Open AccessPreparation of lignosulfonate‐based nanofiltration membranes with improved water desalination performance
Author(s) -
Liu Wangqu,
Geng Xin,
Li Saisai,
Zhan Xia,
Li Jiding,
Wang Luying,
Lei Jiandu
Publication year - 2021
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.202000102
Subject(s) - nanofiltration , membrane , polyethylenimine , polyelectrolyte , chemical engineering , desalination , glutaraldehyde , lignosulfonates , materials science , aqueous solution , chemistry , chromatography , lignin , organic chemistry , polymer , composite material , transfection , biochemistry , engineering , gene
Pulping and papermaking generate large amounts of waste in the form of lignosulfonates which have limited valorized applications so far. Herein, we report a novel lignosulfonate‐based nanofiltration membrane, prepared by using polyethylenimine (PEI) and sodium lignosulfonate (SL) via a layer‐by‐layer (LbL) self‐assembly. As a low‐cost and renewable natural polyelectrolyte, SL is selected to replace the synthetic polyelectrolyte commonly used in the conventional LbL fabrication for composite membranes. The prepared LbL (PEI/SL) 7 membranes were crosslinked by glutaraldehyde (GA) to obtain (PEI/SL) 7 ‐GA membranes with compact selective layer. We characterized (PEI/SL) 7 and (PEI/SL) 7 ‐GA membranes to study the chemical compositions, morphologies, and surface hydrophilicity. To improve the nanofiltration performances of the (PEI/SL) 7 ‐GA membranes for water desalination, we investigated the effects of the crosslinking time, GA concentration and the NaCl supporting electrolyte on membrane structure and performance. The optimized (PEI/SL) 7 ‐GA membrane exhibited a permeating flux up to 39.6 L/(m 2 ·h) and a rejection of 91.7% for the MgSO 4 aqueous solution 2.0 g/L concentration, showing its promising potential for water desalination. This study provides a new approach to applying the underdeveloped lignin‐based biomass as green membrane materials for water treatment.