MINERALS ENGINEERING
·
2021
·
IF 4.765
An Liu,Pan-pan Fan,Feng Han,Hua Han,Zhi-hong Li,Huai-fa Wang,Min-qiang Fan
In this study, the electroflotation of quartz and magnetite with cationic collector dodecylamine (DDA) and anionic collector sodium oleate (NaOL) were investigated to gain a better understanding of the electroflotation process and identify methods to improve it. An interesting phenomenon accompanied with obvious promotion (NaOL is used as collector) and inhibition (DDA-HCl is used as collector) of quartz flotation was observed after electrolysis. The obvious promotion arouse from the supply of the metal cations as active site for the adsorption of negatively charged group and increase active collecting species ionic forms RCOO - and (RCOO) 2 2– . Conversely, the obvious inhibition originated from the decrease of the active collecting species RNH 3 + and (RNH 3 ) 2 2+ . An obvious inhibition phenomenon was observed after the electrolysis for the magnetite. This is because the active collecting species RNH 3 + , (RNH 3 ) 2 2+ , RNH 2 ·RNH 3 + and RCOOH molecule decreased significantly after electrolysis. Furthermore, a comparison test between the regular flotation and electroflotation was conducted in the reverse flotation of magnetic separation concentrate. Compared with the regular flotation process, electroflotation flotation was characterized by simple reagent regime (without pH regulator and activator) and moderate conditions (natural pH), which had mild operation condition superiority. Moreover, the flotation product index of electroflotation can be better through slightly adjusting the reagent regime, and it can be certain that electroflotation is an effective process in the reverse flotation of magnetite. These findings provided a novel perspective for understanding the electroflotation process.
研究领域:
矿物加工工程
·
浮选化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Hongwei Ge,Dafan Chen,Mutai Bao,Dan Zhang,Zhenzong Lu,Xiuping Chen,Yiming Li
The unique stability and complexity of oil-in-water (O/W) nanoemulsions originating from various fields of life and production pose significant challenges for their separation. In this work, a novel oil/water separation membrane (MFC/PPy/Ni–Co–P) is constructed by loading polypyrrole (PPy) particles on cellulose (MFC) membranes to provide growth sites for Ni–Co–P alloys, so as to endow the membrane with in situ bubble-generating capability. Under the external electric field, the MFC/PPy/Ni–Co–P membrane is integrated into the electroflotation filtration system as a cathode, and the effective membrane cleaning and demulsification of nanoemulsions can be realized through the micro-aeration environment constructed in situ . The MFC/PPy/Ni–Co–P membrane demonstrates outstanding performance in gravity-driven separation of various oil/water mixtures, with a rejection rate of >99.99 % and a flux of >3000 L∙m −2 ∙h −1 . The interaction energy between oils with different viscosities and membranes is quantified by the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, revealing the dominant role of acid-base interactions in the anti-fouling process. Notably, the integration of MFC/PPy/Ni–Co–P membrane into an electroflotation separation system enables the coalescence and separation of small-sized, highly stable nanoemulsions with separation efficiencies of >99.86 %. This study provides a novel approach for simultaneous and efficient nanoemulsion separation and membrane fouling remediation, showing a great potential in the development of efficient and sustainable oil/water separation technologies.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Renjie Li,Linhua Rao,Jianzhen Zhang,Liguo Shen,Yanchao Xu,Xiujia You,Bao-Qiang Liao,Hongjun Lin
Efficient separation of oil/water emulsion is still a worldwide challenge. Herein, a new conception/strategy of in-situ electroflotation driven by hydrogen evolution reaction (HER) combining with a polypyrrole (PPy)-Ni-modified fabric membrane was proposed for efficient oil/water separation. To realize this new conception, nickel-decorated polyester fabric membrane was successfully fabricated via facile electroless Ni plating process on the polypyrrole (PPy)-modified surface. The Ni-decorated fabric membrane processed superhydrophilicity, underwater superoleophobicity and excellent electrical conductivity (electrical resistance of ~14.1 Ω), which could serve as cathode for HER. The fabric membrane itself couldn't separate oil/water emulsion, but achieved extremely high permeation (above 12526.5 L m −2 h −1 ) and oil rejection (above 98.6%) for separating stratified oil/water mixtures under gravity force. By applying an extra electric field on the conductive fabric membrane, an in-situ electroflotation process driven by HER can be produced. Under the optimized electroflotation conditions (20.0 V cm −1 electric field intensity, 20 g L −1 electrolyte concentration and 30 min electroflotation time) in this study, this new process could efficiently separate oil/water emulsion with high permeation flux (840.6 L m −2 h −1 ) and oil rejection (98.5%). The present work provided a new conception of in-situ electroflotation-membrane separation process for treatment of oily wastewater, showing strong application significance.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Jing Wang,Binghong Chen,Hongjun Lin,Renjie Li
Electroflotation-membrane separation system with a conductive membrane has recently emerged as a promising technology for oily wastewater treatment . However, the conductive membrane prepared by electroless plating often suffers the problems of low stability and high activation cost. To solve these problems, this work proposed a new strategy regarding surface metallization of polymeric membrane by surface nickel-catalyzed electroless nickel plating of nickel‑copper‑phosphorus alloys for the first time. It was found that, addition of copper source remarkably enhanced the membranes' hydrophilicity, corrosion resistance and fouling resistance. The Ni-Cu-P membrane had an underwater oil contact angle of up to 140°, and simultaneously possessed rejection rate > 98 % with rather high flux of 65,663.0 L·m −2 ·h −1 and excellent cycling stability when separating n-hexane/water mixtures under gravity drive. The permeability is higher than the state-of-the-art membranes for oil/water separation. The Ni-Cu-P membrane as the cathode can be assembled into an electroflotation-membrane separation system, allowing to separate oil-in-water emulsion with 99 % rejection. Meanwhile, the applied electric field significantly improved membrane flux and fouling resistance (flux recovery up to 91 %) when separate kaolin suspensions. Polarization curve and Nyquist curve analysis further confirmed that addition of Cu element obviously enhanced corrosion resistance of the Ni modified membrane. This work provided a novel strategy to make up high-efficiency membranes for oily wastewater treatment.
研究领域:
环境工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）