Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica Nucleare per l'Ambiente, l'Agro-Alimentare ed i Nuovi Materiali (CERMANU), Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy; Dipartimento di Agraria, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy.
Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica Nucleare per l'Ambiente, l'Agro-Alimentare ed i Nuovi Materiali (CERMANU), Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy; Dipartimento di Agraria, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy.
Chemosphere. 2019 Jun;225:150-156. doi: 10.1016/j.chemosphere.2019.03.019. Epub 2019 Mar 5.
Humic Substances (HS) from Leonardite and two different composts were used as biosurfactants to wash heavy metals (Cu, Pb, Zn, Cd, Cr) from a soil added with two metals concentrations and aged for 4 and 12 months. Composts were obtained by mixing manure with either 40 (CM-I) and 20 (CM-II) % of straw as structuring material. For both aging periods and both metal concentrations, HS from CM-I removed more metals than from Leonardite, whereas the washing capacity of HS from CM-II was negligible. C-CPMAS-NMR spectra of HS indicated that while aromatic moieties for CM-I and Leonardite were more abundant than CM-II, HS from CM-I was largest in carboxyl and phenolic carbons. Hence, HS from CM-I had a greater complexing capacity than from both Leonardite and CM-II and effectively displaced heavy metals from soil during the washing treatment. Moreover, the amount of metals removed by solutions of ammonium acetate (AA) and diethylenetriaminepentaacetic acid (DTPA), was found invariably smaller than by HS from CM-I, thereby indicating that HS removed more than one metal specie. The combined washing with HS from CM-I before and after soil treatment by either AA and DTPA revealed significant larger metal removals than by single solutions alone. This shows that humic soil washing also renders residual metals potentially more available to subsequent soil remediation approaches, such as phytoextraction. These results suggest a novel, efficient, and molecularly-based technology to remediate soils from heavy metals can be based on a low-cost and sustainable humic matter produced from recycled biomasses.
腐殖物质（HS）来自于泥煤和两种不同的堆肥，被用作生物表面活性剂，从添加了两种金属浓度并老化了 4 个月和 12 个月的土壤中洗脱重金属（Cu、Pb、Zn、Cd、Cr）。堆肥是通过将粪便与 40%（CM-I）和 20%（CM-II）的秸秆混合作为结构材料制成的。对于这两个老化期和两种金属浓度，CM-I 的 HS 去除的金属量都多于泥煤，而 CM-II 的 HS 的洗脱能力可以忽略不计。HS 的 C-CPMAS-NMR 谱表明，虽然 CM-I 和泥煤的芳香部分比 CM-II 更丰富，但 CM-I 的 HS 羧基和酚基碳原子数量最多。因此，CM-I 的 HS 比泥煤和 CM-II 的 HS 具有更大的络合能力，并且在洗脱处理过程中有效地将重金属从土壤中置换出来。此外，通过乙酸铵（AA）和二乙三胺五乙酸（DTPA）溶液去除的金属量始终小于 CM-I 的 HS，这表明 HS 去除了一种以上的金属物种。在土壤处理之前和之后，先用 CM-I 的 HS 进行联合洗脱，然后再用 AA 和 DTPA 进行洗脱，与单独使用单一溶液相比，金属去除量明显更大。这表明腐殖质土壤洗脱还使残留的金属更有可能被随后的土壤修复方法（如植物提取）利用。这些结果表明，可以基于从回收生物量中产生的低成本且可持续的腐殖质，开发出一种新颖、高效且基于分子的修复受重金属污染土壤的技术。
