Green remediation of contaminated sediment by stabilization/solidification with industrial by-products and CO2utilization

Lei Wang, Liang Chen, Chiu Wa Tsang, Jiang Shan Li, Tiffany L.Y. Yeung, Shiming Ding, Chi Sun Poon

Research output: Journal article publicationJournal articleAcademic researchpeer-review

48 Citations (Scopus)

Abstract

Navigational dredging is an excavation of marine/freshwater sediment to maintain channels of sufficient depth for shipping safety. Due to historical inputs of anthropogenic contaminants, sediments are often contaminated by metals/metalloids, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and other contaminants. Its disposal can present significant environmental and financial burdens. This study developed a novel and green remediation method for contaminated sediment using stabilization/solidification with calcium-rich/low-calcium industrial by-products and CO2utilization. The hydration products were evaluated by quantitative X-ray diffraction analysis and thermogravimetric analysis. The incorporation of calcium carbide residue (CCR) facilitated hydration reaction and provided relatively high 7-d strength. In contrast, the addition of Class-F pulverized fly ash (PFA) and ground granulated blast furnace slag (GGBS) was beneficial to the 28-d strength development due to supplementary pozzolanic and hydration reactions. The employment of 1-d CO2curing was found to promote strength development (98%) and carbon sequestration (4.3 wt%), while additional 7-d air curing facilitated cement rehydration and further carbonation in the sediment blocks. The leachability tests indicated that all studied binders, especially CCR binder, effectively immobilized contaminants in the sediments. The calcium-rich CCR and GGBS were regarded as promising candidates for augmenting the efficacy of CO2curing, whereas GGBS samples could be applicable as eco-paving blocks in view of their superior 28-d strength. This study presents a new and sustainable way to transform contaminated sediment into value-added materials.
Original languageEnglish
Pages (from-to)1321-1327
Number of pages7
JournalScience of the Total Environment
Volume631-632
DOIs
Publication statusPublished - 1 Aug 2018

Keywords

  • Carbon sequestration
  • Cleaner production
  • CO curing 2
  • Eco-paving blocks
  • Sediment remediation
  • Waste valorization

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution

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