Finely divided clays, generated by beneficiating phosphate, are impounded for up to several decades to effect dewatering. Under contract to the Bureau of Mines, several microbiological processes were tested for aggregating suspended clays. Polymers, isolated from leuconostoc mesenteroides, xanthomonas sp., and beijerinckia indica, flocculated dilute phosphatic clay-slime at a rate comparable to polyethylene oxide; however, biopolymer-flocculated clays produced turbid supernatants. Cladosporium cladosporioides, enriched from phosphatic clay-slimes, produced a bioflocculant, and agitated incubation of c. Cladosporioides spores, sugar, and yeast extract with phosphatic clay-slimes induced clay-fungus pelletization. Microbiologically mediated clay removal may have application in industrial wastewater clarification.
Biotechnology & Bioengineering Symp. J Wiley & Sons, Inc., New York, No. 11, 1981, PP. 507-520