Desalination of groundwater and impoundments using Nano-Zero Valent Iron, n-Fe°

Salinization of groundwater is a major problem, particularly in areas with limited infrastructure. 14 diffusion reactors are operated diabatically at -8°C to 20°C to determine the amount of NaCl removed by n-Fe°. The reactors establish NaCl removal by Fe°: (i) 44,000-77,000 nm particle size (PS) = 0.0675-0.1925 g L-1 [feed water (FW) = 0.89 g L-1]; (ii) 50 nm PS = 0.953-1.14 g L-1 [FW = 1.095-1.19 g L-1]; (iii) 50 nm PS under nitrogen saturation (0.1-0.2 MPa) = 9.693 g L-1 [FW = 10 g L-1]; (iv) <0.01 g 50 nm PS L-1 under nitrogen saturation (0.1-0.2 MPa) = 1.564 g L-1 [FW = 4 g L-1]; (v) 50 nm PS modified by nitrogen saturation (PSN) = 5.52 g L-1 [FW = 6.89 g L-1]. Desalination commences at a time, t, after the n-Fe° is added to the water, and continues with an exponential decline until a base (equilibrium) salinity is reached. The effectiveness of n-Fe° as a desalination agent appears to increase with increased water salinity. Placement of PSN in an existing impoundment, or aquifer, may provide a cost effective, zero energy, partial desalination solution, which can be used to support emergency relief, agriculture and extractive industries.