A method of treating a liquid for removal of organic acid anions which comprises contacting a liquid containing organic acid anions with an adsorbent comprising calcium alginate-kaolinite or calcium alginate-quartz and a method of treating a liquid for removal of organic acid anions, heavy metal ions and thermally degraded organic products which comprises contacting a liquid containing organic acid anions, heavy metal ions and thermally degraded organic products with an adsorbent comprising calcium alginate- activated carbon are described.