Abstract

The article presents the results of assessing the effect of humic acids, taken at a concentration of 250 ppm, on the process of induced phytoextraction of heavy metals from soils selected near Norilsk. Phytoextraction was carried out by different types of marigold plants: Tagetes patula and Tagetes erecta. The studies were carried out in greenhouse conditions under controlled spectral illumination (light culture). The experiment lasted 21 days. A time range of vegetation period was chosen due to a short summer period typical of the study region, where it is more rational to keep records of the systemic removal of toxicants from contaminated soils by several cycles of their sowing/cutting per season, already at the juvenile phase of ontogenesis. For elemental analysis, the method of atomic emission spectrometry with inductively coupled plasma was used. To assess the level of efficiency of metal accumulation, the authors developed and used the original computing neural network CompNN, which allows calculating the cognitive significance index (CSI) based on empirical data on the accumulation of toxicants, both in shoots and roots of plants. The study results showed that the introduction of an organic additive in the form of humic acids into the soil led to inhibition of the growth of the above-ground part of T. patula. As for T. erecta, the rate of accumulation of green plant biomass did not change when humic acids were added. The decrease in the biomass of shoots of T. patula plants is explained by an increase in the accumulation of metals for different experiment variants by 91.6% on average. The content of metals in the shoots of T. erecta under the influence of humic acids, on the contrary, decreased by 17.3% on average. A similar result was also observed in the root zone: the trend of change in the fixation of metals for both plant species was 40.8 and 10.8%, respectively. Calculation of CSI indices also showed that the addition of humic acids in T. patula increases the intensity of metal accumulation from the soil in its biomass in all variants, while in T. erecta, on the contrary, it decreases. The performed cluster analysis demonstrated the fixation of metals in the main buffer zone of plants and also made it possible to isolate nickel into a separate homogeneous series. Based the distribution of this element in the shoots during experiment variants, it was shown that it is closely associated with copper. The correlation coefficients of their accumulation with the CSI index in the shoots of both plants were r = 0.82, 0.87 for Cu and r = 0.87, 0.83 for Ni. The proximity of these values indicates the priority nature of the accumulation of these metals in the plant biomass of marigolds and also characterizes the manifestation of certain interactions between them in contaminated soil by the type of antagonism or synergism.

中文翻译：

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万寿菊积累金属的神经网络认知分析

摘要

本文介绍了腐殖酸（浓度为 250 ppm）对从诺里尔斯克附近选定的土壤中诱导植物提取重金属过程的影响的评估结果。植物提取是通过不同类型的万寿菊植物进行的：Tagetes patula和Tagetesectera。这些研究是在受控光谱照明（光培养）的温室条件下进行的。实验持续了21天。选择植被期的时间范围是因为研究区域典型的夏季较短，更合理的做法是通过每个季节的几个播种/切割周期来保存从污染土壤中系统清除有毒物质的记录，已经在个体发生的幼年期。对于元素分析，使用电感耦合等离子体原子发射光谱法。为了评估金属积累的效率水平，作者开发并使用了原始的计算神经网络 CompNN，该网络可以根据植物芽和根中有毒物质积累的经验数据计算认知意义指数 (CSI)。研究结果表明，将腐植酸形式的有机添加剂引入土壤中会抑制孔雀草地上部分的生长。对于直立木，添加腐植酸后绿色植物生物量的积累速率没有变化。不同实验变种的金属积累平均增加了 91.6%，这解释了孔雀草植物芽生物量的减少。相反，在腐殖酸的影响下，直立树芽中的金属含量平均下降了17.3%。在根区也观察到类似的结果：两种植物的金属固定变化趋势分别为 40.8% 和 10.8%。 CSI指数的计算还表明，在孔雀草中添加腐殖酸增加了所有变种生物量中土壤金属积累的强度，而在竖立草中则相反，它降低了。进行的聚类分析证明了金属在植物主要缓冲区中的固定，并且还可以将镍分离成单独的同质系列。根据实验变体期间该元素在芽中的分布，表明它与铜密切相关。两种植物地上部的累积量与 CSI 指数的相关系数为r = 0.82，Cu 和r为 0.87= 0.87，镍为 0.83。这些值的接近程度表明这些金属在万寿菊植物生物量中积累的优先性质，并且还表征了它们在受污染土壤中通过拮抗或协同类型表现出的某些相互作用。