Dynamic leaching behavior of geogenic As in soils after cement-based stabilization/solidification

Jiang Shan Li, Lei Wang, Chiu Wa Tsang, Jingzi Beiyuan, Chi Sun Poon

Research output: Journal article publicationJournal articleAcademic researchpeer-review

11 Citations (Scopus)

Abstract

Cement-based stabilization/solidification (S/S) is a practical treatment approach for hazardous waste with anthropogenic As sources; however, its applicability for geogenic As-containing soil and the long-term leaching potential remain uncertain. In this study, semi-dynamic leaching test was performed to investigate the influence of S/S binders (cement blended with fuel ash (FA), furnace bottom ash (FBA), or ground granulated blast furnace slag (GGBS)) on the long-term leaching characteristics of geogenic As. The results showed that mineral admixtures with higher Ca content and pozzolanic activity were more effective in reducing the leached As concentrations. Thus, cement blended with FBA was inferior to other binders in suppressing the As leaching, while 20% replacement of ordinary Portland cement by GGBS was considered most feasible for the S/S treatment of As-containing soils. The leachability of geogenic As was suppressed by the encapsulation effect of solidified matrix and interlocking network of hydration products that were supported by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results. The long-term leaching of geogenic As from the monolithic samples was diffusion-controlled. Increasing the Ca content in the samples led to a decrease in diffusion coefficient and an increase in feasibility for “controlled utilization” of the S/S-treated soils.
Original languageEnglish
Pages (from-to)27822-27832
Number of pages11
JournalEnvironmental Science and Pollution Research
Volume24
Issue number36
DOIs
Publication statusPublished - 1 Dec 2017

Keywords

  • Dynamic leaching
  • Geogenic arsenic
  • Hazardous waste treatment
  • Mineral admixture
  • Soil remediation
  • Stabilization/solidification

ASJC Scopus subject areas

  • Environmental Chemistry
  • Pollution
  • Health, Toxicology and Mutagenesis

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