Removal of Cells of Olisthodiscus sp. with Aluminium Sulfate and Mechanism

Abstract

Removal of cells of Olisthodiscus sp. using aluminium sulfate was studied by determining the solubility of A1 in seawater under various pH conditions, and examining the direct application of aluminium sulfate to the cell suspension in a jar tester. The solubility of A1 desreased from pH 4.5. The minimum and maximum solubility was at pH 6.3 and pH 8.5, respectively. Above pH 8.5, solubility decreased. A pH buffer action appeared when pH was 4.5-5.0, 8.5 and 10. The aluminium sulfate requirement and pH conditions for a 100% removal of 2 X104 cells/m/ were 50 mg/l (4 mg of Al/l at the most and pH<5.8 and pH>9.5, respectively. These pH conditions were dependent on aluminium sulfate content. When 6.5 <5.8, and positive charged magnesium hydroxide when pH<9.5. The pH change alone or coprecipitation with aluminium hydroxide may not play any important role in the removal mechanism of the cells. © 1984, The Japanese Society of Fisheries Science. All rights reserved.