HEAVY METAL CATION RETENTION BY UNCONVENTIONAL SORBENTS (RED MUDS AND FLY ASHES)

Toxic heavy metals, i.e. copper (II), lead (II) and cadmium (II), can be removed from water by metallurgical solid wastes, i.e. bauxite waste red muds and coal fly ashes acting as sorbents. These heavy-metal-loaded solid wastes may then be solidified by adding cement to a durable concrete mass assuring their safe disposal. Thus, toxic metals in water have been removed by sorption on to inexpensive solid waste materials as a preliminary operation of ultimate fixation. Metal uptake (sorption) and release (desorption) have been investigated by thermostatic batch experiments. The distribution ratios of metals between the solid sorbent and aqueous solution have been found as a...