Red Mud, Calcium Carbide Residue Respectively Solidify Lead-contaminated Granite Residual Soil Effect Comparison

The purpose of this study is to investigate the effect of solidifying lead-contaminated granite residual soil with red mud and calcium carbide slag respectively, and to test the unconfined compressive strength, water stability and lead ion leaching concentration of the solidified soil. The solidification effects of red mud and calcium carbide slag were compared and analyzed in order to provide some ways and ideas for the remediation of heavy metal contaminated soil. In the study, we used different amounts of red mud and calcium carbide slag to solidify the granite residual soil contaminated by lead. With the progression of the curing period, the unconfined compressive strength of the stabilized soil was evaluated. The findings indicate that augmenting the quantity of the curing agent markedly enhances the mechanical robustness of the stabilized soil. Although the strengthening effects of red mud and calcium carbide slag are different in different content, both of them can achieve higher strength curing standard in a certain range. among them, the strengthening effect of calcium carbide slag on the strength of solidified soil is particularly significant. Through the water stability test, it is found that the calcium carbide slag solidified soil can still maintain good stability under the action of soaking, while the red mud solidified soil disintegrates under the same conditions, indicating that the solidification treatment of calcium carbide slag can effectively improve the water erosion resistance of the soil. In addition, we also measured the leaching concentration of lead ions in the solidified soil. The results show that the leaching concentration of lead ion decreases with the increase of curing agent content. Both red mud and calcium carbide slag show good performance in lead ion solidification, but red mud is more outstanding in reducing the leaching concentration of lead ion. To sum up, through the comparative analysis of the curing effect of red mud and calcium carbide slag on lead-contaminated granite residual soil, it is found that both can effectively improve the unconfined compressive strength of the solidified soil and significantly reduce the leaching concentration of lead ions. Calcium carbide slag performs better in water stability and red mud performs better in reducing the leaching concentration of lead ions. These findings can provide ideas for the comprehensive utilization of industrial wastes and provide practical guidance for the green remediation of heavy metal contaminated soils.