Processes for manufacturing organic fertilizer products, such as liquid and solid organic fertilizer, from animal manure are disclosed, together with the fertilizer products produced therefrom.

A dewatering screw press has a hopper, a discharge outlet, a cylindrical screen flexibly mounted to the hopper and rigidly connected to the discharge outlet, a screw mounted to rotate beginning in the hopper and ending at the discharge outlet, the screw having an outer surface contacting the cylindrical screen, and at least one vibrator mounted to the cylindrical screen. Dewatering efficiency is improved by vibrations that are strong near the middle of the screen, while reducing or eliminating vibration near the discharge end of the screen where pressure is highest and a breaking of the seal between the screw and the screen due to vibration can reduce dewatering of sludge near the discharge end of the screen.

A biogas collection and purification system that includes a plurality of sources of biogas and a network of conduits configured to convey the biogas from the sources to a central processing facility for processing the biogas into methane. The central processing facility removes impurities to convert biogas to biomethane and may include an H.sub.2S removal stage; an activated carbon scrubber; a gas drier; and a carbon dioxide removal stage. The facility also has a biomethane gas compressor configured to deliver the biomethane for use in power plants, for CNG production. Ancillaries to the system include fuel cells for direct electricity generation from biogas/biomethane.

A biogas collection and purification system that includes a plurality of sources of biogas and a network of conduits configured to convey the biogas from the sources to a central processing facility for processing the biogas into methane. The central processing facility removes impurities to convert biogas to biomethane and may include an H.sub.2S removal stage; an activated carbon scrubber; a gas drier; and a carbon dioxide removal stage. The facility also has a biomethane gas compressor configured to deliver the biomethane for use in power plants, for CNG production. Ancillaries to the system include fuel cells for direct electricity generation from biogas/biomethane.

The present invention provides for nutrient extraction and recovery devices that use the Donnan Membrane Principle (DMP) to cause spontaneous separation of dissolved ions along electrochemical potential gradients, wherein anions and cations such as H.sub.2PO.sub.4.sup.+, HPO.sub.4.sup.2?, PO.sub.4.sup.3?, Mg.sup.2+, Ca.sup.2+, NH.sub.4.sup.+, and K.sup.+ are moved from manure containing waste streams through cation and anion exchange membranes into a recovery stream thereby precipitating target compounds including but not limited to struvite, potassium struvite and hydroxyapatite.

Novel polyanionic polymers including families of repeat units, such as maleic, itaconic, and sulfonate repeat units. The polymers are at least tetrapolymers and may be in the acid form or as partial or complete salts. The polymers may be synthesized using free radical initiators in the presence of vanadium compounds. The polymers have a variety of uses, particularly in agricultural contexts.

Processes for manufacturing organic fertilizer products, such as liquid and solid organic fertilizer, from animal manure are disclosed, together with the fertilizer products produced therefrom.

Processes for manufacturing organic fertilizer products, such as liquid and solid organic fertilizer, from animal manure are disclosed, together with the fertilizer products produced therefrom.

The present invention provides for nutrient extraction and recovery devices that use the Donnan Membrane Principle (DMP) to cause spontaneous separation of dissolved ions along electrochemical potential gradients, wherein anions and cations such as H.sub.2PO.sub.4.sup.?, HPO.sub.4.sup.2?, PO.sub.4.sup.3?, Mg.sup.2+, Ca.sup.2+, NH.sub.4.sup.+, and K.sup.+ are moved from manure containing waste streams through cation and anion exchange membranes into a recovery stream thereby precipitating target compounds including but not limited to struvite, potassium struvite and hydroxyapatite.

The present invention relates to an improved process for downstream processing of liquid waste fraction from mammalian, such as animal, waste. More specifically the present invention provides an improved and simplified method for downstream processing of liquid fractions of animal waste in which the nitrogen content is preserved and for inhibiting urease activity in said liquid.