Departamento de Ingeniería de Materiales, E.T.S.I. Minas, Universidad Politécnica de Madrid, C/Ríos Rosas No. 21, 28003 Madrid, Spain.
Chemosphere. 2012 Nov;89(11):1354-9. doi: 10.1016/j.chemosphere.2012.05.092. Epub 2012 Jun 23.
Pyrolytic conversion of sewage sludge into biochar could be a sustainable management option for Mediterranean agricultural soils. The aim of this work is to evaluate the effects of biochar from sewage sludge pyrolysis on soil properties; heavy metals solubility and bioavailability in a Mediterranean agricultural soil and compared with those of raw sewage sludge. Biochar (B) was prepared by pyrolysis of selected sewage sludge (SL) at 500°C. The pyrolysis process decreased the plant-available of Cu, Ni, Zn and Pb, the mobile forms of Cu, Ni, Zn, Cd and Pb and also the risk of leaching of Cu, Ni, Zn and Cd. A selected Mediterranean soil was amended with SL and B at two different rates in mass: 4% and 8%. The incubation experiment (200 d) was conducted in order to study carbon mineralization and trace metal solubility and bioavailability of these treatments. Both types of amendments increased soil respiration with respect to the control soil. The increase was lower in the case of B than when SL was directly added. Metals mobility was studied in soil after the incubation and it can be established that the risk of leaching of Cu, Ni and Zn were lower in the soil treated with biochar that in sewage sludge treatment. Biochar amended samples also reduced plant availability of Ni, Zn, Cd and Pb when compared to sewage sludge amended samples.
热解转化污水污泥为生物炭可能是地中海农业土壤的可持续管理选择。本工作的目的是评估热解污水污泥制备的生物炭对土壤性质的影响；与原始污水污泥相比，重金属在土壤中的溶解度和生物有效性。生物炭（B）是通过在 500°C 下热解选定的污水污泥（SL）制备的。热解过程降低了植物可利用的 Cu、Ni、Zn 和 Pb，Cu、Ni、Zn、Cd 和 Pb 的移动形式，以及 Cu、Ni、Zn 和 Cd 的淋溶风险。选择一种地中海土壤，以质量比为 4%和 8%添加 SL 和 B。进行了 200 天的孵育实验，以研究这些处理的碳矿化和痕量金属溶解度和生物有效性。与对照土壤相比，这两种类型的添加物均增加了土壤呼吸。与直接添加 SL 相比，B 的增加较低。在孵育后研究了土壤中金属的迁移性，可以确定在添加生物炭的土壤中，Cu、Ni 和 Zn 的淋溶风险低于添加污水污泥的土壤。与添加污水污泥的样品相比，添加生物炭的样品还降低了 Ni、Zn、Cd 和 Pb 的植物可利用性。
