Evaluation of the Effects of Environmental Materials on Pb and Cd Immobilization

Abstract

Environment materials (humic acid (HA), super absorbent polymers (SAP), fly ash (FM) and zeolite (FS)) were used as amendments to immobilize heavy metal Pb and Cd in artificial contaminated soils. The results showed that soil pH and EC changed after the application of single or combined and co-application amendments. The leaching Pb in the single-Pb contaminated soils amended with HA, FM, C1 (HA, SAP, FM, FS) and C2 (HA, SAP, FM) were 93%, 87%, 59% and 77% of the control without amendments, respectively. The leaching Cd in the single-Cd contaminated soils amended with SAP and C3 (HA, SAP, FS) were 64%, and 83% of the control, respectively, in four-steps leaching. The leaching Pb in the Pb-Cd co-contaminated soil amended with HA, C2 and C3 were 41%, 95% and 77% of the control, respectively. The leaching Cd in the Pb-Cd co-contaminated soil amended with HA, SAP and C3 were 85%, 72% and 55% of the control, respectively. The results indicated that C1 and SAP was the best amendments for single Pb and Cd contaminated soil, respectively. While the combined amendment, HA and C3 could prevent Pb and Cd to be leached from co-contaminated soils, respectively.