FLOC FORMATION IN ACTIVATED SLUDGE

The determination studies were carried out on 12 representative bacteria which were isolated from activated sludge (1), and the following species were identified; Pseudomonas stutzeri (No. 46), Alcaligenes faecalis (No. 32), Pseudomonas diminuta (No. 2), Achromobacter pestifer (No. 18 and No. 27), Pseudomonas fragi (No. 3), Achromobacter superficialis (No. 5), Flavobacterium lutescens (No. 9), Pseudomonas sp. (No. 11), and Brevibacterium ammoniagenes (No. 1 and No. 19).Among them, floc-forming bacteria were Ps. stutzeri (No. 46) and Al. faecalis (No. 32), the former being new as floc-forming bacteria.Floc-inhibiting strains were Ps. diminuta (No. 2), Pseudomonas sp. (No. 21), and Achromobacter pestifer (No. 27). The bacteria which formed flocs in mixed culture were the other seven strains.