Humic acid coupled with coal gasification slag for enhancing the remediation of Cd-contaminated soil under alternated light/dark cycle

In this study, the synthesis of a coal gasification slag-humic acid (SA) hybrid was purposed for the remediation of cadmium (Cd)-contaminated soil. In order to investigate the effect of SA on the Cd-contaminated soil and plant growth, a series of experiments were carried out under different illumination condition. The results showed that the SA has some the photocatalytic activity, and adding 10 wt% of SA to the soil could obviously improve the soil fertility and decrease the mobility of Cd in the soil under alternated light/dark cycle (12L/12D); the content of the residual fraction in the SA-amended soil reached 69.5%, and the Cd decreasing rates for the leaf, stem, and root of Artemisia ordosica were near 100%, 91.3%, and 75.3%, respectively. Characterizations of amendments suggested that the synergistic effect of precipitation and surface complexation played a major role in the remediation of Cd-contaminated soil.

Automated summary

This study aimed to remediate cadmium (Cd)-contaminated soil using a coal gasification slag-humic acid (SA) hybrid material. The experiments conducted under different illumination conditions showed that adding 10 wt% of SA to the soil can improve soil fertility and reduce the mobility of Cd. The addition of SA also significantly decreased the Cd content in the leaf, stem, and root of the Artemisia ordosica plant.