In the present study, it is described that the removal of aqueous ammonium in wastewater released from the steel industry and thermal power plant is possible in using powder MgHPO 4 while the removal nature depends on the solution pH and various contaminant in the wastewater. The removal rate of aqueous ammonium increased with increase of an initial solution pH. Although apparent removal rate increased upon adding phenol that was contained in wastewater from steel industry, it was found that an addition of an excess amount of NaOH into the solution but not phenol directly contributed to the increase of the removal rate. The removal amount decreased upon adding SO 4 2and Ca 2+ that were in wastewater from the thermal power plant.

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Boehmite (Al(OH)O) was employed for the removal of aqueous phosphate in the presence of harmful anions such as carbonate, sulphate, nitrate, nitrite, chloride and fluoride at 298 K. Although boehmite was shown to remove a certain simultaneous removal of phosphate together with fluoride, no influence of the presence of carbonate, sulphate, nitrate, nitrite and chloride on the removal of phosphate by boehmite was observed. In the present study, two kinds of boehmite, a commercially available form and boehmite prepared using a sol-gel technique, were employed for the simultaneous removal of phosphate and fluoride, and it was found that the latter form was superior for such removal. Solid-state 31 P MAS NMR analyses revealed that, in the presence of fluoride, phosphate was removed onto boehmite as different types of phosphate species, depending on the solution pH and the source of boehmite.

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