PH-dependent leaching behaviour and other performance properties of cement-treated mixed contaminated soil

Reginald Kogbara, Abir Al-Tabbaa, Yaolin Yi, Julia A. Stegemann

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Portland cement has been widely used for stabilisation/solidification (S/S) treatment of contaminated soils. However, there is a dearth of literature on pH-dependent leaching of contaminants from cement-treated soils. This study investigates the leachability of Cu, Pb, Ni, Zn and total petroleum hydrocarbons (TPH) from a mixed contaminated soil. A sandy soil was spiked with 3000 mg/kg each of Cd, Cu, Pb, Ni and Zn, and 10,000 mg/kg of diesel, and treated with ordinary Portland cement (CEM I). Four different binder dosages, 5%, 10%, 15% and 20% (m/m) and different water contents ranging from 13%-19% dry weight were used in order to find a safe operating envelope for the treatment process. The pH-dependent leaching behaviour of the treated soil was monitored over an 84-day period using a 3-point acid neutralisation capacity (ANC) test. The monolithic leaching test was also conducted. Geotechnical properties such as unconfined compressive strength (UCS), hydraulic conductivity and porosity were assessed over time. The treated soils recorded lower leachate concentrations of Ni and Zn compared to the untreated soil at the same pH depending on binder dosage. The binder had problems with Pb stabilisation and TPH leachability was independent of pH and binder dosage. The hydraulic conductivity of the mixes was generally of the order, 10-8 m/sec, while the porosity ranged from 26%-44%. The results of selected performance properties are compared with regulatory limits and the range of operating variables that lead to acceptable performance described.

Original languageEnglish
Pages (from-to)1630-1638
Number of pages9
JournalJournal of Environmental Sciences (China)
Volume24
Issue number9
DOIs
Publication statusPublished - Sep 2012
Externally publishedYes

Fingerprint

Leaching
Cements
cement
leaching
Soils
Binders
petroleum hydrocarbon
hydraulic conductivity
stabilization
soil
porosity
Hydraulic conductivity
Petroleum
Portland cement
Hydrocarbons
acid neutralization
geotechnical property
solidification
Stabilization
Crude oil

Keywords

  • Diesel
  • Heavy metals
  • Hydraulic conductivity
  • Porosity
  • Portland cement
  • Stabilisation/solidification

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Science(all)
  • Environmental Chemistry

Cite this

PH-dependent leaching behaviour and other performance properties of cement-treated mixed contaminated soil. / Kogbara, Reginald; Al-Tabbaa, Abir; Yi, Yaolin; Stegemann, Julia A.

In: Journal of Environmental Sciences (China), Vol. 24, No. 9, 09.2012, p. 1630-1638.

Research output: Contribution to journalArticle

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