System and method for treating infectious waste matter

• US 20040018112A1
• Filed: 07/23/2002
• Published: 01/29/2004
• Est. Priority Date: 07/23/2002
• Status: Active Grant

• Current Assignee: Digestor LLC
• Original Assignee: Waste Reduction by Waste Reduction, Inc.
• Inventors: Morris, Kevin A., Weber, Peter B., Kaye, Gordon I., Wilson, Joseph H., Hahn, Robert L.
• Granted Patent: US 7,183,453 B2
• Time in Patent Office: Days
• US Class Current: 422/3
• 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: B09B 3/0075 Disposal of medical waste casings for used articles, e.g. sharps A61B50/362; sterilisation of refuse A61L11/00; disposal of used needles or syringes A61M5/3205; disintegrating medical waste B02C19/0075

Abstract

In accordance with the present invention, a system and method is provided for producing a safely disposable end product from waste matter containing undesirable materials, such as infectious, biohazardous, hazardous, or radioactive elements. The method comprises the steps of providing a highly basic solvent, immersing the waste matter containing the undesirable materials within the highly basic solvent, and heating the solvent. The waste matter containing the undesirable materials is allowed to remain within the solvent until digested, thereby forming a solution void of any infectious or biohazardous elements and/or containing a concentration of radioisotope below the maximum permissible concentration (MPC) for release to a sanitary sewer as defined in applicable federal regulations. The invention further provides a system for producing a safely disposable end product void of any infectious or biohazardous elements and/or containing only a concentration of radioisotope below the MPC for release to a sanitary sewer as defined in applicable federal regulations from waste matter containing such materials. The system comprises a tank or vessel capable of containing a highly basic solvent during a closed digestion reaction, heating means for heating the solvent within the vessel, filtering means, and means for removing the post-digestion aqueous solution and solid waste materials from within the vessel. The post-digestion product in both aqueous and solid form can then by disposed of by conventional means.

Claims

1. A system for digesting or neutralizing undesirable materials by subjecting them to a controlled alkaline hydrolysis cycle to generate a sterile resultant suitable for conventional sanitary or land application disposal, said undesirable materials comprising organic tissue, biohazardous or hazardous agents and regulated medical waste, said system comprising:

(a) means for receiving the undesirable materials, said receiving means being capable of forming a closed reaction vessel;

(b) means for determining the weight of the undesirable materials received within said vessel and for generating weight output data;

(c) means for controlling the operation of the system, for receiving and considering the weight output data generated by said weight determining means in determining the appropriate amounts of water and alkali compound to introduce into the interior of the vessel;

(d) means for introducing water within the interior of said vessel in an amount determined by said control means based on the weight output data;

(e) means for introducing an alkali compound within the interior of said vessel in an amount determined by said control means based on the weight output data; and

(f) means for heating the interior of the vessel to a first predetermined temperature level after the introduction of water and alkali compound into the interior of the vessel for a duration sufficient to produce a safely disposable resultant.

2. The system as in claim 1 further comprising:

(g) means for mixing the contents of the vessel to enhance the interaction between the alkali compound and the undesirable materials.

3. The system as in claim 2 further comprising:

(h) means for venting the interior of the vessel, said venting means being operable to be in the open state upon initiation of the cycle and to be closed by said controlling means when the temperature within the vessel reaches a first predetermined level;

(i) means for cooling the interior of the vessel after the alkaline hydrolysis cycle has run by introducing a coolant to the vessel;

(j) means for creating a vacuum within the interior of said vessel;

(k) means for balancing the vacuum created interior by said vacuum means within the vessel to prevent the vacuum existing within said vessel from exceeding a predetermined level during operation of the system by selectively admitting ambient air into the vessel interior during cycle; and

(l) means to initiate a spray rinse to rinse the digestive solution from the solid remains.

4. The system as in claim 3 further comprising:

(m) means for draining the contents from the interior of said vessel,

said heating means being adapted to heat the interior of the vessel to a second predetermined cycle temperature for a predetermined duration, after which point said cooling means lowers the temperature of the vessel interior to a third predetermined temperature whereby the internal pressure within the vessel reaches about zero pounds per square inch, after which point said water introduction means flushes the interior of the vessel and said control means opens said venting means and said draining means drain the contents from within the vessel interior down to a predetermined level, after which point said drain means closes while the water introduction means continues to flush the vessel interior until the interior is partially full, after which point the vessel interior is sprayed with a final rinsing liquid to rinse away through the drain means any compounds remaining within the interior of the vessel.

5. The system as in claim 3 wherein said rinsing liquid comprises water.

6. The system as in claim 3 wherein said coolant comprises water.

7. The system as in claim 1 wherein said undesirable materials further comprises human and animal tissue, animal carcass, human cadaver, pathological waste, regulated medical waste or radioactively contaminated tissue.

8. The system as in claim 1 wherein undesirable materials comprises embalming agents, toxic contaminants, pathogens, antineoplastic agents or microbial agents.

9. The system as in claim 1 wherein said embalming agents include formaldehyde, glutaraldehyde and phenol.

10. The system as in claim 1 wherein said alkali compound comprises sodium hydroxide (NaOH).

11. The system as in claim 1 wherein said alkali compound comprises potassium hydroxide, calcium oxide, ammonium hydroxide or magnesium hydroxide.

12. The system as in claim 1 wherein said weight determining means comprises weight transducers coupled to the vessel.

13. The system as in claim 1 further comprising thermocouple means for monitoring the temperature within the interior of the vessel.

14. The system as in claim 1 wherein said alkali and water introduction means comprises a loop supply system including conduit means, a pump for pumping the alkaline compound from a supply source to the vessel via the conduit means to be introduced within the vessel interior by way of said agitation means, and a thermocouple means to monitor loop temperature.

20. The method of claim 12 further comprising agitating, circulating, or stirring the highly basic solvent in step (c).

15. A method for digesting or neutralizing waste matter, said waste matter including hazardous or biohazardous agents or regulated medical waste containing infectious agents, said infectious agents comprising hydrolyzable material, said method comprising the steps of:

(a) providing a highly basic solvent;

(b) immersing said waste matter into said highly basic solvent; and

(c) heating said highly basic solvent and said immersed waste matter to a temperature of at least 110°

C. and at a pressure greater than about 2.8 atmospheres and for a time sufficient to digest said hydrolyzable material, whereby a sterile solution comprising non-toxic biodegradable materials and containing sterile solid waste free of said infectious agents is produced.

16. The method of claim 15 wherein said highly basic solvent has a pH in the range of about 13 to about 14.

17. The method of claim 15 wherein said highly basic solvent comprises a mixture of water and an alkali metal hydroxide or alkaline earth-metal hydroxide.

18. The method of claim 15 wherein said heating step (c) is performed at a temperature of at least 130°

C.

19. The method of claim 15 wherein said heating step (c) is performed at a temperature of about 150°

C.

35. The method of claim 19 wherein said vessel is coupled to a heating-cooling means,

wherein the heating step (i) is carried out by introducing steam to said heating-cooling means, and

wherein the cooling step (j) is carried out by introducing water to said heating-cooling means.

21. A method for digesting or neutralizing waste matter, said waste matter including hazardous or biohazardous agents or regulated medical waste containing infectious agents, said infectious agents comprising hydrolyzable material, said method comprising the steps of:

(a) providing a highly basic solvent;

(b) immersing said waste matter into said highly basic solvent; and

(c) heating said highly basic solvent and said immersed waste matter to a temperature of at least 130°

C. and for a time sufficient to digest said hydrolyzable material, whereby a sterile solution comprising non-toxic biodegradable materials and containing sterile solid waste free of said infectious agents is produced.

22. The method of claim 21 wherein said heating step (c) is performed at a pressure of at least about 2.8 atmospheres.

23. A method for digesting or neutralizing undesirable materials such as organic tissue or hazardous or biohazardous agents or regulated medical waste by subjecting them to an alkaline hydrolysis cycle and generating a sterile resultant suitable for conventional sanitary disposal or land application, said method compromising the steps of:

(a) providing a closed reaction vessel coupled to a heating-cooling means;

(b) receiving the undesirable materials within said vessel;

(c) determining the weight of the undesirable materials received within said vessel and generating weight output data;

(d) controlling the operation of the system, including considering the weight output data and determining the appropriate amounts of water and alkaline compound to introduce into the interior of the vessel;

(e) after step (d), introducing an alkali compound within the interior of said vessel in an amount based on the weight output data;

(f) after step (d), introducing water within the interior of said vessel in an amount based on the weight output data; and

(g) after steps (e) and (f), heating the vessel interior to a first temperature for a sufficient duration to produce a safely disposable resultant.

24. The method as in claim 23 further comprising the steps of:

(h) during steps (e) and (f), initiating a vacuum within the vent of the vessel to remove waste odors while filling the vessel;

(i) during steps (e) and (f), mixing the contents of the vessel to enhance the interaction between the alkali compound and the undesirable materials;

(j) after step (g), cooling the interior of the vessel to a predetermined temperature after the digestion cycle has run;

(k) after step (j), venting the interior of the vessel upon the vessel reaching a predetermined second temperature and the pressure reaching about one (1) atmosphere;

(l) during step (k), creating a vacuum within the interior of the vessel to remove odor from therewithin;

(m) during step (k), balancing the vacuum so created to prevent said vacuum from interfering with the draining of the vessel;

(n) after step (m), draining the liquid solution portion of the vessel contents from the interior of the vessel; and

(o) after step (n), rinsing the interior of the vessel to remove any remaining solution residue from any solid remains of the undesirable materials.

25. The method as in claim 24 further comprising the steps of:

(p) during step (o), closing the drain while continuing the rinsing and partially re-filling the vessel and agitating the rinse solution throughout any solid waste remains;

(q) after step (p), circulating the rinse solution for a predetermined duration to allow the rinse solution to remove any entrained digestion solution from any solid waste remains of the undesirable materials; and

(r) after step (q), draining the rinsing solution from the interior of the vessel.

26. The method as in claim 25 further comprising the step of heating the rinse solution during steps (p) or (q).

27. The method as in claim 25 further comprising the steps of:

(s) after step (r), conducting a subsequent rinse of the interior of the vessel to remove any solid waste remains from the undesirable materials; and

(t) during step (s), disposing of the resultant effluent by way of conventional means.

28. The method as in claim 27 further comprising the step of:

(u) after step (t), opening the vessel and removing said solid waste remains for disposal in a sanitary landfill or for usage as solid fertilizer.

29. The method of claim 23 wherein said highly basic solvent has a pH of at least about 13.

30. The method of claim 23 wherein said highly basic solvent comprises a mixture of water and an alkali metal hydroxide or alkaline earth-metal hydroxide.

31. The method of claim 23 wherein said heating step (h) is performed at a temperature of at least 110°

C.

32. The method of claim 23 wherein said heating step (h) is performed at a temperature of at least 130°

C.

33. The method of claim 23 wherein said heating step (h) is performed at a temperature of about 150°

C.

34. The method of claim 23 wherein said heating step (h) is performed at a pressure of at least about 2.8 atmospheres.

36. A method for digesting or neutralizing waste matter, said waste matter including hazardous or biohazardous agents or regulated medical waste containing infectious agents, said infectious agents comprising hydrolyzable material, said method comprising the steps of:

(a) providing a highly basic solvent;

(b) immersing said waste matter into said highly basic solvent; and

(c) heating said highly basic solvent and said immersed waste matter to a temperature of at least 110°

C. and at a pressure greater than about 2.8 atmospheres and for a time sufficient to digest said hydrolyzable material, whereby a sterile solution comprising non-toxic biodegradable materials and containing sterile solid waste free of said infectious agents is produced.