We used engine oil-water emulsion as a model produced water to evaluate the oil sorption properties of exfoliated graphite (EG) and showed that 100mg/L of oil in emulsion can be reduced to a concentration of a 0.1-few mg/L using as-received commercially available EG and surface modified EG subjected to an additional oxidation treatment. Oil at a concentration of less than 15mg/L, the standard of typical water treatment processes. Although EG also sorbs water, it sorbs oil preferentially and the oil concentration of the sorbed phase in EG was estimated to be about 200 times that of the initial untreated emulsion. The sorption mechanism was discussed with the aid of the ab-initio relaxation calculation and classical molecular dynamics (MD) simulation for n-Hexane (C6H14) adsorption on graphene. When EG was incorporated with micron-size iron particles, the oil sorbed EG was found to be effectively recovered from emulsion by using magnetic field. The oil concentration in emulsion treated with EG was able to reduce down to the level comparable to that achieved by nanofiltration (NF) or reverse osmosis (RO) membrane treatment. We concluded that EG from natural graphite can effectively remove oil component during the treatment of emulsion and exhibits high potential for practical use.
AB - We used engine oil-water emulsion as a model produced water to evaluate the oil sorption properties of exfoliated graphite (EG) and showed that 100mg/L of oil in emulsion can be reduced to a concentration of a 0.1-few mg/L using as-received commercially available EG and surface modified EG subjected to an additional oxidation treatment. Oil at a concentration of less than 15mg/L, the standard of typical water treatment processes. Although EG also sorbs water, it sorbs oil preferentially and the oil concentration of the sorbed phase in EG was estimated to be about 200 times that of the initial untreated emulsion. The sorption mechanism was discussed with the aid of the ab-initio relaxation calculation and classical molecular dynamics (MD) simulation for n-Hexane (C6H14) adsorption on graphene. When EG was incorporated with micron-size iron particles, the oil sorbed EG was found to be effectively recovered from emulsion by using magnetic field. The oil concentration in emulsion treated with EG was able to reduce down to the level comparable to that achieved by nanofiltration (NF) or reverse osmosis (RO) membrane treatment. We concluded that EG from natural graphite can effectively remove oil component during the treatment of emulsion and exhibits high potential for practical use.
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U2 - 10.1016/j.jwpe.2015.09.002
DO - 10.1016/j.jwpe.2015.09.002
M3 - Article
AN - SCOPUS:84942585933
VL - 8
SP - 91
EP - 98
JO - Journal of Water Process Engineering
JF - Journal of Water Process Engineering
SN - 2214-7144
ER -