NOVELTY - An organic forward osmosis system (1) for concentrating digester biomass intended for Organic Certified fertilizer comprises acid treatment stage having acid treatment operation to form acid treated, digester centrate stream in forward osmosis reject loop and fertilizer stream; and forward osmosis stage coupled to the stage to receive stream and remove water from stream by diverting stream to one side of membrane and contacting opposite side of membrane with salt brine stream in forward osmosis draw loop (80) and osmotically pulling water across membrane from stream to brine stream.    USE - As organic forward osmosis system for concentrating digester biomass intended for Organic Certified fertilizer; for recovering water for re-use; for simultaneously treating digester centrate, recovering digester biomass intended for Organic Certified fertilizer, and augmenting that biomass with phosphorus and nitrogen (claimed); in organic food production and processing operations; in sustainable food process technology; in a variety of other FO/water treatment applications such as osmotic driven water purification and filtration, desalination of sea water, and purification of contaminated aqueous water streams.    ADVANTAGE - The system allows combined and simultaneous treatment of centrate wastewater from anaerobic digestion, reverse osmosis membrane water treatment waste brines and the production of high grade organic fertilizer. The systems embody the use of an acidic pretreatment of anaerobic digester centrate by the addition of phosphoric acid, nitric acid or CO2 with a follow-on use of forward osmosis (FO) with reverse osmosis (RO) for the simultaneous production of organic fertilizer and advanced water treatment. The system harvest pretreatment process sludge as fertilizer with the phosphorus and nitrogen integrated into it. This integration of processes into a single system (the combination of a phosphorus and nitrogen adding centrate pretreatment with FO/RO water production) achieves the nutrient (nitrogen to phosphorus) balancing of fertilizer production from agricultural biomass digesters while simultaneously harvesting potentially potable water grade water from the process. The use of phosphoric acid in organic fertilizer production to separate out the bulk of the useful organic and nitrogen material prior to the membrane based recovery of 50-80% of the digester centrate water for high grade water recycle for processes normally requiring new fresh water at or near drinking water quality is a unique synergy that has not been previously achieved. By integrating the water recovery with the required additions for balancing the fertilizer the water recovery chemical treatment cost and resource use is essentially 100% offset by the production requirements of fertilizer production.    DETAILED DESCRIPTION - An organic forward osmosis system (1) for concentrating digester biomass intended for Organic Certified fertilizer comprises: an acid treatment stage containing an acid treatment operation configured to produce an acid treated, digester centrate stream in a forward osmosis reject loop and a fertilizer stream; and a forward osmosis stage coupled to the acid treatment stage configured to receive the acid treated, digester centrate stream from the acid treatment stage, where the forward osmosis stage comprises a forward osmosis operation configured to remove water from the acid treated, digester centrate stream by: diverting the acid treated, digester centrate stream to one side of at least one forward osmosis membrane; and contacting an opposite side of the at least one forward osmosis membrane with a salt brine stream in a forward osmosis draw loop (80) and osmotically pulling water across the at least one forward osmosis membrane from the acid treated, digester centrate stream to the salt brine stream using only a concentration gradient and thereby producing a concentrated, acid treated, digester centrate stream and a diluted salt brine stream. The diluted salt brine stream is maintained in the forward osmosis draw loop. The system further comprises a reverse osmosis stage coupled to the forward osmosis stage configured to receive the diluted salt brine stream from the forward osmosis stage, where the reverse osmosis stage comprises a reverse osmosis operation configured to pump under pressure the diluted salt brine stream to at least one reverse osmosis membrane and produce a re-concentrated salt brine stream maintained in the forward osmosis draw loop and a recycled purified water stream for re-use. The acid treatment stage is configured to augment digester biomass with phosphorus and the acid treatment operation comprises using one of Organic Certified phosphoric acid, nitric acid, and CO2 at an Organic Certifiable process pH of 3.5, thereby balancing a P:K:N ratio of the fertilizer stream. The salt brine stream comprises an Organic Certified compatible potash salt. The Organic Certified compatible potash salt comprises one of potassium chloride, potassium carbonate, potassium sulfate, potassium magnesium sulfate, langbeinite, and potassium nitrate. The at least one forward osmosis membrane is one of a semipermeable thin film composite membrane in one of a fiber, plate and frame, and spiral wound membrane configuration, a semipermeable cellulosic membrane in one of a fiber, plate and frame, and/or spiral wound membrane configuration. The at least one forward osmosis membrane comprises forward osmosis membranes that operate in a parallel flow configuration. The system optionally comprises a digester stage containing a digesting operation configured to produce a digester centrate stream from waste.    DESCRIPTION OF DRAWING(S) - The figure shows schematic block diagram of organic forward osmosis system.    Organic forward osmosis system (1)    Standard anaerobic digester system (10)    Settling tank (12)    Water baffles (14)    Variable surface lid (16)    Shaker screen (20)    Air drying bin (30)    Primary separation tank (40)    Microfiltration or ultrafiltration membrane contactor (60)    Forward osmosis loop (70)    Transfer pump (72, 84)    Membrane element (74)    Forward osmosis draw solution loop (80)    Osmotic agent tank (82)