<p>Sustainable sludge management requires strategies that simultaneously achieve nutrient recovery and efficient dewatering. In this study, we developed a novel ternary LDH (FeMgCu-LDH) that is regenerable owing to the intrinsic memory effect of LDHs. This feature enables the material to reconstruct its layered structure and reactive sites after mild alkaline desorption, ensuring long-term stability and recyclability. The FeMgCu-LDH demonstrated an outstanding phosphorus adsorption capacity of 51.24&#xa0;mg/g. It also significantly enhanced sludge dewatering by reducing water content by 25.39% and lowering specific resistance to filtration by 81.43%. Notably, the material retained more than 85% of its initial phosphorus removal efficiency after 10 adsorption–desorption cycles, highlighting its structural robustness and economic feasibility. Mechanistic investigations revealed that the synergistic effect of Fe³⁺, Mg²⁺, and Cu²⁺ ions facilitated interlayer ion exchange, surface complexation, and extracellular polymeric substance disruption, thereby accelerating both phosphorus removal and sludge floc disintegration. The adsorption process followed the Langmuir isotherm and pseudo-second-order kinetics, confirming a monolayer chemisorption pathway governed by diffusion. These results demonstrate that FeMgCu-LDH provides a scalable, low-cost, and environmentally sustainable approach for wastewater treatment, coupling efficient phosphorus recovery with improved sludge management in line with circular economy principles. However, future work will need to address potential challenges, such as scale-up issues and cost comparisons, to fully realize its practical potential.</p>