Enhanced performance for Hg(II) removal using biomaterial (CMC/gelatin/starch) stabilized FeS nanoparticles: Stabilization effects and removal mechanism

•The aggregation of FeS nanoparticles was greatly improved after the biomaterial stabilization.•Both coprecipitation and complexation played an important part in Hg(II) uptake by stabilized FeS.•CMC-FeS, gelatin-FeS and starch-FeS all showed superior Hg(II) adsorption capacities.•Starch-FeS possesses good tolerance to environmental interference factors.