Produced Water Treatment

We would like to know what is available on the market for Produced Water Treatment in onshore scenarios where you do not have dead wells/reservoirs to inject the produced water into. 

We currently re-inject produced water but are facing capacity limitation. We are looking for solutions that could treat the water to a level where it could be safe for agricultural use or ultimately drinking water. 

We are aware of some solutions on the market like ones that convert the produced water into ammonia, and others that vaporize the water to the atmosphere and are keen to receive input from the market such that we can assess all available options.