Partial desalination of saline irrigation water using [FeO(OH)(HO))]

Arable crop yields decrease with increased irrigation water salinity. The low wholesale value ($/m) of most crops coupled with a relatively high irrigation water demand (m/ha) ensures that desalination, or partially desalination, of saline irrigation water is not economically viable in most locations unless the partially desalinated water can be delivered to the field for an incremental processing cost of less than about $0.2/m. Decreases in irrigation water salinity by 20-50% can (depending on crop variety, location, and initial water salinity) have the potential to substantially increase crop yields (e.g., by 20% to more than 500%). Air stable, metal complexes ([FeO(OH)(H2O))]) form an inexpensive, reusable, desalination catalyst which can allow batches of irrigation water to be partially desalinated at source for an incremental cost of less than $0.1/m. The small footprint of the reactor units and low capital cost indicates that this technology could provide an economically viable solution for the provision of 1 to 400 m/d of partially desalinated irrigation water.