Abstract:
In this study, the compound binder of ground granulated blast furnace slag (GGBS)-reactive MgO is used for the carbonization/stabilization treatment of zinc (Zn)-contaminated soil. The unconfined compression and electrical conductivity tests on the carbonated/stabilized Zn-contaminated soil are conducted, and the uncarbonated Zn-contaminated soil after 28-day standard curing is used for comparison. The effects of Zn-ion concentration and binder mixing ratio on the unconfined compressive strength (
qu) of the carbonated/stabilized soils and the conductivity of the pore fluid are investigated. The test results indicate that: (1) When the mixing ratio of curing agent is fixed, the
qu of the carbonated Zn- contaminated soil first increases and then decreases with the increase of Zn ion concentration, while the conductivity increases. (2) When the content of Zn-ion concentration is fixed, the
qu of the carbonated Zn-contaminated soil increases with the increase of reactive MgO content in the binder, but its conductivity decreases slightly. (3) The
qu of the carbonated zinc contaminated soil is higher compared with that of the noncarbonated Zn- contaminated soil (28-day standard curing), but the conductivity is almost the same. This study will provide a new approach for the reuse of industrial wastes and carbon dioxide as well as the low-carbon treatment of Zn-contaminated soil, and be of important significance for accelerating the "carbon peak".