Data for "In-Situ Formation of CaAl-Layered Double Hydroxides with Attapulgite for Synergistic Remediation of Soda Saline-Alkali Soil"

Soda saline-alkali soils pose a severe threat to agricultural productivity due to high pH, elevated carbonate concentration, and poor soil structure. However, achieving rapid alkalinity reduction and long-term stability of immobilized salts remains a significant challenge in remediation research. This study developed a novel composite amendment comprising calcium sulfate, aluminum sulfate, and attapulgite clay (ATP) to induce the in-situ formation of CaAl-layered double hydroxide (CaAl-LDHs) for the efficient remediation of soda saline-alkali soils. Through a 150-day mineralization experiment, the amendment rapidly triggered the formation of crystalline CaAl-LDHs, confirmed by XRD, SEM, TEM, FTIR, and XPS analyses. This process effectively immobilized free CO32− and OH− into the LDHs interlayers, resulting in a significant reduction in soil pH from 10.6 to 7.9 and carbonate concentration by 83%. The treatment also reduced exchangeable Na⁺ by 76% and decreased water-soluble Ca2+, Mg2+, Al3+, and Fe3+ concentrations.