Remediation of Cd(II)-Contaminated Acid Soil Using an Activated Carbon Nanocomposite from Solid Organic Waste

A new composite nanomaterial was synthesized and used to remediate acidic soil contaminated with heavy metal ions. The novel material, named as acidic soil remediation agent (ASRA), was prepared by combining humus (HS), attapulgite (ATP) and hydrated calcium silicate (CSH) in a facile way. ASRA demonstrated the ability to form a dispersed layered porous structure and showed excellent Cd(II) removal efficiency (about 73.53% for 1 day and 92.81% for 5 days), in addition to immobilizing Pb2+ and Cu2+ effectively. Furthermore, the application of ASRA effectively decreased K+ loss by approximately 46.79%, raised the soil pH from 5.38 to 7.37, and achieved the immobilization and passivation of Cd(II) ions through synergistic interactions among the components of ASRA. This work provided an economic strategy for fabricating efficient soil remediation materials and also solved the environmental pollution problems posed by industrial and agricultural wastes, exhibiting great promise in the utilization of solid wastes to address soil and water heavy-metal contaminants.