Fly ash leachate wastewater containing a wide variety of toxic heavy metals either in cationic or oxyanionic forms. Treatment of such water represents a challenge for all researchers due to the higher concentrations and competitive effect of all the existing cations and anions. The process of treatment was investigated using different functional groups anion exchangers to reach the most suitable materials and conditions for lowering the level of contamination for the wastewater reuse. The effects of most abundant anionic species in leachate wastewater such as sulfate on the adsorption of boron, molybdate, chromate, arsenate and selenate oxyanions were studied at different experimental conditions. The data obtained indicate that LAYNAERT is the most suitable anion exchanger for the removal of arsenate and selenate, whereas, IRA743 and A400 are good for the removal of boron and molybdate respectively.