The presence of ammonia in wastewater streams is a prevalent problem. Microelectronics chemical, power, municipal and many other industries face increasing regulatory and social pressures to recover water and reduce their environmental impact. As these regulations become more stringent and social pressures mount, manufacturers are looking at innovative ways to treat wastewater streams containing ammonia more efficiently and reduce discharge costs.
Transmembrane Chemisorption (TMCS) with membrane contactors (as shown in Figure 1) is an alternative solution for removing and recovering ammonia from wastewater. In the TMCS process, ammonia is stripped from the wastewater and converted to ammonium salt in a single process step. Depending on operating conditions, this technique can remove up to 95% of the free ammonia.
Other ammonia removal processes may require excessive amounts of thermal energy, or require vast areas of land to maintain viable bio-processes. The ammonium salt product is cleaner, free of heavy metals, and safer to dispose of compared to a concentrated wastewater stream. In many markets, the ammonium salt may even have commercial value to help recoup operating costs.
Membrane contactors are small and compact, so minimal space is required for TMCS systems and since membrane contactors are modular they can be adapted to meet changes in process flows. System installations incorporating membrane contactors can occur rapidly.