Addressing the substantial yearly production of waste dredged slurry with high water content, it is imperative to adopt effective technical treatments for sustainable development. This paper establishes that the curing-flocculation-vacuum filtration (C-F-VF) method efficiently converts high-water content dredged slurry into back-fill soil, achieving rapid dewatering. The study delves into the mechanism facilitating swift dewatering and the heightened mechanical properties of the dewatered soil. The synergy of curing, flocculation, and vacuum filtration expedites the dewatering process. The pre-addition of a curing agent reduces the zeta potential of the slurry, enhancing its efficiency in subsequent flocculation and vacuum filtration. Although the curing agent experiences some loss during vacuum filtration, over 91.22% remains in the dewatered soil, fortifying its strength. Soil strength correlates with the water content post-vacuum filtration and the amount of cement added pre-filtration, with a proposed relevant strength prediction formula.

Flocculent is commonly used in mining activities to improve the concentration of tailing slurry by enhancing the sedimentation process of small tailings particles. The presence of flocculent in thickened tailings is unavoidable, and it affects the heavy metal leaching performances and mechanical and rheological characteristics of tailing-based cemented paste backfill (CPB). This study is carried out to investigate the physicochemical and leachability of CPB amended with flocculants and lime-activated ground granulated blast-furnace slag (GGBS). The stabilized samples were subjected to a series of model tests, including toxicity characteristics leaching procedure (TCLP) and pH, unconfined compressive strength (UCS), scanning electron microscopy (SEM), and X-ray diffraction. Moreover, the CPB amended with anionic polyacrylamide (APAM) demonstrated better performance in terms of a decrease in heavy metal leachability besides higher mechanical strength than poly aluminum chloride (PAC) and poly ferric chloride (PFC) samples. Furthermore, the UCS results showed that increasing binder content up to 15% negatively influences strength improvement of all stabilized samples because of weak connections between soil particles and cementitious material, resulting in high leachability of heavy metals. The analysis of XRD and SEM showed that anionic polyacrylamide (APAM) cases exhibited more voluminous hydration products, resulting in a compact stabilized matrix and substantially reduced heavy metal leachability.