Concentration-driven selective adsorption of Congo red in binary dyes solution using polyacrolein: Experiments, characterization and mechanism studies

In this paper, the adsorption properties of polyacrolein (PA-1) for congo red (CR) and acid blue 93 (AB93) dyes were studied. The effects of pH value, temperature, and contact time on the adsorption effect were investigated, and the prepared PA-1 was characterized. In the binary dyes system, PA-1 can significantly adsorb CR, which can be attributed to the hydrogen bonding interaction between PA-1 and CR, matched molecular size and chemical reaction. Additionally, the concentration of these dyes can be adjusted to regulate the selective adsorption of CR by PA-1. According to molecular dynamics (MD) calculations, the affinity of dimer acrolein (DA) with CR is stronger than that of DA with AB93 and the complexes of DA with CR are more stable, which is the reason why PA-1 can selectively absorb CR. Therefore, PA-1 has a promising prospect in the treatment of multicomponent dyes wastewater.