Process and apparatus for further processing of sewage sludge and other materials to reduce pathogens and toxins
View Patent ↗An apparatus and a method for treating a composition containing toxic materials or biosolids, wherein the apparatus has a hydraulically sealable top that can be opened to allow loading of the composition or closed to seal the apparatus. The apparatus also includes a reagent injection system for injecting a reagent into the apparatus, a mixing device for mixing the composition with the reagent, a heater system for heating the composition, or the mixture of the composition and the reagent, an internal vapor recovery system for recovering gases, vapors, and odors from the toxic materials or biosolids, or from the reagents, a reagent recovery system for recovering the reagent after it has been mixed with the composition, a discharge mechanism for discharging the treated composition, and a control panel comprising temperature and pressure measurements.
1. A method of treating a Biosolid composition contaminated with one or more pathogenic microorganisms comprising the steps of:
placing the composition into a pressure sealable treatment vessel having a reagent injection system, a mixing device, a heating system, and a vapor recovery system;
controlling the pressure or temperature in the vessel such that anhydrous ammonia inside will exist in a substantially gaseous state;
injecting anhydrous ammonia into the vessel through the reagent injection system;
mixing the composition in the presence of anhydrous ammonia using the mixing device to kill at least a portion of the pathogenic microorganisms in the composition; and
recovering anhydrous ammonia gas that has not reacted in the composition through the vapor recovery system;
introducing phosphoric acid into the vessel following the step of mixing the composition in the presence of anhydrous ammonia; and
mixing the composition with the phosphoric acid using the mixing device to convert residual ammonia in the composition into a nitrogenous fertilizer salt.
2. The method of claim 1 , wherein the Biosolid composition is selected from the group consisting of: a sludge from a sewage or wastewater treatment facility; a sludge comprising residue of production matter from a food processing facility and a sludge comprising waste matter from a livestock processing facility.
3. The method of claim 1 , wherein the treatment vessel is adapted for mobility, the method further comprising the step of:
transporting the treatment vessel from a first site to a second site at which a supply of the composition is located.
4. The method of claim 3 , wherein the treatment vessel includes wheels to facilitate the mobility of the vessel.
5. The method of claim 4 , wherein the vessel includes a lift mechanism adapted to elevate the vessel with respect to a support surface, the method further comprising the step of:
placing the vessel on a support surface at the second site;
elevating the vessel with respect to the support surface using the lift mechanism to facilitate discharge of the composition from the vessel; and
discharging the composition from the vessel.
6. The method of claim 1 further including the step of:
dewatering the composition using the heating system prior to the step of injecting anhydrous ammonia into the vessel.
7. The method of claim 1 , wherein the vessel includes a filter arranged for receipt of the composition, and wherein the step of placing the composition into the vessel includes the step of directing the composition through the filter.