Abstract
Scanning electron micrograph for (A) CTAB-EC and (B) CTAB-EC adsorbed with Congo red.
•First time it is demonstrated that surfactant activated eichhornia is excellent adsorbent.•The basic nature of the adsorbent was evidenced by pH, pHZPC.•Kinetic study alluded that adsorption follows second order kinetic model.
Eichhornia charcoal modified with cationic surfactant is used as an adsorbent. The characterization was done by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, X-ray diffraction, scanning electron micrograph, and point of zero charge measurements. Effect of contact time, initial dye concentration, adsorbent dose and temperature were studied. Experimental data were contemplated for various kinetic models and thermodynamic models and interpreted that adsorption followed second order kinetic model. Langmuir model deduced the maximum adsorption capacity as 103.2mgg−1 at 323K. Gibbs free energy, enthalpy and entropy have been calculated and the present adsorption system is speculated as spontaneous and endothermic in nature.