TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method further comprises providing the acid-treated anaerobic digester wastewater to the evaporation system, and degasifying the acid-treated anaerobic digester wastewater stream prior to and/or intermittently during the vaporization. The bottoms liquid is collected using a collection system. The degasifying step: removes a gas formed by the conversion of ammonia to ammonium; comprises agitating, heating, adding a defoamer, and/or applying a vacuum to the acid-treated anaerobic digester wastewater stream; and is carried out under conditions to prevent foaming of the acid-treated anaerobic digester wastewater stream. The conversion step comprises reacting ammonia with an acid to produce ammonium, where the acid is added following providing the acid-treated anaerobic digester wastewater to the evaporation system. The acid-treated anaerobic digester wastewater stream is acid-treated by addition of an organic acid. In the method, substantially all or all of the ammonia in the bottoms liquid is in the form of ammonium. The pressure during the vaporizing step and/or during degasifying is 10-29 inches mercury (Hg) vacuum, or 15-29 inches Hg vacuum, 20-29 inches Hg vacuum, 25-29 inches Hg vacuum, 26-29 inches Hg vacuum, 27-29 inches Hg vacuum, 28-29 inches Hg vacuum, 25 inches Hg vacuum, 26 inches Hg vacuum, 27 inches Hg vacuum, 28 inches Hg vacuum, or 29 inches Hg vacuum. Preferred Components: The bioreactor wastewater stream is an anaerobic digester wastewater stream. The gas is carbon dioxide. The acid-treated anaerobic digester wastewater stream comprises one or more organic compounds, which comprise one or more byproducts of an anaerobic digestion process. One of the organic compounds is a surfactant. The acid comprises inorganic acid including sulfuric acid, phosphoric acid, citric acid (preferred), nitric acid, hydrochloric acid, and/or acetic acid. The pH of the acid-treated anaerobic digester wastewater stream prior to vaporization is 1-8, 2-8, 3-8, 4-8, 5-7, 6-7, 1, 2, 3, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8. The pH of the acid-treated anaerobic digester wastewater stream is greater than 2, 2-8, 3-8, 4-8, 5-8, 6-8, 2, 3, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8, when the acid is sulfuric acid, nitric acid, phosphoric acid, or hydrochloric acid. The pH of the acid-treated anaerobic digester wastewater stream is greater than 3, 3-8, 4-8, 5-8, 6-8, 3, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8, when the acid is acetic acid or phosphoric acid. The pH of the acid-treated anaerobic digester wastewater stream is greater than 4, 4-8, 5-8, 6-8, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8, when the acid is acetic acid or citric acid. The second concentration is 1.5 times, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, 15 times, 20 times, 30 times, 40 times, 50 times, 60 times, 70 times, 80 times, 90 times, or 100 times greater than the first concentration. The second concentration of ammonia and/or ammonium is greater than 5 wt.%, greater than 6 wt.%, greater than 7 wt.%, greater than 8 wt.%, greater than 9 wt.%, greater than 10 wt.%, greater than 15 wt.%, 5-15 wt.%, or 5-10 wt.%. The second concentration of ammonia and/or ammonium is less than 43%, or 5-43 wt.%, 5-40 wt.%, 5-30 wt.%, 5-20 wt.%, 5-15 wt.%, or 5-10wt.%, when the acid is sulfuric acid. The second concentration of ammonia and/or ammonium is less than 66%, 5-66 wt.%, 5-60 wt.%, 5-50 wt.%, 5-40 wt.%, 5-30 wt.%, 5-20 wt.%, 5-15 wt.%, or 5-10 wt.%, when the acid is nitric acid. The second concentration of ammonia and/or ammonium is less than 59%, 5-59 wt.%, 5-50 wt.%, 5-40 wt.%, 5-30 wt.%, 5-20 wt.%, 5-15 wt.%, or 5-10 wt.%, when the acid is acetic acid. The second concentration of ammonia and/or ammonium is less than 17%, 5-17 wt.%, 5-15 wt.%, or 5-10 wt.%, when the acid is phosphoric acid. The second concentration of ammonia and/or ammonium is less than 27%, 5-27 wt.%, 5-20 wt.%, 5-15 wt.%, or 5-10 wt.%, when the acid is hydrochloric acid. The second concentration of ammonia and/or ammonium is less than 40%, 5-22 wt.%, 5-40 wt.%, 5-30 wt.%, 5-20 wt.%, 5-15 wt.%, or 5-10 wt.%, when the acid is citric acid.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The evaporation system comprises a container, a spray nozzle, and a baffle positioned in the container above the spray nozzle. The evaporation system is a flash evaporation system. ACTIVITY - Fertilizer.    MECHANISM OF ACTION - None given.