Polyethylenimine and dithiocarbamate decorated melamine sponges for fast copper (II) ions removal from aqueous solution

Here a highly porous melamine sponge based matels absorbent (MF-PEI/CS2) possessing abundent imine and dithiocarbamate groups was prepared via a simple two-step process including crosslinking reaction with polyethylenimine (PEI) under the assistance of epichlorohydrin and esterification with CS2 under a basic condition. The combination of melamine sponge with large surface area and polyethylenimine and dithiocarbamate groups with strong metals chelating ability into one composite ensures MF-PEI/CS2 sponge an excellent multi-metals removal performance. This monolithic product, which is easily separated from treated water, can quickly chelate amounts of metals in a short time as its absorption capacity reaches about 96% of the saturation absorption capacity (93 mg/g) in 25 min and reach the saturation point (97 mg/g) after 35 min without stirring toward Cu (II) ions.