Carboxymethyl Cellulose Stabilized Acetylene Black Doped Zero-Valent Iron for Adsorption and Reduction of Cr(VI) in Aqueous Solution

Cr(VI) is a highly toxic substance that poses a significant threat to the environment and public health. A new type of composite material, consisting of iron nanoparticles and acetylene black-carboxymethyl cellulose, was developed for the purpose of adsorbing and reducing Cr(VI) in aqueous solutions. The acetylene black nanoparticles were evenly dispersed within the zero-valent iron particles, which were then coated with carboxymethyl cellulose to create an irregular porous shell structure. Carboxymethyl cellulose stabilized acetylene black doped zero-valent iron (ZVI/AB-CMC) demonstrated excellent Cr(VI) removal capability due to its high specific surface area and electrical conductivity, which are favorable for adsorption and reduction of Cr(VI). ZVI/AB-CMC was able to remove 98.6% of Cr(VI) in just 2 h at a concentration of 50 mg L −1 , with a maximum adsorption capacity of 116.30 mg g −1 . X-ray photoelectron spectroscopy analysis indicated that the removal of Cr(VI) involved electrostatic attraction, reduction, and precipitation. Cr(VI) ions were first adsorbed onto the surface of ZVI/AB-CMC by electrostatic attraction, then reduced to less toxic Cr(III), and finally immobilized on the composite material. Compared to other traditional and newly reported materials, ZVI/AB-CMC demonstrated superior adsorption activity for Cr(VI) and was an effective treatment option for Cr(VI)-contaminated wastewater.