Distribution equilibria have been investigated for the adsorption of phenol on two macroporous adsorbent resins (Amberlite XAD-4 and Lewatit OC-1064). The experiments were done using a batch technique. The effects of solution pH, temperature, and ionic strength were studied. Results with a new commercial resin (Lewatit OC 1064) have been compared with measurements on the well-established adsorbent resin Amberlite XAD-4 : The Langmuir equation was selected to analyze the effect of pH, temperature, and ionic strength on the equilibrium. The influence of the pH has been interpreted in terms of the phenol dissociation. The fraction of free water has been considered in evaluating the influence of the sodium sulfate concentration.