| US 7,544,299 B1 | ||
| Biological nutrient removal process and process control for same | ||
| Adrian F. Carolan, Pinson, Ala. (US); William F. Foreman, III, Birmingham, Ala. (US); and John K. Shepherd, Jr., Cropwell, Ala. (US) | ||
| Assigned to Schreiber, LLC, Trussville, Ala. (US) | ||
| Filed on Jun. 25, 2008, as Appl. No. 12/146,371. | ||
| Application 12/146371 is a division of application No. 11/361403, filed on Feb. 24, 2006, granted, now 7,416,669, filed on Aug. 26, 2008. | ||
| Int. Cl. C02F 3/30 (2006.01) | ||
| U.S. Cl. 210—614 [210/630; 210/631; 210/903; 210/906] | 23 Claims |
| 1. A method for the biological treatment of a liquid in a single reactor basin containing an activated sludge material, said
method comprising the steps of:
a. subjecting said liquid to an oxic phase by creating in said reactor basin an oxygen-rich environment and maintaining said
oxygen-rich environment until a oxic phase ending criteria has been achieved;
b. after said oxic phase endpoint has been achieved, subjecting said liquid to an anoxic phase by creating in said reactor
basin a limited oxygen environment and maintaining said limited oxygen environment until an anoxic phase ending criteria has
been achieved;
c. after said anoxic phase endpoint has been achieved, subjecting said liquid to an anaerobic phase by creating in said reactor
basin an oxygen-starved environment and maintaining said oxygen-starved environment until an anaerobic phase ending criteria
has been achieved, said anaerobic phase ending criteria selected from the group consisting of: (i) the expiration of the minimum
time period for the anaerobic phase and a rate of change of phosphate concentration falling below a pre-set value; and (ii)
the occurrence of an anaerobic phase preemptive end criteria, where said anaerobic phase preemptive end criteria is an ammonia
concentration of about 5 mg/L or greater or a phosphate concentration of about 3 mg/L or greater;
d. And repeating steps a)-c) until a desired level of treatment of said liquid is achieved.
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