Environment and Ecology Research Vol. 14(2), pp. 142 - 151
DOI: 10.13189/eer.2026.140205
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Enrichment Patterns and Geochemical Behavior of Rare Earth Elements in the Sediments of the Linggi River, Malaysia

Kumar Krishnan ^1,2,*, Chee Kong Yap ³, Suganthi Muthusamy ⁴, Prakash Balu ⁵, Kim Eng Foo ⁶, Jeevamalar Rugmangathan ¹, Modupeola Chukwudi ^7
1 Faculty of Health and Life Sciences, INTI International University, Malaysia
² Faculty of Health Sciences, Shinawatra University, Thailand
³ Department of Biology, Faculty of Science, University Putra Malaysia, Malaysia
⁴ Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, India
⁵ Department of Biotechnology, Vels Institute of Science, Technology and Advanced Studies (VISTAS), Pallavaram, Chennai - 600117, Tamil Nadu, India
⁶ Faculty of Engineering and Quantity Surveying, INTI International University, Malaysia
⁷ School of Natural Resources & Environmental Studies, University of Juba, Juba, South Sudan

ABSTRACT

Sediment samples from seven sites along the Linggi River (Malaysia) were collected in the dry season to study their spatial distribution, enrichment patterns, and geochemical behavior of REEs and Fe. Surface sediments were analyzed by neutron activation analysis, adhering to strict quality control procedures that included standard reference materials IAEA-Soil-7, SL-1, and MIX PTS-16/17. The results obtained show that total REE concentrations range from 166.6 to 206.1 ppm, with a dominance of LREEs over HREEs (LREE/HREE = 7.4–10.5). The concentrations of La (47.7–60.4 mg/kg), Ce (93–116 mg/kg), and Sm (8.2–10.4 mg/kg) are constantly greater than their UCC values, whereas Dy (7.6–14 mg/kg), Tb (1.4–1.8 mg/kg), and Yb (5.3–8.7 mg/kg) are enriched up to fourfold. Spatial patterns include the following: upstream Dy and Yb enrichment, midstream variability related to industrial inputs, and downstream increases of La and Ce due to estuarine trapping. Ce/Ce* ratios of between 0.95 and 1.11 indicate stable oxic depositional conditions, while a negative Eu anomaly (Eu/Sm = 0.09–0.14) reflects felsic lithological sources. Enrichment factors (EF): Moderate to strong enrichment of Dy, Tb, and Yb is suggested by EF values up to 6.8, whereas the values of Igeo (-0.99 to 1.42) suggest the sediment to be non-polluted to slightly polluted, having hotspots at S1 and S5. Taken together, the results imply that the present REE concentration patterns in the sediment of the Linggi River are mainly controlled by felsic weathering materials, overlain by industrial influences.

KEYWORDS
Environmental Pollution, Mangrove, Rare Earth, Neutron Activation

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Kumar Krishnan , Chee Kong Yap , Suganthi Muthusamy , Prakash Balu , Kim Eng Foo , Jeevamalar Rugmangathan , Modupeola Chukwudi , "Enrichment Patterns and Geochemical Behavior of Rare Earth Elements in the Sediments of the Linggi River, Malaysia," Environment and Ecology Research, Vol. 14, No. 2, pp. 142 - 151, 2026. DOI: 10.13189/eer.2026.140205.

(b). APA Format:
Kumar Krishnan , Chee Kong Yap , Suganthi Muthusamy , Prakash Balu , Kim Eng Foo , Jeevamalar Rugmangathan , Modupeola Chukwudi (2026). Enrichment Patterns and Geochemical Behavior of Rare Earth Elements in the Sediments of the Linggi River, Malaysia. Environment and Ecology Research, 14(2), 142 - 151. DOI: 10.13189/eer.2026.140205.