title: A low-cost mullite-titania composite ceramic hollow fiber microfiltration membrane for highly efficient separation of oil-in-water emulsion.
abstract: Oil-in-water (O/W) emulsion is considered to be difficult to treat. In this work, a low-cost multi-layer-structured mullite-titania composite ceramic hollow fiber microfiltration membrane was fabricated and utilized to efficiently remove fine oil droplets from (O/W) emulsion. In order to reduce membrane cost, coal fly ash was effectively recycled for the first time to fabricate mullite hollow fiber with finger-like and sponge-like structures, on which a much more hydrophilic TiO2 layer was further deposited. The morphology, crystalline phase, mechanical and surface properties were characterized in details. The filtration capability of the final composite membrane was assessed by the separation of a 200 mg·L(-1) synthetic (O/W) emulsion. Even with this microfiltration membrane, a TOC removal efficiency of 97% was achieved. Dilute NaOH solution backwashing was used to effectively accomplish membrane regeneration (∼96% flux recovery efficiency). This study is expected to guide an effective way to recycle waste coal fly ash not only to solve its environmental problems but also to produce a high-valued mullite hollow fiber membrane for highly efficient separation application of O/W emulsion with potential simultaneous functions of pure water production and oil resource recovery.
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, PR China; Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, PR China; Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, PR China.
authors.forename: Mingliang
authors.initials: M
authors.lastname: Chen
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, PR China; Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, PR China. Electronic address: ycdong@iue.ac.cn.
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: Chuyang Y
authors.initials: CY
authors.lastname: Tang
authors.affiliation: Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, PR China.
authors.forename: Aisheng
authors.initials: A
authors.lastname: Huang
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology, PR China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Li
mesh_terms: D002516:Ceramics / Q000737:chemistry; D003031:Coal; D004655:Emulsions; D052918:Environmental Restoration and Remediation; D005374:Filtration / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007220:Industrial Waste; D008567:Membranes, Artificial; D009821:Oils / Q000737:chemistry*; D011522:Protons; D059027:Recycling; D012037:Refuse Disposal / Q000379:methods*; D012044:Regression Analysis; D012972:Sodium Hydroxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*; D018508:Water Purification
chemical_list: D003031:Coal; D004655:Emulsions; D007220:Industrial Waste; D008567:Membranes, Artificial; D009821:Oils; D011522:Protons; D014874:Water Pollutants, Chemical; D014867:Water; C009495:titanium dioxide; D012972:Sodium Hydroxide; D014025:Titanium
keywords: Ceramic membrane; Hollow fiber membrane; Mullite-titania composite membrane; Oil-in-water emulsion; Solid waste recycling