Lead Contaminated Soil Characterization and Remediation Technologies Assessment

• Main Authors: Min-siou Lin, 林旻秀
• Other Authors: Shu-Fen Cheng
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/36259341612974412982

碩士 === 朝陽科技大學 === 環境工程與管理系碩士班 === 100 === Lead is the common pollutant in soil, which is mainly from the lead accumulator manufacturing, smelting, cartridge and metal casting procedures. Characteristics of soil polluted by different pollution sources and lead compounds may vary. This study conducted an analysis on the soil characteristics and lead bonding states of soil polluted by different pollution sources. The results showed that, the exchangeable was negatively correlated with pH (r = -0.580, P < 0.01), carbonate bound was negatively correlated with organic matter (r = -0.328, P < 0.01), and Fe-Mn oxides bound (r = 0.450, P < 0.01) and residual (r = 0.637, P < 0.01) were positively correlated with CEC. Factors affecting the lead speciation state included pH, CEC, and organic matter. The second part of this study focused on two remediation technologies, which are soil washing and phytoremediation in lead-polluted soil. HCl, HNO3, AlCl3, FeCl3, CaCl2, MgCl2, and EDTA-4Na were used as the cleaning agent for soil washing to discuss on the removal effect of the 7 cleaning agent on the lead content and bonding states in soil. Phytoremediation site was a lead-polluted place. Absorption accumulation ability of native plant at site on lead was analyzed, and Bidens pilosa, Amaranthus viridis as well as Helianthus annuus were treated as the plant for phytoremediation to discuss their absorption accumulation ability of lead in soil. The results of soil washing showed that, for the soil with lead under carbonate bound and Fe-Mn oxides bound, HCl and HNO3 were able to remove the lead for 70% or above. For the soil with lead under exchangeable, HCl and HNO3 were able to remove the lead for 80% or above. With regard to the ability to remove all the speciation, the removal ability of HCl and HNO3 on carbonate bound and Fe-Mn oxides bound was 80% or above; that of AlCl3 and FeCl3 on carbonate bound was 66~96%; that of EDTA-4Na on exchangeable and carbonate bound was 70% or above and on Fe-Mn oxides bound was 58~96%. The results on phytoremediation showed that, the absorption volume of the aboveground part of native plant, such as Ludwigia octovalvis, Bidens pilosa, Eleusine indica, Physalis angulata L., Solanum nigrum L., Sphenoclea zeylanica Gaertn, Amaranthus viridis, at site on the lead was 100 mg kg-1 or above. The aboveground part of Bidens pilosa had the highest absorption volume on lead, and was able to transfer the lead from the underground part to the aboveground part. The plant had a high survival rate, which was easy to be planted and had the potential to be the plant for phytoremediation.