The present invention refers in general to treatment of fluids containing biological matter for the purpose of their disinfection as well as for improving various environmental parameters of waste waters like for example Bio Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Nitrogen Phosphor Potassium rating (N—P—K) and content of solids. The disinfection is ensured by virtue of applying electrical current to biologically contaminated fluid. The current destroys cells of biological matters and kills various pathogens contained therein. By virtue of such treatment the environmental parameters of intracellular material which is extracted from the fluid medium are improved.
In particular the present invention concerns a system and a reactor vessel for use with the system in which the above mentioned treatment can be carried out.
As an example of a fluid medium suitable for treatment by the present invention one can mention liquid waste waters originated from various industrial and agricultural installations, municipal sewage, waste waters originating from slaughter houses, from mining installations, fracturing waste waters, waste waters originating from food industry, from cosmetic industry, from pharmaceutical industry, etc.
By treatment of contaminated waste waters in the system and reactor vessel of the present invention it is possible to.
There are known methods of treatment of liquids containing biological matter by applying electrical current thereto.
So, for example in U.S. Pat. No. 6,141,905 there is described process and apparatus for utilizing animal excrement. According to this invention an aqueous mixture containing solid feed excrements from animals is subjected to treatment with an alternating electric current at a frequency of a predetermined magnitude and for a predetermined period of time, when the mixture passes through a tubular reactor.
In U.S. Pat. No. 6,344,349 there is disclosed process and system for electrical extraction of intracellular matter from biological waste materials, e.g. animal and human compost. The process comprises preparation of a mixture biological matter with electro conductive fluid and then passing thereof through a processor unit while electrifying the mixture by transmitting thereto controlled cycles of pulses and pauses of electrical current by means of flat electrodes located within a processor unit.
Both patents describe in details electrical parameters of the process and provide some schematic description of reactor vessel in which the treatment takes place without however providing detailed explanation of the reactor vessel construction.
Here by “reactor vessel” or simply “vessel” is meant any suitable tubular receptacle, container or reservoir defining a space through which flows fluid medium containing biological matter while this medium being treated by electrical current supplied by electrodes retrofitted within the reactor vessel. Such tubular receptacle can be defined either by circular or non-circular cross-section and it would be suitable either for continuous operation or for batch operation.
The reactor vessels used for treatment of various liquids containing organic matter are provided with electrodes for supplying electrical current and those electrodes usually are located inside the vessel.
One important parameter, which should be taken into consideration while designing suitable reactor vessel for electrical treatment is electrical conductivity of a liquid to be treated. Depending on this parameter one should properly select geometry of electrodes, their surface area, their amount as well as the distance between adjacent electrodes in order to ensure that the most efficient treatment in terms of capacity and environmental parameters could be achieved.
In WO 2008155315 there is described a device for cleaning and sterilizing fluids, in particular water. The device comprises elongated tubular container having an inlet and an outlet and a couple of flat electrodes installed within the container so as to be in the flow path of the fluid treated. According to the patent at least one electrode is coated with porous ceramic coating on the side facing the opposite electrode. The devices comprises also an impulse generator unit electrically connected to the electrodes and capable for applying to the fluid of pulsed coronal discharges with the filed strength of at least 100 kV/cm.
In US 2012000782 there is disclosed a uniform electrical field dielectric barrier discharge reactor for purifying of air, sterilizing of fluids or treatment of waste material. The reactor comprises an electrode unit, a dielectric catalyst container and an insulative housing. The electrode unit comprises electrode plates with discharge needles distributed on the insulative plane frame structure.
It can be appreciated that for treating of liquids having dissimilar electrical conductivity within the same reactor vessel different electrodes would be required and therefore it would be desirable that fast, convenient and simple access to the electrodes for their replacement and/or for maintenance could be possible. To conform to these requirements the construction of the electrodes and of the vessel should allow easy assembling and disassembling and there exist various attempts for providing such a possibility.
In some of the known reactors the electrodes are electrically connected to respective fittings which mechanically couple the electrodes to the cover. The fittings pass through the cover and protrude from the cover outside such that they can be electrically connected with a current source for feeding electrical current from the source to the electrodes. When the cover is removed and the fittings are loosened the electrodes can be evacuated from the reactor vessel for cleaning, maintenance or replacement. Fitting arrangement of this type can be found for example in JP 2000046627.
IN JP2000046627 is described electrode holder, which can be used for fixing an electrode holder to a reactor vessel.
In CN 102060357 there is disclosed electrolysis reactor for treatment of high salinity waste waters. The reactor is designed as a cylindrical tube through which passes central water inlet pipe. The reactor is provided with radially installed flat electrodes.
It is stated in the patent that the reactor can be assembled and disassembled, cleaned and maintained conveniently since all its parts are movable.
In CN 201623198 there is described cylindrical reactor for use in microbial fuel cell. The reactor is provided with a couple of flat electrodes immersed in the electro genesis substrate within the reactor. It is stated in the patent that the fuel cell has simple structure and low construction cost.
In JP 7299464 there is described multipurpose water treatment tank for sterilizing, cleaning and electrolyzing water. The tank is designed as a vessel of cylindrical configuration. The vessel is provided with a couple of concentric circular electrodes mounted to a cover such that they face each other. The electrodes are arranged in the water tank and the cover can be screwed to the vessel body to constitute non-diaphragm type electrolytic apparatus.
In CN 102437360 there is disclosed multi electrode microbial fuel cell comprising a housing accommodating therein detachable circular partition plates of different diameter and detachable circular electrode plates of different diameters. Both the circular plates and the circular electrodes divide the housing into cathode chamber and anode chamber and they can be disassembled.
In CN101187038 there is described reactor for fluorination and electrolysis, which comprises electro pads, negative and positive electrode terminals, negative and positive electrode fitted rods and a generator. It is stated in the patent that the reactor has simple construction, it can be conveniently assembled and disassembled and has high volume rate.
Thus it can be appreciated that despite of many attempts to design reactor vessels for treatment of liquids containing organic matter there still is felt a strong need in a new and improved system and reactor vessel, which would be suitable for efficient treatment of various liquid wastes and in particular would be suited for the peculiarities of extraction of intracellular matter from fluid biological waste materials.
The main object of the present invention is to provide for a new and improved system and reactor vessel suitable for efficient extracting intracellular matter from waste waters containing organic matter by applying electrical current thereto, irrespective of the electrical conductivity of the waste waters to be treated.
The further object of the present invention is to provide for a new and improved system and reactor vessel, in which there is provided a possibility that upon demand the electrodes of the reactor vessel can be fast and easily replaced, repaired, cleaned or otherwise maintained.
The above mentioned objects are achieved by providing the reactor vessel with a elongated tubular housing adapted for passing therethrough of the treated waste waters, said housing being closed by a cover carrying at least one couple of flat electrodes, which are separated by a distance D and have a surface area S, the electrodes being adapted for electrical connection with a source of electrical power, while the above parameters are calculated by the following formulae:
wherein in the above formulae
V0 is given voltage which is supplied by the source of electrical power during the treatment,
I0 is electrical current which is supplied by the source of electrical power during the treatment,
j0 is density of electrical current needed for the treatment, I0/S,
T0 is treatment time,
Q0 is flow rate of the waste waters during the treatment,
ρ0 is electrical resistance of the waste waters to be treated,
and the cover is adapted for assembling with and disassembling from the housing such that upon demand the cover could be conveniently separated from the reactor vessel together with the electrodes to provide easy access to its interior for electrodes replacement, repair, cleaning or for other type of maintenance.
With reference to
The system comprises a reservoir 12 filled with the fluid medium to be treated, a reactor vessel 14, in which the treatment of the fluid medium takes place, a source of electric power with a control panel 16 and a pump 16. The source of electric power supplies alternating current with the required electrical parameters for the treatment of the fluid medium. The pump is required for supplying the fluid medium from reservoir to the reactor vessel and then, upon expiration of the treatment time from reactor vessel back to the reservoir. The direction of movement of the fluid medium is schematically designated by arrows and it can be seen that the fluid medium is forcibly displaced by the pump in the clockwise direction, such that the fluid medium circulates continuously and in a closed loop. The circulation is repeated the required number of times until the required level of disinfection of the fluid medium is obtained. It is not shown in details, but should be appreciated that inside the reservoir is provided at least one couple of flat electrodes 20, 22, which are electrically connected to the source of electrical power by corresponding power lines 24, 26. For the sake of simplicity it is depicted in
One should also appreciate that the system of the present invention is not necessary operates continuously and in a closed cycle. It can function in a periodical (batch) manner as well, i.e. after each period of treatment the disinfected fluid medium can be evacuated into a dedicated reservoir instead of reservoir 12 and the treatment cycle then would be resumed.
In
The walls constituting one pair of lateral walls are designated by respective reference numerals 28, 30 and the opposite end walls are designated by respective reference numerals 32, 34. It can be seen that lateral wall 28 is in fact an upper wall of the housing, while lateral wall 30 is a side wall. On each end wall of the housing is arranged a port for passing the fluid medium to be treated, such that if the fluid medium is displaced clockwise, on the left end wall 32 thereof is provided an entrance port 36 and on the right end wall 34 is provided an exit port 38. It is preferable that the ports are not aligned, i.e. the entrance port would be situated lower than the exit port.
The main dimensions of the reactor vessel and in particular height and length of its walls and diameter of its ports are selected in order to allow the required flow rate of the fluid medium through the reactor vessel as might be required by the treatment conditions and the required capacity of the system. The main dimensions will be detailed further with reference to
In
Referring now to
In
With reference to
One can appreciate that by virtue of removable arrangement of receptacle 42 on the housing as well as by virtue of detachable cover 44 an easy, fast and convenient access to conductor pins or to the housing's interior is provided as might be required for inspection, maintenance or replacement of the electrodes.
In
In
When reactor vessel is assembled the electrodes are located within the housing being immersed into fluid medium to be treated. The treatment takes place when electrical power with required parameters is applied to electrodes from source 16 through power lines 24, 26 such that alternating electric current passes through the fluid medium. The electrodes are preferably flat and they are positioned inside the housing parallel to respective lateral walls 68, 70.
It can be seen that electrodes are separated from each other by a distance D such that there is provided a small interval d between the electrodes and the lateral walls. In practice this distance is about 0.1-1 mm, depending on the size of reactor vessel. The electrodes are preferably configured as rectangular plates defined by a length dimension L, by a height dimension H and by a surface area S.
It will be presented further an analytical expression which can be used for defining the surface area of the electrodes depending on electrical parameters of the treatment, as well as on the treatment time and flow rate of the fluid medium. The electrodes are situated within the housing such that when the closure is secured on the flange of the housing there is provided a small distance t between the electrodes and a bottom wall of the housing. In practice this distance is 1-5 mm.
Referring now to
With reference to
In
In
In practice interior of the reactor vessel is configured as rectangular parallelepiped having the following main dimensions: length dimension l of about 1010 mm, height dimension h of about 316 mm and width dimension w of about 112 mm. Flange 40 defines access opening 46 intended for evacuation from or placement into reactor vessel of the electrodes. The access opening has rectangular configuration.
Referring now to
Passing through wall 28′ conductor pin 66 is seen, which is secured on the wall 28′ by a lower washer 72, an upper washer 74 and a fixing nut 76. Situated between wall 28′ and washer 74 an insulating ring 78 is provided for electrical insulation. A couple of connecting nuts 80, 82 screwed on the upper part of the conductor pin are seen. The nuts secure an end of electrical cable (not shown) between a couple of washers 84, 86.
A sealing gasket 88 is provided between removable closure 28′ and flange 40 for sealing the housing's interior after the closure is put on the flange and secured.
Referring now to
If required the electrodes can be easily and conveniently replaced before returning the modular unit back to the housing.
In
Now with reference to
In
In
In an embodiment shown in
In an embodiment seen in
In
In accordance with the present invention it has been empirically revealed that for easy, convenient and fast evacuation of flat working electrodes from the housing and at the same time for efficient treatment of biologically contaminated fluid medium in the reactor vessel the above mentioned parameters D and S electrodes should be calculated by the following formulae:
wherein in the above formulae
V0 is given voltage which is supplied by the source of electrical power during the treatment,
I0 is electrical current which is supplied by the source of electrical power during the treatment,
j0 is density of electrical current needed for the treatment, I0/S,
T0 is treatment time,
Q0 is flow rate of the waste waters during the treatment,
ρ0 is electrical resistance of the waste waters to be treated.
After calculating the surface S one can calculate the length dimension L and the height dimension H of the electrodes.
Now it will be shown how the system and reactor vessel of the present invention were used in practice for treatment of biologically contaminated fluid medium. The treatment was carried out for reduction the amount of pathogens, phosphorus and odor from industrial waste waters and thus for improving of at least some of the environmental parameters of the fluid medium. The system was provided with a source of electrical power capable to supply alternating voltage of 110 or 220 volts. The system control instrumentation was equipped with a PLC (Programmed Logical Controller) and with a current transducer for comparing values of the current flowing through the electrodes. The system instrumentation comprised also a SSR (Solid State Relay) for changing the current and a frequency controller for changing the flow rate of the fluid medium.
The electrical parameters were varied during the treatment session such that current density J was kept between 0.055 A/cm2 and 0.1 A/cm2.
Construction parameters of reactor vessel, like electrodes surface area S, length dimension L and height dimension H as well as distance D between electrodes were calculated by formulae (1) and (2) for given electrical parameters, at constant flow rate of 6.6 m3/hour and for a given electrical resistance of the fluid medium. The results are summarized in non-limiting table 1 below.
By virtue of the above described system and reactor vessel it was possible to reduce environmental parameters of the fluid medium as well as amount of pathogens, phosphorus and nitrogen as seen in non-limiting table 2 below.
From the obtained results it is evident that the system and reactor vessel according to the present invention have improved properties in terms of efficiency of the treatment and of convenience in exploitation.
It should be appreciated that the present invention is not limited by the above described embodiments and that one ordinarily skilled in the art can make changes and modifications without deviation from the scope of the invention as will be defined below in the appended claims.
In one alternative embodiment the housing can be made from electrically conductive, e.g. metallic material and coated by a non-conductive coating.
In the embodiment presented in
Furthermore, the electrodes should not be merely rigidly connected to the conductor pins. The electrodes not necessarily have to be flat. One could contemplate a situation, in which the electrodes are configured as graphite rods arranged as an array of rods, confined within a cassette. A couple of such cassettes could be located within the housing, while the cassettes would be separated by the distance D and the electrodes would have the surface area S. The electrodes would be provided with detachable copper cups for electrical connecting to the conductor pins.
It should also be appreciated that features disclosed in the foregoing description, and/or in the foregoing drawings, and/or examples, and/or tables, and/or following claims both separately and in any combination thereof, be material for realizing the present invention in diverse forms thereof.
When used in the following claims the terms “comprise”, “contain”, “have” and their conjugates mean “including but not limited to”.