A process for the treatment of effluent, particularly acid mine drainage, is provided which includes the steps of a. neutralising acid; b. removing cations by ion exchange using a cation resin; c. regenerating the cation resin; d. treating the eluates of the cation ion exchange step; e. adsorbing anions from the effluent of the cation removal step using an anion exchange resin; and f. regenerating the anion exchange resin.