Departamento de Biologia, Campus de Santiago, Universidade de Aveiro, 3810-193, Aveiro, Portugal.
Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193, Aveiro, Portugal.
Environ Sci Pollut Res Int. 2020 Feb;27(4):4423-4441. doi: 10.1007/s11356-019-07098-3. Epub 2019 Dec 12.
Phytoremediation has been proposed as a potential biotechnological strategy to remediate effluents before their release into the environment. The use of common aquatic plant species, such as macrophytes (e.g., Lemna spp.) as a cleanup solution has been proposed decades ago. However, the effectiveness of such processes must be assessed by analyzing the toxicity of resulting effluents, for the monitoring of wastewater quality. To attain this purpose, this work intended to quantify the efficacy of a Lemna-based wastewater phytoremediation process, by analyzing toxicological effects of domestic and textile effluents. The toxic effects were measured in Lemna minor (same organisms used in the phytoremediation process, by quantifying toxicological endpoints such as root length, pigment content, and catalase activity) and by quantifying individual parameters of Daphnia magna (immobilization, reproduction, and behavior analysis). Phytoremediation process resulted in a decrease of chemical oxygen demand in both effluents and in an increase in root length of exposed plants. Moreover, textile effluent decreased pigments content and increased catalase activity, while domestic effluent increased the anthocyanin content of exposed plants. D. magna acute tests allowed calculating a EC and Toxic Units interval of 53.82-66.89%/1.85-1.49, respectively, to raw textile effluent; however, it was not possible to calculate these parameters for raw and treated domestic effluent (RDE and TDE). Therefore, in general, the acute toxicity of effluent toward D. magna was null for RDE, and mild for the treated textile effluent (TTE), probably due to the effect of phytoremediation. Exposure to textile effluents (raw and treated) increased the total number of neonates of D. magna and, in general, both textile effluents decreased D. magna distance swim. Moreover, although both effluents were capable of causing morphological and physiological/biochemical alterations in L. minor plants, organisms of this species were able to survive in the presence of both effluents and to remediate them.
植物修复技术已被提议作为一种潜在的生物技术策略，用于在排放到环境中之前对废水进行修复。几十年前，就有人提议使用常见的水生植物物种，如大型藻类（如浮萍属）作为一种清理解决方案。然而，为了监测废水质量，必须通过分析废水毒性来评估此类过程的有效性。为此，本研究旨在通过分析家庭和纺织废水的毒性作用，量化基于浮萍的废水植物修复过程的功效。采用定量分析浮萍属生物的毒性终点（如根长、色素含量和过氧化氢酶活性）和分析大型溞的个体参数（固定化、繁殖和行为分析）来测量毒理学效应。植物修复过程降低了两种废水中的化学需氧量，并增加了暴露植物的根长。此外，纺织废水降低了色素含量，增加了过氧化氢酶活性，而家庭废水增加了暴露植物的花色素含量。大型溞急性试验允许计算出原始纺织废水的 EC 和毒性单位间隔分别为 53.82%-66.89%/1.85-1.49，而原始和处理后的家庭废水（RDE 和 TDE）则无法计算这些参数。因此，总的来说，RDE 对 D. magna 的急性毒性为零，而 TTE 对纺织废水的毒性则较为轻微，这可能是由于植物修复的作用。暴露于纺织废水（原始和处理）增加了大型溞的新生幼体总数，而且一般来说，两种纺织废水都减少了大型溞的游泳距离。此外，尽管两种废水都能够引起 L. minor 植物的形态和生理/生化改变，但该物种的生物能够在两种废水存在的情况下存活并对其进行修复。
