Department of Environmental Science and Engineering, National Pingtung University of Science and Technology, Pingtung, Taiwan.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2013;48(13):1748-56. doi: 10.1080/10934529.2013.815571.
In situ immobilization of heavy metals using reactive or stabilizing materials is a promising solution for soil remediation. Therefore, four agronomic and industrial by-products [wood biochar (WB), crushed oyster shell (OS), blast furnace slag (BFS), and fluidized-bed crystallized calcium (FBCC)] and CaCO3 were added to acidic soil (Cd = 8.71 mg kg(-1)) at the rates of 1%, 2%, and 4% and incubated for 90 d. Chinese cabbage (Brassica chinensis L.) was then planted in the soil to test the Cd uptake. The elevation in soil pH caused by adding the by-products produced a negative charge on the soil surface, which enhanced Cd adsorption. Consequently, the diethylenetriamine pentaacetic acid (DTPA)-extractable Cd content decreased significantly (P < 0.05) in the incubated soil. These results from the sequential extraction procedure indicated that Cd converted from the exchangeable fraction to the carbonate or Fe-Mn oxide fraction. The long-term effectiveness of Cd immobilization caused by applying the 4 by-products was much greater than that caused by applying CaCO3. Plant shoot biomass clearly increased because of the by-product soil amendment. Cd concentration in the shoots was < 10.0 mg kg(-1) following by-product application, as compared to 24 mg kg(-1) for plants growing in unamended soil.
利用反应性或稳定化材料原位固定重金属是一种很有前途的土壤修复解决方案。因此，将四种农业和工业副产品[木屑生物炭 (WB)、碎牡蛎壳 (OS)、高炉渣 (BFS) 和流化床结晶碳酸钙 (FBCC)]和 CaCO3 以 1%、2%和 4%的比例添加到酸性土壤（Cd = 8.71 mg kg(-1)) 中，并孵育 90 天。然后在土壤中种植白菜（ Brassica chinensis L.），以测试 Cd 的吸收情况。添加副产品导致土壤 pH 值升高，在土壤表面产生负电荷，从而增强了 Cd 的吸附。因此，DTPA 可提取的 Cd 含量在孵育土壤中显著降低（P < 0.05）。连续提取程序的这些结果表明，Cd 从可交换态转化为碳酸盐或铁锰氧化物态。与施用 CaCO3 相比，施用 4 种副产品对 Cd 固定的长期效果要大得多。由于添加了副产品，植物地上生物量明显增加。与未添加土壤的植物相比，添加副产品后，植物地上部 Cd 浓度<10.0 mg kg(-1)，而未添加土壤的植物地上部 Cd 浓度为 24 mg kg(-1)。
