Electrolysis: processes – compositions used therein – and methods – Electrolytic material treatment – Water – sewage – or other waste water
Reexamination Certificate
2000-07-25
2002-03-19
Phasge, Arun S. (Department: 1741)
Electrolysis: processes, compositions used therein, and methods
Electrolytic material treatment
Water, sewage, or other waste water
C205S755000, C205S756000, C205S757000, C204S275100, C204S277000, C204S278000
Reexamination Certificate
active
06358398
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to waste water treatment method and apparatus and more particularly, the present invention relates to separating contaminants from an aqueous solution using mass transfer techniques and electrocoagulation.
BACKGROUND OF THE INVENTION
The problem of separating or removing contaminants from aqueous systems has been a complication that the art has lamented over for many decades. To this end, the art developed along with further industrial processes as water contamination grew commensurately with industrial progress. Initially, water treatment was simply a matter of adding materials suitable for inducing precipitation of certain materials, filtration, ion exchange and other processes. With the continual increase in strict requirements for clean water, electro chemistry was brought into favor. Broadly, the use of electrodes disposed within a cell and subjected to electric current was found to be useful for treating solutions containing contaminants. In some instances, other unit operations were combined with this treatment process in order to render inert compounds.
One of the references that was selected for review is U.S. Pat. No. 1,095,893, issued to Landreth, May 5, 1914. This patent relates to electrochemical treatment and in this patent, the patentee has identified that such cells are useful for the treatment of water. As stated in the disclosure electrodes of copper, aluminum, brass or other alloys are useful as cell plate material. In addition, the disclosure discusses the fact that settling tanks may be useful to assist in material settling (floccing). Column 2 of the disclosure indicates that the series of electrodes are arranged so that the water passes up through the apparatus and is forced to “. . . to take a circuitous course whereby any material added to it or found in it may be thoroughly mixed and all particles of the liquid be brought into contact with the electrodes . . . ”. It is also as stated in the text at column 2, that the electrodes are in the form of horizontally disposed plates and that the plates may be provided with apertures which may be centrally arranged with the plates of alternating series of other plates have recesses at their ends. Column 3 of the disclosure states:
“To provide for the proper passage or circulation of the liquid between plates
14
and its movement throughout the apparatus, alternate plates are provided with apertures indicated at
14
A, while the intermediate plates have their cut-away comers notched or recessed as at
14
B as clearly illustrated in
FIGS. 8 and 9
. By this means, the liquid under treatment is diverted in its flow and caused to contact with the entire surface of the respective plates, insuring the desired electrical treatment”
Although this disclosure is useful for instructing the procedure for electrochemical treatment of water, there is no indication of the addition of an oxidant material such as ozone. Further, the teachings of this patent are limited to electrochemistry; the disclosure fails to set forth any details with respect to dissolved air flotation, fluid hydrodynamics, cavitation, flocculation or any other fluid dynamic principles that would augment the utility of the electrochemical cell taught in this patent.
In U.S. Pat. No. 1,146,942, issued to Landreth, Jul. 20, 1915, a variation on what has been discussed in the previous patent is set forth. In this reference, there is a clear indication that the electrodes are of a different polarity and that a suitable pole changing switch, an example is given as number
26
in the drawings, could be used to switch the current in order that one set of plates act as cathodes for a certain length of time while another set of plates act as anodes during this period of time. This reference advanced the art by providing a reverse polarity arrangement for changing the polarity of the individual cells within the unit. The reference, similar to its companion, is deficient on appreciation of countercurrent oxidation with a dissolved gas. Further, it is believed that this apparatus would not be particularly well suited to handling a wide variety of contaminant types (organic, inorganic, combinations thereof, etc.)
In a further reference issued to Landreth, namely U.S. Pat. No. 1,131,067, issued Mar. 9, 1915, there is a discussion of reintroducing treated liquid for further treatment by the apparatus as well as a discussion concerning oxidizing treatment or a treatment for the production of flocculent formed either from the metal electrodes or from simple chemical reaction or the latter stimulated by electric current; or any other treatment. At column 2, beginning at line 25 et seq., discusses recirculation of the material for further treatment in the apparatus.
Preis et al., in U.S. Pat. No. 3,728,245, issued Apr. 17, 1973, teach an apparatus for treating sewage incorporating a series of electrolytic plates for the purpose of electrocoagulation. The patentees discuss a need for maintaining pressure in the circuit so that chlorine and ozone are maintained in solution in order to enhance bactericidal action. This reference advanced the art developed by Landreth et al., by employing an oxidant to enhance the electrocoagulation. The reference, although providing further instruction in this art, is deficient any discussion cavitation or floc generation by pressure discontinuities in an outlet stream of treated aqueous material.
Other generally relevant references include U.S. Pat. No. 913,827, issued to Korten, Mar. 2, 1909, U.S. Pat. No. 3,523,891, issued to Mehl, Aug. 11, 1970, U.S. Pat. Nos. 5,928,493; 5,705,050; 5,746,904 and 5,549,812, 3,846,300, 5,587,057 and 5,611,907.
The electrolytic processes were found to be generally useful, however, the cellular design was such that the electrodes often would accrue debris and, therefore, would change the requirements of the current of the cell. In addition, many of the plates in the existing arrangements were fairly large and did not provide any improvement to enhance the surface area to therefore increase the number of reactions with the contaminants to be treated in the water. This, of course, leads to lower degree of interactions and a higher cost of running the cell in terms of the current requirements due to debris buildup.
It has also been proposed to employ dissolved air flotation systems. One such arrangement is made by the Precision Environmental Systems Company. This company manufactures devices which are useful for flocculation and coagulation within the same unit. This unit is quite useful for the purpose for which it was designed, however, the arrangement has an extremely large footprint and does not provide for different chemical processes to occur within the same unit.
Of the more desirable arrangements that have evolved in this art for water treatment are perhaps the use of dissolved gases for the purpose of oxidation has been moderately successful. In the art that is currently known, typically oxidation cells are open to atmospheric pressure where a gas dissolved in solution is allowed to evolve out of the solution. The arrangement in the art provide a tortuous path or other applied force in order to keep the bubbles in solution as long as possible. This has the advantage of providing a reaction site (the surface of the bubble) of the oxidant material so that the contaminant can be oxidized. Once the gaseous material then evolves to the surface, the contaminant is flocculated and the materials then separated. This is broadly known as aeration and various devices have been proposed in this art in order to maintain the bubbles in solution and thus enhancing the degree of interaction of the bubble surface with the material to be oxidized or otherwise decontaminated.
It would be desirable if there were a process whereby a gaseous oxidant could be introduced into a reservoir or other chamber or confined area under sufficient pressure to maintain the gas in solution. This affords the opportunity for the smallest possible bubbles in solution to oxidize contaminan
Halldorson Jacob
Kresnyak Steve
Lambert Lawrence
(Marks & Clerk)
Applied Oxidation Technologies (2000) Inc.
Phasge Arun S,.
Sharpe Paul S.
LandOfFree
Waste water treatment method and apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Waste water treatment method and apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Waste water treatment method and apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2848566