Multicomponent column optimization of ternary adsorption based removal of phenolic compounds using modified activated carbon

The removal of phenol (P), 4-chlorophenol (CP), 4-nitrophenol (NP), catechol (C), resorcinol (R) and hydroquinone (HQ) from P-CP-NP and C-R-HQ ternary systems, via multicomponent column adsorption on modified activated carbon (MAC), was evaluated in this study to determine the characteristic parameters of the column for ternary systems. A Taguchi L9 orthogonal array matrix was applied to investigate the effect of process parameters such as flow rate (Q), bed height (Z) and column diameter (D) on the breakthrough point of the process. The BET surface area of MAC was found to be 1245 m(2)/g. Higher flow rate, and lower bed height and diameter resulted in faster breakthrough. Statistical analysis of the data revealed that column diameter was the most significant factor (p < 0.05) for simultaneous adsorbate removal from ternary systems. Elution of phenol, 4-chlorophenol and 4-nitrophenol or elution of catechol, resorcinol and hydroquinone from their respective ternary mixtures showed that the thermal desorption may be a better option over that of solvent desorption. MAC worked well for at least seven adsorption-desorption cycles, with the continuous decrease in adsorption efficiency after each them desorption/regeneration. Owing to its heating value, spent-MAC can be used as co-fuel in the boiler-furnace.

Automated summary

This study evaluated the removal of multiple phenolic compounds from ternary systems using modified activated carbon, with a focus on the impact of column parameters on the breakthrough point. The results showed that column diameter was the most significant factor affecting adsorption efficiency. Thermal desorption may be a better option than solvent desorption, and spent-MAC can be utilized as a co-fuel due to its heating value.