Advancing the reutilization of spent activated carbon for sculptural media: composites formulation and characterization

The disposal of spent activated carbon (SAC) remains a major environmental challenge worldwide, particularly in tropical regions where coconut husks serve as the primary precursor for activated carbon production. Conventional disposal methods, such as landfilling and incineration, raise ecological and health concerns due to the leaching of adsorbed contaminants and the release of greenhouse gases. This study investigates the potential of SAC as a sustainable additive in sculpturing composites. SAC was incorporated into epoxy, acrylic gel, Portland cement, and clay matrices at varying loadings (10–40 wt%). The composites were characterized for workability, durability, mechanical strength, bulk density, chemical stability, and aesthetic properties. Epoxy-SAC composites demonstrated superior strength (compressive 68 MPa; flexural 21 MPa), durability (< 2% weight loss in wet–dry cycles), and chemical stability, making them suitable for indoor and outdoor sculptures. Cementitious–SAC composites exhibited moderate strength (35 MPa) and durability (4% weight loss), making them ideal for outdoor applications. Acrylic-SAC composites provided excellent matte-black aesthetics for indoor art, while clay-SAC composites exhibited limited durability and low strength. The study confirms SAC’s feasibility as a value-added material for sculpting applications, contributing to circular economy principles and environmental sustainability.