NOVELTY - The system comprises stages for removing phosphorus from wastewater effluent from an anaerobic digestion stage, a stage for removing ammonia from the wastewater effluent from the anaerobic digestion stage, and a pH readjustment stage (36), where the effluent from the ammonia removal stage is combined with raw biogas (12) from the anaerobic digestion stage. The ammonia removal stage produces an effluent having a pH of 9-12. One of carbon dioxide and hydrogen sulfide in the raw biogas is absorbed by the effluent resulting in lowering a pH of the effluent and production of scrubbed biogas.    USE - The system is useful for processing anaerobic digestion of waste material such as animal waste to recover nitrogen and phosphorus.    ADVANTAGE - The system is capable of effectively and economically processing the byproducts of the anaerobic digestion of the waste material without complexity.    DETAILED DESCRIPTION - The system comprises stages for removing phosphorus from wastewater effluent from an anaerobic digestion stage, a stage for removing ammonia from the wastewater effluent from the anaerobic digestion stage, and a pH readjustment stage (36), where the effluent from the ammonia removal stage is combined with raw biogas (12) from the anaerobic digestion stage. The ammonia removal stage produces an effluent having a pH of 9-12. One of carbon dioxide and hydrogen sulfide in the raw biogas is absorbed by the effluent resulting in lowering a pH of the effluent and production of scrubbed biogas. The phosphorus removal stages are configured to separate phosphorus containing solids from a supernatant, and include a unit for allowing settling of solids and a unit for allowing the addition of flocculants (18), coagulants and chelating agents. The ammonia removal stage includes a closed loop air recirculation system operating in conjunction with packed towers configured for ammonia stripping. The packed towers include trays with guide holes that are configured to direct liquid and air in specified directions. The pH readjustment stage allows for bubbling the raw biogas through the effluent. INDEPENDENT CLAIMS are included for:    (1) an ammonia removal system for processing ammonia laden wastewater from an anaerobic digestion system;    (2) a method of treating animal waste to separate phosphate-containing solids and to produce low-pH ammonia-stripped effluent and scrubbed biogas; and    (3) an integrated closed loop system for treating animal waste.    DESCRIPTION OF DRAWING(S) - The diagram shows a flow chart of an animal waste treatment process.    Raw biogas (12)    Wastewater (14)    Flocculants (18)    Fertilizer (20)    Readjustment stage. (36)