Use of sludge produced from reject brine as a supplementary cementitious material with enhanced carbonation capability
Artikel i vetenskaplig tidskrift, 2025

Sludge obtained from reject brine via a novel two-step approach involving precipitation and filtration was used as a supplementary material in reactive magnesia cement (RMC) and Portland cement (PC) mixes. Detailed evaluation of the performance and microstructure of the resultant cement pastes revealed the underlying mechanism. Incorporating 25 % (of the binder content) sludge in RMC mixes significantly increased the compressive strength under ambient and carbonation-based curing, which was more than doubled under the latter condition. While the strength of PC mixes decreased with the use of sludge, it still exceeded 30 MPa under carbonation. Increase in hydration heat observed in sludge-containing mixes was attributed to the presence of brucite acting as nucleation sites. ∼30 % reduction in CO2 emissions and ∼25 % reduction in energy consumption was achieved by simply incorporating sludge in the designed mixes. Furthermore, sludge enhanced carbonation in RMC and PC mixes by increasing the amount of CO2 sequestered at 28 days by 25.9 % and 41.1 %, respectively. Overall, the feasibility of re-purposing reject brine by directly using the produced sludge was demonstrated, offering a sustainable alternative for concrete production with a significantly reduced environmental impact.

Waste management

Sludge

Carbonation

MgO

Blended cement

Reject brine

Författare

Tangwei Mi

School of Civil and Environmental Engineering

Yongqiang Li

Chalmers, Arkitektur och samhällsbyggnadsteknik, Byggnadsteknologi

En Hua Yang

School of Civil and Environmental Engineering

Cise Unluer

University of Manchester

Cement and Concrete Composites

0958-9465 (ISSN)

Vol. 160 106051

Ämneskategorier (SSIF 2025)

Samhällsbyggnadsteknik

Materialteknik

Naturresursteknik

DOI

10.1016/j.cemconcomp.2025.106051

Mer information

Senast uppdaterat

2025-04-01