Sludge treatment system

A method of converting sludge into a fertilizer, comprising the steps of:

• drying dewatered sludge solids in a dryer to produce dried solids to serve as the fertilizer;
• providing heat energy to the dryer from a heat source;
• fueling the heat source with waste oil to produce the heat energy, and during the heat energy production the heat source also producing an exhaust gas containing undesirable by-products;
• filtering the undesirable by-products from the exhaust gas with a bag house prior to venting the exhaust gas to atmosphere;
• conditioning the exhaust gas by adding a conditioner additive selected from the group consisting of sodium bicarbonate and lime, thereto before the filtering step to aid in the collection of the undesirable by-products in the bag house and to facilitate removal of the collected undesirable by-products from the bag house, wherein the conditioner additive reacts with the undesirable by-products to produce desirable sulfates which serve as additional soil nutrient components of the fertilizer;
• reclaiming excess conditioner additive and desirable sulfates from the bag house;
• and
• adding the reclaimed excess conditioner additive and desirable sulfates reclaimed from the bag house to the dried solids.

A method of converting sludge into a granular fertilizer, comprising the steps of:

• promoting flocculation and coagulation of the sludge by adding a polymer to the sludge;
• dewatering the sludge after the polymer has been added thereto to provide dewatered sludge solids;
• drying the dewatered sludge solids in a dryer to produce dried solids;
• and
• adding lime to the dried solids to produce a granular fertilizer from the dried solids having an enhanced shelf life.

A method of converting sludge into a fertilizer, comprising the steps of:

• mixing and sizing dewatered sludge solids to produce a solids mixture;
• drying the solids mixture in a dryer to produce dried solids, and during the drying of the solids mixture also producing a dryer vapor having condensable and noncondensable vapors and particulate matter;
• providing heat energy to the dryer from a heat source;
• separating a substantial portion of the particulate matter from the dryer vapor;
• condensing the dryer vapor to remove a substantial portion of the condensable vapors from the dryer vapor;
• and
• destroying the noncondensable vapors, as wall as any condensable vapors and particulate matter, remaining in the dryer vapor after the separating and condensing steps through combustion at a temperature of substantially at least 1700.degree. F. using the heat source by containing the vapors and matter in the heat source for approximately one second to minimize the escape of odors, by:
• combusting the dryer noncondensable vapors, as wall as any remaining condensable vapors and particulate matter, using a heat source with a firebox heated by a burner having a flame with a prompt flame zone;
• collecting primary air from an enclosure at least surrounding equipment performing the steps of mixing and sizing, and drying;
• providing fuel and collected primary air to the burner for combustion;
• and
• supplementing the primary air with the dryer noncondensable vapors by injecting the noncondensable vapors, as wall as any remaining condensable vapors and particulate matter, int the firebox substantially at the prompt flame zone, thereby destroying a portion of any fugitive odorous compounds escaping from at least equipment performing the mixing, sizing and drying steps.

A method of converting dewatered sludge solids into a granular fertilizer, comprising the steps of:

• drying the dewatered sludge solids in a dryer to produce dried solids;
• mixing lime with the dried solids to form a mixture;
• and
• grinding the mixture to produce the granular fertilizer.

A granular fertilizer product produced from dewatered sludge solids according to a process comprising the step of:

• drying the dewatered sludge solids in a dryer to produce dried solids;
• grinding the dried solids to produce a ground mixture;
• granularizing the ground mixture to produce the granular fertilizer product;
• and
• mixing lime with the dried solids.

A method of converting dewatered sludge solids into a fertilizer, comprising the steps of:

• drying the dewatered sludge solids in a dryer to produce dried solids;
• burning waste oil to generate heat in the dryer and producing a combustion exhaust gas containing odorous by-products;
• injecting lime into the combustion exhaust gas to provide an odor-free discharge gas;
• removing the lime from the combustion exhaust gas prior to discharge;
• and
• adding the removed lime to the dried solids to produce the fertilizer.