Speciation and leaching of trace metal contaminants from e-waste contaminated soils

Jin li Cui, Chun ling Luo, Chloe Wing Yee Tang, Ting shan Chan, Xiangdong Li

Research output: Journal article publicationJournal articleAcademic researchpeer-review

51 Citations (Scopus)

Abstract

� 2017 Elsevier B.V. Primitive electrical and electronic waste (e-waste) recycling activities have caused serious environmental problems. However, little is known about the speciation and leaching behaviors of metal contaminants at e-waste contaminated sites. This study investigated trace metal speciation/mobilization from e-waste polluted soil through column leaching experiments involving irrigation with rainwater for almost 2.5 years. Over the experimental period, Cu and Zn levels in the porewater were 0.14 � 0.08 mg/L, and 0.16 � 0.08 mg/L, respectively, increasing to 0.33 � 0.16 mg/L, and 0.69 � 0.28 mg/L with plant growth. The amounts of Cu, Zn, and Pb released in surface soil (0–2 cm) contributed 43.8%, 22.5%, and 13.8%, respectively, to the original levels. The released Cu and Zn were primarily caused by the mobilization of the carbonate species of metals, including Cu(OH)2, CuCO3, and Zn5(CO3)2(OH)6, and amorphous Fe/Mn oxides associated fractions characterized by sequential extraction coupling with X-ray absorption spectroscopy. During the experiments, trace metals were not detected in the effluent, and the re-sequestration of trace metals was mainly attributed to the adsorption on the abundant Fe/Mn oxides in the sub-layer soil. This study quantitatively elucidated the molecular speciation of Cu and Zn in e-waste contaminated soil during the column leaching process.
Original languageEnglish
Pages (from-to)150-158
Number of pages9
JournalJournal of Hazardous Materials
Volume329
DOIs
Publication statusPublished - 1 Jan 2017

Keywords

  • E-waste contaminated soil
  • Rainfall
  • Speciation and mobilization
  • Trace metal
  • Vegetation

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis

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