ORGANICS AND NUTRIENT RECOVERY FROM ANAEROBIC DIGESTER RESIDUES

摘要

Sludge from an anaerobic digester is treated to recover one or more of fibers, or solids or liquids with a high nutrient content. The solids or liquids can be used as a fertilizer. The fibers can be used in a plant growing medium. Solids are separated from liquids in the sludge and dried. The solids may be dried to produce a flake or pellet. Ammonia in the liquids is recovered and used to produce a concentrated acidic ammonium salt solution. This solution may be mixed with the solids to produce a nitrogen enhanced solid. The fibers and solids or liquids can also be used in combination to produce an enhanced plant growing medium. A device and process for removing ammonia from a liquid can be used in the system or separately.

主权项

1. An apparatus for treating sludge comprising,
(a) one or more of a mechanical dewatering device and a dryer configured to receive the sludge and to output a solids fraction and a liquid fraction; (b) an ammonia recovery system to receive the liquid fraction and output an acidic ammonium salt solution; (c) a pellet making machine to receive the solids fraction and the acidic ammonium salt solution and to combine them into pellets.