Ammonium/ammonia removal from a stream

An ammonium removal method, comprising:

• removing a multivalent cation from a stream comprising ammonium to form a treated stream;
• converting the ammonium in the treated stream to amonia by increasing the pH of the stream;
• and
• stripping the ammonia from the treated stream in a vacuum assisted flash stripping tower to form a separated stream and an ammonia stream.

An ammonium removal method, comprising:

• removing a multivalent cation from a stream comprising ammonium to form a treated stream comprising a total of less than or equal to about 3 ppm by weight of multivalent cations;
• increasing the pH of the stream to a pH at which ammonium converts to ammonia;
• converting the ammonium to ammonia;
• and
• separating the ammonia from the treated stream to form a separated stream and gaseous ammonia.

An ammonium removal method, comprising:

• removing solids from a stream comprising ammonium;
• contacting the stream with an ion exchange metal scavenger to remove a multivalent cation from the stream to form a treated stream;
• increasing a pH of the treated stream to greater than or equal to about 9;
• converting the ammonium to ammonia;
• stripping the ammonia from the treated stream to form a separated stream and an ammonia stream;
• and
• reducing the pH of the ammonia stream.

An ammonium removal system, comprising:

• removing a multivalent cation from a stream comprising ammonium to form a treated stream, wherein the multivalent cation comprises an ion of Mg;
• increasing a pH of the treated stream to greater than or equal to about 9, wherein the ammonium in the stream converts to ammonia;
• and
• separating the ammonia from the treated stream to form a separated stream and an ammonia stream.

An ammonium removal system, comprising:

• removing multivalent cations from a stream comprising ammonium to form a treated stream, wherein each multivalent cation in the stream is removed to a level of less than or equal to about 25 ppm by weight, and wherein the multivalent cations comprises an ion of Mg;
• increasing a pH of the treated stream to greater than or equal to about 9, wherein the ammonium in the stream converts to ammonia;
• separating the ammonia from the treated stream to form a separated stream and an ammonia stream;
• and
• reducing a pH of the ammonia stream to less than or equal to about 5.