Composite membrane based systems

Ammonium is used in the production of fertilizers and feed, plastics, fibers, paper, explosives, and rubber; as a coolant in metalworking; and in the preparation of nitrogenous compounds. Ammonium salts are used as detergents, sanitizers, and food additives, and ammonium chloride is used as a diuretic. The ammonium ion (NH4+) is derived mainly from human or animal excrement, and its presence in water, especially in groundwater, is in some cases due to geological causes such as the degradation of fossil material (such as plant remains and peat deposits). The excessive amount of ammonium in waterways has led to a severe shortage of drinking water worldwide. Traditionally, there have been various methods for ammonium removal but with many drawbacks. The use of membrane technology, with a focus on adsorbent membranes, is considered the most viable to address the current challenges for potable water production due to its outstanding performance attributable to the hybrid process (adsorption and filtration approaches) and because it produces no harmful by-products. Biological processes that can be used to remove ammonium from water by oxidizing it to N2 are energy intensive and have difficulty achieving concentrations below 1 mg/L as expected. In recovering ammonium, the goal is to recover and transform it into other compounds and fertilizers from waste materials, thus significantly reducing the dependence on the Haber–Bosch process for obtaining ammonia and urea, which uses every 1%–2% of world energy supply per year. In the contemporary context of water and environmental emergency the recovery of ammonium from water becomes a dual objective of protecting human health and the environment.