The ability of Phormidium sp. to grow in anaerobically digested swine
waste medium and the use of this organism for tertiary biotreatment of
wastewater was evaluated. In addition to monitoring the growth of Pho
rmidium, the removal of total phosphorus (total P), orthophosphate (P-
PO4), nitrates (N-NO3) and ammonium (N-NH4) were also measured. Diluti
ons from 50 to 10% of the secondary effluent were tested and results c
ompared with Dauta's medium which was used as a control. Results obtai
ned at 25% dilution in 21. graduated cylinders were: 100% removal of o
rthophosphate, 87% of nitrate, 68% of total phosphate and 48% of ammon
ium ion. Removals obtained in a carrousel type reactor were: 48% for o
rthophosphate, 30% for nitrate, 63% for total phosphorus and 100% for
ammonium ion. These removals were higher in both cases than those obta
ined in Dauta's medium. The total ammonium uptake for the 25% dilution
by Phormidium sp. was 7.65 mg/l-d in the glass cylinders and 19.93 mg
/l-d in the carrousel reactor.