The separation of entrained di-nonyl phenyl phosphoric acid (DNPPA) from merchant grade phosphoric acid (MGA) by adsorption on the coconut shell based activated charcoal has been carried out. The effect of various process parameters, such as DNPPA concentration in aqueous phase of MGA, equilibrium time, amount of activated charcoal and temperature upon adsorption capacity of activated charcoal has been studied. The results showed that the adsorption equilibrium was reached after 240 minutes. The adsorption phenomenon followed pseudo-second order kinetics. Adsorption of DNPPA increased with initial concentration of DNPPA in the range of 50 to 200 mg/L. The experimental data fitted well with the Freundlich isotherm model. Decrease in adsorption with increase in temperature suggests that the adsorption process is exothermic in nature. The value of enthalpy change (Delta H = -35.52 kJ/mol) indicated that DNPPA adsorption on activated charcoal is a physisorption phenomenon. Column operation was carried out to obtain a breakthrough curve. Desorption of DNPPA with 10% NaOH yielded near quantitative regeneration of activated charcoal in three contacts.