Abstract: The substantially complete removal from waste water of phenols and other organic compounds that dissociate in solution to produce organic anions and hydrogen ions is obtained by contacting the waste water with char derived from a carbonaceous material whose ash contains a total of at least 15 weight percent calcium, magnesium, potassium and sodium expressed as oxides on a moisture-free basis while maintaining the pH of the resultant slurry at a value such that the ratio of the highest dissociation constant of the organic compounds present to the hydrogen ion concentration of the slurry is less than about 0.1. By adjusting the pH to such a level, the phenols and other organic compounds are maintained in their nonionized, more adsorbable form which insures the substantially complete adsorption of these substances by the char.