Gomes Alessandra R, Antão Arthur, Santos Amanda G P, Lacerda Tomás J, Medeiros Mirelli B, Saenz Luis Alberto I, Alvarenga Stael, Santos Carlos Henrique, Rigobelo Everlon C, Scotti Maria Rita
Department of Botany, Institute of Biological Science and Graduate Program in Plant Biology, Federal University of Minas Gerais, Brazil.
Architecture School and Graduate Program in Built Environment and Sustainable Heritage, Federal University of Minas Gerais, Minas Gerais, Brazil.
Environ Toxicol Chem. 2021 Aug;40(8):2359-2373. doi: 10.1002/etc.5075. Epub 2021 Jun 23.
The tailings spilled by the Fundão Dam rupture in the Doce River basin (Brazil) had a high pH, elevated sodium (Na) and ether amine, and low soil organic matter. With the aim of decreasing the toxic compounds, we established 2 remediation strategies: treatment 1, phytoremediation with tolerant native species of the Atlantic Forest cultivated on scraped sediment plus the incorporation of organic matter; and treatment 2, phytoremediation with native species plus superficial deposition of organic matter. The experimental site was compared with a degraded site that the dam tailings had reached and with a preserved site, a fragment of preserved Atlantic Forest. After 12 mo, plants showed an outstanding growth, especially after treatment 1 (~4 m), and the remediation procedures resulted in significant decreases in pH (from 8.0 to ~ 6.0), Na (from 154 to 22-35 mg/kg), electrical conductivity, and ether amine (from 6.0 to 0.5 mg/kg) in both treatments. By contrast, ammonium, a product of ether amine degradation, showed a significant increase in the experimental site, along with a significant increase in nitrate and improvement of soil microbial populations assessed by phospholipid fatty acid analysis. The treatments also improved soil fertility in the experimental site, as estimated by soil nutrients, cation exchange capacity, and soil aggregation. Based on the parameters analyzed, a principal component analysis showed that samples from the degraded site and the preserved site clustered in an opposite position and those from the experimental site clustered in an intermediate position but closer to the samples from the preserved site. Overall, our results demonstrated that the remediation procedures adopted were effective and resulted in rehabilitation of a riparian forest contaminated with dam tailings that included Na and ether amine. Environ Toxicol Chem 2021;40:2359-2373. © 2021 SETAC.
巴西多西河盆地丰当大坝决堤泄漏的尾矿具有高pH值、高钠（Na）和醚胺含量，以及低土壤有机质含量。为了降低有毒化合物的含量，我们制定了两种修复策略：处理1，在刮除的沉积物上种植大西洋森林的耐性本地物种并添加有机质进行植物修复；处理2，用本地物种进行植物修复并在表面沉积有机质。将实验场地与大坝尾矿到达的退化场地以及一个保存完好的场地（一片保存完好的大西洋森林片段）进行比较。12个月后，植物生长良好，尤其是处理1后的植物（约4米），两种处理的修复程序均使pH值（从8.0降至约6.0）、Na含量（从154降至22 - 35毫克/千克）、电导率和醚胺含量（从6.0降至0.5毫克/千克）显著降低。相比之下，作为醚胺降解产物的铵在实验场地显著增加，同时硝酸盐也显著增加，并且通过磷脂脂肪酸分析评估的土壤微生物种群得到改善。这些处理还提高了实验场地的土壤肥力，这通过土壤养分、阳离子交换容量和土壤团聚性来估算。基于分析的参数，主成分分析表明，退化场地和保存场地的样本聚集在相反位置，而实验场地的样本聚集在中间位置，但更接近保存场地的样本。总体而言，我们的结果表明所采用的修复程序是有效的，能够使受大坝尾矿（包括Na和醚胺）污染的河岸森林得到恢复。《环境毒理学与化学》2021年；40:2359 - 2373。© 2021 SETAC。
