Assessment the impact of palygorskite modified by chlorides on speciation and environmental risk of heavy metals in soil contaminated.

This study aims to evaluate the effectiveness of palygorskite (PAL) modified with various chlorides (PMNaCl), (PMCaCl), (PMMgCl), (PMFeCl) and (PMAlCl) in stabilizing Cu and Ni in contaminated soils. Characterization methods involving Scanning Electron Microscopy (SEM), X-ray deflection (XRD and Fourier Transform Infrared Spectroscopy (FT-IR) were used to characterize the effects of palygorskite on the chemical functional groups of chloride stick and the construction of stabilizers. The Diethylene Triamine Pentaacetic Acid ("DTPA extraction") and Toxicity Characteristic Leaching Procedure (TCLP) were conducted to assess the bioavailability and mobility of Cu and Ni in soil with PAL-modified chlorides. The germinated index (GI) was employed to examine and analyze the microstructure and physico-chemical properties of the contaminated soil. The residue speciation concentration enhanced substantially, illustrating that the heavy metal speciation had stabilized after being with PAL-modified chloride. After the amendment of the PAL-modified chlorides the soil pH was enhanced by 1.33 units, whereas Electrical Conductivity (EC) increased significantly (P < 0.05) from 2.61 to 4.95 µS cm, Cation Exchange Capacity (CEC) increased significantly (P < 0.05) from 11.50 to 13.00 cmol/kg, while the available potassium (K) was significantly (P < 0.05) increased from 51.67 to 69.30, and the available phosphate (P) was significantly (P < 0.05) increased from 0.38 to 0.63. The most significant Sequential Extraction Procedure (BCR) in residual fraction for Cu and Ni in soil treated by PMFC and PMMC were significantly (P < 0.05) increased by 37.37% and 39.33%, respectively. Our findings indicate that PAL-modified chlorides significantly stabilize heavy metals in soil, making them promising candidates for soil remediation.