Rule of Fe0 nano-particles and biopolymer structures in kinds of the connected pairs to remove Acid Yellow 17 from aqueous solution: Simultaneous removal of dye in two paths and by four mechanisms

► A nano-bio agent containing Fe0 nanoparticles and cross-linked pectin was used to remove Acid yellow 17 (AY 17). ► Cyclohexane 1,3,5-tericarboxylic acid and β-isopropylglutaric acid were used to obtain the cross-linked pectin. ► The bidentate bridging and monodentate interaction were as primary mechanisms for binding biopolymer molecules to Fe0 NPs. ► The TEM images showed that the diameter of Fe0 NPs was not less than 10 nm and about 80% of them were between 30 and 45 nm.