Arsenic K-edge X-ray absorption near-edge spectroscopy to determine oxidation states of arsenic of a coastal aquifer–aquitard system

• Published in: Environmental pollution (1987) Vol. 179; pp. 160 - 166
• Main Authors: Wang, Ya, Jiao, Jiu Jimmy, Zhu, Sanyuan, Li, Yiliang
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2013; Elsevier
• Subjects: absorption; Applied sciences; Aquifer–aquitard system; Arsenic; Arsenic - analysis; Bioavailability; Biological and physicochemical properties of pollutants. Interaction in the soil; Boreholes; China; Coastal; environmental fate; Environmental Monitoring - methods; Exact sciences and technology; groundwater; Groundwater - chemistry; oxidation; Oxidation states; Oxidation-Reduction; Pollution; river deltas; rivers; Sediments; Soil and sediments pollution; Spectroscopy; The Pearl River Delta; Toxicity; Valence; Water Pollutants, Chemical - analysis; X-radiation; X-Ray Absorption Spectroscopy; X-rays; XANES analysis; China; Asia; China, People's Rep; The Pearl River Delta; Arsenic; Aquifer–aquitard system; XANES analysis; Oxidation states; XANES spectrometry; Sedimentary rock; Pollutant behavior; Quaternary; Aquifer―aquitard system; Determination; Sediments; Coastal zone; Aquifer system; Trace element; Valence
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2013.04.005

Determination of oxidation states of solid-phase arsenic in bulk sediments is a valuable step in the evaluation of its bioavailability and environmental fate in deposits, but is difficult when the sediments have low arsenic contents and heterogeneous distribution of arsenic species. As K-edge X-ray absorption near-edge spectroscopy (XANES) was used to determine quantitatively the oxidation states of arsenic in sediments collected from different depths of boreholes in the Pearl River Delta, China, where the highest aquatic arsenic concentration is 161.4 μg/L, but the highest solid arsenic content only 39.6 mg/kg. The results demonstrated that XANES is efficient in determining arsenic oxidation states of the sediments with low arsenic contents and multiple arsenic species. The study on the high-resolution vertical variations of arsenic oxidation states also indicated that these states are influenced strongly by groundwater activities. With the help of geochemical data, solid arsenic speciation, toxicity and availability were further discussed. •XANES is efficient in determining arsenic oxidation states of the bulk sediments.•Distribution of arsenic oxidation states is consistent with geochemical conditions.•Arsenic oxidation states are influenced strongly by groundwater activities. As K-edge X-ray absorption near-edge spectroscopy is efficient in determining arsenic oxidation states of the bulk sediments with low arsenic contents and heterogeneous distribution of arsenic species.