Stable and easily detachable cellulose-based membrane system inspired by water hyacinth for efficient heavy metals removal from water

A rapid extracted and concentrated system engineered by green polymers is attractive but there is still a challenge with respect to both materials and processes. Water hyacinth root cells have evolved as a biological membrane system that can transport and concentrate metal ions from water to the plant body rather than simply utilizing the intrinsic trapping properties of cellulose/lignin. This has inspired a novel biological membrane system (BMS), namely, a porous nanocellulose/lignin microdevice (NLMD) accommodated with a stripping agent that is dispersed in an organic phase. In practice, in water, metal ions can be efficiently transported through an organic membrane phase and finally locked in the NLMD, as demonstrated by extraction efficiency (3 min, ~ 90%), as well as high-enrichment (~ 27 times) toward Pb, Zn, and Cu ions. The NLMD was fabricated using nanocellulose and reinforced using lignin–polyamide epoxy chloropropane nanoaggregates that endow the high mechanical stability and good W/O interfacial affinity of the NLMD. Significantly, the BMS could be facilely detached via simple filtration and shape recovery, offering a high-performance and facile regeneration pathway that are hardly attainable by the conventional cellulose-based adsorbents.