Harnessing the composition of dissolved organic matter in lagoon sediment in association with rare earth elements using fluorescence and UV-visible absorption spectroscopy

Philomina Onyedikachi Peter; Binessi Edouard Ifon; François Nkinahamira; Kayode Hassan Lasisi; Jiangwei Li; Anyi Hu; Chang-Ping Yu

doi:10.1016/j.scitotenv.2023.168139

Harnessing the composition of dissolved organic matter in lagoon sediment in association with rare earth elements using fluorescence and UV-visible absorption spectroscopy

Sci Total Environ. 2024 Jan 15:908:168139. doi: 10.1016/j.scitotenv.2023.168139. Epub 2023 Oct 25.

Authors

Philomina Onyedikachi Peter¹, Binessi Edouard Ifon¹, François Nkinahamira², Kayode Hassan Lasisi¹, Jiangwei Li³, Anyi Hu⁴, Chang-Ping Yu⁵

Affiliations

¹ CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China.
³ CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
⁴ CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: ayhu@iue.ac.cn.
⁵ CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: cpyu@iue.ac.cn.

PMID: 37890635
DOI: 10.1016/j.scitotenv.2023.168139

Abstract

Dissolved Organic Matter (DOM) plays a pivotal role in influencing metal binding and mobility within lagoon sediments. However, there exists a gap in understanding the compositional alterations of DOM concerning Rare Earth Elements (REEs) across varying pollution gradients. This study aimed to characterize DOM and examine its relationship with REEs in sediment cores from different pollution levels in Yundang Lagoon, China using excitation-emission matrix-parallel factor analysis (EEM-PARAFAC). The results raveled four distinct fluorescent components. Among these, two correspond to humic-like substances, while the remaining two are attributed to protein-like substances. Remarkably, the prevalence of protein-like compounds was observed to exceed 58% of the total fluorescence intensity across all the investigated sites. Furthermore, a substantial discrepancy in total fluorescence intensity was detected between the Songbai Lake and the Inner and Outer Lagoon, indicating a variance in DOM content. In terms of REEs, the average concentration of total REEs was notably elevated within the Songbai Lake sediments (318.36 mg/kg) as compared to the Inner and Outer Lagoon sediments (296.36 and 278.05 mg/kg, respectively). Of significance is the enrichment of Light Rare Earth Elements (LREEs), particularly Ce, La, Pr, and Nd, over Heavy REEs (HREEs) across all surveyed locations. Intriguingly, a coherent trend emerged wherein the fluorescence intensity and LREE concentrations exhibited a synchronized increase from Outer to Inner to Songbai Lake core sediments. This observation substantiates a strong correlation between DOM content and pollution levels (p < 0.05). By shedding light on the intricate interplay between DOM and REEs within urban aquatic sediments, this study imparts novel insights which enrich our comprehension of urban environmental dynamics.

Keywords: Dissolved organic matter; EEM-PARAFAC; Lagoon; Rare earth elements; Sediment.