| 主权项 |
1. A method of making an ion exchange agent for adsorbing cations, the agent comprising charred material, wherein the charred material is not activated and is produced by charring living plant material at a temperature of 300-700° C. in the absence of an oxidizing agent,
wherein the living plant material is selected from the group consisting of nettle, beet, an algae, seaweed, straw, cabbage, garlic, bracken, horsetail, rye grass and oil seed rape, wherein the charred material has an ash content of at least 15% (by weight), and wherein K, Ca, Mg, Mn and/or P make up at least 10% of the charred material weight. |
