Aeration curing for recycling construction-generated sludge and its effect of immobilizing carbon dioxide

Shinya Inazumi, Motoki Shiina, Koki Nakao

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The aspirations of Sustainable Development Goals (SDGs) are central to the construction industry. The introduction and evaluation of aeration curing, as a novel strategy for managing construction-generated sludge (CGS), was at the heart of this study. The essence of aeration curing lies in the chemical transformation it generates, namely, the calcium hydroxide found in CGS reacts with carbon dioxide, culminating in the production of calcium carbonate. This duel-purpose reaction serves to neutralize the soil and facilitate the capture of carbon dioxide. Experimental evaluations were carried out to determine the effects of different agitation frequencies and surface depths on the effectiveness of aeration curing. They were then compared with those of traditional neutralization methods. In particular, the results showed that increasing the agitation frequency resulted in a significant reduction in the pH of the soil. Furthermore, aeration curing stood out because of its superior ability to immobilize carbon dioxide compared to standard neutralizers. This resulted in a reduction in the amount of neutralizer required. The focus of this study was primarily aeration curing, which is the preferred technique for carbon dioxide immobilization. The characteristics of aeration curing were elucidated and the amount of captured carbon dioxide was measured using a formulated theoretical equation through rigorous testing on CGS. Specifically, the technique showed promise as a first step in the treatment process, reducing the amount of neutralizer subsequently required and, at the same time, limiting the increase in the electrical conductivity (EC) value. This highlighted the potential of aeration curing as both an economical and environmentally friendly approach to neutralization. It was revealed, however, that the theoretical equation used to estimate the immobilized carbon dioxide needs to be refined. It is essential that the real neutralization reactions occurring in the soil are taken into account in order to ensure its applicability and accuracy in real-world contexts. In conclusion, aeration curing appears to be a promising, green solution for managing CGS and for sequestering carbon.

Original languageEnglish
Article numbere02704
JournalCase Studies in Construction Materials
Volume20
DOIs
Publication statusPublished - 2024 Jul

Keywords

  • Aeration curing
  • Construction-generated sludge
  • Immobilization of carbon dioxide
  • Neutralization
  • Theoretical estimation

ASJC Scopus subject areas

  • Materials Science (miscellaneous)

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