Innovative solidification/stabilization of lead contaminated soil using incineration sewage sludge ash

Jiangshan Li, Chi Sun Poon

Research output: Journal article publicationJournal articleAcademic researchpeer-review

48 Citations (Scopus)

Abstract

In this study, ordinary Portland cement (OPC) and blended OPC containing incinerated sewage sludge ash (ISSA) were used to solidify/stabilize (S/S) soils contaminated with different concentrations of Pb. After curing for 7 and 28 d, the S/S soils were subjected to a series of strength, leaching and microscopic tests. The results showed that replacement of OPC by ISSA significantly reduced the unconfined compressive strength (UCS) of S/S soils and leached Pb. In addition, the leaching of Pb from the monolithic samples was diffusion controlled, and increasing the ISSA addition in the samples led to a lower diffusion coefficient and thus an increase in the feasibility for “controlled utilization” of S/S soils. Furthermore, the proposed S/S method significantly decreased the amount of Pb associated with carbonates and increased the amount of organic and residual Pb in S/S soils, reflecting that the risk of Pb contaminated soils can be effectively mitigated by the incorporating of ISSA. Overall, the leachability of Pb was controlled by the combined effect of adsorption, encapsulation or precipitation in the S/S soils.
Original languageEnglish
Pages (from-to)143-152
Number of pages10
JournalChemosphere
Volume173
DOIs
Publication statusPublished - 1 Jan 2017

Keywords

  • Incineration sewage sludge ash
  • Leachability
  • Lead contaminated soil
  • Solidification/stabilization

ASJC Scopus subject areas

  • Environmental Chemistry
  • Chemistry(all)

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