Electrodialysis stacks, systems, and methods for recovering ammonia and monovalent salts from anaerobic digestate

摘要

Electrodialysis stacks comprising a series of electrodialysis cells and anaerobic digestion systems incorporating the electrodialysis stacks are provided. Also provided are methods of using the electrodialysis stacks and systems to recover nitrogen, in the form of ammonia, from separated anaerobic digestate. The electrodialysis stacks use monovalent-selective cation exchange membranes to concentrate ammonium ions and other monovalent ions in a concentrate stream, while discriminating against multivalent cations, which, as a result, are retained in a diluate stream. The electrodialysis stacks may use monovalent-selective anion exchange membranes to discriminate against multivalent anions, which, as a result, are selectively retained in a diluate stream.