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.
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.
Water Res. 2016 Mar 1;90:277-285. doi: 10.1016/j.watres.2015.12.035. Epub 2015 Dec 22.
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.
水包油（O/W）乳液被认为难以处理。在这项工作中，制备了一种低成本的多层结构莫来石-二氧化钛复合陶瓷中空纤维微滤膜，并将其用于有效去除（O/W）乳液中的细小油滴。为了降低膜成本，首次有效回收了粉煤灰，以制备具有指状和海绵状结构的莫来石中空纤维，其上进一步沉积了更亲水的 TiO2 层。详细表征了形态、晶体相、力学和表面性能。通过分离 200mg·L(-1) 的合成（O/W）乳液评估了最终复合膜的过滤性能。即使使用这种微滤膜，TOC 的去除效率也达到了 97%。使用稀 NaOH 溶液反冲洗可有效完成膜再生（通量恢复效率约为 96%）。本研究有望为粉煤灰的有效回收提供一种途径，不仅可以解决其环境问题，还可以生产出具有高附加值的莫来石中空纤维膜，用于高效分离 O/W 乳液，同时具有纯水生产和油资源回收的潜在功能。
