Electrodialytic removal of cadmium from straw combustion fly ash

Fly ash from straw combustion contains valuable nutrients when returned to agricultural soils. In many instances, however, this fly ash may contain heavy metals, such as cadmium, at levels which often exceed the limits given by the Danish legislation. Thus before utilizing the nutrients, cadmium must be removed from these ashes. The use of an electrodialytic remediation method to remove cadmium from fly ash arising: from straw combustion and containing 11.2 mg Cd kg(-1) DM (dry matter) was accessed. After 36 days of remediation at a constant current density of 5.6 mA cm(-2) more than 97% of the cadmium had been removed from around 150 g ash on a dry basis. (C) 2004 Society of Chemical Industry.