Sustainable, biocompatible, and mass-producible superwetting water caltrop shell biochars for emulsion separations

Chih-Feng Wang; Xin-Yu Huang; Hong-Ping Lin; Jem-Kun Chen; Hsieh-Chih Tsai; Wei-Song Hung; Chien-Chieh Hu; Juin-Yih Lai

doi:10.1016/j.jhazmat.2022.129567

Sustainable, biocompatible, and mass-producible superwetting water caltrop shell biochars for emulsion separations

J Hazard Mater. 2022 Oct 5:439:129567. doi: 10.1016/j.jhazmat.2022.129567. Epub 2022 Jul 12.

Authors

Chih-Feng Wang¹, Xin-Yu Huang², Hong-Ping Lin³, Jem-Kun Chen⁴, Hsieh-Chih Tsai⁵, Wei-Song Hung⁵, Chien-Chieh Hu⁵, Juin-Yih Lai⁶

Affiliations

¹ Graduate Institute of Applied Science and Technology, Advanced Membrane Materials Research Center, National Taiwan University of Science and Technology, Taipei 106, Taiwan. Electronic address: cfwang@mail.ntust.edu.tw.
² Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
³ Department of Chemistry, National Cheng Kung University, Tainan, Taiwan. Electronic address: hplin@mail.ncku.edu.tw.
⁴ Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
⁵ Graduate Institute of Applied Science and Technology, Advanced Membrane Materials Research Center, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
⁶ Graduate Institute of Applied Science and Technology, Advanced Membrane Materials Research Center, National Taiwan University of Science and Technology, Taipei 106, Taiwan; R&D Centre for Membrane Technology, Chung Yuan University, Taoyuan 320, Taiwan; Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan.

PMID: 36104894
DOI: 10.1016/j.jhazmat.2022.129567

Abstract

The separation of oily wastewater, specifically emulsions, is a crucial global issue. Possible strategies for the efficient separation of emulsified oil/water mixtures through sustainable and environmentally friendly materials have recently drawn considerable attention. In our study, we prepared superwetting water caltrop shell biochar (WCSB) via a top-lit-updraft carbonization procedure. The as-prepared WCSB was characterized by superhydrophilicity, underwater superoleophobicity, underoil superhydrophilicity, and underoil water adsorption ability. Because of its superwetting properties, WCSB was used for the separation of both surfactant-stabilized oil-in-water emulsions (SOIWEs) and surfactant-stabilized water-in-oil emulsions (SWIOEs) with very high fluxes (up to 74,700 and 241,000 L m^-2 h^-1 bar^-1 for SOIWE and SWIOE, respectively). The separation performances were excellent, with oil contents in all SOIWE filtrates lower than 10 ppm and oil purities in all SWIOE filtrates higher than 99.99 wt%. Moreover, WCSB was applied to separate dye-spiked emulsions. Due to their high emulsion separation ability, sustainability, good biocompatibility, and ease of mass production, the as-prepared WCSBs have notable potential for utilitarian applications.

Keywords: Biochar; Emulsion separation; Superwetting property; Sustainability; Water caltrop shell.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Charcoal
Emulsions
Oils*
Surface-Active Agents
Wastewater*

Substances

Emulsions
Oils
Surface-Active Agents
Waste Water
biochar
Charcoal