Adsorption of Cr(VI) from aqueous solutions using novel activated carbon spheres derived from glucose and sodium dodecylbenzene sulfonate

Cr(VI) is a common wastewater pollutant. Various adsorbents including carbon-basedmaterials are used for the removal of Cr(VI) owing to their high adsorption capacity. Chemical activation is an effective method to increase the specific surface area of adsorbents and, thus, further improve their adsorption capacity. However, research on the adsorption and removal of Cr(VI) from aqueous solutions by chemically activated carbon spheres is limited. Here, glucose and sodium dodecylbenzene sulfonate were used to produce carbon spheres (CSs) via hydrothermal synthesis. Activated carbon spheres (ACSs) were then derived using KOH. The adsorption of Cr(VI) in solution by CS and ACS was investigated through batch experiments. The results indicate that the specific surface area of the ACSwas 1491.21 m(2) g(-1), which was much higher than that of the CS. The adsorption kinetics of the sorbent was consistentwith the pseudo-second-order kinetic model and the adsorption isothermfollowed the Langmuir model. This indicated that the adsorption process of the ACS with respect to Cr(VI) wasmainly via single molecular layer adsorption and chemisorption. In a 200 mg L-1 Cr(VI) solution, the maximum amount of Cr(VI) adsorbed by the ACSwas 230.15 mg g(-1), and some of these adsorbed Cr(VI) were reduced to Cr(III). These results show that ACSs have strong potential for application in the removal of Cr(VI) from aqueous solutions. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Chemically activated carbon spheres were synthesized for the removal of Cr(VI) from aqueous solutions, showing high adsorption capacity and potential application prospects. The adsorption process of the activated carbon spheres towards Cr(VI) was mainly through single molecular layer adsorption and chemisorption, indicating their effectiveness in removing Cr(VI) pollutants.