Assessing anthropogenic levels, speciation, and potential mobility of rare earth elements (REEs) in ex-tin mining area

• Published in: Environmental science and pollution research international 2016-12, Vol.23 (24), p.25039-25055
• Main Authors: Khan, Aysha Masood, Yusoff, Ismail, Bakar, Nor Kartini Abu, Bakar, Ahmad Farid Abu, Alias, Yatimah
• Format: Article
• Language: English
• Subjects: Anthropogenic factors; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Contaminated sediments; Contamination; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Environmental studies; Factor analysis; Gadolinium; Geochemistry; Geologic Sediments - chemistry; Lake sediments; Lakes; Lakes - chemistry; Lanthanum; Magnetic resonance imaging; Malaysia; Mass spectrometry; Mass spectroscopy; Metals, Rare Earth - analysis; Mineralization; Mining; Mobility; Pollutants; Principal components analysis; Rare earth elements; Research Article; Rivers; Rivers - chemistry; Scientific imaging; Sediment samplers; Sediments; Soil Pollutants - analysis; Speciation; Statistical analysis; Surface water; Tin; Tin - analysis; Trace elements; Waste Water Technology; Water analysis; Water Management; Water Pollutants, Chemical - analysis; Water Pollution Control; Water sampling; Yttrium
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-016-7641-x

A study was carried out to determine the level of rare earth elements (REEs) in water and sediment samples from ex-mining lakes and River in Kinta Valley, Perak, Malaysia. Surface water and sediments from an ex-mining lake and Kinta River water samples were analyzed for REEs by inductively coupled plasma mass spectrometry. The total concentration of REEs in the ex-mining lake water samples and sediments were found to be 3685 mg/l and 14159 mg/kg, respectively, while the total concentration of REEs in Kinta River water sample was found to be 1224 mg/l. REEs in mining lake water were found to be within 2.42 mg/l (Tb) to 46.50 mg/l (Ce), while for the Kinta River, it was 1.33 mg/l (Ho) to 29.95 mg/l (Ce). Sediment samples were also found with REEs from 9.81 mg/kg (Ho) to 765.84 mg/kg (Ce). Ce showed the highest average concentrations for mining lake (3.88 to 49.08 mg/l) and Kinta River (4.44 to 33.15 mg/l) water samples, while the concentration of La was the highest (11.59 to 771.61 mg/kg) in the mining lake sediment. Lu was shown to have the highest enrichment of REEs in ex-mining lake sediments (107.3). Multivariate statistical analyses such as factor analysis and principal component analysis indicated that REEs were associated and controlled by mixed origin, with similar contributions from anthropogenic and geogenic sources. The speciation study of REEs in ex-tin mining sediments using a modified five-stage sequential extraction procedure indicated that yttrium (Y), gadolinium (Gd), and lanthanum (La) were obtained at higher percentages from the adsorbed/exchanged/carbonate fraction. The average potential mobility of the REEs was arranged in a descending order: Yb > Gd > Y = Dy > Pr > Er > Tm > Eu > Nd > Tb > Sc > Lu > Ce > La, implying that under favorable conditions, these REEs could be released and subsequently pollute the environment.