NOVELTY - The system comprises an ammonia removal and recovery process (ARR) subsystem (110), an activated sludge (AS) subsystem (126), a controlled eutrophication process (CEP) subsystem (130), a chemical precipitation subsystem, a post treatment or polishing process subsystem, an anaerobic treatment subsystem, and a biogas addition of carbon dioxide and a biogas cleaning pre-treatment system. The ARR subsystem: is configured to perform ammonia degassing and ammonia recapture processes; and acts to remove and recapture ammonia and to destroy volatile organic compounds.    USE - The system is useful for treating nitrogen-rich wastewater including landfill leachate, municipal solid waste anaerobic digester effluent, agricultural anaerobic digester effluent, municipal wastewaters, agricultural wastewaters, and other contaminated wastewaters, where the digester effluent is useful as a fertilizer for human consumption products such as nutraceuticals, food or other high value products and the leachate is useful for making high value products such as nutraceuticals and pharmaceuticals.    ADVANTAGE - The system ensures efficient, economical and easy treatment of the nitrogen-rich wastewater without salts and environmental pollution.    DETAILED DESCRIPTION - The system comprises an ammonia removal and recovery process (ARR) subsystem (110), an activated sludge (AS) subsystem (126), a controlled eutrophication process (CEP) subsystem (130), a chemical precipitation subsystem, a post treatment or polishing process subsystem, an anaerobic treatment subsystem, and a biogas addition of carbon dioxide and a biogas cleaning pre-treatment system. The ARR subsystem: is configured to perform ammonia degassing and ammonia recapture processes; acts to remove and recapture ammonia and to destroy volatile organic compounds; functions to recycle air internal to the ARR subsystem; facilitates base degassing and acid recapture; acts to conserve heat, to minimize the amount of exiting air flow that requires incineration and to produce an ammonium sulfate fertilizer by-product; and reuses and recycles heat and carbon dioxide given off by biogas flares and biogas incineration emissions. The AS subsystem is configured to perform bacterial treatment process, and acts to remove biodegradable organics and lowers biological oxygen demand (BOD) to allow increased algae culturing in the CEP subsystem. The CEP subsystem: is configured to perform an algae-based water treatment process; acts to remove recalcitrant organic compounds; improves UV transmissivity and UV disinfection; and includes algal growth reactors operated for a function of a mass removal CEP, maximizing algal productivity, algae harvest, a function of a polisher CEP and minimizing effluent concentration of nutrients and other pollutants. The post treatment or polishing process subsystem includes a microfiltration membrane filter, reverse osmosis and ozone oxidation sub-system. The anaerobic treatment subsystem comprises an anaerobic digester (141). The biogas addition of carbon dioxide and a biogas cleaning pre-treatment system is configured for biogas cleaning/scrubbing process using ARR liquid effluent resulting in a removal of hydrogen sulfide and carbon dioxide from the biogas, a pH neutralization of the ARR liquid effluent and the reuse of this carbon dioxide by the CEP algae. An INDEPENDENT CLAIM is included for a method for treating nitrogen-rich wastewater.    DESCRIPTION OF DRAWING(S) - The diagram a schematic view of a process for treating nitrogen-rich wastewater.    ARR subsystem (110)    Pretreated leachate (125)    Activated sludge subsystem (126)    CEP subsystem (130)    Anaerobic digester. (141)