Details

Autor(en) / Beteiligte

• Xu, Dongyun
• Chen, Songchao
• Xu, Hanyi
• Wang, Nan
• Zhou, Yin
• Shi, Zhou

Titel

Data fusion for the measurement of potentially toxic elements in soil using portable spectrometers

Ist Teil von

• Environmental pollution (1987), 2020-08, Vol.263 (Pt A), p.114649, Article 114649

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2020

Quelle

MEDLINE

Beschreibungen/Notizen

• Soil contamination posed by potentially toxic elements is becoming more serious under continuously development of industrialization and the abuse of fertilizers and pesticides. The investigation of soil potentially toxic elements is therefore urgently needed to ensure human and other organisms’ health. In this study, we investigated the feasibility of the separate and combined use of portable X-ray fluorescence (pXRF) and visible near-infrared reflectance (vis-NIR) sensors for measuring eight potentially toxic elements in soil. Low-level fusion was achieved by the direct combination of the pXRF and vis-NIR spectra; middle-level fusion was achieved by the combination of selected bands of the pXRF and vis-NIR spectra using the Boruta feature selection algorithm; and high-level fusion was conducted by outer-product analysis (OPA) and Granger–Ramanathan averaging (GRA). The estimation accuracy for the eight considered elements were in the following order: Zn > Cu > Ni > Cr > As > Cd > Pb > Hg. The measurement for Cu and Zn could be achieved by pXRF spectra alone with Lin’s concordance correlation coefficient (LCCC) values of 0.96 and 0.98, and ratio of performance to interquartile distance (RPIQ) values of 2.36 and 2.69, respectively. The measurement of Ni had the highest model performance for high-level fusion GRA with LCCC of 0.89 and RPIQ of 3.42. The measurements of Cr using middle- and high-level fusion were similar, with LCCC of 0.86 and RPIQ of 2.97. The best estimation accuracy for As, Cd, and Pb were obtained by high-level fusion using OPA, with LCCC >0.72 and RPIQ >1.2. However, Hg measurement by these techniques failed, having an unacceptable performance of LCCC <0.20 and RPIQ <0.75. These results confirm the effectiveness of using portable spectrometers to determine the contents of several potentially toxic elements in soils. [Display omitted] •pXRF and vis-NIR spectra used to measure contents of 8 potentially toxic elements in soil.•Three levels of data fusion were employed and compared.•Cu and Zn could be measured by pXRF spectra alone; neither spectra could measure Hg.•Other potentially toxic elements were best measured by high-level fusion of both spectra. Capsule: Soil potentially toxic elements could be estimated rapidly with good accuracy by portable spectrometers and sensor fusion could further improve estimation accuracy.