TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The biological contactor is a natural bacteria (preferably nitrosomonas or nitrobacter).    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The earth filter is a zeolite. The pH adjustment system utilizes at least one organic base, sodium bicarbonate, calcium carbonate, calcium oxide, calcium hydroxide, magnesium hydroxide, sodium hydroxide, aluminum hydroxide, or dihydroxyaluminum sodium carbonate.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: Anaerobic digestion of biomass involves either method A: providing biomass as feed stream; aerobically hydrolyzing at least one portion of stream in a hydrolysis stage; transferring at least one portion of feed stream after hydrolysis to acidifying stage; anaerobically acidifying at least one portion of stream at first temperature; transferring at least one portion of feed stream after acidifying to thermophilic stage; and anaerobically converting at least one portion of feed stream in the thermophilic stage at a second temperature, where converting includes forming acetic acid, methane and carbon dioxide; method B: providing a biomass as a feed stream; aerobically hydrolyzing at least one portion of the feed stream in a hydrolysis stage to form volatile solids in solution comprised of simplified biomolecules; transferring at least one portion of the feed stream after hydrolysis to an acidifying stage; performing acidogenesis on the feed stream at a first temperature to form acidified solids comprising long chain fatty acids; transferring at least one portion of the feed stream after acidogenesis to a thermophilic stage; performing anaerobic digestion on at least one portion of the feed stream in the thermophilic stage at a second temperature to form acetic acid, decomposed solids, methane and carbon dioxide; and drying at least one portion of the decomposed solids for use in forming a Class A biosolid; method C: providing a biomass as a feed stream; aerobically hydrolyzing at least one portion of the feed stream in a hydrolysis stage to form volatile solids in solution comprised of simplified biomolecules; transferring at least one portion of the feed stream after hydrolysis to an acidifying stage; performing acidogenesis on at least one portion of the feed stream at a first temperature to form acidified solids comprising long chain fatty acids; transferring at least one portion of the feed stream after acidogenesis to a thermophilic stage; performing anaerobic digestion on at least one portion of the feed stream in the thermophilic stage at a second temperature to form acetic acid, decomposed solids, methane and carbon dioxide; and separating at least one portion of the decomposed solid in solution to form at least one product that include a first liquid fertilizer; or method D: providing a biomass as a feed stream; aerobically hydrolyzing at least one portion of the feed stream in a hydrolysis stage to form volatile solids in solution comprised of simplified biomolecules; transferring at least one portion of the feed stream after hydrolysis to an acidifying stage; performing acidogenesis on at least one portion of the feed stream at a first temperature to form acidified solid comprising long chain fatty acids; transferring at least one portion of the feed stream after acidogenesis to a thermophilic stage; performing anaerobic digestion on at least one portion of the feed stream in the thermophilic stage at a second temperature to form acetic acid, methane and carbon dioxide; transferring at least one portion of the feed stream after the thermophilic stage to a mesophilic stage; performing anaerobic digestion on at least one portion of the feed stream in the mesophilic stage at a third temperature to form decomposed solids in solution; and separating at least one portion of the decomposed solids in solution to form at least one product that include a liquid fertilizer; or method E: providing a biomass as a feed stream; adjusting the biomass to a desired suspended solids content; transferring the biomass to a first vessel, where the first vessel is for hydrolysis, and hydrolysis occurs for 12-36 hours; transferring at least one portion of the biomass from the first vessel to a second vessel, where the second vessel is for acidogenesis; performing acidogenesis on at least one portion the biomass in the second vessel; transferring at least one portion of the biomass from the second vessel to a third vessel, where temperature is raised via a heat exchanger between the second vessel and the third vessel, and the pH is adjusted via a sodium bicarbonate infusion; performing a first methanogenesis on at least one portion of the biomass in the third vessel, where the first methanogenesis produces at least one first biogas and a first decomposed solids in solution, at least one portion of the first biogas is recirculated in the third vessel by a recirculating system, at least another portion of the first biogas is diverted and treated to purify at least one portion of the first biogas, and at least one portion of the first decomposed solids in solution are diverted and separated into solids and liquid; transferring at least one portion of the biomass from the third vessel to a fourth vessel, and temperature is lowered via a heat exchanger between the third vessel and the fourth vessel; and performing a second methanogenesis on at least one portion the biomass in the fourth vessel, where the second methanogenesis produces at least a second biogas and a second decomposed solids in solution, at least one portion of the second biogas is recirculated in the fourth vessel by a recirculating system, at least another portion of the second biogas is diverted and treated to purify the portion of the second biogas, and at least one portion of the second decomposed solid in solution is diverted and separated into solids and liquid. In the method A, the acidifying stage includes a pH of 5.8-6.2, the hydrolysis stage includes a temperature of up to 85 degrees F; and the first temperature is 95-100 degrees F. The method (A1), further involves transferring at least one portion of feed stream to a mesophilic stage after anaerobically converting at least one portion of the feed stream in the thermophilic stage; anaerobically converting at least one portion of the feed stream in the mesophilic stage at a third temperature, where converting includes forming at least acetic acid, methane and carbon dioxide; residing in the hydrolysis stage for 12-36 hours; residing in the acidifying stage for 12-24 hours; residing in the thermophilic stage for 24-96 hours; and residing in the mesophilic stage for 96-168 hours. In method B, providing the biomass feed stream includes adjusting a percent total solid suspension to 2-15%. The method B further involves transferring at least one portion of the feed stream after the thermophilic stage to a mesophilic stage; performing digestion on at least one portion of the feed stream in the mesophilic stage at a third temperature to form decomposed solids in solution; transferring the post-mesophilic stage feed stream to a dewatering stage to separate solids from liquid; transferring the liquid to a container or pipe; and drying the solids for use in forming a Class A biosolid. The dewatering stage uses at least one belt press, cyclone separator, screw press, or evaporator to separate the liquid from the solids. In method B, the pH of hydrolysis stage and acidogenesis stage are 5.8-6.2; and the pH of thermophilic stage and mesophilic stage are 6.8-7.2. The method C further involves transferring at least one portion of the feed stream from the thermophilic stage to a mesophilic stage; performing digestion on at least one portion of the feed stream in the mesophilic stage at a third temperature to form decomposed solids in solution; separating at least one portion of the decomposed solids in solution from the mesophilic stage to form at least one product including a second liquid fertilizer; using an eductor tube to lift a gas that includes carbon dioxide produced in the acidogenesis stage or to lift a gas that includes at least one first biogas produced in the thermophilic stage; compressing the gas; recirculating the gas into the acidogenesis stage or thermophilic stage to mix the contents; measuring chemical oxygen demand levels in the thermophilic stage; and injecting dissolved air to raise dissolved oxygen in response to a high chemical oxygen demand measurement so that the chemical oxygen demand in the thermophilic stage is lowered. The separating step includes a dewatering stage that uses at least one belt press, a cyclone separator, a screw press, or an evaporator. The methods preferably involve providing a biomass as a feed stream; aerobically hydrolyzing the feed stream in a hydrolysis stage to form volatile solids in solution comprised of simplified biomolecules to generate a hydrolyzed feed stream; transferring at least one portion of hydrolyzed feed stream to an acidifying stage; performing acidogenesis on at least one portion of the received feed stream at a first temperature to form acidified solids comprising long chain fatty acids to generate an acidogenisis feed stream; transferring at least one portion of the acidogenisis feed stream to a first thermophilic stage; performing anaerobic digestion on at least one portion of the acidogenisis feed stream in the first thermophilic stage at a second temperature to form methane and carbon dioxide, and a first thermophilic feed stream that includes acetic acid and decomposed solids; transferring at least one portion of the first thermophilic feed stream from the first thermophilic stage to a second thermophilic stage; performing anaerobic digestion on at least one portion of the first thermophilic feed stream in the second thermophilic stage to form acetic acid and hydrogen; receiving at least one portion of a feed stream generated in the second thermophilic stage to a mesophilic stage; performing anaerobic digestion on at least one portion of the received feed stream in the mesophilic stage, where the pH in the mesophilic stage is 6.8-7.2, performing anaerobic digestion by forming acetic acid and methane (where the second temperature is 130-135 degrees F, and the second thermophilic stage is provided at a temperature of 135-158 degrees F); producing a biogas in the first thermophilic stage; transferring at least one portion of the biogas to a drying stage; drying the transferred biogas; transferring the dried biogas to a gas stripper; stripping the biogas to produce methane; transferring methane to the second thermophilic reactor via a pipeline, and providing in the feed stream when between the acidifying stage and the first thermophilic stage a solution to quickly adjust pH of the feed stream; or involves providing a biomass as a feed stream; aerobically hydrolyzing at least one portion of the feed stream in a hydrolysis stage to form volatile solids in solution comprised of simplified biomolecules; transferring at least one portion of the feed stream after hydrolysis to an acidifying stage; performing acidogenesis on at least one portion of the feed stream at a first temperature to form acidified solids comprising long chain fatty acids and at least a first biogas that includes carbon dioxide; transferring at least one portion of the feed stream after acidogenesis to a first thermophilic stage; performing anaerobic digestion on at least one portion of the feed stream in the first thermophilic stage at a second temperature to form acetic acid, decomposed solids and at least one second biogas that includes methane and carbon dioxide; removing at least one portion of the second biogas from the first thermophilic stage for further use; transferring at least one portion of the feed stream from the first thermophilic stage to a second thermophilic stage; performing anaerobic digestion on at least one portion of the feed stream in the second thermophilic stage to form acetic acid, decomposed solids, and at least a third biogas that includes hydrogen; removing third biogas from the second thermophilic stage for further use; lowering temperature of post second thermophilic stage products in solution to a third temperature; transferring the post thermophilic stage products in solution to a mesophilic stage; performing anaerobic digestion on the post thermophilic stage products in solution generating effluent and a fourth biogas; transferring the effluent to a dewatering stage; separating liquid from solids in the dewatering stage to form at least one product selected from liquid fertilizer, a pathogen-reduced liquid fertilizer, a biosolid, a Class A biosolid, and a biosupplement; removing the first biogas and optionally compressing the first biogas; recirculating the first biogas into the acidogenesis stage; recirculating at least one portion of the second biogas into the first thermophilic stage; compressing the second biogas after removal; recirculating at least one portion of second biogas into the first thermophilic stage; diverting a portion of compressed biogas; introducing the diverted biogas into the second thermophilic stage; measuring chemical oxygen demand levels in at least one of the first thermophilic and second thermophilic stages; injecting dissolved air to raise dissolved oxygen in response to a high chemical oxygen demand measurement in at least one of the thermophilic stages to lower the measured chemical oxygen demand (where steps of removing include using a gas lifting mixing device); purifying portion of any of the second biogas, third biogas and fourth biogas by at least one vessel comprising at least one zeolite. The pH in the first thermophilic stage is 6.8-7 (preferably 6.8), in the second thermophilic stage is 6.4-7 (preferably 6.4), and in the hydrolysis/acidifying stage is 5.8-6.2, and the temperature in the hydrolysis stage is up to 85 degrees F. The transferring of the feed stream involves adjusting the temperature of the feed stream. In the method (B1), the pH is adjusted through at least one feed stream at a location of first and second digestion systems, and between the acidogenesis stage and at least one methanogenesis stage; and the step of removing includes removing biogas from a thermophilic phase vessel or mesophilic phase vessel in the first digestion system via a pipeline and transferring the biogas for filtering to produce methane. The adjusted percent total solid suspension in the first feed stream is 2-15%, and the adjusted percent total solid suspension in the second feed stream is less than 4%. The method B1 further involves introducing methanol into at least one anaerobic methanogenesis stage; and diverting a portion of a feed stream after at least one anaerobic methanogenesis stage from the first digestion system to the at least one methanogenesis stage in the second digestion system. The unit for treating includes passing the gas through a first zeolite to remove hydrogen sulfide, and subsequently passing the gas through a second zeolite to remove carbon dioxide; or passing the gas through a zeolite to remove carbon dioxide, and subsequently passing the gas through an activated carbon source. The methods further involve introducing methanol at a location to affect at least the first thermophilic stage or the second thermophilic stage. Preferred System: A system (S1) comprises a separate vessel for each of an aerobic hydrolysis stage, an anaerobic acidogenesis stage and at least one anaerobic methanogenesis stage; unit for moving a feed stream between each of the separate vessels; unit for adjusting pH of at least one location in the system; unit for modifying temperature of at least one location in the system; unitfor mixing contents in at least two of the separate vessels; unit for adjusting biologic oxygen demand in at least one of the separate vessels; unit for removing at least one portion of a gas produced in at least one of the separate vessel; unit for recirculating at least one portion of gas produced in at least one of the separate vessel; unit for introducing a gas into the system; unit for diverting at least one portion of the feed stream exiting at least one of the separate vessel for the methanogenesis stage to a dewatering system; unit for separating solids from liquid in the feed stream to produce any one of a pathogen reduced liquid fertilizer, Class A biosolids and biosupplements; and a unit for treating at least one portion of the gas removed from the separate vessel. A system (S2) comprises a biomass provided as a feed stream; a first pipeline for transferring at least one portion of the biomass to a first vessel for receiving the biomass and for performing hydrolysis; a second pipeline for transferring at least one portion of the biomass from the first vessel to a second vessel for receiving the biomass and for performing acidogenesis; a third pipeline for transferring the biomass from the second vessel to a third vessel; a pH adjustment system for adjusting pH of the third pipeline; a first heat exchanger for adjusting temperature of the third pipeline third vessel for receiving the biomass and for performing a first methanogenesis; a first diversion system in cooperation with the third vessel for diverting at least one portion of first biogas produced in the third vessel; a recirculating system for recirculating at least one portion of first biogas into the third vessel; a second diversion system in cooperation with the third vessel for diverting at least one portion of first decomposed solid produced in the third vessel; a fourth pipeline for transferring at least one portion of the biomass from the third vessel to a fourth vessel for receiving the biomass and for performing a second methanogenesis; a third diversion system in cooperation with the fourth vessel for diverting at least one portion of a second biogas produced in the fourth vessel; a recirculating system for recirculating at least one portion of second biogas into the fourth vessel; a fourth diversion system in cooperation with the fourth vessel for diverting at least one portion of a second decomposed solids produced in the fourth vessel; at least one separation system for receiving decomposed solids in solution selected from first decomposed solids, and/or second decomposed solids, and for separating liquid from the received decomposed solids; and at least one treating system for receiving gas selected from first biogas, and/or second biogas, and for purifying the gas. At least one of the vessels has an inner bottom surface that slopes to a center. The system (A2) further comprises an eductor tube in at least one of the vessel; a recirculating system in at least one of the vessel; at least one anaerobic mesophilic stage vessel for receiving at least one portion of the feed stream that has been anaerobically converted in the anaerobic thermophilic stage vessel, and anaerobically converting at least one portion of the received feed stream to acetic acid, and a second biogas; a dissolved air system operable to inject dissolved oxygen into the system to decrease the chemical oxygen demand in at least one of the at least one anaerobic thermophilic phase vessel and at least one of the anaerobic mesophilic phase vessel; at least one anaerobic mesophilic stage vessel for receiving at least one portion of the feed stream from at least one thermophilic stage vessel, and anaerobically generating at least a second biogas; a second gas lifter for removing at least one biogas from the anaerobic mesophilic stage vessel; and a diversion system operable for diverting a portion of the feed stream exiting at least one anaerobic mesophilic stage vessel to a dewatering system, where the dewatering system separates solids from liquid in the received feed stream to produce a product that includes at least one product selected from a liquid fertilizer, a pathogen-reduced liquid fertilizer, biosolids, Class A biosolids, and biosupplements. The pH adjustment system is operable to adjust the pH of the feed stream in at least one location that includes the feed stream before entering the anaerobic thermophilic stage vessel, the feed stream in the anaerobic thermophilic stage vessel, and the feed stream after leaving the anaerobic thermophilic stage vessel. The heat exchanger is operable to adjust the temperature of the feed stream in at least one location that includes the feed stream before entering the at least one anaerobic thermophilic stage vessel, feed stream in the at least one anaerobic thermophilic stage vessel, and the feed stream after leaving the at least one anaerobic thermophilic stage vessel. The pH adjustment system operates in parallel with at least one heat exchanger, and the adjustment system and the heat exchanger are operable to access at least one point in the system located at or between the vessels. The unit for moving a feed stream includes at least one pump, piping, valve, channel, and/or weir. The unit for modifying temperature includes at least one heating element, heating pad, internal heat source, and/or heat exchanger. The unit for mixing includes at least one pump, a jet, a diffuser, a gas lifting device, a mechanical mixing device, or hydraulic mixing device. The unit for adjusting biologic oxygen demand includes at least one dissolved oxygen adjustment system, recirculation pump, suction line, venturi type assembly, diffuser, and/or discharge line. The unit for removing at least one portion of gas includes piping with at least one control valves routed to at least one compressor or pump. The unit for recirculating at least one portion of gas includes piping with at least one control valves routed to at least one recirculation compressor or a pump. The unit for introducing a gas includes at least one injection line with at least one control valves and at least one pump or a compressor. The unit for diverting at least one portion of the feed stream exiting any one of the separate vessels includes at least one pipeline and control valves, and at least one pump or a compressor. The unit for separating solids from liquid in the feed stream includes a dewatering system selected from a belt press, a cyclone separator, a screw press, and an evaporator. The unit for treating at least one portion of the gas includes at least one filter, stripping vessel, zeolite, an activated carbon source, and a column elution using a resin. The system (A2) further comprises at least one eductor tube in at least one of the vessel; at least one gas lift mixing device in cooperation with at least one educator tube; at least one gas inlet opening in at least one of the vessels; and at least one gas lift mixing device providing gas via the gas inlet; an accumulator plate disposed in at least one of the vessel. The system preferably comprises at least one hydrolysis stage vessel for receiving a feed stream comprising a biomass; at least one anaerobic acidic stage vessel for receiving a feed stream from the hydrolysis stage vessel, and generating an acidified feed stream; at least one pH adjustment system for modifying pH of at least one location of the system; at least one heat exchanger for modifying temperature of at least one location in the system; at least one anaerobic thermophilic stage vessel for receiving the previously formed acidified feed stream and generating at least a first biogas; at least one anaerobic mesophilic stage vessel for receiving a feed stream from the at least one thermophilic stage vessel and generating at least a second biogas; a diversion system operable for diverting a portion of the feed stream exiting the mesophilic stage vessel to a dewatering system; or comprises at least one hydrolysis stage vessel for receiving a feed stream comprising a biomass; at least one acidic stage vessel for receiving at least one portion of a feed stream from the hydrolysis stage vessel, and for producing an acidified feed stream; at least one pH adjustment system for modifying pH of at least one location in the system; at least one heat exchanger for modifying temperature of at least one point in the system; a first anaerobic thermophilic stage vessel for receiving at least one portion of the previously formed acidified feed stream; a second anaerobic thermophilic stage vessel for receiving at least one portion of a feed stream from the first thermophilic stage vessel; at least one anaerobic mesophilic stage vessel for receiving at least one portion of a feed stream from the first thermophilic stage vessel and the second thermophilic stage vessel; at least one diversion system operable for diverting a portion of the feed stream exiting at least one of first thermophilic stage vessel, the second thermophilic stage vessel or mesophilic stage vessel to a dewatering system; and further comprises at least one gas lifter for removing a biogas from at least one of first thermophilic stage vessel, second thermophilic stage vessel, or mesophilic stage vessel; and at least one treating system operable to filter the biogas removed from at least one of first thermophilic stage vessel, second thermophilic stage vessel, or the mesophilic stage vessel. The system (A2) further comprises a methanol injection system operable to introduce methanol into the thermophilic stage vessel. The system (S1) further comprises unit to recycle water from a liquid effluent separated in the units for separating solids from liquid in the feed stream. EXAMPLE - No suitable example given.