Inactivation of microorganisms and virus in liquids and sludge
View Patent ↗A method of inactivating pathogens contaminating water and sludge, such as sewage sludge from wastewater treatment plants by exposing the contaminated material to an intense alternating mechanical field, at sonic and/or ultrasonic frequencies, producing and sustaining cavitation along spiral-shaped like paths between two or more disks, where at least one disk rotates or more than one disk rotates or the disks counter-rotate at high RPM. Alkaline material may be added to enhance the inactivation of pathogens. Heavy metals, which may also be present in the sewage sludge may be extracted from the sludge by adsorption.
1. A method comprising:
exposing a pathogen-containing material to alternating mechanical stress and strain fields at at least a sonic frequency; and
cavitating the material between at least two counter-rotating disks.
2. The method of claim 1 , further comprising:
adjusting a pH of the material to an alkaline range.
3. The method of claim 1 , further comprising:
adjusting a pH of the material in an alkaline range of about pH 9 to pH 12.
4. The method of claim 1 , wherein the material contains at least one heavy metal.
5. The method of claim 4 , further comprising:
adding at least one sorbent material for the sorption of the heavy metal(s) in the material.
6. The method of claim 5 , wherein the sorbent material is of one of a solid phase, a liquid phase, or a gaseous phase.
7. The method of claim 1 , wherein the disks are rotating at an average velocity of at least 4000 revolutions per minute.
8. The method of claim 1 , wherein the disks are rotating at an average velocity on the order of 6000 revolutions per minute.
9. The method of claim 1 , wherein the pathogen-containing material comprises a class B sludge.
10. A method comprising:
exposing a Class B sludge to alternating mechanical stress and strain fields at at least a sonic frequency by cavitating the sludge between at least two counter-rotating disks; and
upgrading the Class B sludge to a Class A biosolid.
11. The method of claim 10 , wherein the disks are rotating at an average velocity of at least 4000 revolutions per minute.
12. The method of claim 10 , wherein the disks are rotating at an average velocity on the order of 6000 revolutions per minute.
13. The method of claim 10 , the method further comprising:
dewatering the Class A biosolid.