Mediated electrochemical oxidation of animal waste materials

• US 7,488,409 B1
• Filed: 10/04/2002
• Issued: 02/10/2009
• Est. Priority Date: 10/05/2001
• Status: Expired due to Fees

• Current Assignee: Lnc Scimist
• Original Assignee: Scimist Corporation
• Inventors: Carson, Roger W., Bremer, Bruce W.
• Primary Examiner(s): Phasge; Arun S.
• Application Number:
  US10/263,810
• Time in Patent Office: 2,321 Days
• Field of Search: 205/701, 205/688, 205/703, 205/746, 205/749, 588/204, 204/252, 204/259, 204/262, 204/263, 204/266
• US Class Current: 205/701
• CPC Class Codes: A61L 11/00 Methods specially adapted for refuse disintegrating medical waste B02C19/0075; disposal of medical waste B09B3/00
• CPC Class Codes: A61L 2/035 Electrolysis

Abstract

Animal waste is contacted with an electrolyte containing the oxidized form of one or more reversible redox couples, produced electrochemically by anodic oxidation at the anode of an electrochemical cell. The oxidized forms of any other redox couples present are produced either by similar anodic oxidation or reaction with the oxidized form of other redox couples present and capable of affecting the required redox reaction. The oxidized species of the redox couples oxidize the organic waste molecules and are themselves converted to their reduced form, whereupon they are reoxidized by either of the aforementioned mechanisms. The redox cycle continues until all oxidizable waste species, including intermediate reaction products, have undergone the desired degree of oxidation. The entire process takes place between zero degrees centigrade and slightly below the boiling point of the electrolyte, avoiding formation of either dioxins or furans. Ultrasonic energy and/or ultraviolet radiation provide reaction enhancements.

Claims

1. A process for treating and oxidizing animal waste materials comprising disposing an electrolyte in an electrochemical cell, separating the electrolyte into an anolyte portion and a catholyte portion with an ion-selective membrane or semipermeable membrane applying a direct current voltage between the anolyte portion and the catholyte portion, placing the animal waste materials in the anolyte portion, and oxidizing the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process, wherein the anolyte portion further comprises oxidizing species as a mediator in aqueous solution and the electrolyte is an acid, neutral or alkaline aqueous solution, further comprising introducing an ultrasonic energy into the anolyte portion, rupturing cell membranes of biological cells in the animal waste materials by momentarily raising local temperature within the biological cells with the ultrasonic energy to above several thousand degrees, and causing cell membrane failure.

2. The process of claim 1, wherein the membrane is an ion-selective membrane, or semi permeable membrane, microporous polymer membrane, porous ceramic membrane, or glass frit.

3. A process for treating and oxidizing animal waste materials comprising disposing an electrolyte in an electrochemical cell, separating the electrolyte into an anolyte portion and a catholyte portion with an ion-selective membrane or semipermeable membrane applying a direct current voltage between the anolyte portion and the catholyte portion, placing the animal waste materials in the anolyte portion, and oxidizing the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process, wherein the anolyte portion further comprises oxidizing species as a mediator in aqueous solution and the electrolyte is an acid, neutral or alkaline aqueous solution, further comprising adding a surfactant to the anolyte portion for promoting dispersion of the animal waste materials or intermediate stage reaction products within the aqueous solution when the animal waste materials or reaction products are not water-soluble and tend to form immiscible layers.

4. The process of claim 3, wherein the membrane is an ion-selective membrane, or semi permeable membrane, microporous polymer membrane, porous ceramic membrane, or glass frit.

5. A process for treating and oxidizing animal waste, comprising circulating ions of mediator oxidizing species in an electrolyte through an electrochemical cell and affecting anodic oxidation of reduced forms of reversible redox couples into oxidized forms, contacting the ions with the animal waste in an anolyte portion of the electrolyte in a primary oxidation process, involving superoxidizer ions, having an oxidation potential above a threshold value of 1.7 volts at 1 molar, 25°

C. and pH1, wherein when said superoxidizers are present there is a free radical oxidizer driven secondary oxidation process, adding energy from an energy source to the anolyte portion and augmenting the secondary oxidation processes, breaking down hydrogen peroxide and ozone in the anolyte portion into hydroxyl free radicals, and increasing an oxidizing effect of the secondary oxidation processes, wherein the mediator oxidizing species are selected from the group consisting of (a.) simple ion redox couples described in Table I as below;

(b.) Type I isopolyanions complex anion redox couples formed by incorporation of elements in Table I, or mixtures thereof as addenda atoms;

(c.) Type I heteropolyanions complex anion redox couples formed by incorporation into Type I isopolyanions as heteroatoms any element selected from the group consisting of the elements listed in Table II either singly or in combination thereof, or (d.) heteropolyanions complex anion redox couples containing at least one heteroatom type element contained in both Table I and Table II below or (e.) combinations of the mediator oxidizing species from any or all of (a.), (b.), (c.), and (d.)

6. Apparatus for treating and oxidizing animal waste materials comprising an electrochemical cell, an aqueous electrolyte disposed in the electrochemical cell, a semi permeable membrane, ion selective membrane, microporous polymer, porous ceramic or glass frit membrane disposed in the electrochemical cell for separating the cell into anolyte and catholyte chambers and separating the electrolyte into aqueous anolyte and catholyte portions, electrodes further comprising an anode and a cathode disposed in the electrochemical cell respectively in the anolyte and catholyte chambers and in the anolyte and catholyte portions of the electrolyte, a power supply connected to the anode and the cathode for applying a direct current voltage between the anolyte and the catholyte portions of the electrolyte, and oxidizing of the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process wherein the anolyte portion further comprises a mediator in aqueous solution for producing reversible redox couples used as oxidizing species and the electrolyte is an acid, neutral or alkaline aqueous solution, further comprising an anolyte reaction chamber and buffer tank housing the bulk of the anolyte solution, an input pump to enter liquid animal waste into the anolyte reaction chamber, a spray head and stream head to introduce the anolyte from the electrochemical cell into the anolyte reaction chamber in such a manner as to promote mixing of the incoming anolyte and the anolyte mixture in the anolyte reaction chamber, a hinged lid to allow insertion of waste into the anolyte portion as liquid, solid of combination of both, a locking latch to secure the lid during operation of the system, a suction pump attached to the buffer tank to pump anolyte from the buffer tank to the anolyte reaction chamber, a input pump to pump anolyte from the anolyte reaction chamber back to the buffer tank, and an air pump to pump off gases from the anolyte reaction chamber back to the buffer tank for further oxidation.

7. Apparatus for treating and oxidizing animal waste materials comprising an electrochemical cell, an aqueous electrolyte disposed in the electrochemical cell, a hydrogen or hydronium ion-permeable or selective membrane, disposed in the electrochemical cell for separating the cell into anolyte and catholyte chambers and separating the electrolyte into aqueous anolyte and catholyte portions, electrodes further comprising an anode and a cathode disposed in the electrochemical cell respectively in the anolyte and catholyte chambers and in the anolyte and catholyte portions of the electrolyte, a power supply connected to the anode and the cathode for applying a direct current voltage between the anolyte and the catholyte portions of the electrolyte, and oxidizing of the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process wherein the anolyte portion further comprises a mediator in aqueous solution for producing reversible redox couples used as oxidizing species and the electrolyte is an acid, neutral or alkaline aqueous solution, further comprising an ultrasonic source connected to the anolyte for augmenting secondary oxidation processes by heating hydrogen peroxide containing electrolyte to 4800°

C., at 1000 atmospheres for dissociating hydrogen peroxide into hydroxyl free radicals and thus increasing concentration of oxidizing species and rate of waste destruction and for irradiating biological cell membranes in animal materials to momentarily raise the temperature within the biological cell membranes to above several thousand degrees, causing biological cell membrane failure, and creating greater exposure of biological cell contents to oxidizing species in the anolyte.

8. The apparatus of claim 7, wherein the membrane is an ion-selective membrane, or semi permeable membrane, microporous polymer membrane, porous ceramic membrane, or glass frit.

9. Apparatus for treating and oxidizing animal waste materials comprising an electrochemical cell, an aqueous electrolyte disposed in the electrochemical cell, a hydrogen or hydronium ion-permeable or selective membrane, disposed in the electrochemical cell for separating the cell into anolyte and catholyte chambers and separating the electrolyte into aqueous anolyte and catholyte portions, electrodes further comprising an anode and a cathode disposed in the electrochemical cell respectively in the anolyte and catholyte chambers and in the anolyte and catholyte portions of the electrolyte, a power supply connected to the anode and the cathode for applying a direct current voltage between the anolyte and the catholyte portions of the electrolyte, and oxidizing of the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process wherein the anolyte portion further comprises a mediator in aqueous solution for producing reversible redox couples used as oxidizing species and the electrolyte is an acid, neutral or alkaline aqueous solution, further comprising an anolyte reaction chamber holding most of the anolyte portion and a foraminous basket, a penetrator attached to the basket to puncture solids increasing the exposed area, and further comprising an external CO₂ vent connected to the reaction chamber for releasing CO₂ into the atmosphere, a hinged lid attached to the reaction chamber allowing insertion of waste into the anolyte portion as liquid, solid, or mixtures of liquids and solids, an anolyte pump connected to the reaction chamber, an inorganic compounds removal and treatment system connected to the anolyte pump for removing chlorides, and other precipitate forming anions present in the animal waste being processed, thereby precluding formation of unstable oxycompounds, further comprising thermal control units connected to heat or cool the anolyte to a selected temperature range when anolyte is circulated into the reaction chamber through the electrochemical cell by the anolyte pump on the anode chamber side of the membrane, a flush for flushing the anolyte, and a filter is located at the base of the reaction chamber to limit the size of exiting solid particles to approximately 1 mm in diameter.

10. The apparatus of claim 9, wherein the membrane is an ion-selective membrane, or semi permeable membrane, microporous polymer membrane, porous ceramic membrane, or glass frit.

11. Apparatus for treating and oxidizing animal waste materials comprising an electrochemical cell, an aqueous electrolyte disposed in the electrochemical cell, a hydrogen or hydronium ion-permeable or selective membrane, disposed in the electrochemical cell for separating the cell into anolyte and catholyte chambers and separating the electrolyte into aqueous anolyte and catholyte portions, electrodes further comprising an anode and a cathode disposed in the electrochemical cell respectively in the anolyte and catholyte chambers and in the anolyte and catholyte portions of the electrolyte, a power supply connected to the anode and the cathode for applying a direct current voltage between the anolyte and the catholyte portions of the electrolyte, and oxidizing of the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process wherein the anolyte portion further comprises a mediator in aqueous solution for producing reversible redox couples used as oxidizing species and the electrolyte is an acid, neutral or alkaline aqueous solution, further comprising an anolyte recovery system connected to a catholyte pump, a catholyte reservoir connected to the cathode portion of the electrochemical cell, a thermal control unit connected to the catholyte reservoir for varying the temperature of the catholyte portion, a bulk of the catholyte portion being resident in a catholyte reservoir, wherein the catholyte portion of the electrolyte flows into a catholyte reservoir, and further comprising an air sparge connected to the catholyte reservoir for introducing air into the catholyte reservoir.

12. The apparatus of claim 11, further comprising an anolyte recovery system for capturing the anions and for reintroducing the anions into the anolyte chamber upon collection from the catholyte electrolyte, an off-gas cleaning system connected to the catholyte reservoir for cleaning gases before release into the atmosphere, and an atmospheric vent connected to the off-gas cleaning system for releasing gases into the atmosphere, wherein cleaned gas from the off-gas cleaning system is combined with unreacted components of the air introduced into the system and discharged through the atmospheric vent 47.

13. The apparatus of claim 11, further comprising a screwed top on the catholyte reservoir to facilitate flushing out the catholyte reservoir, a mixer connected to the catholyte reservoir for stirring the catholyte, a catholyte pump connected to the catholyte reservoir for circulating catholyte back to the electrochemical cell, a drain for draining catholyte, a flush for flushing the catholyte system, and an air sparge connected to the housing for introducing air into the catholyte reservoir, wherein the catholyte portion of the electrolyte is circulated by pump through the electrochemical cell on the cathode side of the membrane, and wherein contact of oxidizing gas with the catholyte portion of the electrolyte is enhanced by promoting gas/liquid contact by mechanical and/or ultrasonic mixing.

14. The apparatus of claim 11, wherein the membrane is an ion-selective membrane, or semi permeable membrane, microporous polymer membrane, porous ceramic membrane, or glass frit.

15. Apparatus for treating and oxidizing animal waste materials comprising an electrochemical cell, an aqueous electrolyte disposed in the electrochemical cell, a hydrogen or hydronium ion-permeable or selective membrane, disposed in the electrochemical cell for separating the cell into anolyte and catholyte chambers and separating the electrolyte into aqueous anolyte and catholyte portions, electrodes further comprising an anode and a cathode disposed in the electrochemical cell respectively in the anolyte and catholyte chambers and in the anolyte and catholyte portions of the electrolyte, a power supply connected to the anode and the cathode for applying a direct current voltage between the anolyte and the catholyte portions of the electrolyte, and oxidizing of the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process wherein the anolyte portion further comprises a mediator in aqueous solution for producing reversible redox couples used as oxidizing species and the electrolyte is an acid, neutral or alkaline aqueous solution, wherein the electrochemical cell is operated at high membrane current densities above about 0.5 amps/cm² for increasing a rate of waste destruction, also results in increased mediator ion transport through the membrane into the catholyte, and further comprising an anolyte recovery system positioned on the catholyte side, air sparging on the catholyte side to dilute and remove off-gas and hydrogen, wherein some mediator oxidizer ions cross the membrane and are removed through the anolyte recovery system to maintain process efficiency or cell operability.

16. The apparatus of claim 15, wherein the membrane is an ion-selective membrane, or semi permeable membrane, microporous polymer membrane, porous ceramic membrane, or glass frit.

17. Apparatus for treating and oxidizing animal waste materials comprising an electrochemical cell, an aqueous electrolyte disposed in the electrochemical cell, a hydrogen or hydronium ion-permeable or selective membrane, disposed in the electrochemical cell for separating the cell into anolyte and catholyte chambers and separating the electrolyte into aqueous anolyte and catholyte portions, electrodes further comprising an anode and a cathode disposed in the electrochemical cell respectively in the anolyte and catholyte chambers and in the anolyte and catholyte portions of the electrolyte, a power supply connected to the anode and the cathode for applying a direct current voltage between the anolyte and the catholyte portions of the electrolyte, and oxidizing of the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process wherein the anolyte portion further comprises a mediator in aqueous solution for producing reversible redox couples used as oxidizing species and the electrolyte is an acid, neutral or alkaline aqueous solution, further comprising a controller, a microprocessor, a monitor and a keyboard connected to the cell for inputting commands to the controller through the keyboard responding to the information displayed on the monitor, a program in the controller sequencing the steps for operation of the apparatus, program having pre-programmed sequences of operations the operator follows or chooses other sequences of operations, the controller allows the operator to select sequences within limits that assure a safe and reliable operation, the controller sends digital commands that regulate electrical power to pumps, mixers, thermal controls, ultraviolet sources, ultrasonic sources, CO₂ vents, air sparge, and the electrochemical cell, the controller receives component response and status from the components, the controller sends digital commands to the sensors to access sensor information through sensor responses, sensors in the apparatus provide digital information on the state of components, sensors measure flow rate, temperature, pH, CO₂ venting, degree of oxidation, and air sparging, the controller receives status information on electrical potential across the electrochemical cell or individual cells in a multi-cell configuration and between the anodes and reference electrodes internal to the cells and the current flowing between the electrodes within each cell.

18. The apparatus of claim 17, wherein the membrane is an ion-selective membrane, or semi permeable membrane, microporous polymer membrane, porous ceramic membrane, or glass frit.

19. A animal waste destruction system, comprising a housing constructed of metal or high strength plastic surrounding an electrochemical cell, with electrolyte and a foraminous basket, an AC power supply with a power cord, a DC power supply connected to the AC power supply, the DC power supply providing direct current to the electrochemical cell, a control keyboard for input of commands and data, a monitor screen to display the systems operation and functions, an anolyte reaction chamber with a basket, status lights for displaying information about the status of the treatment of the animal waste material, an air sparge for introducing air into a catholyte reservoir below a surface of a catholyte, a CO₂ vent incorporated into the housing to allow for CO₂ release from the anolyte reaction chamber, an atmospheric vent facilitating the releases of gases into the atmosphere from the catholyte reservoir, a hinged lid for opening and depositing the animal waste in the basket in the anolyte reaction chamber, a locking latch connected to the hinged lid, and in the anolyte reaction chamber an aqueous acid, alkali, or neutral salt electrolyte and mediated oxidizer species solution in which an oxidizer form of a mediator redox couple initially may be present or may be generated electrochemically after introduction of the waste and application of DC power to the electrochemical cell.

20. The system of claim 19, wherein the waste is introduced when the anolyte is at room temperature, operating temperature or intermediate temperature, and the animal waste material is rapidly oxidized at temperatures below boiling point of anolyte at ambient pressure, and further comprising a pump circulating an anolyte portion of an electrolyte, an in-line filter preventing solid particles large enough to clog electrochemical cell flow paths from exiting the reaction chamber, an inorganic compound removal and treatment system and drain outlets connected to the anolyte reaction chamber, whereby residue is pacified in the form of a salt and may be periodically removed, and a removable top connected to a catholyte reservoir allowing access to the reservoir for cleaning and maintenance.

21. A animal waste oxidizing process, comprising an operator engaging an ‘

ON’

button on a control keyboard, a system controller which contains a microprocessor, running a program and controlling a sequence of operations, a monitor screen displaying process steps in proper sequence, status lights on the panel providing status of the process, opening a lid and placing the animal waste in a basket as a liquid, solid, or a mixture of liquids and solids, retaining a solid portion of the waste and flowing a liquid portion through the basket and into an anolyte reaction chamber, activating a locking latch after the waste is placed in the basket, activating pumps which begins circulating the anolyte and a catholyte, once the circulating is established throughout the system, operating mixers, once flow is established, turning on thermal control units, and initiating anodic oxidation and electrolyte heating programs, energizing an electrochemical cell to electric potential and current density determined by the controller program, using programmed electrical power and electrolyte temperature ramps for maintaining a predetermined waste destruction rate profile as a relatively constant reaction rate as more reactive waste components are oxidized, thus resulting in the remaining waste becoming less and less reactive, thereby requiring more and more vigorous oxidizing conditions, activating ultrasonic and ultraviolet systems in the anolyte reaction chamber and catholyte reservoir, releasing CO₂ from the animal waste oxidizing process in the anolyte reaction chamber, activating air sparge and atmospheric vent in a catholyte system, monitoring progress of the process in the controller by cell voltages and currents, monitoring CO₂, CO, and O₂ gas composition for CO₂, CO and oxygen content, decomposing the animal waste into water and CO₂, the latter being discharged out of the CO₂ vent, air sparging drawing air into a catholyte reservoir, and discharging excess air out of an atmospheric vent, determining with an oxidation sensor that desired degree of waste destruction has been obtained, setting the system to standby, and executing system shutdown using the controller keyboard system operator.

22. The process of claim 21, further comprising placing the system in a standby mode during the day and adding animal waste as it is generated throughout the day, placing the system in full activation during non-business hours, operating the system at low temperature and ambient atmospheric pressure and not generating toxic compounds during the destruction of the animal waste, making the process indoors compatible, scaling the system between units small enough for use by a single practitioner and units large enough to replace hospital incinerators, releasing CO₂ oxidation product from the anolyte system out through the CO₂ vent, and venting off-gas products from the catholyte reservoir through the atmospheric vent.

23. The process of claim 21, further comprising introducing the waste into a room temperature or cooler system with little or none of the mediator redox couple in the oxidizer form, depending upon reaction kinetics, heat of reaction and similar waste characteristics.

24. A process for treating and oxidizing animal waste materials comprising disposing an electrolyte in an electrochemical cell, separating the electrolyte into an anolyte portion and a catholyte portion with an ion-selective membrane, semipermeable membrane, microporous polymer, porous ceramic, or glass frit, applying a direct current voltage between the anolyte portion and the catholyte portion, placing the animal waste materials in the anolyte portion, and oxidizing the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process, wherein the anolyte portion further comprises oxidizing species as a mediator in aqueous solution and the electrolyte is an acid, neutral or alkaline aqueous solution, and wherein the mediator oxidizing species are selected from the group consisting of (a.) simple ion redox couples described in Table I as below;

(b.) Type I isopolyanions complex anion redox couples formed by incorporation of elements in Table I, or mixtures thereof as addenda atoms;

(c.) Type I heteropolyanions complex anion redox couples formed by incorporation into Type I isopolyanions as heteroatoms any element selected from the group consisting of the elements listed in Table II either singly or in combination thereof;

or (d.) heteropolyanions complex anion redox couples containing at least one heteroatom type element contained in both Table I and Table II below or (e.) combinations of the mediator oxidizing species from any or all of (a.), (b.), (c.), and (d.)

25. A process for treating and oxidizing animal waste materials comprising disposing an electrolyte in an electrochemical cell, separating the electrolyte into an anolyte portion and a catholyte portion with an ion-selective membrane, semipermeable membrane, microporous polymer, porous ceramic, or glass frit, applying a direct current voltage between the anolyte portion and the catholyte portion, placing the animal waste materials in the anolyte portion, and oxidizing the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process, wherein the anolyte portion further comprises oxidizing species as a mediator in aqueous solution and the electrolyte is an acid, neutral or alkaline aqueous solution, and wherein the mediator oxidizing species are selected from the group consisting of (a.) simple ion redox couples described in Table I as below;

(b.) Type I isopolyanions complex anion redox couples formed by incorporation of elements in Table I, or mixtures thereof as addenda atoms;

(c.) Type I heteropolyanions complex anion redox couples formed by incorporation into Type I isopolyanions as heteroatoms any element selected from the group consisting of the elements listed in Table II either singly or in combination thereof, or (d.) heteropolyanions complex anion redox couples containing at least one heteroatom type element contained in both Table I and Table II below or (e.) combinations of the mediator oxidizing species from any or all of (a.), (b.), (c.), and (d.)

26. Apparatus for treating and oxidizing animal waste materials comprising an electrochemical cell, an aqueous electrolyte disposed in the electrochemical cell, a semi permeable membrane, ion selective membrane, microporous membrane, porous ceramic or glass frit membrane disposed in the electrochemical cell for separating the cell into anolyte and catholyte chambers, and separating the anolyte and catholyte portions, electrodes further comprising an anode and a cathode disposed in the electrochemical cell respectively in the anolyte and catholyte chambers and in the anolyte and catholyte portions of the electrolyte, a power supply connected to the anode and the cathode for applying a direct current voltage between the anolyte and the catholyte portions of the electrolyte, and oxidizing of the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process wherein the anolyte portion further comprises a mediator in aqueous solution for producing reversible redox couples used as oxidizing species and the electrolyte is an acid, neutral or alkaline aqueous solution, wherein the mediator oxidizing species are selected from the group consisting of (a.) simple ion redox couples described in Table I as below;

(b.) Type I isopolyanions complex anion redox couples formed by incorporation of elements in Table I, or mixtures thereof as addenda atoms;

(c.) Type I heteropolyanions complex anion redox couples formed by incorporation into Type I isopolyanions as heteroatoms any element selected from the group consisting of the elements listed in Table II either singly or in combination thereof, or (d.) heteropolyanions complex anion redox couples containing at least one heteroatom type element contained in both Table I and Table II below or (e.) combinations of the mediator oxidizing species from any or all of (a.), (b.), (c.), and (d.)

27. Apparatus for treating and oxidizing animal waste materials comprising an electrochemical cell, an aqueous electrolyte disposed in the electrochemical cell, a semi permeable membrane, ion selective membrane, microporous membrane, porous ceramic or glass frit membrane disposed in the electrochemical cell for separating the cell into anolyte and catholyte chambers and separating the anolyte and catholyte portions, electrodes further comprising an anode and a cathode disposed in the electrochemical cell respectively in the anolyte and catholyte chambers and in the anolyte and catholyte portions of the electrolyte, a power supply connected to the anode and the cathode for applying a direct current voltage between the anolyte and the catholyte portions of the electrolyte, and oxidizing of the animal waste materials in the anolyte portion with a mediated electrochemical oxidation (MEO) process wherein the anolyte portion further comprises a mediator in aqueous solution for producing reversible redox couples used as oxidizing species and the electrolyte is an acid, neutral or alkaline aqueous solution, wherein the mediator oxidizing species are selected from the group consisting of (a.) simple ion redox couples described in Table I as below;

(b.) Type I isopolyanions complex anion redox couples formed by incorporation of elements in Table I, or mixtures thereof as addenda atoms;

(c.) Type I heteropolyanions complex anion redox couples formed by incorporation into Type I isopolyanions as heteroatoms any element selected from the group consisting of the elements listed in Table II either singly or in combination thereof, or (d.) heteropolyanions complex anion redox couples containing at least one heteroatom type element contained in both Table I and Table II below or (e.) combinations of the mediator oxidizing species from any or all of (a.), (b.), (c.), and (d.)