Santos O S H, Avellar F C, Alves M, Trindade R C, Menezes M B, Ferreira M C, França G S, Cordeiro J, Sobreira F G, Yoshida I M, Moura P M, Baptista M B, Scotti M R
J Environ Qual. 2019 Mar;48(2):439-449. doi: 10.2134/jeq2018.04.0168.
The rupture of the Fundão mine dam in Mariana municipality, Minas Gerais State, Brazil, spilled the tailings across the Doce River basin. These tailings, composed of residues discarded from the beneficiation of iron ore, are rich in SiO and AlO, as well as some ether amine compounds and NaOH. The aim of this study was to assess the distribution of these sediments, as well as their effect on the riparian zones reached, as compared with preserved sites. Sediment deposition in the river resulted in a morphological change from a meandering profile to a braided aspect. The nutrient and mineral content (P, K, Ca, Mg, Cu, Fe, Mn, Zn, and NO) and soil organic matter of the sediments were depleted, whereas NH, Na, and pH increased. A random presence of ether amines in the sediments was confirmed by quantitative and chromatographic analyses, with concentrations ranging from 0 to 57.8 mg kg; Na reached values as high as 150 mg kg. The impact of the dam tailings on biota was assessed by estimating total microbial biomass (phospholipid fatty acids), which were depleted in sediments relative to soils from preserved sites. Overall plant mortality, as well as a low resilience capacity, were also observed. Ether amines and Na present in the sediments had a strong toxic effect in the environment. Identification of these substances as the main impact factors will help guide future remediation efforts.
巴西米纳斯吉拉斯州马里亚纳市丰当矿坝决堤，尾矿泄入多西河盆地。这些尾矿由铁矿石选矿过程中丢弃的残渣组成，富含二氧化硅和氧化铝，以及一些醚胺化合物和氢氧化钠。本研究的目的是评估这些沉积物的分布情况，以及与未受影响区域相比，它们对所到达的河岸带的影响。河流中的沉积物沉积导致河道形态从蜿蜒型变为辫状。沉积物中的养分和矿物质含量（磷、钾、钙、镁、铜、铁、锰、锌和硝酸盐）以及土壤有机质减少，而铵、钠和pH值升高。通过定量和色谱分析证实沉积物中随机存在醚胺，浓度范围为每千克0至57.8毫克；钠含量高达每千克150毫克。通过估算总微生物生物量（磷脂脂肪酸）评估了尾矿对生物群的影响，与未受影响区域的土壤相比，沉积物中的微生物生物量减少。还观察到总体植物死亡率以及较低的恢复能力。沉积物中存在的醚胺和钠对环境具有强烈的毒性作用。将这些物质确定为主要影响因素将有助于指导未来的修复工作。
