Date stones of Phoenix dactylifera and jujube shells of Ziziphus lotus as potential biosorbents for anionic dye removal.

This study investigated the biosorption of Congo Red (CR) from aqueous solution by Date stones (DS) of Phoenix dactylifera and jujube shells (JS) of Ziziphus lotus. Batch operations were carried out in the liquid phase to observe the effect of various experimental parameters such as contact time, pH, temperature, and initial dye concentration on removal of CR. The characteristics of the DS and JS were also examined by Fourier transform infrared analysis. The biosorption data of CR on DS and JS samples were well fitted with the Langmuir isotherm and pseudo-second kinetics model with a maximum biosorption amount of 45.08 mg g(-1) for DS and 59.55 mg g(-1) for JS at pH = 4, temperature of 50°C, and an initial concentration of 100-800 mg L(-1) after 90 minutes of contact time. The outcomes indicated that DS and JS can be used as a good low-cost alternative for the treatment of effluents containing CR in water.