Abstract
A commercial calcinated sand, Cleansand-205 (abbr. Kls-205 : a silica sand coated by a special procedure with a mixtutre of the oxides of Si, Al, Ti, and Ag), was tested for its ability to inhibit the growth of algae in a laboratory (batch-system) experiment. The growth of algae in water taken from a domestic gold fish basin was inhibited almost completely by about 5%(w/v) of Kls-205, under the conditions where fairly amounts of both nitrogen and phosphorus were present. However. Kls-205 (5 %) showed little inhibition on algae which had already abundantly grown, and did not suppress further growth. The abilities of Kls-205 to adsorb nitrogen, phosphorus and carbon dioxide required for the growth and photosynthesis of algae were weak. The amounts of beta- and gamma-radiation and harmful heavy metal ions were the same levels as those from non-treated natural water. The dissolution of any antialgal substances and the generation of active oxygens were not observed. The possible role of Ag and/or its oxide with oligodynamie in inhibiting the growth of algae by Kls-205 was discussed.
