 Liquid metal cleaner for aqueous system |
| We claim: 1. A process for removing corrosive deposits from a metal surface exposed to an aqueous ... |
|
| Method for inhibiting the formation and deposition of silica scale in water systems |
| OF PRESENTLY PREFERRED EMBODIMENTS This invention specifically relates to the use of a polyamide ... |
|
| Filter for removing leucocytes |
| The copolymer containing 40 to 80% by weight of units derived from glucosyloxyethyl methacrylate ... |
|
| Whole blood leukodepletion and platelet filter |
| Most blood available as a source for cell separation is whole, and not pre-fractionated. It ... |
|
| Storm drain filter system |
| In accordance with an important feature of the invention, the filter system is constructed in ... |
|
| Apparatus for trapping, signalling presence of and collecting debris in waterways |
| It has been one object of the invention to provide underground, in-line apparatus for trapping and ... |
|
| Filter system |
| The invention is a filter system having filter material, e.g., absorbent material, to treat liquid ... |
|
| Floor drain odor control device |
| The floor drain odor control device of the present invention removably inserts into standard floor ... |
|
| Plastic self-relieving curb inlet filter |
| OF THE PREFERRED EMBODIMENTS Two of the preferred embodiment of the invention are projected from ... |
|
| Storm drain systems for filtering trash and hydrocarbons |
| The system includes the use of a quantity of appropriately formed bodies comprising copolymer-... |
|
|
Aerated hot membrane bioreactor process for treating recalcitrant compounds
| Details |
Inventors: Tonelli, Fernando A.; Behmann, Henry;
Assignee: Zenon Environmental Inc. (Burlington, CA)
Primary Examiner: Wyse; Thomas G.
Assistant Examiner:
Attorney, Agent or Firm: Lobo; Alfred D.
A wastewater feed containing an ultimate BOD/COD ratio >0.6 is well-suited for especially acclimated thermophilic and/or caldo-active living micro-organisms ("hot cells") which thrive in an autothermal aerobic (ATA) reaction zone having an ATA bioreactor ("ATAB") operating at substantially ambient atmospheric pressure in combination with a MF or UF membrane filtration device from which a solids-free permeate may be withdrawn. This combination, of ATAB and membrane device is a "membrane bioreactor" (ATA MBR), which operates autothermally with a feed containing biodegradable organic materials having a BOD of at least 5,000 mg/L, preferably at least 10,000 mg/L (10 g/L) with a minor portion of "municipal" wastewater or domestic sewage. Operation of the ATAB, preferably in the thermophilic range from 45.degree. C.-75.degree. C., with constant HRT from 1 to 12 days, is contingent upon maintaining a stable population of live hot cells. Such cells enhance the biokinetics of degradation and allow operation of the ATAB at higher COD loading and a lower concentration of TSS, than would be possible at a lower temperature. A surprisingly high membrane productivity allows production of much less sludge to be disposed of outside the system, than would have to be disposed of with a conventional mesophilic reactor in normal operation with a HRT of less than 24 hr. A combination of an MP MBR with an ATA MBR is highly effective when the MPB produces high BOD concentration mixed liquor for destruction by the ATAB. |
|
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The ATA process may be adapted for use in any environment in which the economics of minimizing sludge production warrants using a "hot" process other than a conventional mesophilic activated sludge process.
This "hot" process is not directed to the oxidation of nitrogen compounds, most particularly not to waste fluids which contain sufficient ammonia to be volatilized under the conditions of this ATA process.
In a preferred embodiment, this "hot" system is specifically intended for use by those concerned with the cost of treating wastewater having a high COD content greater than 10,000 mg/L, economically and effectively.
At this high COD autothermal operation of a bioreactor at a minimum temperature of 40.
degree.
C.
is achieved.
Most preferred operation of the bioreactor is in the thermophilic range from 50.
degree.
C.
-55.
degree.
C.
to achieve a balance between swift acclimation of normally mesophilic cells, and low sludge production.
Higher COD loadings will typically allow operation in the range from 60.
degree.
C-75.
degree.
C.
and may include preheating of the feed if the economics of doing so are favorable.
Though a typical industrial, chemical or agricultural plant generates waste fluid in a relatively small volume, compared with the volume of domestic wastewater generated by a metropolitan area, the problem of disposing of the small volume with recalcitrant components requires that the waste fluid be disposed of by the operators of the plant.
The main reason for this responsibility of the operators is that their waste fluids typically have very high COD contents, often above 10 g/L.
Even without recalcitrant components, a municipal sewage disposal facility is unable to treat such waste fluids at an acceptable COD loading if the COD of such waste rises above 1,000 mg/L.
Such typical waste fluid streams which lend themselves to effective treatment in an ATA zone are represented by the discharge of whey from a cheese factory; plasticizers from a chemical plant; wastewater from a meat packing plant; etc
|
|
Liquid Purification 
