high content of sulfur in liquid stream removal via new carbonous nano adsorbent: equilibrium, kinetic study

This research evaluates dibenzothiophene (dbt) adsorptive removal from the liquid stream on the graphitic carbon nitride (gcn) as a synthesized adsorbent at 25 °c with 3 g for 600 min. the morphological properties of gcn have been investigated by brunauer–emmett–teller (bet), transmission electron microscopy (tem), scanning electron microscopy (sem), and x-ray diffraction (xrd). the study of the characteristic properties of nano adsorbent proves the suitability of the synthesized gcn in mercaptan adsorption process with the obtained data showing a good agreement with freundlich model. the equilibrium capacity of dbt adsorption has been calculated at about 39.1 mg/g. this has also been 25.8 mg/g for tbm (tertiary butyl mercaptan). the adsorption capacity has increased by adding to the adsorbent dosage. thermodynamic studies expose the negative values for δs^0 (-8.99 kj/mol. k), δh0 (-21.05 kj/mol), and δg^0 (8.91 kj/mol), which demonstrate that dbt adsorption has been a natural exothermic process. in addition, this experiment verifies that the substitution of n into the carbon structure improves the dbt removal efficiency in comparison with pristine cnt as an adsorbent. the removal efficiency of dbt onto gcn has been approximately 80%, i.e. 20% higher than that of pure cnt. results show that the adsorption capacity of dbt as a cyclic source of mercaptan has been higher than tertiary butyl mercaptan (tbm) as a liner one. the dbt adsorption mechanism is done by π–π electron interactions between the aromatic structures of dbt, lone-pair electrons of the s atoms, and the pyridinic gcn planes band.