Hydrophobic-modified metal-hydroxide nanoflocculants enable one-step removal of multi-contaminants for drinking water production
Zhen Yang,
Lina Zhao,
Min Hu,
Di Cai,
Ziqi Tian,
Jan Baeyens,
Raf Dewil,
Peiyong Qin,
Weiben Yang,
Nigel J.D. Graham
Affiliations
Zhen Yang
School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China; Corresponding author
Lina Zhao
School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China
Min Hu
School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China
Di Cai
College of Life Science and Technology, National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, China
Ziqi Tian
Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo 315000, China
Jan Baeyens
College of Life Science and Technology, National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, China; Department of Chemical Engineering, Process and Environmental Technology Lab, KU Leuven, 2860 Sint-Katelijne-Waver, Belgium
Raf Dewil
Department of Chemical Engineering, Process and Environmental Technology Lab, KU Leuven, 2860 Sint-Katelijne-Waver, Belgium
Peiyong Qin
College of Life Science and Technology, National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, China
Weiben Yang
School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China
Nigel J.D. Graham
Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK
Summary: Flocculation is a mainstream technology for the provision of safe drinking water but is limited due to the ineffectiveness of conventional flocculants in removing trace low-molecular-weight emerging contaminants. We described a synthesis strategy for the development of high-performance nanoflocculants (hydrophobic-organic-chain-modified metal hydroxides [HOC-M]), imitating surfactant-assembling nano-micelles, by integration of long hydrophobic chains with traditional inorganic metal (Fe/Al/Ti)-based flocculants. The core-shell nanostructure was highly stable in acidic stock solution and transformed to meso-scale coagulation nuclei in real surface water. In both jar and continuous-flow tests, HOC-M was superior over conventional flocculants in removing many contaminants (turbidity, UV254, and DOC: >95%; TP and NO3-N: >90%; trace pharmaceuticals [initial concentration: 100 ng/L]: >80%), producing flocs with better structural and dewatering properties, and lowering the environmental risk of metal leaching. The rationally designed nanoflocculants have large application potential, as a solution to increasing public concern about micro-pollutants and increasing water quality requirements.
