Water-soluble chitosan promotes remediation of Pb-contaminated soil by <i>Hylotelephium spectabile</i>

doi:10.1007/s11783-024-1847-9

Front. Environ. Sci. Eng.

2024, Vol. 18

Issue (7) : 87 https://doi.org/10.1007/s11783-024-1847-9

Water-soluble chitosan promotes remediation of Pb-contaminated soil by Hylotelephium spectabile

Bingxin Guo¹, Yiwei Zhang¹, Junxing Yang^2,³, Tianwei Qian¹(

), Junmei Guo^1,²(

), Xiaona Liu¹, Yuan Jiao¹, Tongbin Chen^2,³, Guodi Zheng^2,³, Wenjun Li⁴, Fei Qi⁵

¹. College of Environmental Science and Engineering, Taiyuan University of Technology; Shanxi Key Laboratory of Earth Surface Processes and Resource Ecological Security in Fenhe River Basin; Shanxi Engineering Research Center of Low Carbon Remediation for Water and Soil Pollution in Yellow River Basin, Jinzhong 030600, China
². Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
³. University of Chinese Academy of Sciences, Beijing 100049, China
⁴. Shanxi Transportation Holding Ecological Environment Co., Ltd., Shanxi 030000, China
⁵. Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China

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Abstract

● WSC improves physicochemical properties of soil for plant growth.

● Water-soluble and acid-extractable Pb in soil increase with WSC dose.

● Amino and hydroxyl groups in WSC play important roles in mobilizing Pb in soil.

● WSC improves phytoremediation capacity of Pb-contaminated soil by H. spectabile .

Water-soluble chitosan (WSC) has been studied for its ability to mobilize soil Pb and promote the phytoremediation by Hylotelephium spectabile in Pb-contaminated fields. We aimed to clarify the internal mechanism by which WSC impacts phytoremediation by examining plant growth and Pb accumulation performance of H. spectabile as well as the Pb form, functional groups, and mineral phases of Pb-contaminated soil. WSC effectively decreased soil pH and activated Pb migration in rhizosphere soils, with a considerable increase in water-soluble and acid-extractable Pb by 29%–102% and 9%–65%, respectively, and a clear decreasing trend in reducible and oxidizable Pb. Fourier-transform infrared spectroscopy revealed a significant increase in amino and hydroxyl groups in the soil generated by WSC. The coordination of Pb with amino and hydroxyl groups may play an important role in the formation of Pb complexes and activation of Pb in soil. In field trials, the application of WSC significantly increased Pb accumulation in H. spectabile by 125.44%, reaching 92 g/hm². Moreover, the organic matter and nitrogen in the soils were increased by WSC, which improved the growth conditions of H. spectabile. No obvious growth inhibition was observed in either the pot or field trials. Therefore, WSC is a promising chelating agent for mobilizing Pb in soil. Additionally, WSC can be potentially used to boost H. spectabil-mediated phytoremediation of Pb-contaminated farmland.

Keywords Phytoremediation Pb-contaminated soil Water-soluble chitosan Hylotelephium spectabile Fourier transform infrared spectroscopy

Corresponding Author(s): Tianwei Qian,Junmei Guo

About author:

Li Liu and Yanqing Liu contributed equally to this work.

Issue Date: 15 April 2024

Cite this article:

Bingxin Guo,Yiwei Zhang,Junxing Yang, et al. Water-soluble chitosan promotes remediation of Pb-contaminated soil by Hylotelephium spectabile[J]. Front. Environ. Sci. Eng., 2024, 18(7): 87.

URL:

https://academic.hep.com.cn/fese/EN/10.1007/s11783-024-1847-9
https://academic.hep.com.cn/fese/EN/Y2024/V18/I7/87

Fig.1 Effect of WSC on the physicochemical properties of JY (a), LC (b), MZ (c), and SM (d) soils. pH (r), rhizosphere pH; pH (n-r), non-rhizosphere pH.

Fig.2 Effects of WSC on the chemical speciation of Pb in rhizosphere (a) and non-rhizosphere (b)

Fig.3 Biomass (a) and root-shoots Pb concentration (b) of H. spectabile; Pb uptake in the roots (c) and shoots (d) of H. spectabile. Data marked by the different lowercase letters represent statistically significant differences at p < 0.05 based on LSD test. Values are mean ± SE (n = 4).

Fig.4 Correlation analysis between different indicators. Biomass (R), root biomass; Biomass (S), shoots biomass; Pb concentration (R), root Pb concentration; Pb concentration (S), shoots Pb concentration; Pb uptake (R), the uptake amount of Pb in the root; Pb uptake (S), the uptake amount of Pb in shoots.

Fig.5 Fourier transform infrared spectroscopy of WSC (a); XRD of JY soil under different treatments. ‘a’ is the characteristic peak of quartz; ‘b’ is the characteristic peak of montmorillonite; ‘c’ is the characteristic peak of PbSO₄ (b); Fourier transform infrared spectroscopy of four different soils(c)–(f).

Tab.1 Peaking results of FTIR spectra of JY soil (1020 cm^?1) and (3440 cm^?1)

Fig.6 Pb concentration in the shoots of different populations. Data marked by the different lowercase letters represent statistically significant differences at p < 0.05 based on LSD test. Values are mean ± SE (n = 4).

Fig.7 Shoot biomass of different populations (a) and Pb uptake in the shoots of different populations. (b) Data marked by different lowercase letters represent statistically significant differences at p < 0.05, based on LSD test. Values are mean ± SE (n = 4).

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