Bose Sutapa, Bhattacharyya A K
School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067, India.
Chemosphere. 2008 Jan;70(7):1264-72. doi: 10.1016/j.chemosphere.2007.07.062. Epub 2007 Sep 6.
The concentrations of different forms of Zn, Cu, Mn, Ni, Cd, Cr, Pb and Fe metals were determined for the roadside sludge collected from pickling-rolling and electroplating industrial area. In sludge the relative abundance of total heavy metals were Fe>Mn>Cr>Ni>Cu>Pb>Zn>Cd and DTPA-extractable metals were in the order--Fe>Ni>Mn>Cr>Cu>Zn>Pb>Cd. Pot-culture experiment was conducted in soils amended with sludge (0%, 10%, 20%, 30%), pretreated with lime (0%, 0.5% and 1%). The soils were alkaline in nature (pH>8.3) with organic carbon contents were 0.34% and 0.72%. The most abundant total and bio-available metal was Fe. Two wheat seedlings were grown in each pot containing 3kg sludge-amended or control soil and the experiment was conducted till harvesting. Application of sludge increased both total and bio-available forms of metals in the soils, while lime application decreased the bioavailability of heavy metals in sludge-amended soils. The content of organic carbon showed positive correlation with all metals except Zn, Cr and Pb. CEC also showed a strong positive correlation (R2>0.7) with Fe, Mn, Cu, Ni and Cd. Though wheat plants are not accumulators, the translocation efficiency was appreciably high. The translocation factor from shoot to grain was found smaller than that of root to shoot of wheat plants. This makes an implication that the heavy metal accumulation was proportionally lesser in grain than in shoot. In, 10% sludge with 0.5% lime-amended soils; each of these toxic heavy metals was found to be within permissible range (USEPA). Hence, on the basis of present study, the best possible treatment may be recommended.
测定了从酸洗-轧制和电镀工业区采集的路边污泥中不同形态的锌、铜、锰、镍、镉、铬、铅和铁金属的浓度。污泥中总重金属的相对丰度为铁>锰>铬>镍>铜>铅>锌>镉，二乙三胺五乙酸（DTPA）可提取金属的顺序为铁>镍>锰>铬>铜>锌>铅>镉。在添加了污泥（0%、10%、20%、30%）并经石灰预处理（0%、0.5%和1%）的土壤中进行了盆栽试验。土壤呈碱性（pH>8.3），有机碳含量分别为0.34%和0.72%。含量最丰富的总金属和生物可利用金属是铁。每个装有3千克添加污泥或对照土壤的花盆中种植两株小麦幼苗，试验持续到收获。污泥的施用增加了土壤中金属的总量和生物可利用形态，而石灰的施用降低了添加污泥土壤中重金属的生物有效性。有机碳含量与除锌、铬和铅之外的所有金属呈正相关。阳离子交换量（CEC）也与铁、锰、铜、镍和镉呈强正相关（R2>0.7）。虽然小麦植株不是重金属富集植物，但其转运效率相当高。发现小麦植株从地上部到籽粒的转运系数小于从根部到地上部的转运系数。这意味着籽粒中重金属的积累比例低于地上部。在添加10%污泥和0.5%石灰的土壤中，发现这些有毒重金属中的每一种都在允许范围内（美国环境保护局标准）。因此，基于本研究，可推荐最佳可行的处理方法。
