Abstract

One of the challenges of integrating phytoremediation into a waste treatment system is the sensitivity of plant species to fluctuations in environmental conditions and the difficulty in estimating subsequent changes to their rates of uptake. In this study, we examine a method using the exponential decay equation to approximate the median uptake rate (MUR) of nutrients for three aquatic macrophyte species, Salvinia molesta, Spirodela polyrhiza, and Lemna minor. These MUR values were then used to directly evaluate the phytoremediation performance between species and at varying levels of salinity stress. The results of this study indicate that an exponential decay relationship produced the most accurate models of the nutrient uptake profile for each species, with highest correlation values in 74.1% of tests for the three species at increasing salinity over a period of 14 d. S. polyrhiza and L. minor began to show significant reductions in nutrient uptake and growth at salinity concentration above 10 g/L. Using MUR, direct comparisons can be made between species in a time and mass-independent manner, allowing for the rapid assessment of phytoremediation performance under conditions of increasing salinity stress.

Novelty statement

In this study, we propose the use of an exponential decay model and the use of median uptake rate (MUR) obtained from the model coefficients as a method for directly comparing species performance under different conditions. Subsequently, we show how the use of MUR values obtained from three species of aquatic macrophytes allows for the direct comparison of species performance under increasing salinity stress. The method proposed in this study would improve the ability for easy comparison between species performance under varying environmental conditions. Future works could further build on the parameters proposed in this study and optimize the performance of phytoremediation systems developed for nutrient-affected wastewater management. This study is especially beneficial to phytoremediation researchers and environmental engineers who are implementing or designing macrophyte phytoremediation systems.

摘要

将植物修复整合到废物处理系统中的挑战之一是植物物种对环境条件波动的敏感性以及难以估计其吸收率的后续变化。在这项研究中，我们研究了一种使用指数衰减方程来近似三种水生大型植物物种的养分吸收率 (MUR) 的方法，Salviniamoleta、Spirodela polyrhiza和Lemna minor. 然后使用这些 MUR 值直接评估物种之间和不同盐度胁迫水平下的植物修复性能。这项研究的结果表明，指数衰减关系为每个物种产生了最准确的养分吸收曲线模型，在 14 d 期间盐度增加的三个物种的 74.1% 测试中，相关值最高。S. polyrhiza和L. minor在盐度浓度超过 10 g/L 时开始表现出养分吸收和生长的显着减少。使用 MUR，可以以独立于时间和质量的方式在物种之间进行直接比较，从而可以在盐度压力增加的条件下快速评估植物修复性能。

新颖性声明

在这项研究中，我们建议使用指数衰减模型和使用从模型系数获得的中值吸收率 (MUR) 作为直接比较不同条件下物种性能的方法。随后，我们展示了如何使用从三种水生大型植物中获得的 MUR 值允许直接比较物种在盐度增加压力下的表现。本研究中提出的方法将提高在不同环境条件下轻松比较物种性能的能力。未来的工作可以进一步建立在本研究中提出的参数的基础上，并优化为受营养影响的废水管理而开发的植物修复系统的性能。