Food waste concentration system and related processes

A forward osmosis system and process for producing fertilizer and recycling water from a food waste methane digester wastewater stream. The process includes: forming a residual wastewater stream from food waste using digesters; coarse filtering the residual wastewater stream; acid treating the filtered, residual wastewater stream so that ammonium is retained therein; diverting the acid treated, filtered residual wastewater stream to one side of at least one forward osmosis membrane; and concentrating the acid treated, filtered, residual wastewater stream to form fertilizer by contacting a saturated salt brine in a forward osmosis draw loop to an opposite side of the at least one forward osmosis membrane and osmotically pulling water across the at least one forward osmosis membrane from the acid treated, filtered, residual wastewater stream to the saturated salt brine, thereby diluting the saturated salt brine.