Lebrun Manhattan, Miard Florie, Trakal Lukáš, Bourgerie Sylvain, Morabito Domenico
University of Orleans, INRA USC1328, LBLGC EA 1207, Rue de Chartres, BP 6759, 45067, Orléans, Cedex 2, France.
University of Orleans, INRA USC1328, LBLGC EA 1207, Rue de Chartres, BP 6759, 45067, Orléans, Cedex 2, France.
Chemosphere. 2022 Aug;300:134592. doi: 10.1016/j.chemosphere.2022.134592. Epub 2022 Apr 14.
In remediation of metal(loid) polluted soils, it is crucial to improve soil conditions and reduce metal(loid) toxicity to permit plant growth. To do that, amendments, such as biochar, activated carbon, and redmud, can be applied to the soil. Their effects are dependent on their type and properties. The aims of this study were thus to evaluate the potential of diverse biochars, activated carbons, and redmuds to reduce phytotoxicity of a former mine technosol polluted with As and Pb. Two pots experiments were set up. The first one applied on Pontgibaud technosol ten biochars, eight activated carbons, and three redmuds, at 2% for the biochars and activated carbons and 1% for the redmud. Soil pore water properties (pH, electrical conductivity), metal(loid) mobility, and Phaseolus vulgaris growth were monitored. In a second experiment, the five best amendments, one redmud associated with two biochars and two activated carbons, selected based on their ability to improve soil conditions, immobilize metal(loid)s and improve plant growth, were applied. The same plant species was used and soil and plant parameters were measured. Results demonstrated that not all amendments were capable of ameliorating soil conditions and reducing soil phytotoxicity. Moreover, the five selected amendments (biochars from oak bark sapwood and bamboo, activated carbons from vegetal feedstock chemically activated and physically activated, modified redmud) showed good sorption capacity towards Pb, with maximum sorption capacity between 63 and 217 mg g, depending on the amendment, and their combined application led to better soil properties improvement than the single amendments. However, plant growth was only ameliorated further than a single application in the redmud-biochar combination but not in the association of redmud with activated carbon. This study is one of the first to deliver a rapid phytotoxicity test screening demonstrating that redmud associated with particular biochar could be beneficial in reducing the phytotoxicity of technosol polluted with As and Pb and thus allow plant growth and a phytomanagement process.
在修复金属（类金属）污染土壤时，改善土壤条件并降低金属（类金属）毒性以促进植物生长至关重要。为此，可以向土壤中添加生物炭、活性炭和赤泥等改良剂。它们的效果取决于其类型和特性。因此，本研究的目的是评估不同生物炭、活性炭和赤泥降低受砷和铅污染的废弃矿质技术土壤植物毒性的潜力。进行了两个盆栽试验。第一个试验在蓬日博技术土壤上施用了10种生物炭、8种活性炭和3种赤泥，生物炭和活性炭的施用量为2%，赤泥的施用量为1%。监测了土壤孔隙水性质（pH值、电导率）、金属（类金属）迁移率和菜豆生长情况。在第二个试验中，根据其改善土壤条件、固定金属（类金属）和促进植物生长的能力，施用了五种最佳改良剂，一种赤泥与两种生物炭和两种活性炭组合。使用了相同的植物品种，并测量了土壤和植物参数。结果表明，并非所有改良剂都能改善土壤条件并降低土壤植物毒性。此外，所选的五种改良剂（橡木边材和竹子制成的生物炭、植物原料经化学活化和物理活化制成的活性炭、改性赤泥）对铅具有良好的吸附能力，最大吸附容量在63至217毫克/克之间，具体取决于改良剂，并且它们的联合施用比单一改良剂能更好地改善土壤性质。然而，只有赤泥 - 生物炭组合进一步改善了植物生长，而赤泥与活性炭组合则没有。本研究是首批进行快速植物毒性测试筛选的研究之一，表明特定生物炭与赤泥结合可能有利于降低受砷和铅污染的技术土壤的植物毒性，从而促进植物生长和植物修复过程。
