Meenaakumari M, Shoba S, Manikandan E, Karthigeyan K A, Nithyapriyan S A, Meikeerthivasan V, Hemeshwar S
School of Electronics Engineering, Vellore Institute of Technology, Chennai Campus, India.
Centre for Advanced Data Sciences, Vellore Institute of Technology, Chennai Campus, India.
Heliyon. 2024 Sep 29;10(19):e38326. doi: 10.1016/j.heliyon.2024.e38326. eCollection 2024 Oct 15.
The primary focus of this study investigates the potential of continuous-wave terahertz frequency-domain spectroscopy(CW-THz-FDS) as a rapid, non-destructive technique for detecting microplastic contamination in soil. Focusing on low-density polyethylene (LDPE) as a model microplastic, we prepared soil mixtures with varying LDPE concentrations (1 %,5 %,10 %,15 % by weight). We used a THz-FDS system operating between 0.1 and 0.7 THz to analyze the optical properties (transmission coefficient, attenuation and refractive index) of these mixtures and LDPE samples separately. Notably both soil and LDPE particles were of micrometer scale. Our results revealed distinct, concentration-dependent variations in these properties. The refractive index for the higher concentration (15 %) ranged from 2.2 to 2.3, while the attenuation coefficient varies between 10 and 14 cm. Crucially, we identified polylactic acid [PLA] as a suitable sample holder material due to its high transmission in the THz range. Consequently, this study suggests that terahertz spectroscopy can be a promising technique for detecting microplastic contamination in soil, offering a non-destructive and sensitive method for environmental monitoring.
本研究的主要重点是探究连续波太赫兹频域光谱技术（CW-THz-FDS）作为一种快速、无损检测土壤中微塑料污染的技术的潜力。以低密度聚乙烯（LDPE）作为典型微塑料，我们制备了不同LDPE浓度（按重量计为1%、5%、10%、15%）的土壤混合物。我们使用了一个在0.1至0.7太赫兹之间运行的太赫兹频域光谱系统，分别分析这些混合物以及LDPE样品的光学特性（透射系数、衰减和折射率）。值得注意的是，土壤颗粒和LDPE颗粒均为微米级。我们的结果揭示了这些特性存在明显的、与浓度相关的变化。较高浓度（15%）时的折射率在2.2至2.3之间，而衰减系数在10至14厘米之间变化。至关重要的是，我们确定聚乳酸[PLA]是一种合适的样品架材料，因为它在太赫兹范围内具有高透射率。因此，本研究表明太赫兹光谱技术可能是一种用于检测土壤中微塑料污染的有前景的技术，为环境监测提供了一种无损且灵敏的方法。
