Phosphate Recovery
Home | Introduction | The phosphates file | Current research projects | Bibliography | Contact us
"PHOSNIX" P-RECOVERY PROCESS
1.General Description
"PHOSNIX" is a trade name of a process to recover phosphate from waste water stream
as granules of Magnesium Ammonium Phosphate(MgNH4PO4?6H2O, MAP or struvite) developed
by Unitika Ltd. Reaction of MAP formation is well known but separation of fine
crystals formed in the process is very difficult.
In the "PHOSNIX" process, fine crystals of MAP formed in a reaction vessel stick on
granules of MAP for easy separation.
2. Operation Experience
| Waste Water Capacity | Operation started in | Type of Waste Water | Production of MAP |
| 500 m3/day | 1987 | Night soil digestion | 400 Kg/day |
| 150 m3/day | 1992 | Sewage side stream | 155 Kg/day |
| 100 m3/day | 1995 | Industrial waste water | 400 Kg/day |
| 500 m3/day | Sewage side stream | 400 Kg/day |
Photographs below show the latest plant of "PHOSNIX" process and recovered MAP granules.
Latest "PHOSNIX" Plant built in 1998 for Sewage
Product used as Fertilizer
3. Process Description
Flow diagram of PHOSNIX" PROCESS is shown above.
Waste water containing phosphate is fed into the center of a reaction vessel where
Magnesium ion and pH control agent are dosed and then fine MAP crystals are formed
immediately. In the bottom part of the reaction vessel, MAP granules fluidized by
air are retained and fine MAP crystals stick on the surface of the granules growing
their size. Grown up MAP granules are discharged periodically from bottom of the
reaction vessel.
4. Plant Description
A "PHOSNIX" plant is composed of the following equipment.
(1) Reaction Vessel one set
(2) Chemical Supply Tanks two sets
(3) Granule Separation Device one set
(4) Waste Water Feed Pump two sets(one for stand-by)
(5) Chemical Dosing pumps three sets(one for stand by)
(6) Blower for Granule Fluidizing one set
(7) pH Indicator/Controller one set
(8) Control Panel one set
(9) Magnesium Dosage Control Instrument Option
(10) Product Packaging Device Option
Unitika supplies "PHOSNIX" plant for 100 m3 to 500 m3/day of waste water and 100 Kg
to 500 Kg /day of MAP production.
5. Product Description
Product from "PHOSNIX" process, MAP, is an excellent fertilizer and currently is sold
to fertilizer manufacturers at about 200 US$ per ton in Japan.
The table below shows contents of the product.
| P | Mg | N | SS | TOC | COD | |
| Actual | 13.3% | 11.5% | 5.3% | 0.3% | 0.08% | 0.3% |
| Theoretical | 12.6% | 9.9% | 5.7% | - | - | - |
Only trace of heavy metals is existed in the product and it is quite applicable for
agricultural applications.
6. For more Information please contact the following address.
Unitika Ltd. Engineering Division
1-4-3 Kyutaromachi, Chuo-ku, Osaka, Japan
Phone 81-6-281-5314
Fax 81-6-281-5313
Mr.Christpher Thornton September 29, 1998
Research and communications coordinator for CEEP
Dear Mr. Thornton,
I am sending you a catalogue for "Phosnix" P-recovery process by E-mail above.
If you have any questions on the content, please contact me on Fax.
Sincerely yours
Hideo Katsuura
Unitika Ltd. Engineering Division