Enhanced adsorption of Rhodamine B over Zoysia sinica Hance-based carbon activated by amminium chloride and sodium hydroxide treatments

A Zoysia sinica Hance-based activated carbon (ZBAC) was synthesized via two-step method combining NH4Classisted hydrothermal pretreatment and NaOH activation for the removal of Rhodamine B (RhB) in aqueous. The physical and chemical properties of the as-prepared activated carbon were investigated through the usage of Xray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) analysis. A series of batch experiments have been used to visually evaluate the various parameters (pH, dosage, reaction time and actual water condition) affecting the adsorption experiments. Results revealed that the aimed activated carbon exhibited superior adsorption capacities for RhB (1375.8 mg/g) due to its specific surface area (1307 m2/g) and available porosity. In addition, the adsorption of RhB could well-fitted by the Langmuir isotherms model and pseudo-second-order kinetic model, corresponding to monolayer and chemical adsorption respectively. As for the study of adsorption mechanism, ion exchange interactions and hydrogen bonding may be dominant for adsorbing RhB molecules by the activated carbon. The findings of the present work could provide a promising strategy to develop high-performance adsorbents for dye removal from wastewater using biochar derived from waste grass cuttings.

Automated summary

The Zoysia sinica Hance-based activated carbon (ZBAC) showed superior adsorption capacity for Rhodamine B (RhB) removal from aqueous solutions due to its specific surface area and available porosity. The adsorption process followed the Langmuir isotherms model and pseudo-second-order kinetic model, suggesting monolayer and chemical adsorption mechanisms. Ion exchange interactions and hydrogen bonding were found to be dominant in the adsorption of RhB molecules by the activated carbon, providing a promising strategy for developing high-performance adsorbents for dye removal from wastewater.