Sustainable valorization of seaweed industrial by-product: Converting filter cake into valuable resources

Filter cake, a significant by-product of the seaweed industry, poses environmental risks by releasing harmful elements that can contaminate air, soil, and water. Despite its potential, the valorization of this by-product remains underexplored. Therefore, this study developed a novel pathway to valorize filter cake into valuable resources. The by-product was initially processed using practical methods, including drying, grinding, and sieving. Drying kinetics were thoroughly analyzed and compared with 24 thin-layer drying models. Subsequently, the by-product was characterized using TGA, FTIR, EDX, and SEM before calculating the associated costs and carbon dioxide emissions of valorization. Optimal valorization required two days of open sun drying, grinding, and sieving, followed by 150 min in a fluidized bed dryer. The modified Midili-Kucuk equation provided the best fit for the drying process. Valorization cost was estimated at US$ 0.651 per kg, with carbon dioxide emissions of 0.648 kg per kg. The characterization data revealed that the valorized by-product contains organic and inorganic materials, underscoring its potential as a valuable resource, specifically as a recycled aid filter, silica source, and growing medium. However, further studies are required to assess its potential. Ultimately, this research contributes to green manufacturing and chemistry by employing sustainable methods that minimize environmental impact. It also promotes sustainability, reduces costs through by-product reuse, and encourages responsible consumption and production, aligning with Sustainable Development Goals, particularly Goals 12, 9, and 15.