Peter Philomina Onyedikachi, Ifon Binessi Edouard, Nkinahamira François, Lasisi Kayode Hassan, Li Jiangwei, Hu Anyi, Yu Chang-Ping
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.
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.
Sci Total Environ. 2024 Jan 15;908:168139. doi: 10.1016/j.scitotenv.2023.168139. Epub 2023 Oct 25.
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.
溶解有机物（DOM）在影响泻湖沉积物中金属的结合和迁移方面起着关键作用。然而，在理解不同污染梯度下与稀土元素（REEs）相关的DOM组成变化方面仍存在差距。本研究旨在利用激发 - 发射矩阵 - 平行因子分析（EEM - PARAFAC）对中国筼筜湖不同污染水平沉积物岩心中的DOM进行表征，并研究其与REEs的关系。结果揭示了四种不同的荧光成分。其中两种对应于类腐殖质物质，而另外两种归因于类蛋白质物质。值得注意的是，在所有调查地点，类蛋白质化合物的含量均超过总荧光强度的58%。此外，在松柏湖与内湖和外湖之间检测到总荧光强度存在显著差异，表明DOM含量存在差异。就REEs而言，松柏湖沉积物中总REEs的平均浓度（318.36 mg/kg）明显高于内湖和外湖沉积物（分别为296.36和278.05 mg/kg）。重要的是，在所有调查地点，轻稀土元素（LREEs），特别是Ce、La、Pr和Nd，相对于重稀土元素（HREEs）更为富集。有趣的是，出现了一种连贯的趋势，即从外湖到内湖再到松柏湖岩心沉积物，荧光强度和LREE浓度同步增加。这一观察结果证实了DOM含量与污染水平之间存在强相关性（p < 0.05）。通过揭示城市水生沉积物中DOM与REEs之间的复杂相互作用，本研究提供了新的见解，丰富了我们对城市环境动态的理解。
