CHARCOALS

摘要

A method of preparing an ion exchange agent for adsorbing cations is disclosed, wherein the method comprises charring non-woody plant material to produce charred material, wherein the charring comprises heating the non-woody plant material to a temperature of between 300 Deg. C and 700 Deg. C, wherein the ash content of the charred material is at least 15% (by weight), and wherein K, Ca, Mg, Mn and/or P make up at least 10% of the charred material weight. This ion exchange agent is suitable for the removal or binding of cationic species in an environment wherein the cationic species may be one or more metal species, and the environment may be selected from soil, solid waste, a slurry or an aqueous waste, and wherein the treatment of the environment is effected by trapping the agent in a vehicle and passing a liquid over or through the vehicle, thereby to contact the trapped charred material and permit removal of some or all of the contaminating cations. Said is also suitable to remove a cationic dye from a solution such as a waste stream.