Scavenging of Nitrate ions in Sandy Soil Using Mg/Al layered double hydroxide Nano plates for Reducing Leaching

Applying chemical fertilizers such as nitrogen fertilizers, leads to enhancing nitrateconcentration over acceptable limit in water sources and their pollution. With respect tohealth, environmental and economical fields, nitrate leaching is an important issue. Thepurpose of this research was to synthesize and characterize Mg-Al-LDH chloride nano platesand their application for reducing nitrate leaching from soil in saturated condition. Mg-AlLDH was synthesized hydrothermally and then characterized using XRD, TEM, SEM, FeSEM. Microscopic images of synthesized nano plates using electron microscopes SEM Feand SEM indicated that the dimensions of nano plates was at nanometer scale, so that theirmean diameter was about 20 nm. High magnification of LDH is representative of its flakeyshape. XRD pattern shows LDH with sharp and asymmetric reflections. In order to study theability of LDH to adsorb and retain nitrate ion in laboratory condition and in saturated soil, anexperiment with four treatments were designed; one of them was related to control (withoutLDH) and other three treatments had 2, 4, 8 g LDH/kg soil, respectively. This research wasperformed in triplicates using complete randomized block design. Applying 2, 4, 8 g LDH perkg soil leads to 43.92, 63.27, and 80.06 percent reduction in nitrate leaching, respectively.Applying 2, 4, 8 g LDH per kg soil causes 17.79, 38.13, and 44.56 percent reduction inaverage velocity of water in soil. It is proposed to study the effects of LDHs on nitrateleaching in clayey soils and loamy soils. It is also suggested to use LDH for removing otheranions such as carbonates and phosphates from soil and study their efficiency.

Keywords:

nitrate , layered double hydroxide (LDH) , leaching , nanoplates , hydrothermal